TW202142383A - Method for manufacturing a recyclable flexible foam molded product - Google Patents

Abstract

This document discloses a process for manufacturing recyclable injection molded microcellular foams for use in, footwear components, seating components, protective gear components, and watersport accessories. The process includes the steps of providing a thermoplastic polymer which comprises at least one monomer derived from depolymerized post-consumer plastic, inserting a fluid into a barrel of a molding apparatus. The fluid is introduced under temperature and pressure conditions to produce a super critical fluid. The process further includes mixing the thermoplastic polymer and super critical fluid so as to create a single phase solution, and injecting the single phase solution into a mold of an injection molding machine under gas counter pressure. The process further includes foaming the single phase solution by controlling the head and temperature conditions within the mold.

Description

Method for manufacturing recyclable flexible foam molded products

[Cross-reference of related applications]

This application claims priority to the U.S. Provisional Patent Application No. 62/853,805 entitled "RECYCLABLE AND CHEMICAL-FREE INJECTION MOLDED MICROCELLULAR FLEXIBLE FOAMS, AND A METHOD OF MANUFACTURING THE SAME" and filed on May 29, 2019 And rights, and is part of the continuation of the 16/418,968 patent application titled "BIODEGRADABLE AND INDUSTRIALLY COMPOSTABLE INJECTION MOLDED MICROCELLULAR FLEXIBLE FOAMS, AND A METHOD OF MANUFACTURING THE SAME" filed on May 21, 2019. The patent The application claims the priority and rights of U.S. Provisional Patent Application No. 62/674,544 whose title is "BIODEGRADABLE AND INDUSTRIALLY COMPOSTABLE INJECTION MOLDED MICROCELLULAR FLEXIBLE FOAMS, AND A METHOD OF MANUFACTURING THE SAME" and filed on May 21, 2018, The disclosures of these patent applications are all incorporated herein by reference in their entirety for all purposes.

The present disclosure relates to injection molding of bio-derived thermoplastic polymers that are recyclable or biodegradable and industrially synthesizable for use in, for example, footwear components, seat components, protective device components, and water sports accessories. The micro-pore foaming process is composed of various flexible foams.

Degradation by composting is an important process used to regenerate resources used in the production of finished products. However, when their finished products involve foams, decomposition can become a problem. Specifically, there are several shortcomings of the conventionally known methods for manufacturing flexible foams. For example, such shortcomings include the selection and use of non-renewable polymers, chemical blowing agents, and chemical additives. Such non-renewable polymers, chemical blowing agents, and chemical additives are used in the foam manufacturing industry and inherent processing The ones used in the procedure are usually not biodegradable, and such non-renewable polymers, chemical foaming agents, and chemical additives are usually regarded as harmful to the environment. This lack of biodegradation means that many conventional flexible foam materials and products contained with such conventional flexible foam materials end up in landfills anywhere for decades to hundreds of years.

This has also become a problem because the overuse of landfills in the world today has a direct negative impact on both the environment and the economy. For example, landfills are the third largest source of methane emissions in the United States. In addition, the aforementioned non-biodegradable polymers and chemicals used in conventional flexible foams are especially derived from non-renewable resources.

These materials are not naturally renewable, as in the state of bio-derived raw materials, and therefore, the actual production of these materials is a net loss to the environment, because the materials are usually obtained, used, and then unsustainably discarded. In addition, even if renewable polymers are selected for use in conventionally known methods of flexible foam manufacturing, chemical blowing agents and cross-linking by these methods may not be biodegradable or compostable. Of additives contaminate renewable polymers. Therefore, make it zero and gain. Still further, the cross-linking of biopolymers will also likely hinder any suitable end-of-life solutions for biodegradation or composting, because the precursor components cannot be separated, thereby leading to more waste generation and burial. More material for the field.

Therefore, although composting and recycling are important processes that provide a renewable and sustainable future, their integration in the manufacturing industry is very limited. However, if the fabricated material can be made synthesizable, the process will be very useful for the environment, for example. For example, the composting and biodegradation of flexible foam materials produces opportunities for waste disposal that represent a net benefit to the environment and economy. For example, by composting these materials, it is possible to reduce the total amount of waste sent to landfills and mass burning incinerators.

In addition to reducing waste, the composting process will also produce usable products that are nutritious and can be used to improve poor soils to grow food or fertilize gardens. Therefore, no matter how novel the real concept of flexible foam composting and biodegradation is, it can make huge changes in the entire value chain while adhering to the principles of the so-called circular economy. There are two typical forms of composting: industrial composting and household composting. Both of these composting methodologies have benefits and drawbacks.

Industrial composting is a large-scale composting form designed to dispose of very large volumes of organic waste. Industrial composting is carried out in large-scale facilities at temperatures between 50°C and 60°C. Household composting is a form of composting that disposes of organic waste from a family. Specifically, home composting refers to composting at a relatively low temperature, such as those composts that can be found in a compost pile in a home's backyard, hence the title "family". In contrast to industrial composting, household composting involves aerobic decomposition of organic materials such as garden cuttings, kitchen waste, wood shavings, cardboard, and paper or waste coolers. The volume to be disposed of in home compost is significantly smaller than in industrial compost and compost is usually used in private gardens. This process is usually implemented in small-scale compostors and piles. In this method, the temperature is usually in the range of low temperature (0°C to 20°C) to medium temperature (20°C to 45°C) (as explained below). Therefore, different technologies exist, but the general treatment is the same: the next is the controlled process of solidified reactive compost.

The active composting period usually lasts at least 21 days. Under these conditions, microorganisms grow on the organic waste, thereby decomposing the organic waste into CO ₂ and water, and using the organic waste as nutrients. During composting, organic waste accumulates in the reactor, and therefore part of the composting energy is released as heat. When the temperature of the composting reactor increases, the microbial population shifts: microorganisms that adapt to the surrounding temperature, such as mesophilic organisms, cease their activities, die one after another, and are replaced by microorganisms that are adapted to live at high temperatures, such as thermophiles. For the purpose of sanitation, for household composting, the temperature should be maintained above 60°C for at least one week in order to eliminate pathogenic microorganisms. In contrast, the solidification period of industrial compost slows the decomposition rate to a consistent pace, and the compost matures at a temperature in the lower medium temperature range below 40°C.

The main problem of industrial composting is that the input raw materials should be properly placed so that they can be effectively processed. That is, logistical challenges are obstacles because of the need for proper collection, sorting, and transportation to industrial composting facilities. The combined composting and recycling conversion rate in the United States is about 35%. This situation indicates that society has a long way to go before most infrastructure "closes the loop" on waste conversion. One way to overcome this loss is to better educate end users and build a local network of recovery options that feed into larger recovery options. The goal is to develop sufficient convenience and accessibility so that industrial composting becomes regular and always present in daily life.

Likewise, the prevalent disadvantage in home composting is the amount of effort involved. All of the required composting raw materials need to be carried and/or delivered to the composting reactor. Once the compost pile is large enough to start generating energy and thereby generating heat, it is necessary to turn to make the decomposition faster and more thorough, which can be laborious work. When the organic matter is fully decomposed, the household compost must be transported away for use in soil improvement. Another disadvantage of home composting is the limited amount of usable compost that ordinary people can produce in the home environment. A limited amount of compost produced may give limited use, and therefore, the motivation of ordinary people to invest in household composting efforts may be low.

Because of these shortcomings, traditionally, the manufacturing industry has avoided the use of raw materials and precursor components that have the possibility of biodegradation or composting. In addition, this has traditionally been avoided, because the required technical performance properties of these materials are generally inferior to the conventional non-biodegradable and non-synthetic variants. For example, some but not all of the limiting factors for synthesizable precursor ingredients may have the tendency of these ingredients to decompose and/or degrade before the end of the product's useful life. An example of this would be UV-sensitive products, whereby the biodegradable and synthesizable precursors can be attacked and weakened by repeated sunlight exposure, which can eventually lead to product failure before the end user is about to discard the product.

In the context of plastics, thermoplastics, and other products produced using fossil fuels, recycling conventionally involves mechanically shredding the finished product, melting the shredded content, and then pelletizing the resulting material for later use in manufacturing middle. Although recycling reduces the need for fossil fuels and transfers products from landfills, recycling can result in quality loss of recycled polymers due to pollution or impurities added to the raw materials, and most plastic and thermoplastic products can only be recycled a limited number of times. In addition, the chemical blowing agents, cross-linked polymers, and chemical additives used in the manufacture of conventional flexible foams lead to end products, which may not be decomposed into their constituent polymers for use in minor applications. Later used in the manufacture of recycled products. Therefore, when the product has reached the end of its usable life, the conventionally manufactured flexible foam product is not recyclable.

In addition, the current concerns for modern manufacturing are about the net neutrality of emissions and waste, about the sustainability of the materials used in the manufacturing process, and about the end-of-life of products and their materials that are renewable. As such, in addition to the synthesizable nature of the final product, such as _{the net neutrality with respect to CO 2} emissions has become important in selecting appropriate materials for use in the manufacture of consumer products.

Therefore, compared with the more traditional manufacturing process currently presented, it is a key driver for the current manufacturing process disclosed in this article, because manufacturers produce end products that consider the environment, and thus, carefully consider using them in these end products It is useful to balance the material used in the manufacturing of the material and the expected useful life of the product. Examples of products that should be considered but unresolved challenges during production are standard finished products in the production of foams such as bumpers (such as for furniture), and/or hair products such as those used in the manufacture of running shoes. Foam products.

For example, running shoes are high-tech products that are exposed to repeated abuse such as impact, abrasion and all environmental exposures for a considerable amount of time; depending on the frequency of use, it may be 1 to 3 years. It is important to consider the above requirements when considering sustainable materials used in the manufacture of buffers for furniture or shoe soles, midsoles, and/or shoe insoles for running shoes. Failure to dispose of repetitively abused materials before failure will not produce a satisfactory pair of running shoes. In addition, any material that has the potential to decompose or weaken to the point of failure during normal product use will be unacceptable before the end of the predetermined life.

To solve this problem, technicians must find specialized materials that have the correct balance of technical performance properties and sustainable aspects such as compostability with managed end-of-life solutions. The managed end-of-life solutions are about The harmful emissions are net neutral (or negative). Specifically, because furniture cushions are bulky and running shoes are demanding products, household composting materials are not a suitable solution for their production, because the lower decomposition temperature will be transferred to furniture or running shoes. Running shoes will tend to break long before their intended lifespan ends. In this example, industrially composted materials are a much better option because they can handle higher temperature challenges and provide a larger size close to or equal to their non-industrially synthesizable and non-biodegradable counterparts. The nature of technical effectiveness. In essence, furniture or a pair of running shoes made of industrially synthesizable materials will have a good effect on the usable life of the product, and only at the end of the usable life of the product, the material has to be directed to be used in a "closed loop" The right to choose in the industrial composting setting of waste conversion.

Therefore, where possible, in order to reduce the destructive footprint that often accompanies the manufacturing process, the materials and manufacturing process should be formulated in a way that allows the preparation of compost after the end of the product's life. However, as indicated above, this is difficult because there are very limited commercially available biodegradable and synthesizable precursors. Those that do not exist are not necessarily designed and able to solve all of the combined challenges of performance and long-term availability, and are easily composted and biodegradable in a controlled setting at the end of their useful life. Their precursors that solve some of the aforementioned challenges fail to solve other challenges and this leads to panic among consumers and possible bad reviews of products containing these precursors. Despite these significant shortcomings, materials that can be composted at industrial facilities or in the home will theoretically be used to start products in renewable, sustainable, and green manufacturing.

Another aspect of this manufacturing process concerns the production of flexible foams. Flexible foam is a type of object formed by trapping air pockets in liquid or solid, whereby the resulting foam part is said to be flexible due to its malleability. Flexible foams are commonly used in cushioning applications such as footwear, furniture, padding and other sports goods. Flexible foams are generally divided into two types: closed-cell flexible thermoplastic polymer foams and open-cell flexible polyurethane foams. Each of these foam types has very different manufacturing methods.

Closed-pore flexible thermoplastic polymer foams are usually produced in a dry process, in which suitable artificial polymers are selected and blended with various chemical additives, crosslinking agents and chemical foaming agents for the production of "dough", The dough is then kneaded and extruded into a flat sheet. The sheets are then stacked on top of each other and placed in a heat press under controlled pressure. This mixture of material and chemical blowing agent reacts and expands inside the cavity of the heat press. The result is a "round bun" or "square" of a closed pore flexible foam that is then sliced to a thickness. In contrast, open-cell flexible polyurethane foams are usually produced in a liquid casting process or a liquid molding process, in which artificial polyols, isocyanate chemicals and other chemical additives are cast or injected into a molded shape. Such as "round bun" or "square" when reacting together. The result is an open-cell flexible foam that is then sliced to thickness.

Consistent with the above content, one of the problems with the flexible foams currently available on the market is that these flexible foams almost only use non-renewable materials and hazardous chemicals in their manufacture. In addition, due in part to the chemical cross-linking that occurs in the above-described methods of manufacturing conventional flexible foams, the physical structure of these flexible foams cannot be composted, biodegraded, or recycled. This is largely due to its designed chemical composition and its inability to separate back into its root precursor composition. That is, at the end of the life of the conventional flexible foam, the conventional flexible foam is not used further and cannot be successfully reprocessed into a new material by any known commercially advantageous method.

Therefore, in view of the above content, this article presents flexible foams and manufacturing processes. These flexible foams and manufacturing processes can be used to produce end products. These end products are renewable and renewable. Continuous and/or environmentally explainable, these materials and end products can be used continuously without breakage, but quickly degrade and compost after the end of their life. Both the flexible foam and the semi-flexible foam can be included in the same kind of flexible foam because they are derived from having a glass transition (Tg) lower than their service temperature. For polymers, the service temperature is usually at room temperature. The details of one or more embodiments are set forth below in the accompanying description and regarding the presented drawings and their features. Other features and advantages will be apparent from both the description and the drawings and the scope of the self-applied patent.

This document presents a process for the modification of injection molding of biodegradable and industrially synthesizable thermoplastic resins to form various flexible foams with micro-pores. At present, almost all known flexible foams in the world are derived from non-renewable raw materials, and if not all, most flexible foams are not biodegradable or industrially composted. The purpose of the present invention is to produce flexible foams that cause the least amount of environmental hazards, but also have technical performance equal to or greater than that of conventional non-degradable petrochemical flexible foams Significant technical effectiveness of nature. By selecting plant-derived raw materials for the production of biopolymers, the present invention helps to sequester greenhouse gases from the atmosphere, greatly reduces the dependence on non-renewable petroleum, and significantly reduces the bio-non-degradable waste that ends in landfills every year Things.

In various embodiments, the flexible foams thus produced can be formulated to be industrially composted instead of home composting, but it is envisaged that home composting may have uses in some instances, depending on the market. In various instances, industrial composting is useful because it ensures that the flexible foam will continue the useful life of the resultant product that is functionalized into the flexible foam and does not break or break during use in the finished product. For example, it would be harmful for a person to purchase a pair of shoes made only of the flexible foam of the present invention so that the foam degrades during normal use before the end of the useful life of the shoe.

Therefore, in one aspect, the process for manufacturing a biodegradable and industrially synthesizable flexible foam (regardless of open or closed pores) can be provided herein and can include one or more of the following steps : Production of thermoplastic biopolymer blend masterbatch for foaming; injection molding of thermoplastic biopolymer blend into a suitable mold shape with inert nitrogen; dynamic mold temperature control to ensure the best pore structure; Control the biopolymer melt, pressure and time so that the desired flexible foam is formed; and use the gas back pressure in the injection molding process to ensure that there are the smallest number of surface defects and a few on the outside of the foamed part The best foam structure until there is no plastic skin.

Consistent with carefully selected bio-derived, renewable and recyclable raw materials, the manufacturing process of this disclosure leads to an environmentally friendly closed-loop process. This closed-loop process begins with material selection. For example, the selection of inert and rapidly renewable polymer materials that can be synthesized by third parties ensures that the principles of circular economy are adhered to. For these purposes, the selected fast renewable polymer raw material begins its life as a form of renewable plants or minerals. Once converted into suitable polymers, these environmentally interpretable precursors can be combined with other environmentally interpretable precursors and ingredients for functionalization into custom biopolymer compounds that can be Used in the disclosed manufacturing process.

Specifically, once a suitable biopolymer compound is produced, it is processed in the chemical-free manufacturing method of this disclosure. The resulting flexible foaming system is non-crosslinked, and in many instances, is biodegradable and synthesizable. Therefore, at the end of its usable life, the foams produced can be carefully pulverized into small pieces and industrially composted in a limited facility to decompose their constituents (for example, 100%) back into usable Biomass. This usable biomass can then be used to grow more inert and rapidly renewable polymer feedstock materials, and the process continues in a loop. Therefore, this document describes a biodegradable and industrially synthesizable microporous flexible foam and a method for manufacturing the biodegradable and industrially synthesizable microporous flexible foam. The foam may be a closed-cell foam, but it may also be formed as an open-cell foam.

In various implementation schemes, biodegradable and industrially synthesizable flexible foams can be made to have the same properties and characteristics as conventional petrochemical ethylene vinyl acetate (EVA) foams, etc., And still contains a high percentage of biomass carbon content. For example, flexible EVA foaming systems are now commonly used materials in the industry. What makes EVA foam so popular is its relatively low cost and ease of handling, while maintaining the generally acceptable technical performance properties for a given product. EVA foam is used for many undersides. The materials are usually derived from non-renewable raw materials and are chemically cross-linked with chemical blowing agents for the production of flexible foams that are not easily biodegradable, synthesizable, or recyclable.

There are many configurations and embodiments that can be utilized depending on the desired physical properties and the intended end-use surface of the product, and these configurations and embodiments should not be limited by this disclosure.

One factor that makes the progress presented herein so useful is that the biodegradable foam performs in a manner similar to EVA, and as such, its technical performance properties are similar to those of EVA without chemical additives and cross-linking. The result is a commercially acceptable flexible foam. The flexible foam can be used as an occasional replacement for universal EVA, but the flexible foam provides greatly reduced environmental impact and environmental impact. Explainable managed end-of-life solutions.

Therefore, in one aspect, a method for manufacturing a biodegradable and industrially synthesizable flexible foam molded product is provided. In various examples, the method may include one or more of the following steps. For example, the method may include the introduction of a thermoplastic biopolymer blend masterbatch for foaming into the barrel of a molding device. The method may additionally include introducing the fluid into the barrel under temperature and pressure conditions to produce a supercritical fluid that produces a thermoplastic foamed melt when in contact with the thermoplastic biopolymer blend masterbatch. In addition, the method may include injecting a thermoplastic foamed melt into a cavity of a suitable mold shape, and applying a gas back pressure to the cavity. Finally, the cavity can be cooled to produce a molded product.

In various examples, the introduction of one or more of the thermoplastic biopolymer masterbatch is through a sprue bushing, such as where the thermoplastic biopolymer blending masterbatch is produced by a twin screw extruder. In one embodiment, the thermoplastic biopolymer blending masterbatch includes polylactide acid (PLA), polyhydroxyalkanoate (PHA), cellulose acetate (CA), starch, and petroleum derivatives. One or more of thermoplastics. In various instances, the flow system is introduced into the barrel by a metering unit. In a specific example, the supercritical fluid includes one or more of nitrogen and carbon dioxide. The supercritical fluid may be introduced under pressure and at temperature, such as where the pressure ranges from about 150 bar to about 300 bar, and the temperature ranges from about 150°C to about 350°C. Likewise, the gas back pressure ranges from about 5 bar to about 50 bar, and is applied for a length of time between 1 second and 25 seconds. In some instances, the temperature can be controlled by dynamic mold temperature control.

In addition, in another aspect, an injection molding device is provided for producing biodegradable and industrially synthesizable flexible foam molded products. In various examples, the injection molding equipment may include one or more of the following. A funnel may be included, such as where the funnel is configured to receive and introduce a plurality of thermoplastic biopolymers into a molding device, such as where the thermoplastic biopolymer forms a masterbatch to be blended.

A metering unit may be included, such as where the metering unit is configured to receive the fluid and, under conditions, introduce the received fluid into the molding equipment so as to produce the supercritical fluid after the introduction. The molding apparatus may include a barrel with a first cavity configured to receive the blended thermoplastic biopolymer masterbatch and fluid so that when they are introduced into the barrel, the supercritical fluid When contacting the blended thermoplastic biopolymer masterbatch in the cavity of the barrel, the thermoplastic foamed melt is produced. The gas back pressure delivery unit may also be included, wherein the GCP is configured to deliver the gas back pressure to the first cavity so as to control the expansion of the foamed melt. In addition, it may also include a mold having a cavity in fluid communication with the cavity of the barrel, wherein the cavity of the mold is configured to receive the foamed melt and produce a flexible foaming mold when the melt is cooled. Shaped products.

In various embodiments, the injection molding equipment may include a reciprocating screw that is configured to compress the foamed melt in the cavity of the barrel and transport the compressed foamed melt to the cavity of the mold. Therefore, there may be a duct between the cavity of the barrel and the cavity of the mold, where the duct includes a nozzle with a sprue bushing to form a seal between the barrel and the mold.

