JP4724521B2 - Molding method of waste plastic granulation for chemical raw materials - Google Patents

Description

  The present invention relates to a technique relating to a method for producing a granulated product produced by compression molding waste plastic for recycling as a chemical raw material. The waste plastic granulated material for chemical raw material of the present invention is used in a gasification furnace, an oilification apparatus, a coke oven, an iron blast furnace, and other chemical reaction processes.

  Polyethylene, polystyrene, vinyl chloride, and other plastics are excellent in moldability and durability, and are therefore used in a wide variety of applications such as containers, packaging, outer frames of household electrical appliances, and toys. However, as a result, a large amount of waste is discarded. Plastics generated as waste are discarded after use, such as waste plastics (hereinafter referred to as waste plastics) generated from processing processes such as uncut scraps after cutting and uncut scraps during molding. There is used recovered plastic (hereinafter referred to as used plastic).

  The generation of large amounts of plastic waste has become a major social problem, and in particular, there are significant environmental and resource problems. That is, when these waste plastics are incinerated as waste, there is a problem that the combustion temperature rises too much and damages the incinerator, and harmful gases and dioxins are generated during combustion. In particular, when landfilling used plastics, there is a problem that the soil does not solidify because the plastics do not rot other than the lifetime problem of the disposal site.

  Therefore, recycling these waste plastics is advantageous from the viewpoint of energy saving and resource saving as well as solving the above-mentioned problems, and various methods have been implemented. For example, as a method of material recycling, there is a method of using polyethylene terephthalate bottles as raw materials for plastics and fibers. In the case of chemical recycling, methods such as gasification and oil conversion are performed. Furthermore, for recycling to fuel, a method is generally used in which granulated material produced by compression molding after removing vinyl chloride is used as fuel for boilers or industrial furnaces.

  Among these, chemical recycling is an excellent recycling technique from the viewpoint of saving resources that can be used for a wide range of applications and replacing natural raw materials. Chemical recycling is a gasification method that converts to hydrogen, carbon monoxide, and other gases, an oil conversion method that converts to polymer oil, a coke oven, etc. There are blast furnace reduction methods that are used as a reducing agent.

In order to recycle waste plastic as a fuel or raw material, it is necessary to granulate after separating foreign matter. As these pretreatment methods, for example, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 8-99318), waste plastic is crushed to an appropriate size for reuse and melted. It is common practice to produce granular plastic by compression molding. The technology for melting and granulating waste plastics requires special equipment for melting, and has a problem that the gas generated during melting must be processed, compared to the compression molding method. The processing was expensive. The compression molding method has an advantage that the processing cost is low because the waste plastic is compression molded at a relatively low temperature. This plastic granular material is used in the recycling process for fuel and raw materials, and this plastic granular material can also be used for chemical recycling.
JP-A-8-99318

  As mentioned above, recycling plastic waste is an important way to address environmental and resource issues. However, waste plastics contain a mixture of inorganic foreign matter and moisture, and efficient treatment of these contaminants has been an important technical issue for promoting the recycling of waste plastics. Furthermore, in plastic recycling as a chemical raw material, when the density of the plastic particles is low, the handling property is deteriorated, and the powder generated due to the molding failure is caused by staying in the transportation route and the storage device. There were problems such as problems. That is, for chemical raw materials, high-quality plastic granular materials are required in terms of shape.

  Used plastic collected from households (hereinafter referred to as general waste plastic), which is generated in large quantities, generally contains a large amount of foreign matter. Then, as much as 30% by mass of foreign matter is mixed. Moreover, since there are many plastic films in general waste and the specific surface area is large, there is a problem that the amount of adhering water is large.

  It is recognized that mixed foreign substances can cause operational and quality problems such as damage to the cutting blades and wear of the hole mold of the compression molding machine. Therefore, a method of removing these foreign substances by machine sorting is taken. For removing small foreign matter, a method of combining various machines as described in JP-A-9-313966 has been invented, and this method and similar methods are effective techniques.

