KR100783523B1 - Fabrication method of cellular plastic substances and a equipment for that - Google Patents

Abstract

A method of manufacturing cellular plastic substances and a manufacturing apparatus thereof are provided to improve strength and allow molding to be easily carried out by using a mixture resin of polypropylene and polyethylene as a material of media. A method of manufacturing cellular plastic substances includes a first step of mixing thermoplastic material, talc, foam agent, and an evaporation material; a second step of melting the mixture and transmitting the molten mixture to a die; a third step of extruding the molten material into a semi-product having a predetermined cross section; a fourth step of cooling the semi-product; and a fifth step of cutting the cooled semi-product into a predetermined length.

Description

Fabrication Method of Synthetic Resin Molded Product Having Porous Open Cell and Manufacturing Method Thereof {Fabrication Method of Cellular Plastic Substances and a Equipment for That}

1 is a drawing of the apparatus for producing a synthetic resin molding according to the present invention.

2 is a real photograph of a compact molding.

3 is a real picture of a large molding.

4 is a surface micrograph of the molding.

5 is a longitudinal cross-sectional micrograph of the molding.

6 is a cross-sectional micrograph of a molding.

※ Important Component Number

10: hopper, 20: mixer, 30: feed screw, 40: dice,

50: blower, 60: water tank, 70: cutter, 80: motor, 90: controller.

The present invention relates to a method for molding a synthetic resin and a device thereof, and more particularly, to a method and a device for molding a porous synthetic resin product having a rough surface and a pore connected to each other therein.

Such porous synthetic resin products are used for a special purpose, one of which is a microorganism carrier (Media) used in biological treatment process applied to treat contaminated wastewater or sewage.

Waste water or plant waste treatment processes consist mainly of three stages, the first of which is the process of filtering, cutting or sedimenting suspended solids. The next step is chemical treatment, which removes contaminants or heavy metals through various chemical reactions, adjusts pH, and removes colloidal contaminants by flocculants. And, the final step is the exaggeration of the decomposition and removal of organic matter by the metabolism and degradation of microorganisms as a biological treatment process.

There are several types of biological treatments using microorganisms in wastewater treatment plants. The most commonly used method is activated sludge. This is a method of decomposing contaminants in a state in which microorganisms contributing to the contaminant are not fixed at a part but suspended in the waste water. At this time, the microorganisms are well attached to the stationary phase, so the microorganisms attach to and use an object, which is called a carrier (Media). When a carrier is used for food waste treatment, a large amount of microorganisms are attached to the carrier to increase the decomposition efficiency of contaminants. Therefore, many studies have been conducted on biological treatment processes for activated sludge methods using a carrier.

Natural carriers such as chaff, sawdust, or waste tires, yogurt bottles, yarns, or the like were used as carriers for this purpose, and carriers having a certain shape made of ordinary plastic were used. However, all of these carriers have a dense surface and cannot inhabit many microorganisms, thus limiting the sewage treatment capacity.

Accordingly, in recent years, in order to increase the amount of microorganisms, many studies have been made and patents have been applied to artificial carriers using various porous materials.

Representatively, Heo Sung et al., Department of Advanced Plastics Engineering, Inje University, developed a biofilm carrier for wastewater treatment using discarded oyster shells. Korean Utility Model Registration No. 20-0362634 "Medium for advanced treatment of sewage and sewage and wastewater" suggests a carrier mixed with waste vinyl fluff, masato, rice straw and the like. In addition, Korean Patent Registration No. 10-0313240, "Method of preparing a filler for wastewater treatment and its filler", suggests a carrier prepared by pulverizing ceramic, kaolin, activated carbon, and clam bark.

However, since the wastewater treatment carriers all use natural materials, it is difficult to mass produce, high cost of products, complicated processes, large facilities, and wastes in the manufacturing process. have. In addition, it is also a big problem to dispose of a carrier which has been used sufficiently and has a poor treatment capacity.