Therefore, the injection molding equipment may include one or more of the following: a hopper, where the thermoplastic material is supplied to the molding machine in the form of pellets. The funnel on the injection molding machine holds these pellets. The pellets can be gravity fed from the funnel to the barrel and screw assembly through the funnel throat. It can also include a barrel, where the barrel of the injection molding machine supports a reciprocating plasticizing screw and can be heated by an electric heater strip.

Reciprocating screws can also exist, where the reciprocating screws are used to compress, melt, and transport materials. The reciprocating screw can include three zones: a feed zone, a compression (or conversion) zone, and a metering zone. There may also be nozzles where the nozzle connects the barrel to the sprue bushing of the mold and forms a seal between the barrel and the mold. The temperature of the nozzle can be set to the melting temperature of the material or just below the melting temperature. When the barrel is in its fully forward processing position, the radius of the nozzle can be nested and sealed in the concave radius in the sprue bushing with the positioning ring. During the cleaning of the barrel, the barrel can be retracted from the sprue so that the flushing compound can fall freely from the nozzle.

In addition, molds and hydraulic systems can also be provided. The mold system can include straps, fixed and mobile platforms, and a molded plate (substrate) containing a cavity, gate and runner system, ejector pins, heating and cooling channels, and temperature sensors and pressure Sensor. The mold is essentially a heat exchanger in which the molten thermoplastic solidifies to the desired shape and dimensional details defined by the cavity. The hydraulic system can also exist on the injection molding machine to provide power to open and close the mold, build and maintain the clamping tonnage, rotate the reciprocating screw, drive the reciprocating screw, and excite the ejector pins and move the mold core. Many hydraulic components are needed to provide this power, including pumps, valves, hydraulic motors, hydraulic fittings, hydraulic pipes, and hydraulic reservoirs.

A control system can also be provided. The control system can be configured to provide consistency and repeatability in machine operation. The control system monitors and controls processing parameters, including temperature, pressure, supercritical fluid (SCF) batching, injection speed, screw speed and position, and hydraulic position. Process control can have a direct impact on the quality of the final part and the economics of the process. The process control system can range from simple relay on/off control to extremely complex microprocessor-based closed-loop control.

A clamping system can also be provided. The clamping system can be assembled to open and close the mold, support and carry the component parts of the mold, and generate sufficient force to prevent the mold from opening. The clamping force can be generated by a mechanical (two-state thixotropic) lock, a hydraulic lock, or a combination of the two basic types. Conveying system can also be provided. The conveying system that provides a path for molten plastic from the machine nozzle to the part cavity usually includes: gates, cold slug wells, main runners, branch runners, gates, and so on.

Therefore, in yet another aspect, a system for producing biodegradable and industrially synthesizable flexible foam molded products is provided. The system may include injection molding equipment for producing biodegradable and industrially synthesizable flexible foam molded products as described above. The system may additionally include a supercritical gas batching system that is configured to receive fluid and introduce the received fluid into the first cavity of the barrel under conditions so as to produce supercritical fluid after the introduction When the supercritical fluid contacts the blended thermoplastic biopolymer masterbatch in the first cavity, the supercritical fluid produces a foamed melt. The system may further include a dynamic temperature control system configured to control the temperature in one or more of the first cavity and the second cavity. A gas back pressure delivery unit configured to deliver the gas back pressure to the first cavity so as to control the expansion of the foamed melt may also be included. In addition, it may include a control unit with one or more microprocessors, wherein the control unit is configured to control injection molding equipment, supercritical gas batching system, dynamic temperature control system, And gas back pressure delivery unit.

Specifically, the system components may include an injection molding machine system including a hopper, a barrel, a reciprocating screw, a nozzle, a mold system, a hydraulic system, a control system, a clamping system, and a conveying system. The SCF gas batching system can include and include inert gas tanks such as nitrogen, air compressors, SCF metering and control devices, SCF injectors, and specially designed reciprocating screws, and both front and rear check valves . Dynamic temperature control system can also be provided and includes heating unit, cooling unit, sequence valve, and computer control. In addition, there are heating elements and cooling channels located in the main body of the mold. The heating elements and cooling channels are fed by a dynamic temperature control system, and the heating or cooling medium is circulated by the dynamic temperature control system. Its function is temperature regulation on the mold surface. And a gas back pressure system can be provided, where the gas back pressure system includes, for example, a tank of inert gas such as nitrogen, an air compressor, a gas pump, a gas release valve, a gas pressure sensor, and computer control.

The system and/or any of its subsystems may include one or more sensors, such as temperature, pressure, accelerometer, gyroscope, and orientation sensors, such as one or more sensors configured for Positioned in communication with one or more of the other components such as the injection molding device in one or more cavities of the injection molding device. In various embodiments, the sensor may be a smart sensor and include a communication module, such as having a network connection, so as to perform wireless communication. Therefore, any part of the system and/or its various parts may include a communication module, which may be coupled to one of the control module, the supercritical gas batching system, the dynamic temperature control system, and the gas back pressure control unit. Or more, such as where the communication module is configured to perform one or more wireless communication protocols including WIFI, Bluetooth, Bluetooth Low Energy, and 3G, 4G, and 5G cellular communication.

In another aspect, the present disclosure describes a recyclable microporous flexible foam and a method for producing the recyclable microporous flexible foam. The foam is preferably a closed-cell foam, but it may also be formed as an open-cell foam. The production of recyclable micro-pore flexible foam structure starts with suitable high-performance polymers, such as those of polyamide origin, and so on. A non-limiting example of a suitable polymer is polyamide 66 copolymer marketed by Ascend Performance Materials, LLC, Houston, TX under the trade name Vydyne. Other non-limiting examples of suitable polymers include many polyamide block copolymers, such as polyether-block-amide (PEBA), PAE, TPA, TPE-A, COPA, and the like. The aforementioned thermoplastic polymers have shown advantageous technical properties in forming the optimal microcellular flexible foam structure of the present invention. Some of the enhanced technical properties include abnormal aging properties, excellent elongation, tensile strength, and compression set, among other benefits. In addition, recycled raw materials can be utilized in the manufacture of suitable recyclable polymers or polymer blends of the present invention. For example, in one aspect, the recyclable flexible foam thermoplastic polymer contains at least one monomer or polymer derived from a post-consumer or post-industrial recycled raw material such as Caprolactam, recycled polyether block amide polymer, etc. By way of explanation, caprolactam can be derived from such recycled raw materials by depolymerizing post-industrial or post-consumer materials containing polyamide, such as fishing nets, carpet fibers, Or industrial waste. Some non-limiting examples of depolymerized post-consumer or post-industrial recovered caprolactam include ECONYL® caprolactam supplied by Aquafil USA Inc., Cartersville, Georgia, whether in flakes, liquid, or molten. Thermoplastic polymers may additionally or alternatively comprise polyamide polymers derived from post-industrial or post-consumer polyamide carpet fibers that have been collected, sorted, melted, and reprocessed. This example will use post-industrial polyamide carpet fibers that have been collected, sorted, melted, and reprocessed into upcycled usable polyamide materials. An exemplary polyamide polymer derived from post-industrial carpet fibers is Econyl manufactured by the Aquafil USA Inc., Cartersville, Georgia. In addition, polyamide waste is collected in or around the world's oceans in the form of fishing nets or the like, and then can be sorted, melted, and reprocessed into usable polyamide materials for upgrading. An exemplary polyamide polymer derived from collected post-industrial fishing nets is Akulon Repurposed manufactured by Koninklijke DSM N.V., Heerlen, the Netherlands. The purpose of the present invention is to use recycled polymer raw materials whenever possible.

The best polyamide alone cannot produce recyclable flexible foam without a suitable foaming agent and foaming process. The most widely known blowing agent used today is a chemical called azodicarbonamide (ADA). ADA is usually pre-impregnated into the conventional thermoplastic masterbatch resin used in the conventional injection molding foaming process. Unfortunately, ADA is not environmentally friendly, and it is a suspected carcinogen. In addition, the conventional foaming process using ADA is cross-linked during the manufacturing process and thus produces a type of non-recyclable flexible foam. In order to achieve recyclable flexible foam, inert nitrogen or carbon dioxide is used as the physical blowing agent in the modified injection molding process. The modified physical foaming process is used consistently with suitable thermoplastic polymers or polymer blending masterbatches, so that the polymer or blending polymer and foaming agent work in harmony with recyclable and flexible foams. The preferred injection molding process of the present invention utilizes homogeneous pore nucleation that occurs when a single-phase solution of polymer and supercritical fluid (SCF) is delivered to the mold cavity of the modified injection molding machine through the injection gate. When the solution enters the mold, the pressure drops, causing the SCF to come out of the solution, resulting in pore nuclei. The pores then grow until the material fills the mold and the expansion capacity of the SCF is exhausted. This manufacturing process runs on injection molding machines that have been modified to allow SCF to be metered, delivered, and mixed into the polymer to produce a single-phase solution. Dynamic mold temperature control (DMTC) is used to ensure a consistent pore structure in the expanded polymer melt. DMTC can be best described as heating elements and cooling channels located in the main body of the mold. The heating elements and cooling channels are fed by a dynamic temperature control system, and the heating or cooling medium is circulated through the dynamic temperature control system. Its function is temperature regulation on the mold surface. Gas counter pressure (GCP) is also used in the manufacturing process to ensure that the resulting flexible foam has a small amount to the best foam structure without skin. GCP can best be described as a process that includes a pressurized mold cavity that is injected with nitrogen to resist the expansion of the gas in the melt. When the back pressure is released, the gas bubbles that break through the surface as usual are trapped inside to produce a smooth skin. GCP controls foaming by surface quality, foam structure and skin thickness.

The production of a single-phase solution in which SCF is completely dissolved and uniformly dispersed in the molten polymer occurs inside the injection barrel under carefully controlled process conditions: SCF must be accurately measured by mass flow to the polymer for a constant amount of time . And during the batching cycle, the correct temperature, pressure and shear conditions must be established in the barrel. Back pressure, screw speed and barrel temperature control, as well as gas back pressure and SCF delivery system all play a role in establishing the process conditions to produce a single-phase solution.

The thermoplastic polymer used to make the flexible foam that is recyclable and chemical-free can be optionally produced from many polyamides or polyamide copolymers and the like. Non-limiting examples of suitable polymers include polyamide 6, polyamide 6/6-6, and polyamide 12. Alternatively, the thermoplastic polymer may include many polyamide block copolymers, such as polyether-block-amide (PEBA), PAE, TPA, TPE-A, COPA, and the like. Any suitable polymer type can be used in the present invention as long as it meets the required hardness, moderate melt flow, high elongation, and reusability.

In addition, blends of two or more thermoplastic polymers provide a combination of properties and prices not found in a single thermoplastic polymer. There are many ways to successfully blend polymers together. One method can use twin screw extrusion to melt two or more polymer resins together and then extrude the molten polymer resin blend into strands that are cooled and fed into a pelletizer for Produce a series of pellets called master batches. Another method of polymer resin blending is to use compatibilizers to join the different chemical components together in the polymer blend. This can use twin screw extrusion or the like to melt the compatibilizer and two or more polymers together in the non-limiting thermoplastic polymer types described above.

In one embodiment, the method includes the step of recovering the aforementioned flexible foam by depolymerizing the foam into one or more monomers. The depolymerization process includes the following steps: mechanically separate the thermoplastic polymer of the recyclable foam from the waste, introduce the depolymerization catalyst into the separated thermoplastic polymer, heat the thermoplastic polymer and the catalyst to produce distillate, and remove the water And the obtained monomers are separated from other by-products, oxidized water-containing monomers, concentrated and oxidized water-containing monomers, purified and concentrated monomers, and repolymerized monomers to produce thermoplasticity used in the method of making recyclable flexible foams polymer. The resulting monomers can include caprolactam or other monomers that can be repolymerized into thermoplastic polymers.

Depending on the application, additives can also be utilized in polymer formulations. For example, fillers such as precipitated calcium carbonate, oolitic aragonite, starch, biomass, etc. can be used to reduce the cost of parts while maintaining the recyclable integrity of the finished flexible foam.

Furthermore, the additional additives used in the polymer formulation may include one or more of the following. Nucleating agents may be included, such as microlobed talc or high aspect ratio oolitic aragonite. Such nucleating agents can greatly improve the key properties of the resultant flexible foam by preventing pore coalescence, reducing block density, and improving resilience and other beneficially enhanced properties. Several non-limiting examples of nucleating agents used in the production of recyclable and chemical-free injection molded microporous flexible foams are those marketed by Imerys Talc America Inc., Houston, Texas as Mistrocell® Microlobed talc and high aspect ratio oolitic aragonite marketed by Calcean Minerals & Materials LLC, Gadsden, Alabama as OceanCal®.

It may also include colorants, dyes and pigments. For example, various coloring agents such as dyes or pigments can be used in the polymer formulation of the present invention. Several non-limiting examples are pigments that have been customized for use with specific types of thermoplastic polymers, such as the wide range provided by Treffert GmBH & Co. KG, Bingen am Rhein, Germany or by Holland Colours Americas Inc., Richmond, Indiana Provided by them.

The details of one or more embodiments are set forth in the accompanying description below. Other features and advantages will be self-descriptive and self-applying patent scope is obvious.

This document describes the biodegradable and industrially synthesizable micro-pore flexible foam, the recyclable micro-pore flexible foam, and the production of the biodegradable and industrially-synthesizable micro-pore flexible foam Body, the method for recovering micro-pore flexible foam. The foam is preferably a closed-cell foam, but it may also be formed as an open-cell foam. In various implementation schemes, biodegradable, industrially synthesizable and recyclable flexible foams can be made to have the same properties and characteristics as conventional petrochemical ethylene vinyl acetate (EVA) foams, etc., and still contain High percentage of biomass carbon content. [Biodegradable and industrially synthesizable injection-molded flexible foam and micro-porous flexible foam used to manufacture the biodegradable and industrially synthesizable injection-molded flexible foam Body method]

The present disclosure relates to a process for producing biodegradable and industrially synthesizable microporous flexible foam and a method for manufacturing the biodegradable and industrially synthesizable microporous flexible foam . As discussed above, the foaming description involves the process of capturing air pockets in liquids or solids. Generally, the industry uses foaming to produce lightweight polymer materials. This is an advantageous solution for many types of products, because foamed materials give a lot of added value, such as soft cushioning, comfort, and impact protection.

In various examples, it is useful that the foamed material is in the form of a microcellular foam. Microcellular foaming systems are specifically manufactured in the form of plastics containing many (for example, billions) of tiny bubbles, which are smaller than about 50 microns in size. This type of foaming system is formed by dissolving gas into various types of polymers under high pressure to produce a uniform arrangement of gas bubbles, and this dissolution is commonly referred to as nucleation. The main driver for controlling and adjusting the density of the microporous foam is the gas used to generate the microporous foam. Depending on the gas used, the density of the foam can be anywhere between about 5% to about 99% of the pretreated bioplastic.

Therefore, in various examples, the closed-cell foam of the foaming system is useful. Closed-cell foams are generally known as pores that are generally surrounded by their walls and are therefore not interconnected with other pores. This type of material is useful because it effectively reduces the flow of liquid and gas from the pores. Closed-cell foams such as those produced according to the methods disclosed herein are useful for industries where liquid resistance is critical, such as buffers, footwear, marine, HVAC, and automotive applications.

However, in various examples, it may be useful that the foam is an open-cell foam. When more than half of its pores are open and interconnected with other pores, an open pore foam is usually classified as "open pores". This type of foam that can be produced and utilized in the method disclosed herein can be useful because it operates more like a spring than a closed cell foam, and thus easily returns to it after compression. Original state. "Resilience" is caused by unconstrained air movement and chemical replenishment.

In a specific example, according to the described method, the resulting foam and the products produced from the foam function in a similar manner to flexible ethylene vinyl acetate (EVA) foam. In particular, flexible EVA foam is a universal material used in the manufacturing industry today. What makes EVA foam so popular is its relatively low cost and ease of handling, while maintaining the generally acceptable technical performance properties for a given product. Therefore, the foam produced in the manner disclosed herein can be produced at a relatively low cost, has the ease of manufacture, and at the same time maintains acceptable and generally superior technical performance products, while at the same time being environmentally friendly.

More specifically, as indicated above, the use of EVA foam has many disadvantages. The material is derived from non-renewable raw materials and is chemically cross-linked with chemical blowing agents, which are not easily biodegradable, synthesizable, or recyclable. However, unlike flexible EVA foam, the biodegradable and industrially synthesizable flexible foam of this disclosure does not contain chemicals or crosslinking agents, and when appropriate bio-derived polymers are used in During its manufacture, the biodegradable and industrially synthesizable flexible foams are easily biodegradable and industrially synthesizable.

For example, in various implementation schemes, the system presented in this paper can make it have the similar properties and characteristics of conventional petrochemical ethylene vinyl acetate (EVA) foams, etc., but contain a high percentage of biomass carbon content, which is biodegradable and industrial The above can be synthesized flexible foam. Specifically, in various embodiments, biodegradable, net neutral, and industrially synthesizable foam precursors are used, such as making biodegradable and industrially synthesizable flexibility in an environmentally friendly manner. In the foam. To achieve these goals, any number of suitable bio-derived thermoplastic raw materials can be selected for use, and can be derived from rapidly renewable raw materials that do not normally compete with animal feed or human food. Advantageously, as indicated, the carefully selected bio-derived thermoplastic foam precursors have technical performance properties approximately equivalent or equivalent to those of conventionally used EVA.

This suitable thermoplastic material having technical performance properties approximately equivalent to or equivalent technical performance properties of conventional non-renewable EVA for use in the production of the biodegradable and industrially synthesizable flexible foam of the present disclosure A non-limiting example of a raw material is a bio-derived PBAT copolyester, as described herein below. Therefore, in various examples, the device, system, and method of use thereof can be utilized to produce biodegradable and industrially synthesizable micropore flexible biodegradable and industrially synthesizable bio-derived thermoplastic resins.性foam.

More specifically, the foam precursor that is useful according to the disclosed method can be any suitable type of thermoplastic resin, such as a bio-derived thermoplastic resin or a bio-derived thermoplastic compound produced from a rapidly renewable raw material. Such thermoplastic resins are raw, unshaped polymers that melt and become liquid when applied, and harden and become solid when cooled.

The production of thermoplastics is not a simple task. Complex chemical and mechanical processes are required to make the final product. In its simplest form, thermoplastics are composed of polymers and their polymers are composed of compounds. In order to produce the compounds needed to make polymers and then make thermoplastics, different types of molecules must be broken down and separated. Generally, the foam precursors are used by feeding them into a suitable injection molding machine in the form of pellets. The particles are processed by an injection molding machine, where the particles are liquefied and injected into the cavity of the pre-forming mold. After the injection is completed, the molded part is cooled and ejected from the mold in a solid state. The process implemented in this embodiment will be discussed in more detail below in this article.

Bio-derived thermoplastics can be described by classes. The prevalence of bio-based thermoplastics precursors and biomass. There are two types of biopolyesters: polylactic acid (PLA) and polyhydroxyalkanoate (PHA). PLA is a type of thermoplastic made by bacterial fermentation. PLA is actually the long chain of many lactic acid molecules. To name just a few examples, there are many different biologically derived raw materials used to produce PLA, such as sugar cane, corn, sugar beet, and wood waste. PHA is usually produced by naturally occurring bacteria and food waste. There is a subclass of PHA called polyhydroxybutyrate (PHB), which is a type of PHA that can also be widely used.

In some examples, starch or cellulose fillers, etc. can be optionally included in the formation of the biopolyester blend because its inclusion makes the blend more economical, and in some examples, its use enhances the decomposition rate. An additional type of bio-derived thermoplastic is known as cellulose acetate (CA). CA is a synthetic product derived from cellulose found in every part of the factory. To cite a few examples, the currently used raw materials for the production of CA are cotton, wood, and crop waste. Furthermore, starch is another type of thermoplastic plastic material. Usually, starch is treated with heat, water, and plasticizer to produce thermoplastics. To give strength, starch is usually combined with fillers made of other materials. The currently available raw materials for starch production are maize, wheat, potatoes, and cassava. Several petroleum-derived thermoplastics that are biodegradable are also known. Common types are polybutylene succinate (PBS), polycaprolactone (PCL), polybutyrate adipate terephthalate (PBAT), and polyvinyl alcohol (PVOH/PVA). The aforementioned petroleum-derived thermoplastics can be produced from bio-derived diversity. New bio-derived raw materials for the production of PBS, PCL, PBAT, and PVOH/PVA are being produced, and due to technological progress and breakthroughs, they are becoming more and more commercially available. One or more of these precursors can be produced and utilized according to the methods disclosed herein.

Once the precursors have been produced, the precursors can be foamed and used to make one or more end products, such as by an injection molding process, as disclosed herein. For example, in various examples, the bio-derived thermoplastic precursor can be foamed, such as by injection molding, and used in the end product production process. In conventional foam injection molding, also called direct injection expanded foam molding, the thermoplastic polymer is first melted. When the thermoplastic polymer is uniformly melted, the chemical blowing agent is dispersed into the polymer melt to make the injection compound foamable.