  In order to manufacture the plastic particles using waste plastic as a raw material by the above-mentioned method by the compression molding method of extruding from the hole mold, a part of the waste plastic is in a molten or semi-molten state. Thus, it is desirable to be a binder of unmelted plastic. If there are few plastics in a molten or semi-molten state, the shape of the adhesive will be insufficient, the powder will be generated, and the shape of the plastic will be poor. On the other hand, if there is too much plastic in the molten or semi-molten state, the fluidity of the waste plastic becomes too high, and a phenomenon occurs in which it returns to the inlet direction through the gap of the pushing mechanism. As a result, there was a problem that the operation could not be continued.

  In particular, since the softening temperature and the melting temperature differ depending on the type of plastic, there has been a problem that the compression molding conditions change depending on the case when miscellaneous waste plastic is compression molded. As a result, there are too many plastics with a low melting temperature and excessive melting, or too few plastics with a low melting temperature, even though the same operating conditions are set. There is a problem that the shape quality of the plastic granular material is not stable.

  As described above, water is attached to the waste plastic, and this becomes a problem in compression molding. In particular, many plastic wastes are in the form of films used for containers and packaging, have a large specific surface area, and easily contain moisture during storage and collection at home, so the adhering moisture exceeds 10%. Cases are also allowed. However, in the conventional method, generally only scrap plastic is used as a chemical raw material, and a technique effective for the treatment of plastic with a lot of moisture has not been considered. In addition, conventional compression molding of general waste plastics has been carried out, but it is not intended for recycling, and the main purpose is to reduce the volume of landfill. As for the quality, sufficient technical support has not been made.

  If there is a lot of moisture adhering to the plastic, the moisture will evaporate in the molding machine during compression molding, causing a bumping phenomenon in the semi-molten plastic, and the plastic will discontinuously disengage from the hole mold. There has been a problem that the shape of the molded product that has popped out or granulated has deteriorated. In particular, when there is a large amount of adhering moisture, heat is lost by evaporation of the adhering moisture at the time of compression molding, and the temperature of the waste plastic does not rise, and the plastic does not soften. As a result, the molded plastics are not adhered to each other inside the granular material and often fall apart during transportation.

  For this reason, compression molding using waste plastic mixed with general waste plastic and adhering a lot of moisture has only been able to produce only plastic particles that have poor shape quality and are easily pulverized. In particular, granulated products used as chemical raw materials need to have a high density, so the waste plastic density in the compression molding machine is high, and there is a problem that it is more susceptible to moisture evaporation, but it has not been improved sufficiently. It was

  As described above, in the prior art, the equipment and operation design for each process of foreign matter removal, crushing, moisture management, and compression molding in accordance with the characteristics of waste plastics, especially general waste plastics, is insufficient. Therefore, various problems have occurred. In order to perform processing suitable for compression molding of waste plastic mixed with general waste plastic, a new method and apparatus for coping with the foreign matter mixture and moisture fluctuations have been required.

The present invention is as described in (1) or (2).
(1) is recovered from households after use, and state, and are moisture content of 10 wt% or less, more than 60% by weight total content ratio of the film-like polyethylene is more size 3mm 10 to 60 wt% When molding waste plastic, it is a type of molding machine that has a screw extrusion device inside a barrel-shaped casing, which is a waste plastic holding part, and uses the extrusion device to extrude waste plastic from the end plate hole mold Compressed at a temperature of 55 to 165 kW per ton of waste plastic processed per hour per hour of waste plastic processing, and the output of the heating device and the device that performs molding at 100 to 140 ° C. and performs mechanical work on the waste plastic holding part Molding method for waste plastic granulated chemical raw material, characterized by molding,
(2) is recovered from households after use, and state, and are moisture content of 10 wt% or less, the particle size 3mm above 60 wt% is total 25 to 75% by weight of the content of film-like polyethylene and polypropylene When molding the above waste plastic, it has a screw extrusion device inside the barrel-shaped casing, which is the waste plastic holding part, and uses this extrusion device to extrude the waste plastic from the end plate hole mold The total of the driving power of the device that is molded at 100 to 140 ° C. and performs mechanical work at the waste plastic holding part and the output of the heating device is in the range of 55 to 165 kW per ton of waste plastic processing per hour A method of molding waste plastic granulated material for chemical raw material, characterized by compression molding.

