WO2017092071A1

WO2017092071A1 - Method and application for recycling and reusing waste pet

Info

Publication number: WO2017092071A1
Application number: PCT/CN2015/097119
Authority: WO
Inventors: 谭亦武
Original assignee: 谭亦武
Priority date: 2015-11-30
Filing date: 2015-12-11
Publication date: 2017-06-08

Abstract

The present application discloses a method and application for recycling and reusing PET. The method comprises melting the waste PET material, and subjecting the waste PET melt to alcoholysis and repolymerization prior to subjecting the melt to spinning or granulation. In the PET material, waste PET bottle sheet material and waste PET film sheet material are in an amount of below 50%, with the balance being spinning grade waste PET material. The method of the present application provides recycled PET which is equivalent in properties to virgin polyester material and which can meet the needs for direct production and use of various PET spunbonded non-fabric materials. The recycled PET obtained by the method of the present application can replace virgin polyester material, is eco-friendly, with a product carbon footprint of about 60 to 70% lower than that of virgin polyester material, and is low in production cost.

Description

Method and application of recycling and recycling of waste PET

Technical field

The present application relates to the field of waste PET recycling, and in particular to a method and application for recycling and recycling waste PET.

Background technique

Polyethylene terephthalate, abbreviated as polyester, abbreviated as PET. Polyester spunbonded non-woven materials are widely used in geotextiles because of their corrosion resistance, aging resistance, thermal stability, good tensile strength, bursting resistance, tear resistance, and good water permeability and water filtration performance. , linoleum base fabric, carpet base fabric, filter material, shoe leather material, automotive interior, home textile products, agricultural materials, packaging materials and transfer printing. It is the youngest and most promising emerging industry in the textile industry and is known as the “sunrise industry” in the textile industry. At present, native spinning grade polyester chips are commonly used in China for the production of spunbonded nonwoven materials. This consumes a large amount of polyester raw materials, resulting in high cost, and is also detrimental to the development of low-carbon environmental protection, recycling economy and comprehensive utilization of waste resources. Therefore, the recycling and recycling of waste PET materials such as waste PET bottles, waste packaging films, waste fibers and used clothes has received increasing attention.

In the prior art, although there is already a process of producing fibers by using recycled PET, the short fibers obtained by melt-spinning the polyester recycled materials are carded and laid, and needle-punched to form a nonwoven fabric; however, short fibers and non-woven fabrics are used. The production of cloth is done separately on two production lines, which are upstream and downstream. And, more importantly, the direct use of waste PET recycled materials, such as recycled bottles, packaging films, waste fibers and used clothing. PET materials, when producing spunbonded nonwoven materials, due to the uneven molecular weight distribution of the PET melt, unstable viscosity, fiber crystallization rate, crystallinity and crystal nucleus size do not meet the requirements for the production of spunbonded nonwovens, resulting in the inability to use 100% waste PET material is stable in the production of spunbonded nonwovens.

Summary of the invention

It is an object of the present application to provide an improved method and application for recycling and recycling waste PET.

This application uses the following technical solutions:

An aspect of the present application discloses a method for recycling and recycling waste PET, comprising: after melting the waste PET material, performing alcoholysis repolymerization treatment on the waste PET melt before spinning the melt, and then using alcoholysis The repolymerized product is spun; and, in the waste PET material, the content of the discarded PET flake material and the waste PET film material is less than 50%, and the balance is a spun-grade waste PET material.

It should be noted that the present application controls the waste PET flake material and waste in the waste PET material. The content of the PET film material makes the obtained molecular weight distribution, viscosity stability, fiber crystallization speed, crystallinity and crystal nucleus size of the recovered PET meet the requirements for producing PET spunbonded nonwoven materials, and the properties of recycled PET and polyester. The virgin material is comparable so that 100% recycled PET can be used to make a variety of PET spunbond nonwovens. The waste PET material of the present application mainly refers to various discarded PET materials, such as mineral water bottles, juice beverage bottles, carbonated beverage bottles, oil bottles, sports beverage bottles, cloth broken foam materials, and spinning waste materials. And packaging waste, etc. As for the scraps in the production process of plastic bottles, such waste PET materials can be directly recycled. Although such waste PET materials can also adopt the method of the present application, the method of the present application mainly focuses on the waste of life. Recycling of PET materials.

It should also be noted that the optimization of the ingredients of the waste PET material in the present application enables the recycled PET prepared to achieve comparable performance to the polyester raw material; it is understood that in order to achieve comparable performance of the polyester raw material, For the impurity control of the waste, the alcoholysis repolymerization treatment, and some treatments before the alcoholysis repolymerization, strict control and optimization are required, and these can be referred to the existing waste PET chemical recovery technology, which is not specifically limited herein. In addition, for the subsequent spunbonding process for preparing the nonwoven material, for example, the melt viscosity is controlled at a level of IV=0.64±0.01, and the molecular chain length is distributed between 18000-20000 ethylene terephthalate units. It ensures that the melt will not break, flutter and stiffen when drafted at high speeds; these can also be referred to the conditions of conventional polyester raw materials. However, it should be noted that the reason why the recycled PET of the present application can meet these conditions or requirements is that the content of the discarded PET flake material and the waste PET film material in the waste PET material controlled by the present application is lower than that. 50%, while the balance uses spinning grade waste PET material.