The homogeneous polymer compound is then injected into a mold to make a foam product. Generally, the injected polymer compound is not classified as a foam until the endothermic reaction in the cavity of the heating mold activates the chemical blowing agent, thereby producing an expanded foam part. Therefore, the size of the mold cavity must be smaller than the size of the final part. The actual part expansion is produced in the thermoplastic polymer formulation so that when the part is ejected from the mold, the part grows to the required part size.

Once the required part size is achieved, when it cools down, it also shrinks or shrinks. This usually requires a secondary molding operation to obtain an accurate cooling part size. Therefore, the process of managing the expansion and contraction of conventional injection molded foams can be regarded as tedious, time-consuming, and complicated. This injection molding technology can be used to produce precursors and foams, as well as products produced therefrom, as discussed herein. However, in a specific example, the conventional injection molding machine can be modified, as disclosed herein, in order to better realize the use of biodegradable, net neutral foam precursors, which are biodegradable and net The neutral foam precursor can be used in the modified process to produce environmentally friendly foams. These environmentally friendly foams can be used in the production of foam products. Such as furniture buffers, shoe components, sports equipment, etc.

Therefore, although the conventional process may be useful in the production of foamed products, in some instances, the conventional process may suffer from some disadvantages, especially regarding the production of synthesizable microporous flexible foams. For example, in various examples, the typical injection molding process may have various deficiencies in various ways when synthesizable bio-derived thermoplastic resins are used to produce synthesizable flexible foams. For example, the above-mentioned conventional unmodified foam injection molding process may be insufficient and inappropriate for the production of biodegradable and synthesizable flexible foam. The main reason for this originates from the true nature of conventional unmodified foam injection molding in which the polymer compound is cross-linked during its manufacture.

As indicated above, cross-linking can be described as the formation of randomly occurring covalent bonds that hold parts of several polymer chains together. The result is a random three-dimensional network of interconnected chains within the foam matrix. This cross-linked foam cannot be easily uncross-linked, and thus, various precursor components cannot be easily separated back to their individual types and biodegraded or composted. Therefore, the advantages currently disclosed are not easily achieved without changing the foaming equipment and its method of use in manufacturing. Therefore, this article presents a manufacturing machine and a process of using the manufacturing machine to produce a foam in a manner suitable for using the non-crosslinked precursor in the injection molding process.

Therefore, in one aspect, this article presents a new injection molding machine. The molding machine can be configured to utilize various flexible foam compositions, including bio-derived thermoplastic plastic precursors, which can be formed by applying the precursors to the new injection molding machine To foam in a way to produce a microporous flexible foam structure that can be synthesized, the new injection molding machine can then be used to produce one or more flexible foam products. Therefore, in one aspect, what this article provides is a new injection molding machine.

Some of the factors that set the manufacturing machine separation of the present disclosure are the use of specialized auxiliary equipment, which is coupled with an attachable micro-pore gas batching system to modify and improve the standard injection molding machine. In essence, as presented herein, the standard injection molding machine has been completely reformed and reorganized to function in a suitable manner for use in accordance with this disclosure. The general method for modification starts with changing the injection molding screw on the injection molding machine to be able to handle supercritical inert gases, such as nitrogen, CO ₂ , and/or non-resistant and/or inert gases.

The gas dosing system can then be assembled to an injection molding machine for, for example, dosing the proper amount of gas into the polymer melt in the screw before injection into a temperature-controlled mold cavity. In addition, a special mold cavity can be used, in which the thermal temperature cycle of the mold can better control the texture and thickness of the resulting foamed outer skin, and reduce the cycle time for the production of parts. In addition, the auxiliary gas back pressure system can be fitted to the injection molding machine for pushing the inert gas back into the mold to resist the liquid polymer melt ortho-injected into the mold.

This back pressure is useful for ensuring that the melted injection injection substantially (if not completely) fills the cavity of the mold, prevents warping and shrinkage of parts, and controls the distribution of pores and the density of pores. In addition, proper back pressure has a beneficial effect on the surface texture and thickness of the parts. Therefore, when the part is ejected from the mold cavity, there is no discernible shrinkage and there is no secondary step required to immediately use the molded foam part. Advantageously, the part is not cross-linked, and therefore, the part is biodegradable or compostable, as long as a suitable bio-derived polymer compound is used in the foam production.

In view of the foregoing, in one aspect, the present disclosure is directed to the production of a microporous flexible foam structure that is biodegradable and can be synthesized (for example, industrially). In particular, in one embodiment, the process starts with a suitable biopolymer or biopolymer blend. For example, in various examples, the biopolymer may be one or more polymers such as those produced from natural resources, chemically synthesized from biological materials or completely biosynthesized by living organisms.

There are mainly two types of biopolymers, one biopolymer is obtained from living organisms and the other biopolymer is produced from renewable resources but requires polymerization. These biopolymers produced by living organisms include proteins and carbohydrates. Unlike synthetic polymers, biopolymers have clearly marked structures. This type of polymer is differentiated based on its chemical structure. What makes the biopolymer of this disclosure particularly useful is that the biopolymer closely mimics non-renewable EVA in terms of technical performance properties.

Likewise, in certain examples, biopolymer blends can be utilized in the production of foam structures, such as custom compounds where the biopolymer blend can be two or more biopolymers. Several unlimited types of biopolymers are sugar-based biopolymers, starch-based biopolymers, biopolymers based on synthetic materials, and cellulose-based biopolymers. The typical ratio of the biopolymer blend combination will depend on the type of product being manufactured and the required technical properties of the resulting part.

More specifically, in a particular embodiment, the biopolymer blend that can be used as a foam precursor includes a plurality of resins, such as one or more that can be added to the melt of the polymer after curing. Solid or viscous materials. Therefore, after polymerization or curing, the resin forms a polymer. For example, suitable resins can be one or more of the following: aliphatic and aliphatic-aromatic copolyester origin. Generally speaking, aliphatic or aliphatic compound refers to or indicates an organic compound in which carbon atoms form an open chain rather than an aromatic ring. Likewise, suitable aliphatic-aromatic compounds are usually random combinations of carbon atoms (aliphatic parts) and stable rings of atoms or open chains of multiple rings (aromatic parts).

Generally, the amount of aromatic acids in the chain is less than 49%, but recent technological advances have shown a great promise to increase this and further aid biodegradation. Examples of aliphatic-aromatics are aliphatic-aromatic copolyesters (AAPE) that can be produced from any number of non-renewable and renewable raw materials, but AAPE from renewable sources is particularly useful. Therefore, in various embodiments, one or more of these aliphatic and/or aliphatic groups may have a copolyester origin. When the polyester is modified, this type of copolyester is produced. For example, when more than one diacid or diol is used in the polymerization process, a copolyester is produced. In the case of aliphatic-aromatic copolyesters, the combination of changes in the precursors essentially hybridizes or "bridges" the aliphatic-aromatic chain and combines more than one additional precursor during the polymerization process.

Non-limiting examples of suitable biopolymer blends are polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (poly(butylene adipate-co-terephthalate); PBAT) . Polylactic acid (PLA) is a biodegradable thermoplastic aliphatic polyester derived from renewable biomass. Typical raw materials used in the production of PLA include fermentation plant starches such as corn, cassava, sugar cane, sugar beet residue, and to a lesser extent lignin waste materials. Similarly, polybutylene adipate terephthalate (PBAT) is a biodegradable random copolymer. In particular, it is usually derived from a copolymer of adipic acid, 1,4-butanediol and terephthalic acid ester. It is advantageous to use PBAT from renewable sources instead of PBAT from non-renewable petroleum sources. In various examples, one or more of these components may be blended.

A blend of two or more thermoplastic biopolymers provides a combination of properties and prices not found in a single polymer or copolymer. There are many ways to successfully blend biopolymers together. A common method is to use twin screw extrusion to melt two or more biopolymer resins together and then extrude the melted biopolymer resin blend into strands, which are cooled and fed into a pelletizer Used to produce a series of pellets called master batches. Another method of biopolymer resin blending is to use a compatibilizing agent in the biopolymer blend to bond different chemical components together. Usually, twin screw extrusion or the like is also used to melt the compatibilizer and two or more biopolymers together in the process described above.

Therefore, it has been determined in this article that the aforementioned blended thermoplastic biopolymer resins show advantageous technical properties in forming the optimal microporous flexible foam structure of the present disclosure. Some of the enhanced technical properties include: acceptable aging properties, excellent elongation, and abnormal compression set, among other benefits. For example, as disclosed herein, the advantage of using biopolymer blends is the enhanced technical performance properties resulting from the formation and use of a given biopolymer blend. In particular, when the correct combination of biopolymer and/or biopolymer-compatibilizer blend is achieved, enhanced properties such as improved elongation, tensile strength, impact strength, and melt flow can all be achieved.

Therefore, these resins can be used according to the methods and machines disclosed herein to produce foaming agents. Therefore, in one aspect, the present disclosure is directed to the foaming process. As described above, the machines and processes disclosed herein can be configured to perform foaming operations, thereby trapping air pockets in liquids or solids, and the foaming can be used to produce lightweight polymer materials. This is an advantageous solution for many types of products, because foamed materials give a lot of added value such as soft cushioning, comfort, technical sports equipment, including shoe components, and impact protection. However, in various examples, the aforementioned optimal aliphatic and aliphatic-aromatic copolyester biopolymers or biopolymer blends alone are useful for producing flexible foams. In various examples Among them, its use in the production of flexible foams can be enhanced by including a suitable foaming agent in the foaming process.

For example, a widely known blowing agent used today is a chemical called azodimethamide (ADA). Azodimethamide is usually pre-impregnated into the petrochemical thermoplastic masterbatch resin used in the conventional injection molding foaming process. In particular, pre-impregnation of chemical foaming agents such as ADA is usually included in the bioplastic blend before foaming. The reason for this is that it requires pre-impregnation of chemical foaming agents such as ADA, because conventional injection molded foaming does not allow customization of foam molding variability. That is, chemical blowing agents such as ADA are limited in their ability to modify or influence the physical aspect of the foaming process during the point of manufacture.

In contrast, the specialized foaming process of the present disclosure benefits from physical foaming provided by inert gas or inert gas such as nitrogen. In this process, the gas (for example, nitrogen) ingredients can be adjusted in terms of concentration in the biopolymer melt, and this has a direct impact on the foaming result, which can be regarded as the specific aspect of the customized foam main advantage. Although there are several petrochemical-derived thermoplastics that are known to be biodegradable and industrially synthesizable, such as PBAT copolyesters, it is advantageous to use renewable sources of raw materials such as pure PBAT copolyesters.

For example, in the production of foaming agents, it may be useful to first produce a customized masterbatch such as a bioplastic blend that is suitable for producing a given type of biodegradable for a given product type And it is a flexible foam that can be synthesized industrially. For example, different types of customized masterbatch compounds can be produced for different types of product applications. This can be explained by indicating what is used to make a specific type of foam in a pair of shoes, for example, can be different from what is needed to make a specific type of foam, such as used in making a piece of furniture . In addition, customized masterbatches can each contain different colorants for use in a given product. In addition, here, different product types require different customization aspects, and the unique ability to produce a single masterbatch is highly advantageous for these specific uses.

Unfortunately, ADA is not environmentally friendly, and it is a suspected carcinogen for human health. Therefore, its use in the present method and the products produced therefrom is limited in terms of its advantages. In addition, conventional petrochemical thermoplastic masterbatch resins are not biodegradable, nor are they industrially synthesizable, and therefore, their advantages are also limited. In view of these deficiencies in the use of ADA and conventional petrochemicals for the production of masterbatches, this article presents the masterbatches that can be used to produce biodegradable and industrially synthesizable microporous flexible foams. The biodegradable, industrially synthesizable, thermoplastic biopolymer resin.

In various instances, as discussed above, in order to achieve better biodegradable and industrially synthesizable flexible foams for use in, for example, environmentally neutral manufacturing molded end products, ultra The critical fluid can be injected into the molding process by the system. Specifically, a supercritical fluid is a substance (liquid or gas) in a state above its critical temperature (Tc) and critical pressure (Pc). At this critical point, gas and liquid coexist, and the supercritical fluid exhibits unique properties that are different from those of liquid or gas, for example, under standard conditions. It is advantageous to use inert supercritical fluids such as nitrogen, CO ₂ , He, Ne, Ar, Xe and other such inert gases in a supercritical fluid state, and these gases can be used as the foaming process according to the method disclosed herein In the foaming agent.

The aforementioned supercritical fluid works by dissolving in the polymer matrix in the barrel of the injection molding machine. When the liquid bioplastic compound is injected into the injection mold cavity under controlled pressure and temperature during the special injection molding process, the gas pushes the polymer melt to fully expand to the maximum limit of the mold cavity. In this process, the gas is useful for maximizing the cell structure of the polymer matrix during the foaming process. This maximization of the specialized foaming process ensures that undesirable sink marks or warpage in the final foamed part are minimized. This is very different from the flexible foam produced by the conventional chemical foaming agent, because the conventional foaming agent is not subject to the same type of supercritical state or pressure, and therefore the conventionally produced foam lacks in the final foamed part. Consistency, and it can contain undesirable sink marks and warpage.

More specifically, in various examples, an inert gas such as nitrogen or carbon dioxide can be formulated in a supercritical fluid state, which can then be used as a physical blowing agent, such as the novel injection molding machine and In process. In this example, the disclosed modified physical foaming process can be used with each of the following: a suitable thermoplastic biopolymer or can be a blended biopolymer masterbatch such that a biopolymer or biopolymer blend And the foaming agent work in coordination to produce the best biodegradable and industrially synthesizable flexible foam.

Suitable biopolymers, bioplastics, and bioplastic blends of this disclosure can be derived from renewable resources, such as those that do not compete with animal feed and human food, and are derived from Renewable resources are their resources in the waste stream. Non-limiting examples of suitable biopolymers found for use in the production of biopolymers or biopolymer blends consist of the following: polylactic acid (PLA), poly(L-lactic acid); PLLA ), poly(butylene adipate-co-terephthalate) (PBAT), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polybutene succinate (PBS) , Polycaprolactone (PCL), polybutylene succinate adipate (PBSA), polybutylene adipate (PBA), and thermoplastic starch (TPS). Suitable biopolymer blends of the present disclosure are any combination of the above-listed biopolymers and bioplastic types, and are made of biomass-containing poly(butylene adipate-co-terephthalate) (PBAT) any hybrid biopolymer blend composed of. A non-limiting example of this situation would be a lignin-containing PBAT blend, where lignin is derived from waste wood and PBAT is derived from renewable resources.

Therefore, in various embodiments, the injection molding device and method of use disclosed herein are useful for producing foams with uniform pore nucleation. As discussed, the equipment and method of use disclosed herein can be used to produce homogeneous pore nucleation in order to produce foam, whereby the foam core is randomly and spontaneously generated, and thus grows irreversibly with little to no impurities The single-phase solution system. For example, as described in this article below, in one aspect, a process for manufacturing a flexible and/or rigid foam is provided. The method can be implemented to derive open-cell or closed-cell foam, such as where the foam has inherently synthesizable, antimicrobial, and/or flame-resistant properties.

In some instances, the method may include one or more of the steps of forming a masterbatch, such as including blending one or more resins, for example, copolymer carrier resins, and various foaming ingredients. In the subsequent steps, the method may include adding antimicrobial compounds so that the foam material can be used in antimicrobial, antibacterial and/or antiviral footwear components, furniture components, yoga mats, clothing, sports goods components, medical devices, And/or flame-resistant products, and other suitable use in the production. In particular, according to the method disclosed in this article, the produced product can be used in a large range of applications, and the production method can usually be decomposed into three distinct stages. First, make bulk polymer products. Next, the polymer is exposed to various processing steps. Finally, the polymer is transformed into its final products, such as clothing, antimicrobial carpets, furniture, automotive components, yoga mats, shoe components, including soles, midsoles, insoles, and so on.

Specifically, this single-phase solution can be utilized to produce nucleation sites in which pores grow and expand by gas diffusion into bubbles. The machines and processes disclosed herein are particularly useful for initiating the foaming process, which results in the generation of homogeneous pore nucleation in such a way that small bubbles are uniformly dispersed in the foam matrix. In particular, unlike conventional foaming, the flexible foam formed by the supercritical fluid of the present disclosure benefits from greatly improved mechanical properties that can be directly attributed to the size of the small bubbles. More specifically, the devices and methods disclosed herein are configured to produce from about 100 microns or more to about 1 micron or less, such as from about 50 microns to about 10 microns, or less, such as from about 20 microns to about 40 microns, including a bubble diameter of about 30 microns, and these bubble diameters are produced by using thermodynamic instability, and all of them are produced without using conventional chemical blowing agents in the production of the foam.

For example, in certain embodiments, the system can be configured to use the novel injection molding machine disclosed herein for the production of biodegradable and industrially synthesizable microporous flexible foams. The degradable and industrially synthesizable microporous flexible foam can be used as a single-phase solution of biopolymer or biopolymer blend and supercritical fluid (SCF) to pass through the injection gate to the injection molding machine Homogeneous pore nucleation can occur in the cavity of the mold. In particular, as explained in more detail below, the injection molding machine is configured to produce molten material, such as by injecting mold precursors into a mold used to produce finished parts or component parts. The injection molding machine may include a material hopper, an injection ram or screw plunger, and a heating unit. This type of injection molding machine is rated in terms of tonnage, which expresses the amount of clamping force the machine can apply.

Therefore, the manufacturing process can start with feeding the granular bioplastic compound from the hopper into the heating barrel by forced hammers. When the particles are slowly moved forward by the special reciprocating screw plunger, the supercritical fluid is introduced through the ejector by a separate supercritical metering auxiliary machine, which can be directly connected to the feed to the screw Injection molding equipment. Therefore, the supercritical fluid is saturated in the biopolymer melt during the rotation of the screw and this produces a single-phase solution.

The molten mixture is then pushed into the heating chamber with high back pressure, where the molten mixture melts at a temperature controlled by a computer interface. As the plunger advances, the molten bioplastic compound is pushed through the nozzle, which abuts the mold, allowing the molten bioplastic compound to pass through the gate and into the cavity of the mold. Therefore, the foaming process can be configured to be used in a mechanical or physical process of subjecting the polymer material to heat and pressure to be applied to the polymer material in the presence of a foaming agent. The foaming agent may have a chemical origin, such as the conventional closed-cell EVA foaming condition, or the foaming agent may have an inert origin, such as the biodegradable and industrially-synthesizable flexible foam of the present disclosure situation. Therefore, in view of the foregoing, when the solution enters the mold, the pressure drops, which causes the SCF to come out of the solution that produces pore nuclei.

Specifically, the supercritical fluid is saturated in the biopolymer melt during the rotation of the screw, and this produces a single-phase solution at a certain temperature and pressure. The molten mixture is pushed into the heated mold cavity with high back pressure, and the pressure of the single-phase solution drops from the microporous process pressure to atmospheric pressure, so rapid pressure reduction occurs. The nucleation phenomenon occurs due to the gas separated from the mixture. At this time, the nucleus grows into a stable bubble. The bubble size is determined by the saturation, microporous process pressure, and mixture temperature that can all be controlled by the system and method. Therefore, when millions of nuclei are produced and the nuclei are stable, bubble growth begins.

The bubble morphology is determined by the SCF concentration and injection molding process parameters. Therefore, these parameters can be selected for control by the system in order to produce useful and/or determined bubble morphology. At the end of the molding of the part, the mold is cooled and the melt temperature is reduced, which forces the melt to freeze and solidify. In addition, these parameters can be tightly controlled by the system, such as depending on the end product to be produced. Specifically, at this time, the growth of bubbles stops and the shape of the resulting part is fixed. The pores then grow until the material fills the mold and the expansion capacity of the SCF is exhausted.

Therefore, in this process, the molten biopolymer and SCF blend is controllably injected into the cavity of the heated mold and undergoes a sudden pressure drop. Millions of tiny bubbles are produced by nuclear growth, and these bubbles physically force the molten mixture to expand to the maximum confinement of the mold cavity. When the molten mixture expands to the maximum physical possibility, the material cools rapidly in the mold and the formation of bubbles stops, the molten mixture stops expanding, and finally a solidified part is formed. All this happens within a few seconds in the injection molding system.

As indicated, this manufacturing process runs on the injection molding machines described above, which have been modified to finely control: metering, conveying, mixing, temperature, pressure, injection, speed, etc. For example, the auxiliary metering unit can be used to control the metering used to deliver precise SCF gas ingredients into the polymer melt. In particular, a suitable gas batching auxiliary machine can be configured to convert the inert gas into a supercritical fluid state, and to meter the batches delivered by the SCF in the injection molding machine, such as by a computer control mechanism.