  In order to make waste plastics into granular materials for chemical raw materials, those having high shape quality are required, and the present invention provides a method for producing such waste plastic granular materials for chemical raw materials. . By using the present invention, there is provided a means that enables the use of chemical raw materials that have been difficult to manufacture by conventional methods. As a result, the waste plastic can be recycled to a gasifier, an oil generator, a coke oven, a blast furnace, and other reactors at low cost.

  The inventors of the present invention have studied various techniques for producing plastic granules for chemical raw materials by compression molding waste plastics, and the production is performed by the method described below. Also invented a technology to get good things. The waste plastic handled in the present invention is particularly effective for various things including general waste plastics.

  The waste plastic compression molding method of the present invention will be described. Part or all of the waste plastic as the primary raw material is general waste plastic. An example of the apparatus used in the present invention is shown in FIG.

  Waste plastics including general waste plastics are transported to the machine sorting process by the waste plastic supply conveyor 1. The machine sorting process is a combination of some or all of the magnetic sorter 3, eddy current type metal sorter 4, vibration sieve device 5, and wind force sorter 6. The combination of devices changes depending on the degree of contamination of the waste plastic.

  First, in order to remove the iron-based foreign matter, the iron-based foreign matter is removed by the magnetic separator 3 on the waste plastic conveyor 2. In the next step, the eddy current type metal sorter 4 is used to remove nonmagnetic metal such as aluminum. A sieve device is applied to remove fine inorganic foreign matter. In order to improve the efficiency of the sieve and prevent clogging, it is desirable to use a vibrating sieve, and FIG. 1 shows a vibrating sieve device 5 as an example of equipment. The mesh size is preferably set to about 3 to 10 mm from the viewpoint of removing foreign substances and preventing clogging. As the next step, there are many cases in which slightly larger glass of about 5 to 30 mm, pieces of ceramics, etc. are still mixed, and further, the waste plastic is applied to the wind power separating device 6 to remove these slightly larger foreign matters.

  As an effect of using the above machine sorting process, there is prevention of wear of the cutting blade of the plastic crusher 7 and the hole mold of the compression molding machine 9, and prevention of mechanical failure due to foreign matters.

  After passing through the above machine selection process, the plastic crusher 7 crushes to a size appropriate for compression molding in the compression molding machine 9. This is conveyed by the plastic conveyance conveyor 8, and is compression-molded by the compression molding machine 9, thereby producing 100 to 140 ° C waste plastic granular materials. The produced waste plastic granular material is cooled on the cooling conveyor 10 by cooling means such as sprinkling to a temperature of about 100 ° C. to about 40 ° C. or less.

  The compression molding machine may be any machine as long as it has a plastic pushing mechanism and a hole mold. A model that pushes plastic into a cylinder with a hole mold with a push roll, a model that uses heat generated by cutting the plastic inside the device, and a screw that is pushed inside the body with a screw to form a hole mold for the end plate There are models to push in. When using general waste plastic, it is desirable to use a screw-in type that is easy to prevent the occurrence of clogging of foreign objects.

  In the present invention, a screw-in type compression molding machine is shown as an example. This is shown in FIG. In the compression molding machine 9, frictional heat is generated by the mechanical work of pressing, and the temperature of the waste plastic is raised. The waste plastic is pushed by the screw 15 inside the body portion 13. At this time, the temperature of the waste plastic rises due to frictional heat, and the waste plastic softens. This is extruded from the plurality of hole molds 17 of the end plate 16 and cut into a granular material. The granular material is cooled by the cooling conveyor 10.