Preferably, the alcoholysis repolymerization treatment comprises adding 2-10% by weight of ethylene glycol to the waste PET melt, and at a temperature of 285-300 ° C, the glycolysis reaction with the waste PET melt is carried out. The PET macromolecular chain is broken into small molecular chains, and then the ethylene glycol is removed by vacuum, and the small molecular chain of PET is repolymerized to form a macromolecular chain PET melt.

It should be noted that the PET small molecular chain repolymerizes to form a macromolecular chain PET melt, and the molecular chain size of the macromolecular chain PET melt can be controlled by the temperature of repolymerization and the residence time of the melt, depending on the different spunbond. The properties required for the woven material are not specifically limited herein. In one implementation of the present application, the macromolecular chain PET melt formed by repolymerization may have a melt viscosity of IV=0.64±0.01, which is the same as the polyester raw material.

In a preferred embodiment of this example, the alcoholysis repolymerization of the waste PET recovery is integrated with the spunbonded PET nonwoven material, and therefore, after the waste PET melt is subjected to the alcoholysis repolymerization treatment, it is directly used. Spinning.

Preferably, in the waste PET material, the content of PVC is less than or equal to 300 ppm, and the metal content is less than Or equal to 500 ppm, the polyolefin-based impurity content is less than or equal to 300 ppm.

In addition, in order to ensure the performance of the recovered PET, in the preferred embodiment of the present application, PVC impurities, metal impurities, polyolefin impurities, and the like are limited, and these impurities may be removed by filtration or the like.

Preferably, the spinning grade waste PET material is a waste silk bubble material and/or a cloth waste bubble material.

It should be noted that the discarded PET flake sheet material and waste PET film material in the present application include, but are not limited to, mineral water bottles, juice beverage bottles, carbonated beverage bottles, oil bottles, sports beverage bottles, packaging films, plastic sheets, etc. And the spinning grade waste PET material means that the material of the spinning grade can reach the spinning grade, such as cloth broken bubble material, spinning waste bubble material and the like.

Preferably, the intrinsic viscosity of the waste PET material is from 0.40 to 0.8 [?].

Preferably, the waste PET melt has a molecular chain length of from 18,000 to 20,000 ethylene terephthalate units after the alcoholysis repolymerization treatment.

It should be noted that the structural formula of the ethylene terephthalate unit of the present application is:

Equation 1:

Preferably, before the alcoholysis repolymerization treatment, the waste PET melt is mechanically filtered to remove infusible impurities; and, during the alcoholysis repolymerization treatment, vacuum treatment is performed to remove gasification or volatilization. Organic impurities.

The other side of the application discloses a method for preparing a PET spunbonded nonwoven material by using recycled PET, wherein 100% of the raw materials of the PET spunbonded nonwoven material are all recycled PET, and the recycled PET is prepared by the method of the present application. Recycled PET.

Preferably, the waste PET material is batched, dried, melted, and the waste PET melt is pre-filtered, alcohol-depolymerized, re-polymerized and re-filtered, and then passed through a melt static mixer, spinning, air drafting, and wire-wounding. It is made into a mesh and a fiber mesh to form a PET spunbonded nonwoven material.

Among them, the waste PET material ingredient means that after the simple decomposition of the waste PET, the ingredients are prepared according to the requirements of the present application, that is, the content of the discarded PET bottle material and the waste PET film material is less than 50%, and the rest is used for spinning. Grade waste PET material. Pre-filtration is through mechanical filtration. In one implementation of the present application, secondary filtration is used to remove infusible impurities; further filtration includes vacuuming during the alcoholysis repolymerization process, and gasification or evaporation is removed. After the organic impurities, the melt entering the spinning box is filtered to ensure that the melt meets the production requirements of the spunbonded nonwoven material.

It should be noted that in this application, alcoholysis repolymerization is integrated into a production system for preparing a nonwoven material by PET spunbonding. Since the recycled PET of the present application can achieve comparable properties to the polyester raw material, it can be directly used for preparing various PET spunbonded nonwoven materials, thereby allowing the alcoholysis repolymerization and spunbond nonwoven of PET recovery. The material production systems are integrated and the finished PET and PET spunbond nonwovens are prepared directly on a single production line, eliminating the need for separate production lines.

The other side of the application also discloses a 100% PET spunbond nonwoven material prepared by using recycled PET, wherein the recycled PET is the recycled PET prepared by the waste PET recycling method of the present application.

The beneficial effects of the present application are:

The waste PET recycling method of the present application enables the prepared recycled PET to achieve comparable performance to polyester raw materials, and can meet the requirements for direct production and use of various PET spunbond nonwoven materials. The recycled PET obtained by the method of the present application can be used 100% for the preparation of the spunbonded nonwoven material without using the polyester raw material, and truly achieves high value-added utilization of waste recycling, and is environmentally friendly and has low production cost. The PET spunbonded non-woven material prepared by the recycled PET obtained by the method of the present application can meet the national standard GB/T17639-2008 of the People's Republic of China and can replace the polyester raw material.