For example, the operator or a properly configured microcontroller can program the gas batching auxiliary machine to a predetermined SCF gas batching volume. In essence, the auxiliary gas batching machine is an SCF delivery system, which can be electronically and/or physically coupled to the injection molding machine. In particular, the appropriate SCF gas batching auxiliary machine used in this disclosure can be assembled to produce the circuit of the gas batching system, which is designed to convert industrial-grade nitrogen or other inert gases into Supercritical fluid. The gas batching equipment can be assembled to accurately batch and inject SCF into the injection molding machine at a pressure of up to and even more than 275 bar.

In order to operate the gas batching equipment, the operator can use the associated computing device, such as a desktop or laptop computing device, the associated computing device is configured for the production of control system equipment and individual control parameters Such as the graphical user interface (GUI) of the batching equipment. For example, the operator can input selected parameters, such as the desired SCF gas injection parameters, into the GUI. The processing components of the system then calculate all sub-parameters in real time and optimally deliver them to the SCF delivery in the injection molding machine. Therefore, the control unit of the system ensures that the gas batching system and the injection molding machine work cooperatively, such as a network controlled by a computer. Therefore, this gas dosing system is a unique attribute of this disclosure, because supercritical inert gas can replace the chemically reactive blowing agent used in conventional flexible foams and effortlessly be used to produce this disclosure. The biodegradable and industrially synthesizable flexible foam physical foaming agent. This control of mixing SCF into biopolymers is useful for producing single-phase solutions.

In addition, during the injection molding process of the present disclosure, SCF is injected into the polymer melt. The single phase of the polymer-SCF mixed solution is obtained under a clear temperature and pressure in the screw and barrel of the injection molding machine. Temperature and pressure can be variable and controllable, and are directly related to the type of flexible foam being produced and the type of application in which the end product will be used. In this stage, the concentration of SCF is determined by saturation, microporous process pressure, and mixing temperature. Examples can be provided for use in making foamed furniture, automobiles, sports, and/or shoe parts, specifically the biodegradable and industrially synthesizable flexible of the present disclosure in the midsole of the shoe性foam. A non-limiting example of a suitable biopolymer blend for use in this non-limiting example is a rapidly renewable PBAT biopolyester formed into a biopolymer compound.

Therefore, the particulate biopolymer compound is first fed into the injection molding machine via the hopper. Next, when a specific SCF gas ingredient is introduced and homogeneously mixed into the currently molten biopolymer compound, so that the molten biopolymer compound is completely saturated, the biopolymer slowly passes through the injection molding machine screw and The barrel moves. The molten biopolymer compound and SCF are now single-phase solutions. A non-limiting example of the initial SCF gas concentration may be Co = 0.25%, with a melting temperature range between 176°C and 250°C, and more preferably in the range of 180°C.

Additionally, in various embodiments, the temperature within the mold can be finely controlled along with the pressure, such as in a dynamic mold temperature control (DMTC) protocol. For example, the DMTC process can be used to ensure a consistent pore structure in the expanded biopolymer melt. Specifically, the DMTC can be configured to include rapid changes and control of mold temperature and/or pressure during the injection and filling stage. This thereby dynamically controls the mold temperature and/or pressure in terms of both heat and cold heat cycles with or without pressure.

For example, the control module of the system can be configured to control the mold temperature during the injection and filling stage, for example, in such instances, dynamic mold temperature control can be utilized. More specifically, compared with the conventionally known injection molding process, the important feature of the dynamic mold temperature control used herein is that the mold temperature itself can be dynamically controlled. Before the melt of the single-phase solution is injected, the mold can be heated to a preset upper limit first. During the melt filling stage, the temperature of the mold cavity surface can be kept above the upper limit to prevent the melt from solidifying prematurely. When the melt filling process has ended, the mold is rapidly cooled to the lower limit (spray temperature), and then the molded foam parts are sprayed out of the mold cavity.

The dynamic mold temperature control (DMTC) implemented in this paper relies on a control method based on rapid electric pole heating and rapid water cooling. Specifically, the DMTC used in the present disclosure is composed of five main components: an air compressor, a valve exchange device, a computer-controlled mold temperature control unit, an electric heating mold, and a cooling tower. The cooling tower can be used to supply sufficient water cooling to the mold. The air compressor is used to produce compressed air as the driving gas of the pneumatic valve and to remove the residual cooling water after cooling to avoid entering the mold. The valve exchange device is used to switch the valve to transfer different media from the pipeline to the mold, such as heat and cold heat cycles.

Therefore, in various examples, the machines and processes herein may include pipes and other conduits for the transfer of reactive materials, and these pipes are associated with one or more heat exchange units so that the reactants are pumped to the conduits and pipes. The reactants are heated and/or cooled while passing through conduits and pipes. In this example, the exchanger can be controlled to adjust the temperature to the reaction level. A dispensing head may be included on one end of the pipe, which may be associated with one or more valves. In addition, the dispensing head can be hooked up to the processing line. Electric heating molds are used to mold the final shape of foamed parts. The function of mold temperature control will control the heating and cooling of the mold; all this is coordinated with the injection molding machine by computer control.

Likewise, as indicated, the pressure can also be finely controlled, such as by the gas back pressure (GCP) protocol. For example, the GCP protocol can be used in the manufacturing process to better ensure the best foam structure of the end product, and this is done in a way that there is very little to no skin on the resulting flexible foam. For example, using this GCP process, SCF can be injected to pressurize the mold cavity, and the SCF alone and together can act to resist the expansion of the gas in the melt. Specifically, when the back pressure is released, the gas bubbles that have conventionally broken through the surface are trapped inside to produce a smooth skin.

When the foamed part is formed, the gas back pressure process prevents gas bubbles from contacting and penetrating the surface of the foamed material. This is achieved by resisting pressure, which is applied to the mold cavity by the GCP system at the same time or around the same time when the molten single-phase solution is injected and held. The inert gas bubbles experience great force, and therefore the molten single-phase solution is not given an opportunity to release the trapped bubbles to the outside of the foamed structure when the molten single-phase solution is being formed. The result is that the molded foam part forms an aesthetically smooth skin on the outside of the part.

Therefore, as implemented in this article, the controller of the system can implement a gas back pressure (GCP) program that is configured to apply different gases to the melt injection stage of foam injection molding. Pressure to improve the control of the foaming process. For example, by controlling the various components of the system, the control system can be configured to apply changes in the SCF single-phase solution pressure and GCP pressure contained in the screw, such as the appropriate injection size, injection holding time, melt temperature, and mold The temperature is the same.

In this way, an entire system can be produced by which high-quality and commercially acceptable biodegradable and industrially synthesizable flexible foam parts can be produced. In particular, small changes in GCP pressure affect the surface quality of the foam. For example, without using GCP, the bubbles formed in the polymer melt located in the cavity of the mold can be released and the appearance of the resulting foamed part may not be acceptable. In addition, without using GCP, the skin thickness can be undesirably thick because when the molten single-phase solution expands into the mold, there is no back pressure to resist the rapid cooling of the molten single-phase solution. Specifically, a single-phase solution will hit the steel mold boundary during injection and solidify immediately, with an undesirable thick skin that is unacceptable for most commercial applications. In short, the process parameters have a demonstrable impact on the quality of the final part. Therefore, in this way, the GCP process can be controlled in the manner of foaming, such as by one or more of the surface quality, foam structure, skin thickness, and so on.

Therefore, in various embodiments, the system can be configured to produce SCF in a manner so as to form a single phase solution. Specifically, in various embodiments, a single-phase solution is produced in which SCF can be completely dissolved and uniformly dispersed in the molten biopolymer, which occurs inside the injection barrel under carefully controlled process conditions. For example, as discussed, the formation of a single-phase solution is critical for producing molded foam parts that can be mass-produced consistent with this disclosure.

Therefore, the injection molding system process should be configured to be controllable and repeatable in a very consistent manner. To achieve this, the first line of defense will ensure that the biopolymer compound and SCF are homogeneously mixed into a single-phase solution, such as the biopolymer melt in which the single-phase solution is fully saturated and dispersed in the barrel of the injection molding machine. Once a single-phase solution is reached, the system can reliably input the required injection weight, injection holding time, and GCP gas ingredients for customizing continuous and renewable molding in a time-optimized and mass-produced manner Foam parts.

In this way, the SCF should be accurately measured by mass flow rate into the biopolymer for a constant amount of time. For example, the system control module can be configured so that during the batching cycle, the following correct conditions are established in the barrel: temperature, pressure, and shear. Similarly, back pressure, screw speed and barrel temperature can be finely controlled by one or more control elements of the system. In addition, the SCF delivery system can be adjusted to establish process conditions that produce the best single-phase solution.

For example, as discussed above, the control module may be communicably coupled to a mass flow measurement device associated with the system, and the mass flow measurement device associated with the system is configured to measure through one or more of the systems The mass flow rate of the fluid traveling through the container (for example, a pipe). The mass flow rate is the mass of the fluid that travels through a fixed point per unit time. When it relates to the present disclosure, the principle of mass flow measurement is implemented to ensure consistent repeatability in the foam molding process. In particular, as described above, a specially designed ejector is coupled to the injection molded barrel, which can be controlled by a computer-controlled programming control of the processor of the system. Therefore, the system can be configured to deliver specific SCF gas ingredients to the biopolymer melt, and the computer-controlled program can optimize the delivery based on the collection of real-time data from the mass flow rate, such as by Feedback from one or more system sensors. This use of mass flow metering ensures the most optimal process control of the single-phase solution used in the present invention.

Therefore, during the batching cycle, the temperature throughout the system (such as the barrel) can be controlled so as to be between 100°C and 600°C, such as between 200°C and 500°C, for example, between 300°C and 400°C Between, and more specifically, between 320°C and 380°C, including between 360°C and 380°C in the barrel. Similarly, the SCF delivery pressure can be finely controlled so as to be within a range between 1,000 PSI and 8,000 PSI, such as between 1,500 PSI and 6,000 PSI, for example, between 2,000 PSI and 5,500 PSI, and In other words, between 3,000 PSI and 4,000 PSI, and more specifically between 2,600 PSI and 2,800 PSI.

In this way, the control module can be configured so that the temperature and pressure work consistently to produce the optimal core and the resulting bubbles in the biopolymer melt and the resulting foamed matrix. In addition, with regard to the shear force, when the layers of molten biopolymer flow relative to each other, a shear force is established in the barrel. Therefore, during injection, the molten biopolymer compound can be allowed to flow through the melt delivery channel of the barrel nozzle, such as before entering the mold such as a fountain.

Shearing is the stretching of the biopolymer between the rotating screw and the fixed barrel, so that the heat appears in the material. Therefore, the shear force should be controlled during the injection molding process. Therefore, one or more control units of the system can be configured, such as used to control the injection speed, filling time, and tolerances therein, so that in the case of a given injection molding machine size, and in a given injection mold In the case of the size of the screw and barrel of the forming machine, the correct conditions for the production of a given biopolymer compound are achieved.

Back pressure can also be controlled. For example, the back pressure is the pressure applied by the biopolymer when the biopolymer is injected into the mold in the injection molding machine. Specifically, the back pressure is the resistance applied to the injection screw when the injection screw is retracted to load the next biopolymer injected into the mold. As indicated above, various parameters of the system can be configured to control and/or adjust the back pressure.

In addition, the controller of the system can be configured to control and adjust the screw speed. The screw speed can be controlled by computer control. As indicated, during the initial stage of the injection molding operation, the screw rotates within the barrel to homogenize the molten biopolymer compound mixture in accordance with the SCF gas. Non-limiting examples of the screw speed of the present disclosure can be from 1 rpm or 5 rpm or 10 rpm to 75 rpm or 100 rpm or 200 rpm, for example, from 20 rpm, 25 rpm, or 30 rpm to 40 rpm, 50 rpm or 60 rpm.

The system may include a heating and/or cooling control unit, which may be associated with the barrel in order to control the temperature therein. Therefore, the control module can be configured to control the barrel temperature. Therefore, the barrel temperature can be controlled to make the temperature hotter or colder according to the needs of the foaming process.

Therefore, in view of the above, the SCF delivery system may include a control unit that is configured to control the combination of the SCF delivery pressure and the SCF dose weight. The SCF dose weight is usually measured in grams. SCF pressure and dosage can be controlled in a way to affect single-phase solutions. That is, the smaller the SCF dose, the smaller the SCF saturation requirement in the biopolymer melt, and the larger the SCF dose, the greater the SCF saturation requirement in the melt. Likewise, the lower the SCF delivery pressure, the lower the uptake of saturation, and therefore the lower the growth of the nucleus that can grow to form bubbles in the molten biopolymer melt. Likewise, the greater the SCF delivery pressure, the greater the uptake of saturation, and therefore the greater the growth of nuclei that can grow to form bubbles in the molten melt.

Regarding saturation, the system and equipment are configured to deliver gas to the melt chamber at a temperature and a pressure such that supercritical fluid is formed and saturated in the biopolymer melt, such as during screw rotation. Therefore, a single-phase solution is produced at a controlled temperature and pressure. In particular, the single phase of the polymer-SCF mixed solution can be obtained in this article at a specific temperature and pressure in the screw and barrel of the injection molding machine. More specifically, the system controller can variably control the temperature and pressure in a manner that depends on the type of flexible foam being produced and the type of end product being produced.

In this stage, the concentration of SCF can be determined and controlled, such as by a feedback loop, thereby determining the amount of saturation, such as by a sensor, which evaluates the progress of the saturation process and then sets it based on reaching a determination for the saturation level Click to adjust the micro-pore process pressure and mixing temperature. In this example, the supercritical fluid (SCF) is controllably saturated in the biopolymer melt during the rotation of the screw, and this produces a single-phase solution at a defined temperature and pressure. SCF is one part of a two-part molten biopolymer compound mixture, and it is used as a physical blowing agent in the presence of a clear pressure and temperature in the injection mold.

Therefore, in view of the above content, in one aspect, what is provided herein is a machine and a method for using the machine in the production of a biodegradable and industrially synthesizable microporous flexible foam. Specifically, in one example, the foam is produced and/or used in the production of foamed products, such as by a microcellular injection molding (MuCell) process, for example, MuCell manufacturing. MuCell manufacturing utilizes supercritical fluid, as described above, the supercritical fluid is subjected to extremely high pressure and dissolves into the polymer melt in the screw barrel of the manufacturing tool, such as described below, the manufacturing tool is assembled for The SCF formulation is optimized for the purpose of producing molten biopolymer, which is heated to a liquid state.

Therefore, at the center of the injection molding machine are the injection molding machine barrel and screw contained therein, and both the injection molding machine barrel and the screw are usually made of tool steel. The barrel is the main delivery inlet for this single-phase solution before it is metered and then pressed or "injected" into the dynamic temperature control mold assembly. Therefore, the biopolymer melt is transported into the barrel through the hopper of the injection molding machine. And the system controller feeds a given amount of granular bioplastic pellets into the hopper as one of the first steps in the operation of the injection mold machine.

Specifically, during injection, the SCF evaporates and becomes gas bubbles, for example, a foam in the form of a finished molded part. Because the bubbles reach the micron size, the process produces micro-pore foaming. The process described in this article is advantageous over the conventional injection technology because the process results in a product that confirms one or more of the following: less shrinkage, light weight product, with a few sink marks, And can be produced by low-cost precursors. More specifically, with regard to less shrinkage, shrinkage can be controlled by understanding that volume shrinkage is caused by thermal shrinkage, which affects all polymers, and thus, shrinkage can be tracked by the system sensor Advance and finely control barrel conditions in order to adjust the shrinking process to avoid shrinking.

In essence, shrinkage describes the degree to which the volume of a material changes when it changes from a liquid to a solid. In the conventional injection molding, the mold is not temperature controlled under pressure, so the molten polymer used by the conventional method shrinks when it comes into contact with the cold tool steel of the injection mold, and this causes shrinkage. In this machine and system, shrinkage can be controlled, and is usually due to a pressure-controlled mold that ensures that the molten biopolymer fills the largest surface area inside the mold without premature cooling, and further The auxiliary pressurized mold cavity itself applies uniform stress without problems.

Regarding the production of lightweight products as a general rule, the more the polymer swells, the greater the weight loss. However, this system is configured to optimize the single-phase solution by applying adjustment conditions of appropriate pressure, temperature, and time, so that the optimal quality of light-weight foam can be achieved. This is suitable for product applications that require lightweight foams, such as, for example, cushions, foams for footwear, and foams used to produce sports equipment. Similarly, with regard to the control of sink marks in the manufacture of conventional flexible foams, sink marks and voids are caused by localized shrinkage of the material at the thick section without sufficient compensation when the part is cooling.

Specifically, sink marks usually occur on the surface opposite and/or adjacent to the feet or ribs. This occurs due to unbalanced heat removal and/or similar factors. After the material on the outer side of the foamed part has cooled and solidified, the core material begins to cool. The shrinkage pulls the surface of the main wall inward, causing sink marks. If the skin is sufficiently rigid, the deformation of the skin can be replaced by the formation of pores in the core.

Different from the challenges of sink marks and pores in conventional flexible foam molding, the machine configuration and the system parameters are controllable in order to produce the biodegradable and industrially synthesizable flexible of the present disclosure. The flexible foam, which is biodegradable and industrially synthesizable, minimizes these problems. Specifically, in this process, the SCF gas is controlled in a way to adjust, for example, maximize the pore structure of the polymer matrix in the foaming process. This maximization of the specialized foaming process better ensures that there are no undesirable sink marks or voids in the final foamed part.

In addition, as indicated, the useful benefits of this system are that it utilizes low-cost materials and the end products produced have less warpage. Specifically, for many of the reasons discussed above, the present disclosure benefits from a process in which SCF gas is responsible for maximizing the pore structure of the polymer matrix in the foaming process. This maximization of the specialized foaming process ensures that there is minimal warpage in the final foamed part.

Another benefit of this system is that it can be configured to control tolerances. For example, the system can be configured to perform tight tolerance flexible foam injection molding. Specifically, the tight tolerance flexible foam injection molding as presented herein can be used to produce parts that work smoothly together and contribute to the overall lower failure rate of the product.

In order for the product to work reliably and as expected, all of its parts must fit together smoothly. Therefore, the equipment and its component parts have been designed to tightly control tolerances. Usually, these parts are produced with the best possible tolerances. There are different ranges of acceptable tolerances; for example, very tight tolerances of +/- 0.001". Sometimes even a few thousandths of an inch can mean the difference between a mated part and an unfitted part.

Therefore, it is useful to identify tight tolerances early in the design phase. This is because the design engineer must take into account the requirements for the geometry of the foamed part, the size of the total foamed part, and the wall thickness of the foamed part, the geometry of the foamed part, the size of the total foamed part, and the foamed part All of the part wall thickness has an impact on tolerance control, and if all of the foamed part geometry, the total foamed part size, and the foamed part wall thickness are not managed carefully, sink marks can be aggravated, Warpage, and inconsistent part tolerances. This system and equipment overcome most of these design challenges and still use best design practices because SCF gas is responsible for maximizing the pore structure of the polymer matrix during the foaming process. Likewise, the system can be configured for faster cooling in the mold.

As a result of the foregoing, sink marks, warpage and tolerance inconsistencies are greatly reduced. This is largely due to the uniform size and uniform distribution of microscopic pores in the foam matrix. Therefore, in order to achieve these benefits, the microcellular foaming process should be carefully controlled. For example, as indicated, when foaming occurs along the front of the melt, advancement can introduce streaks and flow marks on the molded surface, thereby causing flaws.

In addition to the above, these defects can be further minimized herein by using one or more of co-injection and in-mold decoration techniques. However, in many instances, this can be cost prohibitive. However, this system overcomes such cases of excessive costs by choosing advanced product opportunities, in which the added value of the present disclosure can be accepted and understood.

It should be noted that in various examples, there may be disadvantages of SCF foaming. For example, in some examples, it may cause changes in melt viscosity and other substantial properties. Specifically, when the SCF is uniformly diffused into the polymer melt, the single-phase solution acts as a reversible plasticizer by reducing the viscosity of the polymer by increasing the free volume. This effect also reduces the glass transition temperature of the polymer and the tensile strength of the polymer. This can lead to uneven bubble size.

Uneven bubble sizes can lead to the production of molded foam parts with inconsistent technical performance properties throughout the part and possibly undesirable appearance problems. When trying to produce consistent, renewable, biodegradable and industrially synthesizable flexible foams that contain the same technical performance properties from part to part during mass production, these two are problems. The system is configured to overcome these difficulties.

Therefore, as discussed above, in order to overcome these shortcomings and to more finely control the micro-cell foaming process, the gas back pressure (GCP) discussed above is used. As discussed above, the gas back pressure is finely controlled so that when the foamed part is formed, the gas bubbles are adjusted so as not to contact and penetrate the surface of the foamed material. This is achieved by resisting pressure, which is applied to the cavity of the mold by the GCP system, which can control the holding time in the mold at the same time or about the same time that the molten single-phase solution is injected. Mold temperature and pressure can also be finely controlled for these purposes.