  The present inventors have clarified that a temperature range exists at the time of appropriate compression molding in order to stably produce a plastic granule having a good shape and a low powdering rate. In other words, waste plastics, including general waste plastics, are a collection of polyethylene, polypropylene, polystyrene, polyvinyl chloride and other miscellaneous types of plastics. As an appropriate operation method for a plastic compression molding machine, it is effective to use a part of plastic as a molten or softened state and use it as a solid plastic binder during molding. However, when the whole amount is melted or softened, the fluidity increases too much, and the pressure inside the plastic rises due to the return of the pushing mechanism through the gap, or the generation of water vapor or gas, similar to bumping Phenomenon occurs, operation stops, and molded products with poor shape can be produced. In other words, it is desirable to operate at 100 to 140 ° C., which is a temperature at which only polyethylene or polypropylene having a low melting point is softened, in order to keep the temperature control of the waste plastic inside the compression molding machine 9 and good operation. The present inventors have clarified.

  The results of experiments conducted to elucidate the above fact are shown in FIG. FIG. 3 shows the relationship between the waste plastic temperature, the powdering rate of plastic particles, and the productivity. The compression molding machine used was a screw compression type as shown in FIG. When the waste plastic temperature was 90 ° C. or less, it was found that many plastics became powder and did not present as a molded product. When the waste plastic temperature exceeded 100 ° C., the pulverization rate became 10% or less, resulting in plastic particles that could be used for chemical raw materials.

  However, problems also occurred when the temperature was too high. It was confirmed that productivity deteriorated from the time when the waste plastic temperature exceeded 140 ° C. This is because most of the waste plastic is in a molten or semi-molten state, and the fluidity of the waste plastic becomes so high that the waste plastic is fed back through the gap in the screw, and the waste plastic is sent to the hole mold successfully. This is because an unforeseen phenomenon occurred. That is, in order to ensure productivity, the waste plastic temperature is desirably 140 ° C. or lower.

  As a result of various experiments, the present inventors have found that, as a temperature control method, a method of adjusting the passage resistance in the hole mold to make the friction at the time of pushing appropriate is used. Adjustment of the passage resistance in the hole mold is performed by adjusting the length and taper of the hole mold, and further adjusting the total area of the hole mold. If the temperature cannot be controlled only by adjusting the passage resistance of the hole type, the temperature control is assisted by installing an electric heating device for assisting the heat source. As shown in FIG. 4, various conditions of the compression molding machine are set so that the total power output for driving and the electric heating device per ton of waste plastic processing is 55 to 165 kW, as shown in FIG. If the setting is adjusted, the waste plastic temperature can be controlled to 100 to 140 ° C. In addition, in FIG. 4, it described as a specific output (kWh / t-pl). Here, even if the output is the same, the phenomenon that the temperature of the waste plastic is different is due to the amount of adhering moisture.

  In addition, the present inventors have clarified that it is important to control the moisture adhering to the waste plastic to be low for temperature control during molding and prevention of bumping phenomenon. In other words, if too much moisture is attached, a large amount of heat is taken away by the evaporation of the moisture, making it difficult to raise the temperature of the waste plastic during molding. Furthermore, as a problem of adhering moisture, a large amount of adhering moisture evaporates during molding, and the water vapor pressure inside the plastic assembly in which a part of the molding machine is melted or softened increases. As a result, it was clarified that there is a bumping phenomenon in which water vapor blows discontinuously by breaking the mechanically weak part of the plastic aggregate. As a result of this bumping phenomenon, the molded product blows out from the hole mold discontinuously, and the shape of the plastic granular material deteriorates, or the plastic returns to the inlet side behind the compression molding machine.

  The present inventors further elucidated the adhering moisture ratio that does not adversely affect the shape of the plastic particles. FIG. 5 shows the effect of adhering moisture on the powdering rate of molded plastic granules. As a result of experiments conducted at a plastic temperature of 105 to 110 ° C. during compression molding, the pulverization rate gradually increased from 10% by mass of moisture, and the pulverization rate became extremely high when the moisture was 12% by mass or more. That is, the adhering moisture is desirably 12% by mass or less. On the other hand, in the case of 120 to 135 ° C., which is a slightly high temperature condition, the tolerance for moisture was increased. When the water content was up to 16%, the powdering rate of the plastic granules could be kept relatively low.