In addition to the porous natural material carrier as described above, a carrier molded of a porous synthetic resin can be considered. Such a carrier has a rough surface, so that the microorganisms are easily adsorbed, and the inside of the material is porous so that the microorganism can inhabit a large amount. It should be able to move microorganism and organic substance to be decomposed well by having open cell structure, which is a structure in which pores of each other are connected to each other.

Until now, there are many known methods for molding porous synthetic resin products having a closed cell structure as a thick plate or a relatively large volume, but the porous synthetic resin products having a thin and small open cell structure, such as a carrier, can be easily The method of molding is unknown.

As described above, the conventional carriers have problems in the treatment of food waste or livestock wastewater containing a large amount of organic substances, and thus, a carrier having a high porosity and high microbial habitat density has a high capacity for treating organic substances. As a carrier that satisfies these requirements, a porous synthetic resin molding having an open cell structure is required.

In addition, the porous synthetic resin molded article of the above purpose, as a simple equipment, at a low production cost, should be capable of mass production.

The present invention relates to a method for producing a synthetic resin molded article having a porous open cell and a manufacturing apparatus thereof, and to a method for producing a synthetic resin molded article satisfying the above requirements and a manufacturing apparatus required therefor.

The present invention provides a method of manufacturing a synthetic resin molded article having a porous open cell, and a manufacturing apparatus thereof, by foaming a plastic-based polymer material into an open cell (open cell, which refers to pores connected to each other). It is a method of making a specific surface area large and making the surface rough, and a manufacturing apparatus required for this.

As the raw material used in the present invention, all kinds of plastic-based polymer materials may be used, but it is preferable to use a material that is easy to manufacture and generates less pollutants during incineration after use. Among them, resins such as polyethylene (PE) and polypropylene (PP), which are olefin resins, are suitable as carrier materials as eco-friendly materials which hardly generate soot upon incineration.

Polypropylene has a high strength of the material, but has a problem of brittleness because of its brittleness, and the polyethylene is good in toughness, so the product is stable, but molding is difficult. Difficult to make Therefore, when mixed with polypropylene and polyethylene, the strength is excellent and the molding operation is easy. As a result of the experiment, it was found that a resin (hereinafter referred to as "mixed resin") in which 25% polyethylene and 75% polypropylene were mixed in weight ratio was excellent in strength and easy in molding.

 To roughen the surface of the product, a small amount of talc (also called Tarc, talc powder or stone powder) is added to the mixed resin. As a result, when mixing the talc of 0.3% by weight of the weight of the mixed resin, the surface was found to have a suitable roughness for use as a carrier.

In order to form a plurality of bubbles inside the carrier material, a foaming agent is added to the material to be molded. This blowing agent creates a number of bubbles during the forming process to form pores inside the material. Increasing the amount of blowing agent increases the porosity, decreasing the porosity decreases. For the preparation of the carrier of the present invention, it is most suitable to add a blowing agent of 0.5% by weight of the mixed resin.

The pores thus formed are closed cells, each of which is a spherical independent pore, and are not suitable for use in food or waste water treatment carriers because microorganisms and organic substances to be degraded cannot penetrate the pores. There are a number of ways of forming open cells by connecting the waste holes to each other, but a small amount of evaporation material may be added to the mixture of the mixed resin and the additive to form the open cell. In this case, the evaporation material is evaporated to form a gas in the forming process, and the gas is discharged while passing through the pores formed by the blowing agent while being discharged to the outside of the material, so that the pores are connected to each other to form an open cell. As evaporation materials, evaporable liquids such as water (H ₂ 0) and alcohols and sublimable solids such as naphthalene can be considered, but water is the cheapest, easily procurable, safe, and handled. This is most suitable because it is easy and does not generate pollutants or harmful gas components in the manufacturing process. As the amount of water, 0.2% of the weight of the mixed resin was found to be appropriate.