Once injected, the inert gas bubbles experience great force, and therefore the molten single-phase solution is not given an opportunity to release the trapped bubbles to the outside of the foamed structure when formed. Likewise, the huge force exerted on a single-phase solution helps distribute millions of tiny bubbles within the foaming structure inside the mold, and helps the bubble size uniformity. The result is a molded foam part that has a smooth-surfaced skin formed on the outside of the part and a consistent bubble size with repeatable technical performance properties from part to part during mass production.

For example, the system can be configured to allow the introduction of GCP to control the foaming process, such as by applying different gas pressures and/or temperatures at different melt injection stages. Therefore, the GCP is introduced into the foaming process in the cavity of the mold, and the cavity of the mold is placed in the injection molding machine. First, the inert gas system is pumped into the mold cavity by a gas compressor and a gas pump through a gas control valve. The gas pressure sensor feeds real-time data from the gas control value back to the computer controller.

The system triggers the GCP batching into the mold cavity by setting the batching parameters and holding time in the computer system. The computer system then initiates the proper ingredients for the inert GCP injection into the mold cavity. In the case of not using GCP, the biopolymer melt will enter the cavity of the mold and start to foam immediately, resulting in uneven gas bubbles, which break through the surface and are generated on the outside of the foam Undesirable eddy current markers, this situation is problematic.

Similarly, the injection speed can also be finely controlled. For example, the injection speed can be determined by the difference between the screw pressure (Pscrew) and the gas pressure (Pgas). Specifically, when Pscrew is slightly higher than Pgas, and both parameters are sufficiently high, the SCF dissolved melt flows into the mold cavity without foaming. Setting Pscrew higher than Pgas and Pgas lower than the critical pressure causes local foaming. Finally, the proper selection of Pscrew, Pgas, and the pressure difference combined with the dynamic mold temperature enables more precise control of the bubble size. Therefore, by fine-tuning these parameters, flow-induced streaks can be minimized if they are not completely eliminated.

In particular, these parameters can be determined in part by considerations of flow behavior. For example, in one embodiment, the rheology (flow) is produced by the behavior of polymer melt, and the mold temperature (185℃, 195℃, 205℃), injection speed (5 mm/s, 10 mm/s) , 15 mm/s screw speed), and GCP (50 bar, 100 bar, 200 bar and 300 bar), the polymer melt has been dissolved in 0.4wt% SCF of _{N 2.} In this example, the measured shear rate is in the range of 3000-11000 s-1, and when the GCP is 300 bar, the glass transition temperature Tg decreases from 96°C to 50°C. Similarly, in this example, compared with the conventional injection molding, when the GCP is increased from 50 bar to 200 bar, the melt viscosity decreases by about 30%.

Specifically, when the GCP is 300 bar, the viscosity of the single-phase injection melt without any foaming can be reduced by up to 50%, depending on the injection conditions. This is useful because it reduces pressure requirements and temperature requirements, thereby reducing manufacturing costs, in particular energy costs, and also reducing the cycle time of foamed parts during production. Therefore, these system parameters are all used for greater energy savings due to lower pressure and temperature requirements, and less cycle time. This situation translates to faster production and more parts for less money, such as By selecting the correct biopolymer compound and customizing the process temperature, pressure, and holding time to match the mechanical properties of the material.

In addition, as indicated, the important feature of this machine and system is that it can be configured to control the size of the bubbles so as to be more uniform. As discussed above, this can be achieved in part by controlling temperature, pressure, SCF batching control, GCP, DMTC, and other parameters discussed above. All of these attributes work in unison to ensure the best, most uniform bubble size and its best homogeneous dispersion within the foam matrix. In addition, the surface quality can be improved by controlling the drift of the fluid along the front of the melt.

As its name indicates, the front of the melt is the point where the molten single-phase solution enters the cavity of the mold. The speed in front of the melt is the forward speed in front of the melt. For any mold with complex cavity geometry, part of the cavity can be filled faster than other areas. By controlling the front speed of the melt, such as by controlling temperature, pressure, and SCF batching control, as well as controlling other parameters, a more uniform mold cavity filling speed can be achieved, and this ensures that the surface quality of the resulting foam parts can be Appearance acceptable.

Therefore, once the single-phase solution has been produced, as described above, the modified injection molding machine maintains the solution in a pressurized state until the injection starts. For example, the machine can be configured to achieve this by a combination of turning off the nozzle and controlling the screw position, as indicated above. Specifically, the shut-off nozzle can be configured to act as a connection between the plasticizing barrel (with a reciprocating screw) and the mold. Such shut-off nozzles can be self-controlled or externally controlled, and they can be used to avoid the flow of melt between melt injections and thus prevent pressure relief and premature foaming into the mold.

Therefore, shut off the nozzle to prevent pressure relief and premature foaming into the mold. For example, in the case of an unbroken nozzle, the single-phase solution will not have sufficient pressure in the mold cavity, and the desired molded foam part will not be produced. Likewise, active or passive screw position control can be used to prevent pressure relief by moving the screw backwards.

Specifically, the system can be configured to implement active screw position control, such as where the position of the screw is continuously monitored, and the pressure applied to the back of the screw is adjusted to maintain a determined position set point or remain on the back of the screw Constant pressure. For example, in passive position control, the oil used to adjust the back pressure is prevented from draining to its groove at the end of the screw recovery. This residual oil prevents the screw from moving backward due to the pressure of the single-phase solution.

In addition, as indicated above, proper mold design helps maintain a single-phase solution. In particular, in those instances where the mold includes a hot runner system, one or more valve gates may be included and controlled to prevent material from dripping from the nozzle, such as when the mold is open. More specifically, a hot runner system can be used in injection molding equipment herein, and can include a part system that is physically heated so that the parts can be used more effectively Transfer the molten plastic from the nozzle of the machine to the cavity of the mold tool. For example, a "cold runner" or "hot runner" can be used, such as the cold runner is an unheated physical channel that is used to guide the molten plastic to the mold cavity after the molten plastic leaves the nozzle. In the cavity, and the hot runner is heated while the cold runner is not heated.

Likewise, in various examples, the equipment may include a nozzle circuit breaker that is configured to break contact with the gate bushing during normal operation. This configuration is useful in stacked or tandem molds that utilize shut-off on the gate bushing. Specifically, the sprue bushing can be configured to accept the machine nozzle and thereby allow the molten biopolymer compound to enter the mold. In the case where the machine nozzle must be separated from contact with the gate bushing, the molten biopolymer compound can flow backwards from the gate bushing, and pressure relief of the mold can occur. Any melt flow waste can increase production costs, adversely affect a shot below the melt, and can even prevent proper closing of the mold, which may cause even more problems.

To overcome this, a gate bushing with shut-off can be selected. Otherwise, the pressure from the hot runner will be relieved by the gate bushing. Specifically, when the gate bushing needs to be shut off, in addition to the other benefits mentioned above, the shutoff prevents the pressure in the combined mold from escaping. Any pressure relief from the mold may prevent foaming of the molten part, and therefore the desired molded part will not be formed.

As indicated above, various foaming agents can be used for injection molding of biodegradable and industrially synthesizable microporous foams. In a specific example, these blowing agents may include inert gases and/or passive gases, such as inert nitrogen or carbon dioxide or other gases that can be converted into a supercritical fluid (SCF) state. According to the equipment, system, and method of use disclosed herein, the SCF can be introduced (e.g., injected) into the machine, for example, such as introduced (e.g., injected) into the melt barrel by a specially designed computer-controlled ejector, The specially designed computer-controlled ejector can be coupled, for example, attached to the barrel of an injection molding machine, such as for feeding blowing agent into the molten biopolymer melt in the barrel. The controller of the injection molding machine can be programmed to deliver a specific amount of SCF gas (nitrogen or carbon dioxide, etc.) to the biopolymer melt. The delivery can be optimized by the system controller.

Therefore, each of the aforementioned SCF blowing agents has its status, depending on the technical requirements of the final part being produced. Specifically, as indicated, a useful SCF is carbon dioxide in its supercritical state, which is denser than nitrogen at the same pressure but has a much higher heat capacity. Experiments have shown that carbon dioxide production in the supercritical state can be a dense foam useful in certain buffer applications. In contrast, supercritical nitrogen can be used to produce low-density foamed parts with smaller pores, which are useful for the footwear and sports product applications of the present disclosure.

Therefore, a useful blowing agent for the production of sports goods such as shoes is SCF nitrogen, because SCF nitrogen provides improved weight reduction and fine pore structure at a much lower weight percentage compared to SCF carbon dioxide, but is used for furniture and automobiles A useful blowing agent is carbon dioxide. Carbon dioxide produces a much larger pore structure, even at larger sizes and/or weights. In particular, in various instances, the enhanced weight reduction of foamed parts is a useful feature for product applications that require the least amount of weight. As a non-limiting example, there is a continuing need for running shoes to contain flexible foams that are very light and demonstrate the ability to withstand repeated abuse.

By providing the enhanced weight reduction with the fine pore structure in the aforementioned example, injection molded flexible foam parts will be improved due to their ability to improve the efficiency of runners by making light-weight shoes that can be received. rely. In addition, the aforementioned fine pore structure of the foam will ensure a very durable running shoe with component parts that will be able to handle the repeated impact force caused by the runner. When accelerating, the running shoe The person continuously applies pressure and impact to the foamed parts of the shoe.

In fact, the SCF nitrogen level will usually be at least 75% lower than the SCF carbon dioxide level required to achieve comparable parts. Thus, when mass production of the biodegradable and industrially synthesizable flexible foam of the present disclosure as used in the production of shoe components, the greatly reduced SCF nitrogen level requires that the highest level of nitrogen is ensured when compared with SCF carbon dioxide. Good material saving and time saving. However, SCF carbon dioxide is a useful blowing agent in a variety of specific situations, such as when viscosity reduction is the main processing goal, and/or when the application cannot tolerate the more aggressive foaming action of SCF nitrogen.

In some instances, SCF carbon dioxide is a suitable blowing agent, specifically in semi-flexible foams. Both the flexible foam and the semi-flexible foam can be included in the same kind of flexible foam because they are derived from having a glass transition (Tg) lower than their service temperature. For polymers, the service temperature is usually at room temperature. During the physical foaming process with physical foaming agent, depressions in the glass transition are seen. These differences in the effectiveness of nitrogen and carbon dioxide blowing agents originate from their behavior in biopolymer melts.

For example, carbon dioxide that becomes an SCF fluid at a temperature of 31.1 degrees Celsius and 72.2 bar is four to five times more soluble in biopolymers than nitrogen that becomes a supercritical fluid at a temperature of -147 degrees Celsius and 34 bar. For example, the saturation point of the unfilled biopolymer is approximately 1.5% to 2% by weight of nitrogen, depending on temperature and pressure conditions, while the saturation level of carbon dioxide is closer to 8% by weight. Carbon dioxide also exhibits a greater mobility in biopolymers, allowing carbon dioxide to migrate farther into existing bubbles than nitrogen. From the viewpoint of pore nucleation, greater solubility and mobility means that fewer pores will nucleate, and those nucleated pores will tend to be larger.

However, when the goal is viscosity reduction, solubility becomes an advantage. The SCF dissolved in the biopolymer acts as a plasticizer, thereby reducing the viscosity of the biopolymer. Because the viscosity reduction partly varies with the amount of SCF added to the biopolymer and because carbon dioxide has a higher solubility limit than nitrogen, the ability of carbon dioxide to reduce the viscosity is greater. Carbon dioxide is also useful when the amount of nitrogen required to produce parts is so low that it is impossible to treat the parts consistently.

Because carbon dioxide is a much less aggressive blowing agent, there is an easier time to run low levels of carbon dioxide. For example, carbon dioxide of 0.15% or 0.2% is compared to very low nitrogen levels of less than 0.05%. The examples as indicated in the previous examples mainly occur in the case of soft materials and parts with thick cross-sections. Therefore, the physical blowing agent (which is SCF nitrogen or SCF carbon dioxide or other SCF) plays a useful role in the final foamed part and the final product that will contain the physical blowing agent.

First, it is useful to select a suitable combination of compatible biopolymers or biopolymer compounds and the associated SCF gas. Secondly, proper use of SCF gas with optimal ingredient weight and pressure is critical to ensure the maximum saturation in the single-phase solution and to ensure the minimum of the nuclei used to produce millions of uniform bubbles in the foamed matrix. Good production. In addition, the final result is that the injection molded flexible foam parts formed with the same texture depend on all aspects of the SCF and GCP gas batching process. These aspects are related to the temperature, pressure and holding time of the injection molding machine. Work collaboratively to achieve commercially acceptable molded foam parts, as explained above.

As indicated, in one aspect, a process for manufacturing a flexible foam that is biodegradable and industrially synthesizable (regardless of open pores or closed pores) is provided. In various examples, the manufacturing process includes one or more of the following steps. First, thermoplastic biopolymers can be blended into master batches for foaming. As a non-limiting example, the masterbatch involved can be produced by a twin-screw extruder, in which two or more biopolymers, fillers and/or additives can be homogenously blended into a single polymer such as an extrusion barrel. In the melt. The molten biopolymer blend is then strand-extruded, cooled, and pelletized into particles called master batches, which can then be processed as described above. Any combination of suitable biopolymers, bioplastics, fillers, additives, and colorants can be incorporated into the masterbatch production. Therefore, once produced, the thermoplastic biopolymer blend can be injection molded into a suitable mold shape with SCF such as inert nitrogen or carbon dioxide gas.

As described above, the injection molding can be used in a manufacturing process for producing parts by injecting molten material into a product mold. In the present disclosure, a suitable biopolymer or biopolymer blending compound is selected, such as in the form of particles. The aforementioned particles can be pre-dried in an auxiliary pellet dryer to ensure the removal of any potential moisture. The pre-dried pellets can then be introduced into the hopper of the injection molding machine. The operator then selects the best barrel temperature, nozzle temperature, and mold temperature of the injection molding machine, and inputs these values through computer control.

In addition, the optimal SCF gas ingredient percentage and pressure and the optimal GCP gas ingredient and pressure can be calibrated and these values can be input to the system control unit or determined by the system control unit in other ways, for example, dynamically. Once the system is properly configured, the injection molding machine is ready for operation. The particles can be released into the screw and barrel of the injection molding machine in a specified amount controlled by a computer, where the particles are melted at a specific temperature or temperature setting.

The SCF gas system is introduced into the barrel of the injection molding machine through the SCF ejector under the controlled pressure and dosage by the computer. SCF saturates the now molten particles and produces a single-phase solution. Then, under the condition of proper back pressure and screw positioning, the injection molding machine sends the measurement injection of the single-phase solution to the mold cavity under dynamic temperature control. The melt undergoes nuclear growth, and millions of microporous bubbles are formed in the biopolymer melt. At substantially the same time, the GCP system sends a pre-metered dose of backpressure gas to the mold under computer control, which optimizes the uniformity of pores and adjusts the surface texture for the best appearance. The mold temperature of the dynamic temperature control can then be switched to water cooling, and the formation of bubbles and the expansion of the melt stop. At this point, the flexible foam molded part is now formed and it is ejected from the mold.

Specifically, as indicated above, the system can be configured to implement dynamic mold temperature control, which can be used to produce the best pore structure. For example, as described, dynamic mold temperature control (DMTC) implements rapid electric pole heating and rapid water cooling. More specifically, the DMTC program used herein may include one or more of the following five main components: air compressor, valve exchange device, computer-controlled mold temperature control unit, electrical heating mold, and cooling tower. The cooling tower is configured to provide water cooling to the mold for the execution of the cooling operation, and the properly configured air compressor generates compressed air to drive the gas through the pneumatic valve to remove any residual cooling water to avoid entering after cooling Mold. One or more valve exchange devices can be assembled and used to switch valves to transfer different media from different machine lines to the mold, such as for heat-acting cycles and cold-heat cycles. Electrically controlled heating elements can be included and assembled to mold the final shape of the foamed part. The water tower and the heating element can work together to finely control the mold temperature, so that the heating and cooling of the mold can be quickly heated and/or cooled during the execution of the molding process.

All this is coordinated with the injection molding machine through a properly configured computer processor. For example, a non-limiting example of the cooling water temperature control of the DMTC system of the present invention may be 15°C to 30°C, and a further non-limiting example of the heating element temperature range of the DMTC system may be between 60°C and 150°C, and may be Within the range of 90°C and 130°C, and can be any temperature in between. In this way, the biopolymer melt, pressure, and time can be controlled to form a desired flexible foam.

Specifically, during the injection molding process of the present disclosure, SCF is injected into the polymer melt. The single phase of the polymer-SCF mixed solution is obtained under a clear temperature and pressure in the screw and barrel of the injection molding machine. Temperature and pressure can be variably controlled by computer control, and directly relate to the type of flexible foam being produced and the type of end product application. By applying varying pressure of the SCF single-phase solution contained in the screw and GCP pressure, consistent with the appropriate injection size, injection holding time, melt temperature, and mold temperature, the entire system is produced, high-quality and commercially acceptable Biodegradable and industrially synthesizable flexible foam parts can be produced by the entire system, such as by using gas back pressure in the injection molding process to ensure that there are minimal appearance defects and foam parts There is hardly or even no optimal foam structure on the outside of the plastic skin.

As indicated, a useful benefit of products produced according to the devices, systems, and methods disclosed herein is that the products can be biodegradable and/or synthesizable, such as in household or industrial composting agreements. Specifically, the production of commodities that are assembled for decomposition in an industrial composting system ensures that the flexible foam will last the useful life of the resultant product, such as by preventing the resultant product from breaking or breaking during use in the finished product. The crushing method functionalizes the resulting product. For example, a person buying furniture, a pair of shoes or other sports equipment that is made only of the flexible foam of the present disclosure so that the foam degrades during normal use before the end of the product's useful life will be harmful.

More specifically, the present disclosure benefits from the use of inert physical foaming agents and biodegradable and industrially synthesizable biopolymers or biopolymer compounds. These two aspects together achieve the formation of a functionalized single-phase solution in a specialized flexible foam injection molding system. The result is a biodegradable and industrially synthesizable flexible foam used in many types of end products; non-limiting examples of such biodegradable and industrially synthesizable flexible foam are It is used to make footwear foam for making shoes. The resulting flexible foam is non-crosslinked, chemical-free, and environmentally friendly.

At the end of the life of the biodegradable and industrially synthesizable flexible foam, the biodegradable and industrially synthesizable flexible foam can be redirected to appropriate industrial compost by turning waste Facility, whereby the foam is ground and industrially composted into usable biomass. The end result is a system whereby the so-called circular economy is adhered to. The flexible foam of the present disclosure starts and ends as "waste-to-waste", which means that the natural biological process has been adapted to produce materials and products for human use with the least amount of environmental impact. These flexible foams are neither in their technical performance properties during their useful life, nor are they compromised in their environmentally conscious design.

As discussed above, the devices, systems, and methods of use herein can be used to produce one or more molded end products, such as for use in shoes, seats, automobiles, protective devices, and/or Components in sports equipment. Therefore, in various embodiments, what is provided herein is one or more components useful in the construction of a shoe, such as its sole, midsole, and/or insole, such as where the sole forms the base of the shoe and is assembled For contact with the ground, the midsole forms an intermediate structure and a cushioning element, and the shoe insole is assembled for insertion into the shoe and thereby provides cushioning and/or support for the shoe.

In certain embodiments, the shoe component may include the foam material produced herein, which may be environmentally friendly, biodegradable, and synthetic. In various examples, each individual component can be constructed from a plurality of layers including a base layer and a buffer layer, such as the buffer layer therein. For example, in a specific embodiment, a support member such as a support member coupled to the base layer may be included, and in the case where the component is an insole, it may include one or more of an arcuate contact portion or a heel contact portion.

Specifically, in various embodiments, foam materials can be produced, such as where the foam materials can be used in the production of cushions, cushioning furniture, shoe components such as insoles, cushions, fibers, fabrics, and the like. Other useful products can include gap fillers such as silicone gap fillers, silicone medical gloves, silicone tubing for drug delivery systems, silicone adhesives, silicone lubricants, silicone coatings, And other suitable silicone products, such as condoms. In various embodiments, the foam product can be produced in such a way that the foam material can have one or more anti-microbial, anti-bacterial, anti-fungal, anti-viral, and/or anti-flammability properties.

More specifically, in one aspect, the present disclosure may generally be directed to the manufacturing process for furniture, such as upholstered furniture and/or cushions thereof, such as foams or hair-made in other ways. Furniture made of foam, for example, the foaming system is biodegradable and/or synthesizable. Therefore, the foam of the present disclosure is advantageous for use in the manufacture of furniture including the foam insert produced in this way. Resins and the foams produced and utilized have proven to be beneficial for use as cushioning materials, such as pillows, benches, beds, seat cushions, or other upholstered furniture.

For example, according to the methods disclosed herein, small to large foam molds can be produced to form foam inserts, such as for use in furniture or automobile accessory components. The cube foam can then be cut into smaller cubes of the desired size and shape based on the type and form of the furniture being produced. In particular, the sized and cut squares can then be applied to or otherwise fit within the furniture or frame or other boundary materials, and each of these together can be covered to produce the final furniture product, the final furniture product For pillows, sofas, cushions, such as sofas or car cushions, etc. In addition, if necessary, the outer cover or boundary material can be attached to the frame material, such as by nailing and/or sewing, or otherwise fastened to the frame of the article to be upholstered and made of fabric Or covered with other materials.