DRAWINGS

1 is a block diagram showing a preparation flow of a PET spunbond nonwoven in the embodiment of the present application;

2 is a block diagram of an alcoholysis repolymerization process of waste PET material in PET recycling in the examples of the present application.

detailed description

At present, more than 80% of waste PET materials are beverage bottles. The inventors of the present application have found through long-term research and practice that 1-2% of isophthalic acid, abbreviated IPA, is added to PET sections of beverage bottles. PET is a copolyester, abbreviated as COPET; therefore, the content of the discarded PET flake material and the waste PET film material in the present application is less than 50%, in fact, the content of the copolyester COPET is less than 50%. The purpose of adding isophthalic acid to the beverage bottle is to reduce the crystallization rate of the PET melt and the size of the crystal during the injection-blowing process for producing the bottle to ensure good transparency of the bottle. In the production of fibers, in order to ensure the good physical properties of the monofilament, it is necessary to ensure that the monofilament has a high crystallization rate, high crystallinity and large crystal nucleus size; if short fibers (abbreviation SF) and filaments (abbreviations POY and FDY) are produced Since the spinning speed is lower than 3200 m/min, the macromolecules in the original yarn are only finished in orientation, and the crystallization and setting processes are completed in the post-processing. Therefore, recycled PET flakes can be used to produce recycled PET staple fibers and Filament. The PET spunbonded nonwoven material is produced by air drafting at a speed of more than 4500 m/min. The orientation, crystallization and shaping of the macromolecules are completed in one time; therefore, the recycled PET cannot be directly used for the preparation of spunbond nonwovens. The material needs to be mixed with some polyester raw materials. And waste PET materials, there are A spinning grade PET waste material, such as waste silk or cloth shreds, which is itself a waste material in the production of non-woven materials or in the production of spinning, or a waste non-woven product, in which the PET chips are homopolymerized. Ester with good crystallization rate, crystallinity and nucleation size.

Based on the above research and knowledge, the present application creatively proposes, after classifying the waste PET material, mixing the waste PET flake material and the waste PET film material with the spinning grade waste PET material in an amount of less than 50%. The recovered PET prepared by the alcoholysis repolymerization can effectively raise the content of the homopolymerized PET in the melt to balance the crystallization rate, crystallinity and nucleation size in the spinning process, thereby making the prepared PET spunbond. Nonwoven materials can reach national standards. The recycled PET obtained by the waste PET recycling method of the present application can replace the polyester raw material, and 100% is used for preparing the PET spunbond nonwoven material, that is, 100% of the prepared PET spunbonded nonwoven material. In order to recycle PET, the high value-added production and utilization of recycled PET is truly realized. This is environmentally friendly and cost-effective. The carbon footprint of the product is about 60-70% lower than that of polyester raw materials, and it is in line with the development concept of circular economy, comprehensive utilization of resources and low-carbon environmental protection advocated by the state.

In the present application, PET is an abbreviation for polyethylene terephthalate, and polyethylene terephthalate is also referred to as polyester. PVC is an abbreviation for polyvinyl chloride. Intrinsic viscosity is the most commonly used expression for the viscosity of a polymer solution; it is defined as the reduced viscosity when the concentration of the polymer solution approaches zero; that is, the contribution of a single molecule to the viscosity of the solution is the viscosity that reflects the properties of the polymer. Does not change with concentration; often expressed as [η], the commonly used unit is deciliter / gram. Ppm is the concentration unit, 1 ppg = 1 mg/kg. IV is an abbreviation for viscosity.

The present application will be further described in detail below by way of specific embodiments and the accompanying drawings. The following examples are only intended to further illustrate the present application and are not to be construed as limiting the invention.

Example

In this example, recycled PET is directly used to prepare a spunbonded nonwoven material, and therefore, the alcoholysis repolymerization in the waste PET recovery process is integrated into a production system of a spunbonded nonwoven material. The whole waste PET recycling method is shown in Figure 1, including waste PET material batching, feeding, vibrating screen material, conveying, continuous drying, melting, pre-filtration, alcoholysis repolymerization and re-filtration, static mixer, melting Body booster pump, metering pump, spinning, air drafting, pendulum forming, product shaping, etc. It also includes post-processing steps such as trimming, rolling, packaging, and so on. Among them, before the waste PET material is melted, color masterbatch or additive may be added. Of course, the masterbatch or the additive also needs to be dried and metered beforehand, and then added to the waste PET material to be melted together; The net machine is completed and the product is set by needle punching/hot rolling. Finally, after trimming and winding, it usually includes the inspection of the quality of the finished product. After passing the test, it can enter the subsequent production. The standard of inspection refers to the existing production.