The term specific surface area is used to indicate the degree of porosity of a porous material, which refers to the ratio of the actual surface area to the apparent surface area of the material, which means that the larger the specific surface area, the more pores therein. In the case of the present invention, in the case of a cylindrical carrier having a diameter of 4 mm and a height of 4 mm, its specific surface area is 1500 to 1800.

Synthetic resin molded product is manufactured as follows.

A certain amount of pellet-shaped synthetic resin material, which is a raw material, is improved in a hopper, and additives such as talc, foaming agent, and evaporation material such as water are added in an appropriate ratio, and then installed in the lower part of the hopper. Supply to mixer and feed screw.

The mixer is installed at the bottom of the hopper, and a stirrer is built into the case. This mixer is connected to the feed screw. The mixer and the conveying screw are driven by a single motor, which serves to evenly mix the raw material mixture falling from the hopper.

The feed screw extends from the groove jointer to the molding die, has a certain length, and heats the outside of the feed screw with a heater, steam, or the like during the transfer of the raw material. In this transfer process, the raw materials are melted to form a very viscous liquid, and the additives and the evaporation material are evenly mixed. When heating the feed screw around, it is better to heat it whole step by step rather than heating it to a constant temperature. At first, heat it to a low temperature, then maintain the high temperature in the middle stage, and lower the temperature back in the final stage. good. What is necessary is just to make the conveyance speed into the speed | rate so that resin may fully melt in external heating conditions.

When using the polyethylene and polypropylene as raw materials, the whole heating step is divided into four stages, 140 degrees Celsius in the first stage, 220 degrees Celsius in the second stage, 250 degrees Celsius in the third stage, and the fourth stage in the fourth stage Heating at 180 degrees was found to be the most suitable.

The melted resin mixed in the transfer and heating steps is extruded through a die that can be molded into a cross section of a desired shape. The resin that has passed through the die is a linear semi-finished product having a certain cross section and is continuously extruded through the die.

At the outlet of the die, the air is blown at room temperature with a fan to first cool the product, and the linear semi-finished product having the first cooling passes through a water bath containing cold water. The semi-finished product passing through this tank is completely cooled and fixed in shape to complete molding.

After the tank, a cutter is installed to finish the product by continuously cutting the semi-finished product on the line to a certain length. As a cutting machine, a shearing machine (shearing machine) that repeats the reciprocating motion at a constant speed may be used, or a rotary cutting machine having a blade disposed at a predetermined interval may be used.

The above manufacturing process is relatively simple and can be easily automated.

As shown in Figure 1, the manufacturing apparatus for performing the above process, the hopper 10, the mixer 20, the inlet of which is connected to the outlet of the lower hopper, the transfer screw 30 connected to the outlet of the mixer, the transfer A die 40 connected to the outlet of the screw, a blower 50 installed at the outlet of the die, a water tank 60 connected to the blower and installed at regular intervals with the die, and a cutter 70 located at the rear of the water tank. Is installed in front of the mixer, the motor 80 for driving the mixer and the feed screw, and the controller 90 for controlling the heating temperature of the feed screw portion and drives the motor.

The hopper 10 is a hopper having a general shape such as a funnel, and the inlet of the mixer is connected to a narrow outlet at the bottom of the hopper.

The mixer 20 is a mixer of a general shape in which a stirrer is installed inside the casing, and the inlet of the feed screw is connected to the outlet of the mixer. The shaft of the stirrer is easy to use by extending the feed screw shaft.

The transfer screw 30 is composed of a cylindrical outer cylinder having a heating means such as an electric heater and a steam pipe therein, and an outer diameter of the outer cylinder equal to the inner diameter of the outer cylinder, and rotating in the outer cylinder. One end of the screw is connected to the motor by a power transmission means such as a gear, a spline, a transmission chain, a reduction gear, and is driven by the motor. When the screw is rotated by the motor, the materials in the screw valley are transferred along the screw spiral. The resin materials are melted by a heated outer cylinder while the material is conveyed by the conveying screw.