Therefore, in various embodiments, when manufacturing upholstered furniture such as benches or car seats, the frame may be produced. Various internal (such as structural) components of the furniture can be installed in the frame, such as a spring, etc., and then the foamed sheet produced according to the method disclosed above can be positioned in the spring, on the spring, and around the spring, such as Used for buffering and/or isolation. Of course, other materials may be included, such as a cotton layer, a wool layer, a felt layer, a rubber-based product layer, etc., and then a covering material may be added to cover the frame and complete the product manufacturing.

In particular, the foam and other materials disclosed herein can serve as a cushion or filler together. When the cover material is stretched on the frame, the cushion or filler can be shaped, adjusted and pleated under the cover. rise. In addition, as indicated, in various examples, for a variety of reasons, the foam products produced herein can be used in and outside of foam products known in the art, the most important of which is typical PU and/or EVA The foam is not biodegradable in any way, and the components of the foam produced herein are biodegradable. Therefore, in various embodiments, a method of constructing furniture on an open frame is provided. For example, in one example, the method may include one or more of the following steps.

Specifically, the method may include providing a frame that defines a back, a plurality of side walls, and a base portion, such as where the rear frame portion extends substantially vertically, and the base portion is substantially relative to each other in such a manner that the base portion crosses the vertical portion. Extend horizontally. The method may further include cutting the flat foam sheet to an appropriate size and shape to provide spacers for the back and base and/or side wall portions, and cutting the flat covering material to an appropriate size and shape to complete the back, base and/or Or the side wall part, attach the foam sheet and the covering material together at the spaced position, and compress the foam to form a wavy predetermined design in its outer surface, and form a substantially flat sub-assembly, wherein The foam sheet and the covering material are free to move relative to each other in the middle of the attachment position, and the sub-assembly is formed and attached to the frame. The covering used for foam cushions or cushion products can be any suitable covering materials commonly used in upholstered furniture and covering decorative pillows, such as woven spun woolen fabric, woven nylon fabric, or made of various synthetic fibers And fabrics woven from materials such as leather.

In addition, in another aspect, the present disclosure is generally directed to the manufacturing process of shoe components such as shoe soles, midsoles, and/or shoe insoles, such as shoe components including foams or in other ways A shoe component composed of a foamed body, which can be synthesized into a foamed body, for example. In particular, in specific embodiments, methods for making shoe soles, midsoles, insoles, and/or other shoe inserts are provided. For example, the shoe insert of the present invention may be in the form of a cushioning device adapted to be inserted into or otherwise fitted into shoes such as running shoes or sports shoes. The impact of the foot that hits the surface (for example, the ground), thereby absorbing the vibration to the foot and/or reducing the vibration to the foot.

Specifically, the sole component including the midsole and the insert may include one layer or multiple layers. For example, in some examples, a base layer, a foam layer, and/or a fabric layer may be provided. In particular, it may include a base layer of relatively elastic material, and/or, for example, a foam layer disposed on the base layer, and/or a fabric layer disposed on the foam layer. Therefore, the method may include integrally forming the base layer, the foam layer, and the fabric into a three-layer sheet. In various examples, the support layer may be provided with at least one heel area, and the support layer may be constructed of a rigid material with a higher density than the density of the build-up layer. Adhesives, glues or other attachment mechanisms can be provided and utilized for attachment and forming a three-layer board with a supporting layer.

More specifically, in other examples, the method for making shoe components such as inserts may include the following steps: providing a foam layer and/or providing a fabric layer; heating the foam layer; joining the foam and the fabric layer; providing The base layer, for example, the base layer having the same, greater, or lower density with respect to the foam layer; and heating at least one of the base layer and the foam layer to couple the base layer and the foam layer to form a double Layer board or three-layer board.

The method may further include providing pre-formed support members, such as arcuate supports and/or heel members, which members may have substantially the same density as compared to the foam layer, or a smaller, or larger density. In a specific example, the support member may be formed of a compressed foam material in order to obtain a greater density and thus greater rigidity compared to the other rigidity of the foam layer. In addition, a heat and/or pressure reactive adhesive may be applied between the support and/or heel member and the build-up layer. Molding pressure can then be applied to the composition to cause the three-layer panel to be formed and/or shaped into a support and/or heel member to form a one-piece shoe insert, wherein the pre-formed heel member is formed The back part and/or support member form the middle part of the bottom surface of the finished shoe insert, for example, at its middle and/or heel area, and the base layer forms the bottom surface of the finished shoe insert at its front area.

However, it should be noted that the support and/or heel member need not be included, and in some examples, one or more of the build-up components may be added and may be excluded or other build-up layers. It should be further noted that in certain embodiments, the foam layer may be more flexible and/or cushioned, for example, having a greater durometer than the base layer, which in turn may be more flexible Sexual and/or cushioned, for example, with a larger durometer than the supporting member. Therefore, the more flexible foam and the base layer can be relatively elastic and conform to the desired shoe size and configuration in shape, while the support layer(s) can be relatively more rigid.

Specifically, as indicated, one or more of the foam layer and/or support layer may be constructed from the biodegradable and/or environmentally friendly foam materials disclosed herein. In particular, the support layer may have dense foam, thus making the support layer more rigid. Therefore, in various embodiments, the foam layer may have a density of about 2 pounds/cubic feet or about 3 pounds/cubic feet or about 5 pounds/cubic feet to about 10 pounds/cubic feet or more, such as between The density is within the range of about 4 pounds/cubic foot to 6 pounds/cubic foot. In addition, the foam layer may have a thickness of 1/8"+ or -5%, such as in the thickness range of about 3/32"-5/32".

Similarly, the base layer may also have a density of about 2 pounds/cubic foot or about 3 pounds/cubic foot or about 5 pounds/cubic foot to about 10 pounds/cubic foot or greater, such as between about 4 pounds/cubic foot Density within the range of feet to 6 pounds per cubic foot. The thickness of the base layer can be about 5/16"+ or -10%. However, in various examples, the thickness of the base layer can range from about 1/4" or less to about 7/16" in terms of thickness. The support layer, which can be mainly formed at the arch and/or heel area of the insert, can also be made of the biodegradable and/or synthetic foam disclosed herein.

However, the support layer can be made by being compressed so that the final density is about 22 pounds/cubic foot to 23 pounds/cubic foot. The fabric layer can be constructed of any suitable material such as cotton, polyester or polypropylene knitted fabric. In various examples, the material and foam layers can be laminated together by a flame gluing technique, which utilizes bare fire directed to the foam layer. The bare fire generates sufficient heat on the surface to cause the melting of the flat sheet foam layer. Once melted, the fabric layer can be joined to it and the two sandwiched layers can extend between the quenched rollers, while sufficient pressure is applied between the rollers so that the two layers are joined together.

At this point in the manufacturing process, these layers still remain in the form of a flat sheet. These integrated layers are then joined to the base layer by flame gluing. The previously integrated material and foam layers can be joined to the support layer, and these multilayer layers can then extend between the quenched rollers. At this stage of the stage, these layers still remain in the form of flat sheets. The layers laminated so far are then ready for moulding. This can be performed by heating the laminated layer to a molding temperature of approximately 250 F, such as for a period of about 1 minute to about 5 minutes or more, for example, about 225 seconds. This heats the previously laminated layers sufficiently to allow them to be inserted into the mold.

The following is a description of various implementation schemes of the present disclosure with reference to the accompanying drawings. Therefore, in one aspect, footwear components are provided. Specifically, as illustrated in FIG. 1, an embodiment of the present disclosure is a shoe component, that is, a blend of biodegradable and industrially synthesizable thermoplastic biopolymers (flexible foam 102) The manufactured micro-pore flexible foam shoe midsole 100.

Specifically, the biodegradable and industrially synthesizable injection-molded flexible foam shoe midsole is made of biopolymers and biopolymer blends, such as one or more of thermoplastic biopolymers. Multiple made. Specifically, the thermoplastic biopolymers or biopolymer blends used to produce biodegradable and industrially synthesizable injection-molded flexible foams can be optionally made from any number of fats. And aliphatic-aromatic copolyesters and so on.

Non-limiting examples of suitable biopolymers found for use in the production of biopolymers or biopolymer blends consist of the following: polylactic acid (PLA), poly-L-lactic acid (PLLA), poly(butylene adipate) Diester-co-terephthalate) (PBAT), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS), polycaprolactone (PCL) , Polybutene succinate adipic acid (PBSA), polybutene adipic acid (PBA), and thermoplastic starch (TPS). In addition, the mixed biopolymer blends can be used in the production of biodegradable and industrially synthesizable injection-molded flexible foams with micro-pores. A non-limiting example of a hybrid biopolymer blend consists of algae-containing poly(butylene adipate-co-terephthalate) (PBAT).

In the example provided, the algae portion of the hybrid biopolymer is composed of any suitable species of algae in dry powder form. Some non-limiting examples of suitable algae species include blue-green algae, green algae, red algae, brown algae, and diatoms, and combinations thereof. The dry algae powder mentioned above can be extruded by twin-screw PBAT biopolymer on standard equipment, so that the algae powder can be denatured into PBAT polymer chains. This thereby forms a hybrid biopolymer for use in the production of the biodegradable and industrially synthesizable injection-molded flexible foam of the present disclosure.

The foam product produced may include or otherwise incorporate many of the following ingredients: filler powder and/or one or more additives. Specifically, depending on the application, additives may also be utilized in biopolymer formulations. For example, oligomeric (aspartic acid-co-lactide) (poly(aspartic acid-co-lactide); PAL) can optionally be synthesized into a masterbatch for accelerated biodegradation. In addition, fillers such as precipitated calcium carbonate from aragonite, starch, etc. can be used to reduce the cost of parts while maintaining the renewable and biodegradable integrity of the finished flexible foam.

In addition, additional additives for use in biopolymer formulations can consist of one or more of the following. Nucleating agents such as microlobed talc or high aspect ratio oolitic aragonite may be included. Such nucleating agents can greatly improve the key properties of the resultant flexible foam by preventing pore coalescence, reducing block density, and improving resilience and other beneficially enhanced properties. Some non-limiting examples of nucleating agents used in the production of biodegradable and industrially synthesizable injection molded microporous flexible foams are by Imerys Talc America Inc., Houston, Texas as Mistrocell® Marketed microlobed talc and high aspect ratio oolitic aragonite marketed by Calcan Minerals & Materials LLC, Gadsden, Alabama as OceanCal®.

It may also include colorants, dyes and pigments. For example, various coloring agents such as dyes, pigments or biological pigments can be optionally used in the biopolymer formulation of the present invention. Some non-limiting examples are natural pigments of plant origin that have been customized for use in biopolymers, such as the wide range provided by Treffert GmBH & Co. KG, Bingen am Rhein, Germany or by Holland Colours Americas Inc., Richmond, They are provided by Indiana.

There are many configurations and embodiments that can be utilized depending on the following: the desired physical properties, and the intended end use of the midsole 100, its use for work, recreation, water use, etc. They should not be affected by these examples limit.

A suitable device 200 of the system can be exemplified in Figure 2 and can be used in the production of foam materials as suggested herein. For example, in use, the biopolymer masterbatch 202 is fed into the hopper 204 of any suitable injection molding machine 206. The biopolymer masterbatch is liquefied by heating while being transported through the injection molding machine screw 208. Nitrogen or CO ₂ gas 210 is injected into the biopolymer melt 212 and mixed. In addition, the biopolymer gas mixture is under pressure and injected into the injection molding tool 214 to be consistent with the biopolymer gas injection. The gas back pressure system 216 measures the dose of nitrogen or CO ₂ gas 218 through the gas control valve 220 Send to the press molding tool.

Soon thereafter, the dynamic mold temperature control system (DMTC) 222 controls and adjusts the temperature inside the molding tool 214. The molding tool 214 is then sufficiently cooled and the resulting biodegradable and industrially synthesizable injection molded microporous flexible foam parts are ejected from the injection molding machine.

FIG. 3 provides an example of a method 300 for producing a biodegradable and industrially synthesizable injection molded microporous flexible foam. At step 302, the biopolymer mixture is selected, and at step 304, the mixture is pumped through the material hopper into the injection molding machine. At step 306, the biopolymer mixture is liquefied and homogenized as it is transported by the injection molding machine screw. At step 308, nitrogen or CO ₂ gas is injected into the biopolymer melt. At step 310, the biopolymer gas mixture is under pressure and injected into the injection molding tool. At step 312, the injection molding tool temperature is dynamically controlled to ensure the best pore structure. At step 314, the optimal dose of gas back pressure is applied to the injection molding tool for a sufficient amount of time to ensure an ideal foam structure with a minimum skin thickness. At step 316, the injection molding tool is sufficiently cooled, and the resulting molded foam part is ejected from the injection molding machine.

In some implementations, and without limiting the content disclosed herein, the biodegradable and industrially synthesizable flexible foam manufacturing process includes the steps outlined below. The process setup program surrounds the establishment of controlled SCF ingredients into the injection barrel: at the screw speed, temperature and pressure conditions that result in a single-phase solution.

To ensure that the basic conditions of SCF batching are met, there are mainly seven process setting points to adjust: SCF delivery pressure: set the pressure of the bioplastic, the SCF resists the pressure of the bioplastic and mixes during the rotation of the screw. This refers to the specific biopolymer back pressure during the screw recovery period and also refers to the screw position control during the screw idle period. As a non-limiting example, the pressure set point for biopolymer delivery can be in the range of 2,000 psi and 3,000 psi, and more preferably in the range of 2,700 psi and 2,800 psi. This set point sets the screw position where the SCF dosing starts, which can then set the SCF injector to the open or closed position. The position should be set so that the pressure in the barrel during the screw recovery period has stabilized before the start of the batching. As a non-limiting example, the open position can be in the range of 0.3 inches and 0.4 inches.

The injection size and the percentage of SCF can also be controlled. This controls the actual quality of the SCF batched during each cycle. As a non-limiting example, the shot size can be in the range of 100 grams to 300 grams, and more preferably 200 grams. Non-limiting examples of the SCF percentage may be in the range of 0.45% and 0.75%, and more preferably 0.5%. The system can also be configured to optimize ingredients. This is achieved by maximizing the dosing time and minimizing the flow rate (the pressure difference between the expected volume pressure and the delivery pressure). A non-limiting example of the batching time is between 1 second and 2 seconds, and more preferably 1.7 seconds.

Dynamic mold temperature control (DMTC) can also be implemented. This is a process involving the rapid change and control of the mold temperature during the injection and filling stage in order to thereby dynamically control the mold temperature in terms of thermal and thermal cycles. Before the melt is injected, the mold is first heated to a preset upper limit. During the melt filling stage, the temperature of the mold cavity surface can be kept above the upper limit to prevent the melt from solidifying prematurely.

When the melt filling process is over, the mold quickly cools to the lower limit called the ejection temperature, which is the temperature at which the part is ejected from the cavity of the mold. A non-limiting example of the optimal mold temperature range of the present disclosure is between 40°C and 150°C, where the cooling rate is between 1°C per second and 15°C per second, and more preferably 11°C per second. A non-limiting example of the cooling time of the model of the present invention is between 80 seconds and 100 seconds.

Likewise, the gas back pressure (GCP) can also be controlled. This is a process that involves injecting nitrogen gas to resist the expansion of the gas in the melt to pressurize the mold cavity. When the back pressure is released, the gas bubbles that break through the surface as usual are trapped inside to produce a smooth skin. GCP controls foaming by surface quality, foam structure and skin thickness. A non-limiting example of the gas counter pressure of the present invention is 0 bar/10 bar/30 bar/50 bar, and the holding time is between 1 second and 25 seconds, and more preferably 5 seconds. A non-limiting example of the average micro-pore pore diameter of the present invention can be measured in micrometers (µm) between 1 micron and 100 microns, and more preferably 40 microns.

In view of the above, in some implementation schemes, suitable thermoplastic biopolymer blends are produced. Once the thermoplastic blend is produced, the thermoplastic biopolymer blend can be injection molded into a suitable mold shape, such as with the addition of an inert gas such as nitrogen. In addition, the pressure can also be finely controlled.

For example, the use of gas back pressure in the injection molding process can be implemented. This is also useful for further ensuring that there is the smallest number of surface defects and the best foam structure on the outer side of the foamed part until there is no plastic skin. This is important in the production of foamed products. This foamed product There can be multiple end uses based on the mold shape. The molding process may include the implementation of dynamic mold temperature control. For example, in various embodiments, dynamically controlling the temperature of the molding process is useful for achieving an optimal pore structure. Controllable other elements of the molding process: biopolymer melt, pressure, and time, so that the desired flexible foam is formed.

Therefore, in view of the above, the present disclosure relates to injection molding of biodegradable and industrially synthesizable bio-derived thermoplastic resins for use in, for example, footwear components, seat components, protective device components, and water sports accessories. The formed micro-pore foaming process consists of various flexible foams.

The production of biodegradable and industrially synthesizable microporous flexible foam structures begins with suitable biopolymers or biopolymer blends such as aliphatic and aliphatic-aromatic copolyesters. Non-limiting examples of suitable biopolymer blends are polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT). The aforementioned blended thermoplastic biopolymer resins have shown advantageous technical properties in forming the optimal microcellular flexible foam structure of the present invention. Some of the enhanced technical properties include: acceptable aging properties, excellent elongation, and abnormal compression set, among other benefits.

The best aliphatic and aliphatic-aromatic copolyester biopolymers or biopolymer blends cannot produce flexible foams alone without suitable foaming agents and foaming processes. The most widely known blowing agent used today is a chemical called azodimethamide (ADA). Azodimethamide is usually pre-impregnated into the petrochemical thermoplastic masterbatch resin used in the conventional injection molding foaming process. Unfortunately, ADA is not environmentally friendly, and it is a suspected carcinogen for human health. In addition, conventional petrochemical thermoplastic masterbatch resins are neither biodegradable nor industrially synthesizable. In order to achieve most of the best biodegradable and industrially synthesizable flexible foams used in the aforementioned inventions, inert nitrogen or carbon dioxide in a supercritical fluid state is used as a modified injection molding process Physical foaming agent in China. The modified physical foaming process is consistent with the use of suitable thermoplastic biopolymers or blended biopolymer masterbatches, so that the biopolymers or biopolymer blends and foaming agents work in harmony and are used to produce most of the most advanced biopolymers. Good biodegradable and industrially synthesizable flexible foam.

The injection molding process of the present disclosure relies on homogeneous pore nucleation that occurs when a single-phase solution of biopolymer or biopolymer blend and supercritical fluid (SCF) is delivered to the cavity of the mold through an injection gate. When the solution enters the mold, the pressure drops, causing the SCF to come out of the solution, resulting in pore nuclei. The pores then grow until the material fills the mold and the expansion capacity of the SCF is exhausted. This manufacturing process runs on injection molding machines that have been modified to allow SCF to be metered, delivered, and mixed into biopolymers to produce a single-phase solution. Dynamic mold temperature control (DMTC) is used to ensure a consistent pore structure in the expanded biopolymer melt. DMTC can be best described as the rapid change and control of the mold temperature during the injection and filling stage; this thereby dynamically controls the mold temperature in terms of both thermal and thermal cycles. Gas counter pressure (GCP) is also used in the manufacturing process to ensure the best foam structure with a small amount to no skin on the resulting flexible foam. GCP can best be described as a process involving pressurized mold cavities injected with SCF to resist the expansion of gas in the melt. When the back pressure is released, the gas bubbles that break through the surface as usual are trapped inside to produce a smooth skin. GCP controls foaming by surface quality, foam structure and skin thickness.

The production of a single-phase solution in which SCF is completely dissolved and uniformly dispersed in the molten biopolymer occurs on the inside of the injection barrel under carefully controlled process conditions: SCF must be accurately measured by a mass flow rate to a constant constant amount in the biopolymer time. And during the batching cycle, the correct temperature, pressure and shear conditions can be established in the barrel. Back pressure, screw speed and barrel temperature control, as well as the SCF delivery system all play a role in establishing the process conditions to produce a single-phase solution.

Once the single-phase solution has been produced, the modified injection molding machine maintains the solution in a pressurized state until the injection begins. The machine strives to achieve this by turning off the nozzle and the combination of screw position control. Turn off the nozzle to prevent pressure relief and premature foaming into the mold. Active or passive screw position control prevents pressure relief by moving the screw backwards. During active screw position control, the position of the screw is continuously monitored, and the pressure applied to the back of the screw is adjusted to maintain the position set point or to maintain a constant pressure on the back of the screw. In passive position control, the oil used to adjust the back pressure is prevented from draining to its groove at the end of the screw recovery. This residual oil prevents the screw from moving backward due to the pressure of the single-phase solution.

Proper mold design also helps maintain a single-phase solution. A mold with a hot runner system requires a valve gate to prevent material from dripping from the nozzle when the mold is open. Molds that are in contact with the sprue bushing during normal operation of the machine nozzle circuit breaker, such as in the case of stacked or tandem molds, require shut-off on the sprue bushing. Otherwise, the pressure from the hot runner will be relieved by the gate bushing.