The waste PET material in this example, the waste PET material after cleaning or the waste PET material after granulation treatment, according to requirements, the content of discarded PET bottle material and waste PET film material is less than 50%, and the rest is spinning grade. Discard the PET material, mix the various waste PET materials, and then dry and melt. As for the cleaning and training of waste PET materials, reference can be made to the existing waste PET recycling method. After continuous drying, the melt, pre-filtration and alcoholysis repolymerization can be carried out in the alcoholysis repolymerization system; static mixer, melt booster pump, metering pump, spinning, air drafting, pendulum The preparation process and conditions of the spunbonded nonwoven material of the existing polyester raw material can be referred to the forming of the net, the product setting and the subsequent trimming, rolling, packaging and the like.

In this case, the waste PET material ingredients, after the waste PET material has been refined and cleaned, the quality requirements of the raw materials are: PVC content ≤300ppm, aluminum and other metal content ≤500ppm, polyolefin impurity content ≤300ppm, ash content <0.2%, Intrinsic viscosity 0.40-0.8 [η]. Mix the required waste PET material. The mixed ingredients of this example contained 49% by weight of the beverage bottle and 51% of the waste silk bubble material.

The drying system used in the continuous drying of this example is a drying capacity of a special continuous material drying system for waste PET materials of 800 kg/hr; including: 1) vibrating screen material: removing dust in the raw material and reducing the generation of aggregated particles in the spinning melt. The quality of the spinning melt is ensured, and the vibration frequency of the vibrating screen material is 20-45 times/min, and the specific example is 45 times/min. 2) Pre-drying: By pre-drying the raw materials at a low temperature, the moisture content of the raw materials entering the drying system can be made close to each batch, and in this example, it is dried at 120 ° C for 4 hours. 3) Drying: The pre-dried raw materials are placed in a vacuum filling tower for drying and water removal. Drying temperature: 140 ° C ~ 160 ° C, drying time 8 ~ 10 hours, after drying is completed, the moisture content of the raw material is less than ≤ 80ppm. This example was specifically dried at 160 ° C for 8 hours, and the resulting waste PET material had a moisture content of about 65 ppm.

After the drying is completed, the waste PET material is sent to a screw extruder and melt extruded. The screw extruder used in this example has a packing density of 45-50% lower than that of the original PET chip, that is, the polyester raw material. In order to increase the melt extrusion amount of the waste PET material, a diameter of 170 mm is specially designed. Deep-slot screw extruder ensures that the amount of glue supplied reaches 800kg/hr. In addition, considering the production of higher quality spunbond nonwovens, the original PET spinning grade chips, ie polyester raw materials, will be used. In this example, a polyester original slice is also used on the screw extruder with a diameter of 170 mm. Screw and screw sleeve can also supply 800kg/hr; it is easy to change when converting raw materials to meet the production needs, and ensure the same production efficiency when using different raw materials.

After the waste PET material is melted, the melt of this example is pre-filtered, and the molten waste PET melt is filtered by the second-stage filtration method. The first-stage pre-filtration precision is less than 100 μm, and the second-stage fine filtration precision is less than 40 μm. The replacement period of the spinning assembly is guaranteed to be more than 20 days, thereby solving the fluctuation of the product quality and the increase of the unit consumption due to the excessive pressure rise of the spinning assembly.

In one implementation of this example, the alcoholysis repolymerized material is in the process of a screw extruder It is added, and the alcoholysis repolymerization treatment is carried out simultaneously with the melt pre-filtration and the melt re-filtration. The process of the alcoholysis repolymerization process is as shown in Fig. 2. After the waste PET material is melted, the initial filtration is first performed to remove the mechanical impurities which are not melted, and then enter the alcoholysis repolymerization zone under the control of the control system and the heating system. Integral reaction, usually, a heating aid, such as ethylene glycol, is required before the integration reaction, although ethylene glycol can also be added during the extrusion melting process or added before the initial filtration, after the integration reaction, according to In the online control system of melt quality, additives can be added during the melt transport to achieve the desired viscosity. At the same time, during the melt transport, the volatilization is carried out by condensation and vacuuming. Or the evaporated organic impurities are removed, and finally the alcoholysis repolymerized product is subjected to final filtration to remove the agglomerated particles therein, and then subjected to melt distribution and static mixing, and then enters into a spinning box for spinning.

Specifically, the alcoholysis repolymerization treatment method comprises adding 2-10% by weight of ethylene glycol (abbreviated as MEG) according to the viscosity of the waste PET material during the process of feeding the waste PET material into the screw extruder. The waste PET material is subjected to alcoholysis reaction with MEG during melt extrusion at 285-300 ° C, and the PET macromolecular chains of different lengths are disorderly broken into small molecular chains of different lengths. Specifically, in this example, the MEG amount is 10%, and the melt extrusion temperature is 300 °C. The waste PET melt is firstly passed through 2-3 filters, ie, the melt is pre-filtered, the filtration area is greater than 7 m ² , the filtration precision is coarse and fine, and the filter mesh is reduced from 250 mesh to 100 mesh to remove mechanical impurities in the melt. Then, the melt is sent to the front stage of the alcoholysis repolymerization reactor through a booster pump. At a reaction temperature of 250-260 ° C, on the one hand, the PET and MEG continue to react and are broken into shorter molecular chains while being mixed in the melt. Organic impurities, such as olefins such as PVC, polyethylene, and polypropylene, are vaporized and volatilized at such high temperatures and pumped out of the reaction vessel by a vacuum pump above the reaction vessel to increase the purity of the melt. When the melt enters the latter stage in the reactor, excess MEG and moisture are continuously withdrawn from the reactor by a vacuum pump, at which time the small molecular chains interrupted by the MEG are repolymerized. The viscosity of the melt (abbreviation IV) depends on the requirements of different products of the spunbonded nonwoven material, and can be adjusted by the residence time and reaction temperature of the melt in the reactor; the general residence time is about 40-60 minutes, the temperature Between 270-290 ° C. Specifically, in this example, it was repolymerized in the latter stage of the reactor for 60 minutes at a temperature of 290 °C. Then, the melt passes through the outlet filter of the reaction vessel, the filtration area is 6.5 m ² , and the filtration precision is 50 mesh; the melt pressure is adjusted to the pressure required for spinning by the melt boosting pump, and then sent to the spinning box, and the spinning is generally performed. The required pressure of the wire is greater than 100KG.