The heating of the outer cylinder may be different for each part by providing independent heating means for each part of the outer cylinder, and each heating temperature is adjusted by the controller 90 provided outside. When the electric heater is used as a heating means, an electric resistance wire which is a heating wire may be embedded in the inside of the outer cylinder. When the steam heater is used as the heating means, a steam tube may be embedded in the outer cylinder and steam may be passed through a predetermined temperature.

In the case of the present invention, the resin is divided into four heating parts in the longitudinal direction of the transfer screw for producing a carrier for sewage treatment using a mixed resin of polyethylene and polypropylene, and in the first step connected to the hopper with an electric heater, 140 degrees Celsius. For example, heating at 220 degrees Celsius in the second stage, 250 degrees Celsius in the next stage, and 180 degrees Celsius in the final stage, was found to be most appropriate.

The die 40 is connected to the exit of the transfer screw, the extrusion hole of the die is produced in a desired shape, such as circular, polygonal, star shape. When the molten resin supplied to the feed screw is extruded through the die's extruder, the linear semi-finished product having the same cross section as the shape of the die's extruder is extruded continuously.

The blower 50 is installed adjacent to the outlet of the die and functions to blow air required for primary cooling of the extruded resin to the extruded product.

The water tank 60 is connected with the blower 50, and the extrudate cooled by the blower is completely cooled while passing through the water of the water tank, thereby fixing the shape of the product.

The cutter 70 is installed behind the water tank and continuously cuts the semi-finished product on the line formed through the water tank to a predetermined length to complete the product. As a cutting machine, a shearing machine (shearing machine) that repeats the reciprocating motion at a constant speed may be used, or a rotary cutting machine having a blade disposed at a predetermined interval may be used.

The motor 80 may use a general electric motor, but it may be selected to have a sufficient power to drive the mixer and the feed screw. The motor may be directly connected to the shaft of the feed screw by a coupling or the like, or may be connected to a power transmission device such as a gear or a chain or a speed reducer.

The controller 90 has various switches, switchboards, regulators, and the like therein to drive a motor, set a heating temperature for each portion of the transfer screw, supply electricity to the heating portion, and supply electricity to other necessary portions. It plays a role.

 In the process of manufacturing a porous open cell resin product using the manufacturing apparatus, the surface is roughened by the action of talc in the melting and extrusion process, bubbles are formed inside the material by the action of the blowing agent. When the material is exposed to air at atmospheric pressure through the extrusion die, the evaporated material inside the vaporized gas is discharged to the outside to form an open cell through the walls of adjacent bubbles.

The shape and size of the product can be manufactured in various sizes and shapes from a small cylindrical shape having a diameter of 2 mm and a length of 2 mm to a polygonal column shape of several tens of mm in length and tens of mm in length of the cross section, depending on the choice of the dice. In addition, in the case of a product used as a large carrier, it may be manufactured in a star-shaped cross-sectional shape with protruding edges in order to increase the surface area of the microorganism to increase the habitat area of the microorganism.

The shape of the carrier produced by the above method is the same as the photograph of FIGS. 2 and 3. 2 is a small carrier and FIG. 3 is a large carrier.

The surface micrograph of this carrier is shown in FIG. As can be seen from this photograph, it can be seen that the structure of the surface of the carrier is ruptured by talc and is in a substantially rough state.

Internal cross-sectional photographs of the carrier are shown in FIGS. 5 and 6. Figure 5 is a longitudinal cross-sectional photograph, it can be seen that the pores are connected to each other to form an open cell. Figure 6 is a cross-sectional photograph showing that a large amount of pores are formed inside the material.

Porous synthetic resin molded article produced by the present inventors manufacturing method and manufacturing method, because the surface is rough, the material is an open-cell porous material, it is suitable for use as a carrier for treating food waste or wastewater that biodegradable microorganisms can inhabit with high density Do.

When the carrier is produced using the present manufacturing method and manufacturing apparatus, the raw material is low in price, the quality of the product is constant, the product can be produced in various shapes, and the production process can be automated, allowing mass production. The manufacturing cost is low.