The blowing agent used in injection molding to form biodegradable and industrially synthesizable microcellular foams is inert nitrogen or carbon dioxide in a supercritical fluid (SCF) state. Each of the aforementioned blowing agents has its status, depending on the technical requirements of the final part being produced.

A useful blowing agent for use in the present invention is SCF nitrogen because the SCF nitrogen provides improved weight reduction and fine pore structure at a much lower weight percentage compared to SCF carbon dioxide. In fact, the SCF nitrogen level will usually be at least 75% lower than the SCF carbon dioxide level required to achieve comparable parts. However, SCF carbon dioxide is the preferred blowing agent in two situations: when viscosity reduction is the main processing goal or when the application cannot tolerate the more aggressive foaming action of SCF nitrogen.

The difference in the effectiveness of the two foaming agents originates from their behavior in the biopolymer melt. For example, carbon dioxide that becomes an SCF fluid at a temperature of 31.1 degrees Celsius and 72.2 bar is four to five times more soluble in biopolymers than nitrogen that becomes a supercritical fluid at a temperature of -147 degrees Celsius and 34 bar. For example, the saturation point of unfilled biopolymers is approximately 1.5 to 2% by weight of nitrogen, depending on temperature and pressure conditions, while the saturation level of carbon dioxide is closer to 8% by weight. Carbon dioxide also exhibits a greater mobility in biopolymers, allowing carbon dioxide to migrate farther into existing bubbles than nitrogen. From the viewpoint of pore nucleation, greater solubility and mobility means that fewer pores will nucleate, and those nucleated pores will tend to be larger.

However, when the goal is viscosity reduction, solubility becomes an advantage. The SCF dissolved in the biopolymer acts as a plasticizer, thereby reducing the viscosity of the biopolymer. Because the viscosity reduction partly varies with the amount of SCF added to the biopolymer and because carbon dioxide has a higher solubility limit than nitrogen, the ability of carbon dioxide to reduce the viscosity is greater.

Carbon dioxide is also preferable when the amount of nitrogen required to produce parts is so low that it is impossible to treat the parts consistently. Because carbon dioxide is a much less aggressive blowing agent, there is an easier time to run low levels of carbon dioxide. For example, carbon dioxide of 0.15% or 0.2% is compared to very low nitrogen levels of less than 0.05%. The examples as indicated in the previous examples mainly occur in the case of soft materials and parts with thick cross-sections. [Recyclable injection-molded micro-porous flexible foam and method for manufacturing such recyclable injection-molded micro-porous flexible foam]

4 and 6 illustrate the micro-porous flexible foam 402 formed by recyclable injection molding according to the present disclosure and the method of making the micro-porous flexible foam formed by recyclable injection molding. Referring to FIG. 4, the flexible foam 402 is preferably a closed-cell foam, but may also be formed as an open-cell foam. In various implementation schemes, the flexible foam 402 can be made to have properties and characteristics at least approximately similar to those of conventional non-recyclable ethylene vinyl acetate (EVA) foams and the like.

As discussed in more detail below, the recyclable flexible foam 402 is made from a thermoplastic polymer using the injection molding machine illustrated in FIG. 5. The thermoplastic polymer used to make the recyclable flexible foam 402 can optionally be produced from many polyamide-based thermoplastic polymers, polyamide copolymers, and the like. Non-limiting examples of suitable polymers found for use in the present invention consist of polyamide 6, polyamide 6/6-6, polyamide 12. Alternatively, the thermoplastic polymer may include many polyamide block copolymers, such as polyether-block-amide (PEBA), PAE, TPA, TPE-A, COPA, and the like. Other non-limiting examples of suitable polymers and copolymers include polyamide 66 copolymer marketed by Ascend Performance Materials, LLC, Houston, TX under the trade name Vydyne. The aforementioned thermoplastic polymer resins have shown advantageous technical properties in forming the optimal microcellular flexible foam structure of the present invention. Some of the enhanced technical properties include abnormal aging properties, excellent elongation, tensile strength, and compression set, among other benefits.

In addition, blends of two or more thermoplastic polymers provide a combination of properties and prices not found in a single thermoplastic polymer. There are many ways to successfully blend together thermoplastic polymers. As discussed in more detail below, twin screw extrusion is used to melt two or more thermoplastic polymers together and then extrude the molten polymer resin blend into strands, which are cooled and fed to pelletization The machine is used to produce a series of pellets called master batches. Another method of polymer resin blending is to use compatibilizers to join the different chemical components together in the polymer blend. Typically, twin screw extrusion or the like is also used here to melt the compatibilizer and two or more polymers together in the non-limiting thermoplastic polymer types described above.

In one embodiment, the thermoplastic polymer comprises at least one monomer or polymer derived from raw materials recovered after consumption or after industry. For example, the thermoplastic polymer may include caprolactam, recycled polyether block amide polymer, and the like. By way of illustration, caprolactam can be derived from recycled raw materials by depolymerizing post-industrial or post-consumer materials containing polyamide, such as fishing nets, carpet fibers, or industrial Waste. Non-limiting examples of depolymerized post-consumer or post-industrial recovered caprolactam include ECONYL® caprolactam supplied by Aquafil USA Inc., Cartersville, Georgia, whether in flake, liquid or molten. Thermoplastic polymers may additionally or alternatively comprise polyamide polymers derived from post-industrial or post-consumer polyamide carpet fibers that have been collected, sorted, melted, and reprocessed. One such polyamide polymer derived from post-industrial carpet fibers is Econyl manufactured by Aquafil USA Inc., Cartersville, Georgia. In addition, polyamide waste is collected in or around the world's oceans in the form of fishing nets or the like, and then can be sorted, melted, and reprocessed into usable polyamide materials for upgrading. An exemplary polyamide polymer derived from collected post-industrial fishing nets is Akulon Repurposed manufactured by Koninklijke DSM N.V., Heerlen, the Netherlands.

Depending on the application, additives can also be utilized in polymer formulations. For example, fillers such as precipitated calcium carbonate, oolitic aragonite, starch, biomass, etc. can be used to reduce the cost of parts while maintaining the recyclable integrity of the finished flexible foam.

In addition, the additives used in the polymer formulation can be composed of one or more of the following. Nucleating agents such as microlobed talc or high aspect ratio oolitic aragonite may be included. Such nucleating agents can greatly improve the key properties of the resultant flexible foam by preventing pore coalescence, reducing block density, and improving resilience and other beneficially enhanced properties. Some non-limiting examples of nucleating agents for use in the production of microporous flexible foams that are recyclable injection molding are microlobe-shaped marketed by Imerys Talc America Inc., Houston, Texas as Mistrocell® Talc and high aspect ratio oolitic aragonite marketed by Calcean Minerals & Materials LLC, Gadsden, Alabama as OceanCal®.

Colorants, dyes and pigments can also be included. For example, various coloring agents such as dyes, pigments or pigments can be optionally used in the polymer formulation of the present invention. Several non-limiting examples are pigments that have been customized for use with specific types of thermoplastic polymers, such as the wide range provided by Treffert GmBH & Co. KG, Bingen am Rhein, Germany or by Holland Colours Americas Inc., Richmond, Indiana Provided by them.

The use of recycled raw materials to generate micro-pore flexible foams reduces the environmental impact, which is usually associated with the production of expanded thermoplastic polymer foams by looking for sources of sustainable materials. As discussed in more detail below, the method used to produce the microcellular flexible foam of the present disclosure increases the environmental benefits of using recycled raw materials because the resulting product can be further recycled into thermoplastic polymers, which can subsequently be Use to create new products from micro-porous flexible foams or alternatively use other products of thermoplastic polymers. [Method of Making Flexible Foam]

5 and 6 illustrate an injection molding machine 506 and method 600 for manufacturing the recycled flexible foam 402 shown in FIG. 4. Therefore, in one aspect, the present disclosure is directed to a method of foaming thermoplastic polymers. As described in more detail below, the method can be utilized to produce any of a number of end products from the flexible foam 402, such as technical sports devices including shoe components, and requirements such as cushioning, impact protection, comfort, and others. Features of other products.

As shown 500 in FIG. 5, the injection molding machine 506 includes a hopper 504 configured to receive and introduce a plurality of thermoplastic polymers 502 into the injection molding machine 506. The barrel 507 is connected to the funnel 504 and is configured to receive the thermoplastic polymer 502 and includes a specialized reciprocating screw type plunger 508. The barrel 507 also includes a temperature control unit (not shown) to heat and cool the contents of the barrel 507. As shown in FIG. 5, a computer controller 503 with a temperature and pressure measuring device 505 is configured to sense the temperature and pressure in the barrel 507. The gas dosing system 509 is fluidly connected to the barrel 507 and includes a metering unit 512 configured to receive and introduce the fluid 510 into the barrel 507. The gas batching system 509 maintains the fluid 510 at a critical temperature and pressure (Tc and Pc, respectively) to generate a supercritical fluid (SCF) 510. In the method of the present disclosure, SCF 510 is used as a physical blowing agent that replaces the chemical blowing agent such as azodimethamide (ADA) used in the conventional method of flexible foam production. By way of example, the SCF 510 may include an inert gas or passivation gas such as nitrogen, carbon dioxide, helium, neon, argon, or xenon. Compared with the conventional flexible foam molding method, the method of the present disclosure not only eliminates the environmentally harmful and suspected carcinogen ADA by a self-made process, but also replaces the environmentally harmful and suspected carcinogen ADA with inert SCF or blunt SCF. Improve the environmental impact, and as will be discussed in further detail below, the flexible foam 402 of the present disclosure can be used as a result of the method described herein to undergo a test at the end of the useful life of the flexible foam Recycle.

Referring to FIG. 6, the method for manufacturing the recyclable flexible foam 102 may start at step 602: selecting a thermoplastic polymer 502 and supplying the thermoplastic polymer 502 to the hopper 504 of the injection molding machine 506. Subsequently, in step 604, the thermoplastic polymer 502 is then fed from the hopper 504 into the barrel 507 and heated. In step 606, when the screw-type plunger 508 moves the thermoplastic polymer 502 through the injection molding machine 506, the barrel 507 is heated to melt the thermoplastic polymer 502. In addition, the controller 503 can be configured to control and adjust the screw speed.

In step 608, the SCF 510 is introduced into the barrel 507 by the ejector 511 through the metering unit 512 connected to the injection molding machine 506, and the SCF 510 is dissolved in the molten thermoplastic polymer 502 to produce a single-phase solution. SCF 510 can be adjusted in terms of the concentration in the melt, which affects the degree of foaming obtained. Referring to FIG. 5, the metering system 512 is configured to dose the SCF into the molten thermoplastic polymer 502 in an appropriate amount. A non-limiting example of the initial SCF gas concentration may be Co = 0.25%, and the melt temperature range is between 176°C and 250°C, and more preferably in the range of 180°C. In addition, the controller 503 controls the pressure introduced into the barrel 507 by the SCF 510 through the SCF injector. The SCF 510 saturates the molten thermoplastic polymer 502, thereby producing a single-phase solution. In addition, the screw-type plunger 508 rotates in the barrel 507 at a speed necessary to homogenize the thermoplastic polymer 502 and the SCF 510 and produce a single-phase solution. The screw 508 may rotate between 1 rpm and 200 rpm in the barrel 507, and preferably, rotate from approximately 20 rpm to approximately 60 rpm.

Regarding saturation, the injection molding machine 506 is configured to deliver gas to the barrel 507 under temperature and pressure to saturate the molten thermoplastic polymer 502 during the rotation of the screw. Specifically, the controller 503 is configured to control the combination of SCF delivery pressure and SCF dose weight. SCF pressure and dosage can be controlled in a way to affect single-phase solutions. That is, the smaller the SCF dose, the smaller the SCF saturation requirement in the biopolymer melt, and the larger the SCF dose, the greater the SCF saturation requirement in the melt. Likewise, the lower the SCF delivery pressure, the lower the uptake of saturation, and therefore the lower the growth of the nucleus that can grow to form bubbles in the molten biopolymer melt. In addition, the greater the SCF delivery pressure, the greater the uptake of saturation, and therefore the greater the growth of nuclei that can grow to form bubbles in the molten melt.

The controller 503 variably controls the temperature and pressure in a manner that depends on the type of flexible foam being produced and the type of end product being produced. In particular, the temperature throughout the system (such as in the barrel 507) can be controlled so as to be between 100°C and 600°C, such as between 200°C and 500°C, for example, between 300°C and 400°C , And more specifically, between 320°C and 380°C, including between 360°C and 380°C in the barrel. Similarly, the SCF delivery pressure can be finely controlled so as to be within a range between 1,000 PSI and 8,000 PSI, such as between 1,500 PSI and 6,000 PSI, for example, between 2,000 PSI and 5,500 PSI, and In other words, between 3,000 PSI and 4,000 PSI, and more specifically between 2,600 PSI and 2,800 PSI.

In the embodiment illustrated in FIG. 5, the controller 503 uses a sensor to determine and control the concentration of the SCF 510. The sensor determines the amount of saturation and evaluates the progress of the saturation process and modulates the pressure and temperature. The SCF 510 can controllably saturate the molten thermoplastic polymer 502 during the rotation of the reciprocating screw 508 to produce a single-phase solution at a defined temperature and pressure. SCF is a part of a two-part molten thermoplastic polymer compound mixture, and it is used as a physical blowing agent in the presence of a clear pressure and temperature in the injection mold.

As discussed in more detail below, the SCF 510 foaming agent can be selected from the above-listed list of blunt fluids and inert fluids based on the technical requirements of the final flexible foam 402 product. For example, carbon dioxide in its supercritical state is denser than nitrogen but has a higher heat capacity at the same pressure. The production of carbon dioxide in a supercritical state can be used for dense foams in certain cushioning applications. In contrast, supercritical nitrogen can be used to produce low-density foamed parts with smaller cores that can be used when producing flexible foams 402 for footwear and sports goods.

However, when the goal is viscosity reduction, solubility becomes an advantage. The SCF dissolved in the recyclable thermoplastic polymer 502 acts as a plasticizer, thereby reducing the viscosity of the thermoplastic polymer 502. Because the viscosity reduction partly varies with the amount of SCF added to the recyclable thermoplastic polymer 502 and because carbon dioxide has a higher solubility limit than nitrogen, the ability of carbon dioxide to reduce viscosity is greater. Carbon dioxide is also useful when the amount of nitrogen required to produce parts is so low that it is impossible to treat the end product consistently.

Because carbon dioxide is a less aggressive blowing agent, there are opportunities to run low levels of carbon dioxide more easily. For example, carbon dioxide of 0.15% or 0.2% is compared to very low nitrogen levels of less than 0.05%. The examples as indicated in the previous examples mainly occur in the case of soft materials and parts with thick cross-sections. Therefore, regardless of whether the physical blowing agent is nitrogen, carbon dioxide, or one of the other inert and inert gases listed above, the physical blowing agent plays a role in the final foamed part and the final product containing the physical blowing agent. Useful role.

It is useful to choose an appropriate combination of compatible thermoplastic polymers or thermoplastic polymer compounds and associated SCF gases. Secondly, use SCF gas appropriately to provide a better saturation level in the single-phase solution by the optimal ingredient weight and pressure, and affect the generation of nuclei (the production of many uniform bubbles in the foam matrix, as described in more detail below) describe). In addition, as a final result, injection molded flexible foam parts formed with the same texture depend on all aspects of the SCF gas compounding process and work in coordination with the temperature, pressure and holding time of the injection molding machine. The use of gas counterpressure to achieve commercially acceptable molded foam parts.

5, the reciprocating screw 508 is further assembled to compress and move the molten thermoplastic polymer 502 in the cavity of the barrel 507. The gas back pressure (GCP) system 516 is configured to deliver the gas back pressure to the barrel 507 in order to control the expansion of the molten thermoplastic polymer 502. In the embodiment illustrated in FIG. 5, the GCP system 516 includes a gas pump 515, a gas reservoir 518 including an inert gas such as nitrogen or carbon dioxide, a compressor 517, a pressure sensor 519, and a gas control valve 520. The reciprocating screw plunger 508 and the barrel 507 are also assembled to provide back pressure and deliver the thermoplastic polymer 502 to the mold 514 having a cavity, which is arranged in fluid communication with the barrel 507, and is assembled to receive Melt thermoplastic polymer 502 (described in more detail below). In the embodiment shown in FIG. 5, the screw-type plunger 508 and barrel 507 are assembled to apply between approximately 2,000 psi and approximately 3,000 psi, and more preferably in the range of 2,700 psi and 2,800 psi. The configuration of the screw plunger 508 and barrel 507 also sets the position where the SCF 510 batching starts, and this action can then set the SCF injector to the open or closed position. The position should be set so that the pressure in the barrel becomes stable before the start of the SCF 510 batching during the screw recovery period. As a non-limiting example, the open position can be in the range of 0.3 inches and 0.4 inches.

In addition to the GCP system, the injection molding machine 506 illustrated in FIG. 5 includes a dynamic mold temperature control (DMTC) 522 that is configured to control the temperature in the mold 514. The DMTC 522 can be used in concert with the GCP system 516 to ensure a consistent pore structure within the expanded thermoplastic polymer 502. DMTC 522 can be configured to affect the rapid change and control of mold temperature and/or pressure during the injection and filling stage, and to dynamically control the mold through the use of thermal and thermal cycles with or without back pressure Temperature and/or pressure.

Continuing to refer to FIG. 5, the controller 503 is configured to control the temperature of the mold 514 through the DMTC 522 during the injection stage 610. More specifically, compared with the conventionally known injection molding process, the important feature of the dynamic mold temperature control used herein is that the mold temperature itself can be dynamically controlled. The DMTC 522 illustrated in Figure 5 utilizes fast electric pole heating and fast water cooling. Specifically, DMTC 522 includes five main components: an air compressor (not shown), a valve exchange device 526, a computer-controlled mold temperature control unit (located in the controller 503), and an electrical heating rod (located in the mold 514). Inside), and cooling tower 532. The cooling tower 532 can be used to supply sufficient water cooling to the mold. The air compressor is used to produce compressed air as the driving gas of the pneumatic valve and to remove the residual cooling water after cooling to avoid entering the mold. In the embodiment shown in FIG. 5, the water heating unit 534 is also included, and the valve exchange device 526 is used to switch the valve to transfer different media from the pipeline to the mold 514, thereby providing a heat-heat cycle and a cold-heat cycle. For example, DMTC 522 can provide water cooling in the range between approximately 15°C and approximately 30°C, and the electric heating rod can heat the mold to between approximately 60°C and approximately 150°C, and can optimally Heat the mold to a range of 90°C to 130°C.

The injection molding machine 506 depicted in FIG. 5 includes pipes and other pipes for conveying reaction materials. The pipes are associated with one or more heat exchange units so that the reactants are pumped to the pipes and pipes. Heat and/or cool the reactants while neutralizing and/or passing through conduits and pipes. In this example, the exchanger can be controlled to adjust the temperature to the reaction level. A dispensing head may be included on one end of the pipe, which may be associated with one or more valves. In addition, the dispensing head can be hooked up to the processing line. Electric heating molds are used to mold the final shape of foamed parts. The function of mold temperature control will control the heating and cooling of the mold; all this is coordinated with the injection molding machine by computer control.

Therefore, as implemented herein, the controller 503 implements a gas back pressure to improve the control of the foaming process by applying different gas pressures in the injection stage, as described below. The controller 503 is configured to operate the GCP system 516 and the DMTC 522 to adjust the temperature and pressure and thereby control the nucleation and melting of the resulting bubbles in the thermoplastic polymer 502 and the resulting foamed matrix.

As illustrated in Figure 6, in step 610, the thermoplastic plunger 508 advances, thereby pushing the molten thermoplastic polymer 502 through a nozzle (not shown) that abuts the mold 514 and the nozzle injects the thermoplastic polymer 502 into Mold 514. The injection molding machine 506 sends the measured injection of the single-phase thermoplastic polymer 502 into the cavity of the mold 514 with dynamic temperature control. Before the injection step 610, the DMTC 522 heats the mold 514 to a preset upper limit. During the injection step 610, the DMTC 522 maintains the temperature of the cavity of the mold 514 above the upper limit to prevent the molten thermoplastic polymer 502 from solidifying prematurely. The GCP system 516 conveys the gas back pressure in the mold 514 to control nucleus growth, thereby preventing gas bubbles from contacting and breaking through the surface of the plastic polymer 502 when the foamed part is formed. This is achieved by resisting pressure, which is applied by the GCP system 516 into the cavity of the mold at or about the same time as the single-phase solution of the thermoplastic polymer 502 is injected into the cavity of the mold 514 by the GCP system 516. The inert gas bubbles experience a force sufficient to keep the SCF 510 within the thermoplastic polymer 502 during the injection step 610.