It should be noted that even completely pure bottle flakes are inherently different from fiber-grade slicing, which contain special isophthalic acid, diethylene glycol, toner, heat stabilizer and even trace dyes with different melting points. Characteristics such as rheology, crystallinity, tensile strength, and fracture, which cause differences in polymerization and spinning processes. The original sources of waste PET materials used in this example are different, such as mineral water bottles, juice beverage bottles, carbonated beverage bottles, oil bottles, sports beverage bottles, cloth foam materials, spinning waste materials and packaging waste. , each material has different composition and quality indicators, especially some bottle factories are even themselves Recycled bottles leave the factory and have experienced different thermal history, especially in terms of viscosity. At the same time, different parts of each bottle are not necessarily 100% PET components, such as bottle caps, labels, bottle holders, bottle handles, adhesives, etc. According to the current traditional technology, it is necessary to completely separate by physical technology. Cost, and the intrinsic quality indicator cannot be changed. Therefore, this example employs a method of controlling the components of the waste PET material, and the alcoholysis repolymerization reaction is incorporated into the production process of the spunbonded nonwoven material, so that the recycled PET material can meet the production requirements of the spunbonded nonwoven material.

The alcoholysis repolymerization system of this example relies on an alcoholysis repolymerization reactor to properly depolymerize the polyester melt into a short chain by a controlled alcoholysis technique, and then repolymerize to a molecular chain of the desired length for the production process. Reversible equilibrium reaction of polyester is used to convert waste PET from different sources into a considerable molecular chain length, and then repolymerize according to the probability of collision to obtain a macromolecular chain, which has fundamentally improved both structural uniformity and uniformity of polymerization degree. The viscosity, molecular weight distribution and melting point are changed from the microscopic molecular chain structure to improve the quality of the melt; the residence time and reaction temperature of the melt in the reactor are controlled by an automatic viscosity control system, and the melt viscosity is controlled at The level of IV = 0.64 ± 0.01, which is the same as the native spinning grade PET section, ie the polyester raw material, ensures that the melt does not break during high-speed air drafting. Relying on the alcoholysis repolymerization reactor, the waste PET of different viscosities entering the reactor is subjected to alcoholysis repolymerization to control the length distribution of the molecular chain from 18,000 to 20,000 ethylene terephthalate according to different production requirements. Between the ester units, the quality of the product after drafting, laying and acupuncture or enthalpy is ensured, so that the finally prepared spunbonded non-woven material products reach the national standard level.

The static mixer of this example uniformly mixes the melt in the pipe and is then used for spinning. In this example, the spinning, air drafting, pendulum forming, product setting, trimming, rolling, and packaging. Reference is made to the preparation of conventional spunbond nonwoven materials. Among them, the product can be selected by needle punching, hot rolling and calendering. In this case, the needle punching process is adopted.

It should be noted that the recycled PET melt of this example can basically achieve the properties of the polyester raw material, and therefore, the subsequent spinning air flow drafting, pendulum forming, product setting, trimming, rolling, packaging, etc. Reference is made to the preparation process and conditions of a spunbond nonwoven material of a conventional polyester virgin material.

The equipment used in this example includes wet PET waste conveyor, PET waste crystal dryer, raw material conveyor, screw masterbatch with simple crystal drying or additive metering and mixing device, spinning machine, air drafting device, pendulum Wire machine, laying machine, pre-needle machine, main needle machine, double roll ironing machine, tension storage rack and automatic slitting and winding machine.

The wet PET waste conveyor of this example adopts the positive pressure airflow conveying mode of the Roots blower, the wet PET waste conveyor model LC-30, the conveying capacity of 3000Kg/hr, and the fan power of 11kw.