The manufacturing apparatus of the present invention is relatively simple in configuration, so that the production equipment cost is low.

When the mixed resin of polypropylene and polyethylene is used as a raw material of this support | carrier, it is excellent in strength and also easy to shape | mold. This carrier is recyclable and generates less soot and other air pollutants than other polymer resins during incineration.

The inventors' method of making an open cell is a very simple method of adding a small amount of water to a raw material, which is inexpensive, easy to procure, safe, easy to handle, and also has a Does not generate harmful gas components.

Claims (7)

A method for producing a porous synthetic resin molded article having an open cell structure by sequentially performing the following steps. 1st process: A compounding process which mixes fillet-shaped synthetic water support material, talc, foaming agent, and evaporation material in a predetermined ratio. 2nd process: The conveying process which melt | dissolves the blended raw material and sends it to the shaping | molding die. Third step: A molding step of extruding the molten raw material into a die to form a linear semi-finished product having a certain cross section. 4th process: Cooling process which cools the molded semi-finished product. 5th process: The process of cutting the cooled semi-finished product to predetermined length. The method of claim 1, The synthetic resin raw material of the first step is a mixture of polyethylene and polypropylene, characterized in that the evaporation material is water, A method for producing a porous synthetic resin molded article having an open cell structure. The method of claim 2, The mixing ratio of the synthetic resin of the second step is 75% polypropylene, 25% polyethylene, the weight of the talc is 0.3% of the weight of the synthetic resin mixture, the weight of the blowing agent is 0.5% of the weight of the synthetic resin mixture , The weight of the water is characterized in that the proportion of 0.2% of the weight of the synthetic resin mixture, A method for producing a porous synthetic resin molded article having an open cell structure. The method of claim 3, In the conveying process, the feed screw is divided into four parts in the longitudinal direction, and each part is heated separately, the first part is heated at 140 degrees Celsius, the next part is heated at 220 degrees Celsius, and the next part is Celsius. Heated to 250 degrees, the last part is characterized in that the transfer process is heated to 180 degrees Celsius to melt the raw material sent to the die for molding, A method for producing a porous synthetic resin molded article having an open cell structure. Funnel-shaped conventional hopper 10; Inlet is connected to the outlet of the hopper 10, the conventional mixer 20 is provided with a stirrer inside the casing; An inlet is connected to the outlet of the mixer 20, and includes a cylindrical outer cylinder having a heating means therein, which is an electric heater or a steam heater, and an outer diameter equal to the inner diameter of the outer cylinder, and including a screw rotating in the outer cylinder. A transfer screw 30; The inlet is connected to the outlet of the transfer screw 30, the extrusion port is formed in a desired shape, such as circular, polygonal, star shape, and the molten resin supplied from the transfer screw 30 is extruded through the extrusion port Dice 40; A motor (80) connected to the shaft of the feed screw (30) as driving the mixer (20) and the feed screw (30); And, provided with a switch, switchboard, regulator, etc., to supply electricity to the motor 80, to set the heating temperature for each part of the transfer screw 30, the electricity required for heating the transfer screw 30 A controller 90 for supplying the same; Comprising, comprising a porous synthetic resin molded article manufacturing apparatus of an open cell structure. The method of claim 5, The transfer screw 30 is a transfer screw incorporating an electric heater, divided into four heating portions in the longitudinal direction, each heating portion is characterized in that the transfer screw having an independent electric heater, the temperature is controlled separately. , Open cell structure made of porous synthetic resin molding. The method according to claim 5 or 6, The apparatus for producing a porous synthetic resin molded article having an open cell structure includes a cooling apparatus having an air cooling system using a blower 50 at the rear of the die 40, a water cooling system using a water tank 60, or both of the air cooling system and the water cooling system. Characterized in that it further comprises a cutting machine 70 for cutting the extrudate extruded to a predetermined length, Open cell structure made of porous synthetic resin molding.

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