Referring to FIG. 6, in step 612 and step 614, the controller 503 manipulates the pressure and temperature in the mold 514 to control the physical foaming of the thermoplastic polymer 502. Although the steps of dynamically controlling the temperature of the mold 612 and applying gas back pressure to the mold 614 are illustrated as separate steps in the flowchart of FIG. 6, steps 612 and 614 can be implemented simultaneously or successively, so that the controller 503 controls the mold The temperature and pressure. In steps 612 and 614, the molten thermoplastic polymer 502 undergoes nucleation growth and forms many microporous bubbles. When the controller 503 (FIG. 5) raises and lowers the temperature in step 612, the SCF 510 evaporates and becomes a gas bubble, so that the thermoplastic polymer 502 is foamed in the mold 514. In step 614, the GCP system 516 sends the expected amount of back pressure gas to the mold under computer control to generate substantially uniform bubbles, and the gas back pressure is adjusted for surface texture for the best appearance. The gas bubbles grow until the thermoplastic polymer 502 fills the mold 514 and the expansion capacity of the SCF 510 is exhausted. Because the bubbles reach the micron size, the process produces micro-pore foaming. The concentration of SCF 510 can affect the structure of gas bubbles. Therefore, the controller 503 selects temperature and gas back pressure parameters in order to produce useful and/or determined gas bubble structures. At the end of the molding of the part, the mold cools and the thermoplastic polymer solidifies. In the embodiment depicted in FIG. 6, in step 616, the dynamically temperature-controlled mold temperature is switched to water cooling, and the formation of gas bubbles and the expansion of the thermoplastic polymer 502 are slowed and stopped. The DMTC 522 rapidly cools the mold 514 to the lower limit (spray temperature), and the molded part of the flexible foam 402 is now formed and it is ejected from the mold. [Recyclable microporous flexible foam product formed by injection molding]

Figure 4 shows the footwear component of the present disclosure. More specifically, the recyclable micro-pore flexible foam shoe midsole 400 is made of the recyclable flexible foam 402.

As briefly discussed above, the methods used to make the recyclables discussed above enhance the environmentally beneficial effects of monomers and polymers developed from recycled raw materials, because the resulting products can be further recycled into monomers. Monomers can be polymerized into thermoplastic polymers for use in making new plastic materials. Specifically, the production of commodities assembled for recycling ensures that the flexible foam will last the useful life of the resultant product, such as by making the resultant product not break or break during use in the finished product. The resulting product is functionalized. For example, if a person purchases furniture, a pair of shoes or other sports equipment that is only made of the recyclable flexible foam of the present disclosure so that the foam will degrade during normal use before the end of the product’s useful life, it will be harmful .

More specifically, the present disclosure benefits from the use of the above-listed inert physical blowing agents and thermoplastic polymer compounds, which do not crosslink during the manufacturing process. The resulting recyclable flexible foam 402 is non-crosslinked, free of harmful chemical blowing agents such as ADA, and is environmentally friendly. In addition, the recyclable flexible foam 402 can be used in many types of end products, such as footwear foams used in making shoes.

The recyclable flexible foam 402 can be redirected to an appropriate recycling facility by turning waste at the end of the product's service life. Because the recyclable flexible foam 402 does not use chemical blowing agents such as ADA, and because the method described herein does not utilize thermoplastic polymers that are cross-linked during its manufacture, the recyclable flexible foam 402 It can be ground, pretreated and depolymerized into one or more monomers. One such depolymerized monomer is caprolactam such as ECONYL® caprolactam supplied by Aquafil USA Inc., Cartersville, Georgia, whether in flake, liquid or melt, or by DSM Engineering Plastics Americas, Troy Depolymerized caprolactam provided by Michigan, whether in flakes, liquids or melts.

Referring to FIG. 7, the method of the present disclosure covers a method 700 for recovering a recyclable flexible foam 402 using a thermal and chemical depolymerization process. According to this method, the temperature of a polymer such as PEBA is increased to exceed the maximum temperature, and many Any chemical reagent or catalyst in the chemical reagent or catalyst is used to depolymerize into its constituent monomers. In the embodiment illustrated in FIG. 7, the depolymerization process starts at step 702, which mechanically separates the thermoplastic polymer of the recyclable flexible foam 402 from any waste. In step 704, a depolymerization catalyst is introduced to the separated thermoplastic polymer. Non-limiting examples of depolymerization catalysts include acids such as phosphoric acid and boric acid. In step 706, heat is applied, such as by superheated steam, which can act to distill caprolactam and any other volatile compounds and produce a distillate containing caprolactam monomer. The temperature applied can range from about 100°C to about 325°C. In step 708, the distillate is fractionated to separate water and caprolactam from other by-products of the depolymerization process. In step 710, an oxidant is introduced to the separated aqueous caprolactam. Some non-limiting examples of oxidizing agents include potassium permanganate, hydrogen, oxygen, potassium dichromate, sodium or potassium hypochlorite, perchlorate or perboric acid. In step 712, the water-containing caprolactam is oxidized, such as by evaporation and concentration. In step 714, the caprolactam monomer is purified and concentrated, such as by vacuum distillation.

After the purification of the caprolactam monomer in step 714, the depolymerized monomer can be re-polymerized into a thermoplastic polymer and used to make a more recyclable flexible foam 402. Therefore, in contrast to the use of new original fossil fuels or other non-renewable raw materials, the method of the present disclosure establishes a recycling process, whereby industrial products can be decomposed, manufactured into new products, and re-inserted into commercial streams. In addition, the recyclable flexible foam 402 of the present disclosure neither compromises the technical performance properties during the useful life of the recyclable foam, nor does it compromise its environmentally conscious design.

As discussed above, devices, systems, and methods of use can be used to produce one or more molded end products, such as for use in shoes, seats, automobiles, protective devices, and/or sports Components in the device. Therefore, in various embodiments, what is provided herein is one or more components useful in the construction of a shoe, such as its sole, midsole, and/or insole, such as where the sole forms the base of the shoe and is assembled For contact with the ground, the midsole forms an intermediate structure and a cushioning element, and the shoe insole is assembled for insertion into the shoe and thereby provides cushioning and/or support for the shoe.

In certain embodiments, the shoe component may include a recyclable flexible foam 402 produced according to the method 600 disclosed herein, which may be environmentally friendly and recyclable. In various examples, each individual component can be constructed from a plurality of layers including a base layer and a buffer layer. For example, in a specific embodiment, a support member such as a support member coupled to the base layer may be included, and in the case where the component is an insole, have one or more of an arcuate contact portion or a heel contact portion.

Specifically, in various embodiments, foam materials can be produced, such as where the foam materials can be used in the production of cushions, cushioning furniture, shoe components such as insoles, cushions, fibers, fabrics, and the like. Other useful products can include gap fillers such as silicone gap fillers, silicone medical gloves, silicone tubing for drug delivery systems, silicone adhesives, silicone lubricants, silicone coatings, And other suitable silicone products, such as condoms. In various embodiments, the foam product may be produced in such a way that the foam material may have one or more anti-microbial, anti-bacterial, anti-fungal, anti-viral, and/or anti-flammability properties.

More specifically, in one aspect, the present disclosure may generally be directed to the manufacturing process for furniture, such as upholstered furniture and/or cushions thereof, such as foams or made in other ways. Furniture made of foam, for example, the foaming system is biodegradable and/or synthesizable. Therefore, the recycled foam of the present disclosure is advantageous for use in the manufacture of furniture including the foam insert produced in this way. The recyclable foam produced according to the method of the present disclosure has proven to be advantageous for use as a cushioning material, such as for pillows, benches, beds, seat cushions, or for other upholstered furniture, etc.

For example, the method 600 can be used to produce small to large squares of recyclable flexible foam 402 to form foam inserts for use in furniture or automotive accessory components. The cube foam can then be cut into smaller cubes of the desired size and shape based on the type and form of the furniture being produced. In particular, the sized and cut squares can then be applied to or otherwise fit within the furniture or frame or other boundary materials, and each of these can be covered together to produce the final furniture product, which is Pillows, sofas, cushions, for example, sofas or car cushions, etc. In addition, if necessary, the outer cover or boundary material can be attached to the frame material, such as by nailing and/or sewing, or otherwise fastened to the frame of the article to be upholstered and made of fabric Or covered with other materials.

Therefore, in various embodiments, when manufacturing upholstered furniture such as benches or car seats, the frame may be produced. Various internal (such as structural) components of the furniture can be installed in the frame, such as springs, etc., and then the thin plate of the recyclable flexible foam 402 can be positioned in the spring, on and around the spring, such as for cushioning And/or isolation. Of course, other materials may be included, such as a cotton layer, a wool layer, a felt layer, a rubber-based product layer, etc., and then a covering material may be added to cover the frame and complete the product manufacturing.

In particular, the recyclable foam of the present disclosure and other materials disclosed herein can serve as a cushioning material or a filling material. When the covering material is stretched on the frame, the cushioning material or the filling material can be under the cover Shaped, adjusted and pleated. In addition, as indicated, in various examples, the recyclable foams produced herein are useful among those known in the art for many reasons, the most important of which are typical PU and / Or EVA foam is not recyclable, and the components of the foam produced in this article are recyclable. Therefore, in various embodiments, a method of constructing furniture on an open frame is provided.

In addition, in another aspect, the present disclosure is generally directed to the manufacturing process of shoe components such as shoe soles, midsoles, and/or shoe insoles, such as shoe components including conventional foams or in other ways Shoe components composed of conventional foams. In particular, in specific embodiments, methods for making recyclable shoe soles, midsoles, shoe insoles, and/or other shoe inserts are provided. For example, the shoe insert may be in the form of a cushioning device that is adapted to be inserted into or otherwise fit into a shoe such as a running shoe or a sports shoe. The shoe may be configured to reduce the impact on the surface during running or walking. The impact of the foot (for example, the ground), thereby absorbing the vibration to the foot and/or weakening the vibration to the foot.

Specifically, the sole component including the midsole and the insert may include one layer or multiple layers. For example, in some examples, a base layer, a recyclable foam layer, and/or a fabric layer may be provided. In particular, it may include a base layer of relatively elastic material, and/or a recyclable foam layer disposed on the base layer, and/or a fabric layer disposed on the recyclable foam layer. Therefore, the method may include integrally forming the base layer, the recyclable foam layer, and the fabric into a three-layer sheet. In various examples, a support layer may be placed at the heel area, and the support layer may be constructed of a rigid material such as a higher density than the other components of the build-up. Adhesives, glues or other attachment mechanisms can be provided and utilized for attachment and forming a three-layer board with a supporting layer.

More specifically, in other examples, the method for making shoe components such as shoe insoles may include the following steps: providing a recyclable foam layer, providing a fabric layer, heating the recyclable foam layer, and joining the recyclable foam And a fabric layer, providing a base layer, for example, a base layer having the same, greater, or lower density than that of the recyclable foam layer; and heating at least one of the base layer and the foam layer In order to couple the base layer and the recyclable foam layer to form a double-layer board or a three-layer board.

The method may further include providing pre-formed support members, such as arcuate supports and/or heel members, which members may have substantially the same density as compared to the foam layer, or a smaller, or larger density. In a specific example, the support member may be formed of a compressed foam material in order to obtain a greater density than the recyclable foam layer, and thus greater rigidity. In addition, a heat and/or pressure reactive adhesive may be applied between the support and/or heel member and the build-up layer. Molding pressure can then be applied to the composition to cause the three-layer panel to be formed and/or shaped into a support and/or heel member to form a one-piece shoe insert, wherein the pre-formed heel member is formed The rear part and/or support member forms the middle part of the bottom surface of the finished shoe insert, for example, at its middle and/or heel area, and the base layer forms the bottom surface of the finished shoe insert at its front area.

However, it should be noted that the support and/or heel member need not be included, and in some examples, one or more of the layered components may be excluded or other layered layers may be added. It should be further noted that in certain embodiments, the recyclable foam layer may be more flexible and/or cushioned, for example, with a larger durometer than the base layer, the base layer may in turn be more flexible. Flexible and/or cushioned, for example, having a larger durometer than the supporting member. Therefore, the more flexible foam and the base layer can be relatively elastic and conform to the desired shoe size and configuration in shape, while the support layer(s) can be relatively more rigid.

In particular, the support layer may have a denser recyclable foam, thereby making the support layer more rigid. Therefore, in various embodiments, the recyclable foam layer may have a density of about 2 pounds/cubic foot or about 3 pounds/cubic foot or about 5 pounds/cubic foot to about 10 pounds/cubic foot or greater, such as in Density in the range of about 4 pounds/cubic foot to 6 pounds/cubic foot. In addition, the recyclable foam layer may have a thickness of approximately 1/8", such as in the thickness range of about 3/32" to 5/32".

Similarly, the base layer may also have a density of about 2 pounds/cubic foot or about 3 pounds/cubic foot or about 5 pounds/cubic foot to about 10 pounds/cubic foot or greater, such as between about 4 pounds/cubic foot Density within the range of feet to 6 pounds per cubic foot. The thickness of the base layer can be about 5/16"+ or -10%. However, in various examples, the thickness of the base layer can range from about 1/4" or less to about 7/16" in terms of thickness. The support layer, which can be mainly formed at the arch and/or heel area of the insert, can also be made of the recyclable foam disclosed herein.

However, the support layer can be made by compressing the recyclable flexible foam 402 so that the final density is about 22 pounds/cubic foot to 23 pounds/cubic foot. The fabric layer can be constructed of any suitable material such as cotton, polyester or polypropylene knitted fabric. In various examples, the material and the recyclable foam layer may be laminated together by flame gluing technology, which utilizes a naked fire that generates sufficient heat to melt the surface of the recyclable foam layer. Once melted, the fabric layer is joined to the recycled foam layer and the quenched roller so that the two layers are joined together.

At this point in the manufacturing process, these layers still remain in the form of a flat sheet. These integrated layers are then joined to the base layer by flame gluing. The previously integrated material and foam layers can be joined to the support layer, and these multi-layered layers can then extend between the quenched rollers. At this stage of the stage, these layers still remain in the form of flat sheets. The layers laminated so far are then ready for moulding. This can be performed by heating the build-up layer to a molding temperature of approximately 250 F, such as for a period of about 1 minute to about 5 minutes or more, for example, about 225 seconds. This heats the previously laminated layers sufficiently to allow them to be inserted into the mold.

As mentioned above, SCF physical blowing agent can be selected depending on the desired characteristics of the end product. Carbon dioxide that becomes an SCF fluid at a temperature of 31.1 degrees Celsius and 72.2 bar is 4 to 5 times more soluble in the thermoplastic polymer 502 than nitrogen that becomes a supercritical fluid at a temperature of -147 degrees Celsius and 34 bar. For example, the saturation point of an unfilled recyclable thermoplastic polymer is about 1.52% to 2% by weight of nitrogen, depending on temperature and pressure conditions, while the saturation level of carbon dioxide is closer to 8% by weight. Carbon dioxide also exhibits a greater mobility in biopolymers, allowing carbon dioxide to migrate farther into existing bubbles than nitrogen. From the viewpoint of pore nucleation, greater solubility and mobility means that fewer pores will nucleate, and those nucleated pores will tend to be larger.

In the embodiment discussed above, where the method 600 is used to produce sports goods such as shoes, the SCF 510 contains nitrogen in a critical state. Nitrogen provides improved weight reduction and fine core at a much lower weight percentage compared to SCF carbon dioxide. The SCF 510 nitrogen level is at least 75% lower than the SCF carbon dioxide level required to achieve comparable parts. As such, when mass-produced flexible foams such as the biodegradable and industrially synthesizable flexible foams of the present disclosure used in the manufacture of shoe components, when compared with SCF carbon dioxide, greatly reduced SCF nitrogen levels are required Ensure the best material saving and time saving.

Although carbon dioxide is heavier, it can be a suitable blowing agent in certain applications, such as when viscosity reduction is the goal of the process, and/or when the end product cannot tolerate the more aggressive foaming action of SCF nitrogen Or when in semi-flexible foam. For example, when method 600 is used to produce furniture and automotive products, SCF 510 contains carbon dioxide in a critical state because carbon dioxide produces a much larger pore structure, even at larger sizes and/or weights. During the physical foaming process with physical foaming agent, depressions in the glass transition are seen.

As discussed briefly above, carbon dioxide in the supercritical state can be utilized as a physical blowing agent when the amount of nitrogen required to produce parts is so low that it is impossible to treat the parts consistently. Because carbon dioxide is a less aggressive blowing agent, it is easier to run low levels of carbon dioxide in some applications. For example, 0.15% or 0.2% carbon dioxide (compared to nitrogen levels less than 0.05%) can be utilized to produce soft materials and parts with thick cross-sections.

Although a few embodiments have been described in detail above, other modifications are possible. Other embodiments may be within the scope of the following patent applications.

100: shoe midsole 102: flexible foam 200: device 202: biopolymer master batch 204: funnel 206: injection molding machine 208: injection molding machine screw 210: nitrogen or CO ₂ gas 212: Biopolymer melt 214: Molding tool 216: Gas back pressure system 218: Metering nitrogen or CO ₂ gas 220: Gas control valve 222: Dynamic mold temperature control system (DMTC) 300, 600, 700: Methods 302-316 602～614,702～716: Step 400: Recyclable micro-pore flexible foam shoe midsole 402: Flexible foam 500: Graphic 502: Thermoplastic polymer 503: Controller 504: Funnel 505 : Temperature and pressure measuring device 506: Injection molding machine 507: Barrel 508: Plunger 509: Gas batching system 510: Fluid (SCF) 511: Ejector 512: Metering unit 514: Mold 515: Gas pump 516: Gas Back pressure system (GCP) system 517: compressor 518: gas reservoir 519: pressure sensor 520: gas control valve 522: dynamic mold temperature control (DMTC) 526: valve exchange device 532: cooling tower 534: water heating unit

These and other aspects will now be described in detail with reference to the following drawings.

Figure 1 shows a foamed footwear component, that is, a shoe midsole according to one implementation of the present disclosure.

Fig. 2 illustrates a schematic diagram of a microporous flexible foam system used to produce a biodegradable and industrially synthesizable flexible foam suitable for footwear.

Fig. 3 is a flow chart of a method for manufacturing a biodegradable and industrially synthesizable injection-molded flexible foam.

Figure 4 shows injection molding to produce a recyclable flexible foam according to the present disclosure for use in a midsole of a sports shoe.

Fig. 5 shows a schematic diagram of an injection molding machine used to produce the recyclable flexible foam depicted in Fig. 4.

Fig. 6 is a flow chart of a method for manufacturing the recyclable micro-pore flexible foam of Fig. 4

FIG. 7 is a flowchart showing the steps of recovering flexible foam in combination with the embodiment of the method for manufacturing the recoverable micro-pore flexible foam of FIG. 6.

In the various figures, the same reference symbols indicate the same elements.

200: device

202: Biopolymer masterbatch

204: Funnel

206: Injection molding machine

208: Injection molding machine screw

210: Nitrogen or CO ₂ gas

212: Biopolymer melt

214: Molding tools

216: Gas Back Pressure System

218: Measuring nitrogen or CO ₂ gas

220: Gas control valve

222: Dynamic mold temperature control system/DMTC

Claims (9)

A method for manufacturing recyclable flexible foam molded products, including the following steps: Providing a thermoplastic polymer, the aforementioned thermoplastic polymer comprising at least one monomer derived from depolymerized post-consumer plastic; Insert the fluid into the barrel of the injection molding machine under temperature and pressure conditions to produce supercritical fluid; Mixing the aforementioned thermoplastic polymer and the aforementioned supercritical fluid to produce a single-phase solution; Injecting the aforementioned single-phase solution into the mold of the aforementioned injection molding machine, wherein the aforementioned mold is under gas back pressure; and By controlling the heat and temperature conditions in the aforementioned mold, the supercritical fluid is immersed in a single-phase solution to foam. The method for manufacturing a recyclable flexible foam molded product as described in claim 1, wherein the thermoplastic polymer contains at least 40% of the monomer derived from the depolymerized post-consumer plastic. The method for manufacturing a recyclable flexible foam molded product as described in claim 2, wherein the thermoplastic polymer contains at least 60% of the monomer derived from the depolymerized post-consumer plastic. The method for manufacturing a recyclable flexible foam molded product as described in claim 3, wherein the aforementioned thermoplastic polymer contains 90% or more of the aforementioned monomer derived from depolymerized post-consumer plastic . The method for manufacturing a recyclable flexible foam molded product as described in claim 1, wherein the aforementioned monomer contains caprolactam. The method for manufacturing a recyclable flexible foam molded product as described in claim 1, wherein the aforementioned thermoplastic polymer comprises a polyamide-based thermoplastic elastomer. The method for manufacturing a recyclable flexible foam molded product as described in claim 6, wherein the aforementioned thermoplastic polymer comprises a copolymer, and the aforementioned copolymer comprises at least one caprolactam monomer. The method for manufacturing a recyclable flexible foam molded product as described in claim 1, which further includes recovering the aforementioned recyclable foam by depolymerizing the flexible foam into one or more monomers. Steps of flexible foam. The method for manufacturing a recyclable flexible foam molded product as described in claim 8, wherein the aforementioned flexible foam is depolymerized into caprolactam.

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