In this example, the PET waste crystallization and drying machine adopts a fluidized bed crystallizer, a plunger type main drying tower, and compressed air as a drying medium; the micro-heat regenerative molecular sieve dehumidification system is used for dehumidification; considering the production may use bottle flakes, phase Comparing the polyester chips, the processing capacity of the crystallizer and the drying tower must be increased due to the small packing density of the bottle pieces, and the structure of the equipment is improved accordingly. The diameter of the blanking pipe is increased, which is suitable for crystallization and drying of the bottle pieces to prevent the occurrence of the chips. Agglomeration, runaway and bridging. This example of PET waste crystallization, dryer model FBM-1000, drying capacity 1000kg / hr, residence time 3-5hr, water content <100ppm, compressed air consumption 10Nm ³ /min, compressed air pressure > 7bar, installed capacity 180Kw .

The raw material conveyor of this example adopts a positive pressure airflow conveying mode, and the conveying medium is compressed air after dehumidification. The material conveyor model MC310C-10G has a conveying capacity of 2t/hr and a conveying air volume of 1.7Nm ³ /min.

The screw type masterbatch or additive metering and mixing device with simple crystal drying in this example adopts screw type masterbatch or additive measuring machine, and the control precision can reach 1/100. The upper part of the screw measuring machine is equipped with a storage bin with simple mechanical stirring and air heating circulation system, and has the functions of pre-crystallizing and drying of the masterbatch. Among them, the storage bin size is 250L, the stirring speed is 2.8r/min, the stirring motor power is 0.37kw, the fan power is 0.37kw, the heating power is 9kw, the screw/sleeve size is 15/22, and the measuring machine motor power is 0.37kw.

The spinning machine of this example adopts a spunbond special spinning machine, which is suitable for producing polyester spunbonded non-woven products. The spinning machine is equipped with a double-die double-side spinning box. The spinning assembly is a circular top-loading type. The whole system uses biphenyl steam insulation, and the metering pump transmission is independent variable frequency control; all temperature control, transmission control and pressure The control is integrated into the programmable logic control central control system, abbreviated PLC central control system, to achieve precise control, through the touch screen to achieve the setting and display of operating parameters. Spinning machine model HYFN-III-6150-128/2, screw extruder specifications

Heating power 110Kw, transmission power 180Kw, melt filter filtration accuracy 45μ, biphenyl steam generator power 80Kw, metering pump specifications 3.0cc/rev×2outlet, 3.0cc/rev×4outlet, 3.0cc/rev×8outlet, metering pump Transmission power 1.0Kw/pc, component type: round, top-loading, number of holes in the spinneret 36, number of rows of spinning 2, cooling using horizontal blowing, horizontal cooling, blowing length 1200mm, suction device 16 sets / production line , located on the side of the drafter, used for sucking the silk.

The air drafting device of this example is of type HYQLQ-III-6150-128/2, the drafting speed is >4800 m/min, the drafting pressure is 5.0-6.0 bar, and the drafting pressure automatic adjusting device PLC is used.

The wire oscillating machine of this example adopts a special spinning machine for spunbond, which is suitable for producing polyester spunbonded non-woven products. The spinning machine is equipped with a double-die double-side spinning box. The spinning assembly is a circular top-loading type. The whole system uses biphenyl steam insulation, and the metering pump transmission is independent variable frequency control; all temperature control, transmission control and pressure The control is integrated into the PLC central control system to achieve precise control, and the setting and display of operating parameters are realized through the touch screen. Pendulum machine model HYFN-III-6150-128/2, screw extruder specifications

L/D=28, heating power 110Kw, transmission power 180Kw, melt filter filtration accuracy 45μ, biphenyl steam generator power 80Kw, metering pump specification 3.0cc/rev×2outlet, 3.0cc/rev×4outlet, 3.0cc/ Rev×8outlet, metering pump transmission power 1.0Kw/pc, component type is round, top-loading type, spinneret hole number 36, spinning row number 2 rows, cooling form is horizontal blowing, horizontal cooling type, blowing length 1200mm, suction The wire device is a 16 set/production line located on the side of the drafter for the suction head.

The laying machine of this example consists of mesh curtain, mesh curtain transmission and its control system, mesh curtain deviation correction, mesh curtain support bracket, double suction zone, suction duct, static elimination device, pre-pressure roller and its transmission device, machine Frame and other components. The laying machine drive and the pre-pressing roller adopt frequency conversion speed regulation, and the closed-loop speed control system is regulated. The pre-pressing roller is heated by oil, the maximum surface temperature is 180 °C, and the temperature difference is ±2 °C. The transmission and temperature control control system of the paving machine is integrated into the PLC central control system for precise control, and realizes synchronous linkage with the pre-needling machine, the main needle-punching machine, the tension storage rack and the trimming and winding machine. The operation parameter setting and display are realized by the touch screen. The paving machine model HYPW-III-6150, the product range is 50-700g/m ² , the maximum width of the product is 4000-7000mm, the production speed is 2-12m/min, the driving power of the paving machine is 15Kw, the driving power of the pre-pressing roller is 4Kw, The pre-pressing roller has a heating power of 60 Kw.