  We also investigated the relationship between the moisture adhering to the waste plastic in the compression molding machine and the frequency of bumping of the plastic from the hole mold. Even in this phenomenon, when the water content was 12% by mass or more, the occurrence rate of a phenomenon similar to bumping was high, and when the water content was 16% by mass or more, the operation was impossible. In other words, it is important for manufacturing the plastic granular material for chemical raw materials of high quality stably that the adhered moisture of the waste plastic is 12% by mass or less. To summarize the results, the waste plastic moisture is desirably 12% by mass or less, but up to 16% by mass can be operated with the shape of the plastic granular material being improved.

  We also investigated the relationship between the moisture adhering to the waste plastic in the compression molding machine and the frequency of bumping of the plastic from the hole mold. Even in this phenomenon, when the water content is 12% or more, the occurrence rate of a phenomenon similar to bumping increases, and when it is 16% or more, the operation may be interrupted. In other words, it is an important requirement for stably producing high-quality plastic granular materials for chemical raw materials that the attached plastic has a moisture content of 16% or less.

  As described above, it is a point of the manufacturing method of plastic granular material with good shape quality that the ratio of the semi-molten plastic and the solid plastic is in an appropriate state. As a result of various experiments, the present inventors have clarified that it is an important requirement that the ratio of low melting point polyethylene to polypropylene in the waste plastic is within a certain range.

  In experiments conducted by the present inventors, among low-melting plastics contained in waste plastics, low melting point polyethylene begins to soften at about 95 ° C. and becomes molten at about 130 ° C. Polypropylene starts to soften at 120 ° C. and becomes molten at about 140 ° C. On the other hand, some materials such as polyethylene terephthalate and polyvinyl chloride do not soften so much in the range of 100 to 140 ° C. Therefore, if the mixing ratio of these materials is appropriate, the ratio between the material that functions as a binder and the material that functions as an aggregate is appropriate. As a result, it is possible to produce plastic granular materials with good shape quality.

  First, the present inventors repeated experiments on compression molding of waste plastic, and confirmed the influence of the mixing ratio of polyethylene. The result is shown in FIG. When the ratio of polyethylene is 10% or less, even at 100 to 140 ° C., the polyethylene acting as a binder is insufficient, and a granulated product in which the crushed plastic is not bonded is generated loosely, and the product powder rate Is expensive. On the other hand, when the polyethylene ratio is 10 to 60%, the effect of the binder is sufficient, and the powder rate is as low as 10% or less. However, when the polyethylene ratio is 60% or more, there is a problem that there are too many softened parts of the plastic at 100 to 140 ° C. Therefore, 10 to 60% of the polyethylene ratio is an important operational requirement.

  The inventors of the present invention repeated experiments on compression molding of waste plastics, and elucidated that the total mass ratio of polyethylene and polypropylene has an influence on the shape quality of the granulated material, as shown in FIGS. 7 and 8. FIG. 7 shows the influence of the total mass ratio of polyethylene and polypropylene on productivity when the same compression molding apparatus is used. When the total mass ratio of polyethylene and polypropylene is 75% by mass or more, productivity is lowered. This was due to the fact that the fluidity of the plastic increased so much that the plastic flowed backward from the gap between the screw being pushed in and the body portion.

  FIG. 8 shows the influence of the total mass ratio of polyethylene and polypropylene on the pulverization (5 mm under-sieving ratio) of 20 mm diameter product waste plastic granules. When the total mass ratio of polyethylene and polypropylene is 25% by mass or less, the powdering rate is increased. This was because the ratio of the semi-molten plastic (polyethylene and polypropylene), which serves as a binder, was lowered, and the bonding inside the granular material was deteriorated.

  In other words, in the temperature range of 100 to 140 ° C. of the present invention, the total amount of polyethylene and polypropylene in a semi-molten state is 25 to 75% by mass, and other high melting point plastics have the remaining ratio, Is good and productivity is high. Therefore, the range of the present invention is such that the total of polyethylene and polypropylene is 25 to 75% by mass. The reason for this is that at 100-140 ° C., polyethylene functions as a fairly fluid binder and polypropylene functions as a moderately fluid binder. As a result, the filling rate and hardness of the granulated product can be adjusted to an appropriate range. Therefore, the total mass ratio of polyethylene and polypropylene is also an important operational requirement.

  It has also been clarified that when plastic waste plastics are mixed with polyethylene and polypropylene in film form, it is possible to produce waste plastic granules with good shape. A film-like plastic has a large specific surface area, and therefore has a large friction and good heat transfer. As a result, when film-like polyethylene and polypropylene are mixed, a mixture of semi-melted and solid plastic is formed in a short time, and thus moldability is improved. As a result of repeating various studies, the present inventors have clarified that the above effect is great when 60% or more of polyethylene and polypropylene are in a film form. Therefore, it is desirable that 60% or more of 25% by mass, which is the minimum ratio of polyethylene and polypropylene, is in the form of a film. That is, when the film-like polyethylene and polypropylene are mixed at a ratio of 15% or more with respect to the total mass of the waste plastic, good operation is possible.

  Furthermore, the present inventors have clarified that the ratio of the inorganic substance mixed in the plastic also affects the productivity of molding. The inorganic substance mixed in the plastic includes inorganic foreign matters, metal powder, glass and earth and sand mixed with additives such as zinc oxide originally added in the plastic. In the case of used plastics, in particular, general waste plastics, the contamination ratio of inorganic foreign matters is high, so the problem of inorganic contamination is large.

  The present inventors have further clarified that the ductility of the discarded plastic granular material after cooling is lowered when the inorganic material is mixed in a large amount. The waste plastic granular material having reduced ductility has a low powder rate immediately after production, but has a high ratio of powdering during handling, which causes problems such as staying in the conveyance path and storage silo. Therefore, it is inappropriate to use waste plastics containing a large amount of inorganic substances for the production of chemical raw materials.

  As a result of investigating the influence of the inorganic substance mixing ratio on the powdering ratio during handling, the powdering ratio increased from 18% by mass of the inorganic substance, and when it was 25% by mass or more, it was completely unsuitable for chemical raw materials . Further, if the amount of the inorganic substance is reduced, the wear of the hole mold of the compression molding machine is reduced, which is desirable from the viewpoint of reducing the manufacturing cost.

  The waste plastic granules produced by the method of the present invention show a good shape quality with a low sieving ratio due to powder generation, and are also effective as chemical raw materials from the viewpoint of the material of the waste plastic granules. The conditions under which the waste plastic granular material has good shape quality that can be used as a chemical raw material are polyethylene and polypropylene in the range of 25 to 75% by mass, and the mixing ratio of inorganic substances is 18% by mass or less. At that time, the waste plastic particles have an apparent density of 0.5 kg / liter or more. This waste plastic granular material has good bonding in the granular material and does not cause a problem in raw material handling. The apparent density is a numerical value obtained by dividing the mass of each discarded plastic granular material by the volume calculated by the outer dimensions, and the volume includes the volume of pores inside the discarded plastic granular material.

As described above, in order to make waste plastic into a granular material for chemical raw materials, high shape quality is required, and the present invention provides such waste plastic granular material for chemical raw materials and its A manufacturing method is provided. By using the present invention, there is provided a means that enables the use of chemical raw materials that have been difficult to manufacture by conventional methods.
(Example)
As a result of treating the waste plastic based on the present invention, as shown below, it was possible to produce a plastic granular material for chemical raw materials having a good shape quality as compared with the conventional method. The effect of the present invention is as follows. In the waste plastic compression molding facility shown in FIG. 1, when the 20 mm granular material is manufactured using the screw-in type compression molding machine shown in FIG. Explain the results of the operations that were followed.

  In the examples shown in Table 1, the ratio of polyethylene is 13.8%, and the total ratio of polyethylene and polypropylene is 39.2%, which is within the scope of the present invention. It is within the scope of the present invention. The mechanical work at the time of compression molding to realize this condition was 81 kW per ton per hour of waste plastic processing, which is a condition of the present invention.