The pre-needling machine of this example adopts PET high-speed needle-punching machine for spunbonding, thorn-type stab, double-axis single-needle or double-axis double-needle plate structure, spindle and cloth roller are driven by variable frequency motor, frequency control . The control execution system is integrated into the PLC central control system, and the PLC system is used for precise control to realize the synchronous linkage with the laying machine, the tension storage rack and the trimming and winding machine. The operation parameter setting and display are realized by the touch screen. Pre-needle machine model YYGZ-III-700, product range 100-900g/m ² , machine width 4500-500mm, cloth needle width 6900mm, cloth needle density 2500 pieces / m, needle board size 1150 × 300mm × 6 pieces, It is a double-axis single-needle plate structure with a needle-punching stroke of 40mm, a mechanical needling frequency of Max 1100n/min, a needle punching frequency of Max900n/min, and a production speed of 2-12m/min.

The main acupuncture machine of this example adopts PET high-speed needle punching machine for spinning and spunbonding, barbed barb, double-axis single-needle plate or double-axis double-needle plate structure. The spindle and the output roller are driven by variable frequency motor. . The control execution system is integrated into the PLC central control system, and the PLC system is used for precise control to realize the synchronous linkage with the laying machine, the tension storage rack and the trimming and winding machine. The operation parameter setting and display are realized by the touch screen. Main needle machine model YYGZ-III-700S, product range 100-900g/m ² , machine width 7500mm, cloth needle width 6900mm, cloth needle density 3000 pieces / m, needle board size 1150 × 300mm × 6 pieces, double Shaft single needle plate structure, 30mm acupuncture maneuvering range, mechanical needle punching frequency Max 1100n/min, production needle punching frequency Max 900n/min, production speed 2-12m/min.

The double roll ironing machine of this example is composed of a hot stamping roller, a transmission system, a pneumatic lifting adjustment system, a hot oil heating system, a transmission cooling lubrication system and a frame. The hot stamping temperature is automatically controlled by temperature, and is heated by a hot oil system circulating oil. The double roller gap is adjustable, the cloth is passed through the double roller S-type, the transmission is controlled separately, and the frequency conversion is adopted. The control execution system is integrated into the PLC system, and is precisely controlled by the PLC system, and realizes synchronous linkage with the network forming machine, the needle punching machine and the winding machine, and the setting and display of the operating parameters are realized by the touch screen. The ironing machine is capable of controlling the thickness of the cloth surface, reducing the bulkiness of the cloth surface, and reducing the winding diameter as long as it is subjected to hot pressing or calendering of the needle punching cloth. The demand side is selected according to the production needs. The product range of double roller ironing machine is 100-900g/m ² , the specification of hot stamping roller is Φ550×6400mm, the production speed is 2-12m/min, the maximum working temperature is 250°C, the interval of hot stamping roller is adjustable from 0-10mm, hot oil circulation Pump motor power 11kw, roll motor power 11Kw × 2, heating power 75Kw.

The tension storage rack of this example is YYCB-700, the product range is 100-700g/m ² , and the structure is the balance weight tension storage structure, the diameter of the storage roller

The storage capacity is >40m.

The automatic slitting and winding machine of this example adopts double-roller friction winding, the cylinder presses the disc-shaped knife to cut the edge, and the electric disc cutter cuts and cuts. The package is frictionally driven by a double friction roller. The friction roller is driven and regulated by a variable frequency motor, and has a friction wheel type electronic length measuring device. The control execution system is integrated into the PLC central control system, and the PLC system is used for precise control to realize the synchronous linkage with the paving machine and the needle punching machine. The setting and display of the operating parameters are realized by the touch screen. Automatic slitting and winding machine model YYXT-700A, product range 100-900g/m ² , product width 4000-6000mm, production speed 2-12m/min, maximum package diameter

Winding shaft diameter

The transmission power is 5.5kw, and the longitudinal cutter disk electric cutter is configured according to the product requirements.

Using the above apparatus, according to the method of the present example, the intrinsic viscosity of the waste PET melt is controlled to be between 0.40 and 0.8 [η], and the intrinsic viscosity of the melt entering the spinning box is between 0.64 ± 0.01 [η], Examples of spunbonded nonwoven materials having a basis weight of 100 g/m ² , 200 g/m ² , 300 g/m ² , 400 g/m ² and 500 g/m ² , respectively, and a spunbonded nonwoven material 100 % was prepared entirely from the waste PET material recovered in this example. In addition, five thin spunbonded nonwoven materials were prepared, respectively, and the five thin products had gram weights of 10 g/m ² , 20 g/m ² , 40 g/m ² , 65 g/m ² and 80, respectively. g/m ² .

The performance of the above ten types of spunbonded nonwoven materials was tested by the measurement method of the national standard GB/T17639-2008, and the test results were compared with the corresponding standards in the national standard GB/T17639-2008. The test and comparison results are shown in Tables 1 and 2.

Table 1 Comparison of spunbonded nonwoven materials prepared in this example with national standards

In Table 1, the national standard 1 is the national standard 100 g/m ² spunbonded non-woven material, the national standard 2 is the national standard 200 g/m ² spunbonded non-woven material, and the national standard 3 is the national standard 300 g/m ² spunbond non-woven material. The material, national standard 4 is a national standard 400 g/m ² spunbonded non-woven material, the national standard 5 is a national standard 500 g/m ² spunbonded non-woven material, and the product 1 is a 100 g/m ² spunbond non-woven material prepared in this example. Woven material, product 2 is a 200 g/m ² spunbonded nonwoven material prepared in this example, product 3 is a 300 g/m ² spunbonded nonwoven material prepared in this example, and product 4 is 400 g prepared in this example. /m ² spunbonded nonwoven, product 5 A 500 g/m ² spunbond nonwoven prepared in this example. Test 1 is the mass deviation per unit area, the unit is %; 2 is the thickness, the unit is mm; 3 is the amplitude deviation, the unit is %; 4 is the breaking strength, the unit is Kn/m; 5 is the elongation at break, the unit is %; 6 is CBR Burst strength, unit KN; 7 is the equivalent aperture O90 (abbreviation O95) mm; 8 is the vertical permeability coefficient, the unit cm / s; 9 is the tear strength. Among them, the breaking strength and the tearing strength are both vertical and horizontal, and the CBR breaking strength refers to the breaking strength measured by the CBR tester.

Table 2 Comparison of thin spunbond nonwovens of this example with national standards

In Table 2, the national standard 6 is a national standard 10 g/m ² spunbonded non-woven material, the national standard 7 is a national standard 20 g/m ² spunbonded non-woven material, and the national standard 8 is a national standard 40 g/m ² spunbond non-woven fabric. The material, national standard 9 is the national standard 65 g/m ² spunbonded non-woven material, the national standard 10 is the national standard 80 g/m ² spunbonded non-woven material, and the product 6 is a spun-bonded non-woven fabric of 10 g/m ² prepared in this example. Woven material, product 7 is a 20 g/m ² spunbonded nonwoven material prepared in this example, product 8 is a 40 g/m ² spunbonded nonwoven material prepared in this example, and product 9 is 65 g prepared in this example. The spunbonded nonwoven material of /m ² , product 10 was a spunbonded nonwoven material of 80 g/m ² prepared in this example.

The results of Table 1 and Table 2 show that the ten types of spunbonded nonwoven materials prepared in this example can meet the corresponding types of spunbonded nonwoven materials in the national standard; some performance indicators, such as breaking strength and CBR breakage Strong, the spunbonded nonwovens prepared in this case are even better than the national standard. It can be seen that the waste PET material recovered in this example can replace the polyester raw material for preparing various types of spunbonded nonwoven materials.

It should be noted that although the PET waste recovered in this example can achieve the properties of the polyester raw material and replace the polyester raw material for production; however, in some cases where the performance of the spunbonded nonwoven material is higher, it still needs to be used. Higher quality polyester raw materials are not specifically limited herein.

The above content is a further detailed description of the present application in conjunction with the specific embodiments, and the specific implementation of the present application is not limited to the description. It will be apparent to those skilled in the art that the present invention can be made in the form of the present invention without departing from the scope of the present invention.

Claims

The invention relates to a method for recycling and recycling waste PET, which comprises: after melting the waste PET material, performing alcoholysis repolymerization treatment on the waste PET melt before spinning the melt, and then using alcoholysis repolymerization. The product is spun; and, in the waste PET material, the content of the discarded PET flake material and the waste PET film material is less than 50%, and the balance is a spun-grade waste PET material.
The method according to claim 1, wherein said alcoholysis repolymerization treatment comprises adding a total weight of 2 to 10% of ethylene glycol to the waste PET melt at a temperature of 285 to 300 ° C, The alcohol reacts with the waste PET melt, and the PET macromolecular chain is broken into small molecular chains, and then the ethylene glycol is vacuum extracted, and the small molecular chain of PET is re-polymerized to form a macromolecular chain PET melt.
The method according to claim 1, wherein the waste PET material has a PVC content of less than or equal to 300 ppm, a metal content of less than or equal to 500 ppm, and a polyolefin-based impurity content of less than or equal to 300 ppm.
The method of claim 1 wherein said spun grade waste PET material is waste silk foam and/or cloth foam.
The method of claim 1 wherein said waste PET material has an intrinsic viscosity of from 0.40 to 0.8 [η].
The method according to claim 1, wherein the waste PET melt has a molecular chain length of from 18,000 to 20,000 ethylene terephthalate units after the alcoholysis repolymerization treatment.
The method according to any one of claims 1 to 6, wherein the waste PET melt is mechanically filtered to remove infusible impurities before the alcoholysis repolymerization treatment; and, in the alcoholysis During the polymerization process, vacuum treatment is performed to remove vaporized or volatilized organic impurities.
A method for preparing a PET spunbonded nonwoven material by using recycled PET, characterized in that: 100% of the raw materials of the PET spunbonded nonwoven material are all recycled PET, and the recycled PET is used in any one of claims 1-7. Prepared by the method described.
The method of claim 8 including waste PET material furnishing, drying, melting, pre-filtration, alcoholysis repolymerization and re-filtration, followed by melt static mixer, spinning, air drafting, The wire spun yarn and the web are reinforced to form the PET spunbond nonwoven material.
A 100% spunbonded nonwoven material prepared from recycled PET, characterized in that the recycled PET is prepared by the method of any one of claims 1-7.