  As a result of this operation, the apparent density of the product waste plastic granules was 0.66 kg / liter, which satisfies the conditions of the granules of the present invention. The waste plastic granular material had a powdering rate as low as 2.9%, and had excellent shape quality as a chemical raw material.

  On the other hand, even if the composition of the raw material is the same, the temperature at the time of compression molding was lower than the range of the present invention. As a result of the operation of Comparative Example 1, the apparent density of the granular material is only 0.42 kg / liter. could not. As a result, the powdering rate was 10.3%, and the shape quality as a chemical raw material was insufficient. Further, in Comparative Example 2, which is an example of operation in which the total ratio of polyethylene and polypropylene is small, the apparent density of the granular material was only 0.44 kg / liter, which was low. As a result, the powdering rate was 9.7%, and the shape quality as a chemical raw material was still insufficient.

  As described above, by carrying out the operation based on the present invention, it is possible to provide a granular material of waste plastic having excellent shape quality as a chemical raw material.

  By using the present invention, there is provided a means that enables the use of chemical raw materials that have been difficult to manufacture by conventional methods. As a result, the waste plastic can be recycled to a gasifier, an oil generator, a coke oven, a blast furnace, and other reactors at low cost.

It is an example of the compression molding equipment of the waste plastic used for implementing this invention, and is the whole flowchart. This is an example of a waste plastic compression molding machine, which is a type of device that pushes waste plastic with a screw and pushes it out of the end plate hole mold. It is a figure which shows the influence which the waste plastic temperature in a compression molding machine has on the powdering rate of the granular material of a waste plastic. It is a figure which shows the relationship between the sum total of the electric power of the mechanical work per ton of the plastic processed with a compression molding machine, and a waste plastic temperature. It is a figure which shows the influence which the adhesion water | moisture content of a waste plastic has on the powdering rate of the granular material of a waste plastic. It is a figure which shows the influence which the total ratio of the polyethylene in a waste plastic has on the powdering rate of the granular material of a waste plastic. It is a figure which shows the influence which the mass ratio of the total of polyethylene and polypropylene in a waste plastic has on the productivity of a compression molding machine. It is a figure which shows the influence which the ratio of the sum total of the polyethylene in a waste plastic and a polypropylene has on the powdering rate of the granular material of a waste plastic.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste plastic supply conveyor 2 Waste plastic conveyor 3 Magnetic sorter 4 Eddy current type metal sorter 5 Vibrating sieve device 6 Wind separation device 7 Plastic crusher 8 Crush plastic conveyor 9 Compression molding machine 10 Cooling conveyor 11 Blower pipe 12 Plastic supply part 13 Body 14 Screw shaft 15 Screw 16 End plate 17 Hole mold 18 Cutting machine 19 Waste plastic granular material

Claims (2)

Recovered from households after use, and state, and are moisture content of 10 wt% or less, more than 60% by weight total content ratio of the film-like polyethylene particle size 3mm or more waste plastic 10 to 60 wt% When molding, a barrel-type casing that is a waste plastic holding portion has a screw extrusion device, and the extrusion device is used to extrude waste plastic from a hole mold of an end plate. Compression molding is performed at 140 ° C. and the sum of the driving power of the device that performs mechanical work at the waste plastic holding portion and the output of the heating device is in the range of 55 to 165 kW per ton of waste plastic processing per hour. A method for forming a waste plastic granulated material for chemical raw materials characterized by the following. Recovered from households after use, and state, and are moisture content of 10 wt% or less, waste more than 60% by weight total content ratio of the film-like polyethylene and polypropylene is not less than the particle size 3mm 25 to 75 wt% When molding plastic, it has a screw extrusion device inside a barrel-shaped casing that is a waste plastic holding part, and is a type molding machine that extrudes waste plastic from a hole mold of an end plate using the extrusion device, Compression molding in which the sum of the driving power of the device that is molded at 100 to 140 ° C and performs mechanical work on the waste plastic holding part and the output of the heating device is in the range of 55 to 165 kW per ton of waste plastic processing per hour A method for forming a waste plastic granulated product for chemical raw material, characterized in that:

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