JP7343776B2 - Method for manufacturing waste plastic moldings and apparatus for manufacturing waste plastic moldings - Google Patents

Description

The present invention relates to a method for manufacturing waste plastic moldings and an apparatus for manufacturing waste plastic moldings.

In order to recycle waste plastic contained in household waste, etc., there is a technology that uses a coke oven to turn waste plastic into a chemical raw material. In order to introduce waste plastic into a coke oven, it is necessary to mold the waste plastic into a molded article of a predetermined shape. For example, Patent Document 1 listed below describes a technique for supplying waste mainly consisting of plastic to an extrusion molding machine to produce a block-shaped molded product. In particular, Patent Document 1 listed below describes that water is jetted onto a molded product extruded from an extrusion molding machine to solidify it.

Japanese Patent Application Publication No. 2003-170429

However, in the technique described in Patent Document 1, water is jetted toward the molded product after it has been extruded, and cooling of the molded product during extrusion is not considered. Therefore, there was a problem that the start of solidification of the molded product was delayed, and after the waste plastic was extruded, it swelled and its density decreased.

Therefore, the present invention has been made in view of the above problems, and the objects of the present invention are to provide a new and excellent waste plastic molded product manufacturing apparatus capable of increasing the density of waste plastic molded products, and An object of the present invention is to provide a method for manufacturing waste plastic molded products.

In order to solve the above-mentioned problems, according to one aspect of the present invention, there are provided a raw material inputting step of charging waste plastic raw materials into a container, a kneading and heating step of kneading and heating the waste plastic raw materials in the container, and the above-mentioned a transfer step of transferring the waste plastic raw material heated to 150° C. or higher toward a communication section provided at an end of the container that communicates the inside of the container with the outside; Provided is a method for producing a waste plastic molded product, which includes a cooling step of cooling the communicating portion to 100° C. or less while the waste plastic molded product is being extruded.

Cooling of the communicating portion in the cooling step may be performed by removing heat from the communicating portion using cooling water.

A face plate is provided at the end of the container, and the communicating part has a nozzle protruding from the end face of the face plate on the outer side of the container, and the cooling of the communicating part in the cooling step is performed by the This may be performed by spraying cooling water onto the outer peripheral surface of the nozzle.

A face plate is provided at the end of the container, and the communication portion has a nozzle protruding from an end surface of the face plate on the outer side of the container, and in the transfer step, the waste plastic raw material is transferred to the container. The heat may be generated by friction with the inner circumferential surface of the nozzle.

A heating section may be provided at the end of the container, and the waste plastic raw material may be heated by the heating section in the transfer step.

In order to solve the above problems, according to another aspect of the present invention, there is provided a container that stores waste plastic raw materials inside, and a container that stores the waste plastic raw materials that have been kneaded and heated to 150° C. or higher in the interior of the container. a transfer portion that transfers toward the end of the container; a communication portion that is provided at the end of the container and communicates the inside of the container with the outside of the container; An apparatus for manufacturing waste plastic molded products is provided, which includes a cooling unit for cooling.

As described above, according to the present invention, there are provided a new and excellent waste plastic molded product manufacturing apparatus and a waste plastic molded product manufacturing method capable of increasing the density of waste plastic.

1 is a front view showing a configuration example of a waste plastic molded product manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view showing a configuration example of the waste plastic molded product manufacturing apparatus according to the same embodiment. FIG. 2 is a side view showing a configuration example of the waste plastic molded product manufacturing apparatus according to the same embodiment. FIG. 3 is a partial cross-sectional view schematically illustrating the state of cooling according to the same embodiment. FIG. 4B is an A-A' end view in FIG. 4A. FIG. 2 is an external view schematically illustrating a waste plastic molded product according to the same embodiment. 5A is a B-B' end view in FIG. 5A. FIG. It is a flowchart which shows an example of the manufacturing method of the waste plastic molded article based on the same embodiment. FIG. 7 is a partial cross-sectional view schematically illustrating a state of cooling according to a modified example of the same embodiment. FIG. 7 is a partial cross-sectional view schematically illustrating a state of cooling according to another modification of the same embodiment. It is a side view of the manufacturing apparatus of the waste plastic molding based on the other modification of the same embodiment. As an example, it is a graph showing the measurement results of the average diameter of waste plastic molded products. As an example, it is a graph showing the measurement results of the apparent density of waste plastic molded products.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.

<1. Configuration of waste plastic molded product manufacturing equipment>
With reference to FIGS. 1 to 3, a schematic configuration of an apparatus 100 for manufacturing waste plastic molded products P according to one embodiment of the present invention will be described. FIG. 1 is a front view showing a configuration example of an apparatus 100 for manufacturing waste plastic molded products P according to the present embodiment. FIG. 2 is a plan view showing a configuration example of the apparatus 100 for manufacturing waste plastic molded products P according to the same embodiment. FIG. 3 is a side view showing an example of the configuration of the waste plastic molded product P manufacturing apparatus 100 according to the same embodiment.

The waste plastic molded product P manufacturing apparatus 100 according to the present embodiment processes the waste plastic raw material M by kneading, heating, etc. and then extrusion molds it to produce a waste plastic molded product having a predetermined shape. This is a device for molding P. For example, the waste plastic molded product P is inserted into a coke oven together with coal and recycled as a chemical raw material.

Here, the waste plastic raw material M includes plastic waste such as used plastic containers. Specifically, the waste plastic raw material M includes plastic waste whose main component is a resin material such as polyethylene, polystyrene, or polypropylene.

The waste plastic raw material M may be crushed to some extent before being input into the waste plastic molded product P manufacturing apparatus 100. Further, the waste plastic raw material M may be kneaded and heated to some extent before being input into the waste plastic molded product P manufacturing apparatus 100. In this case, the kneading and heating of the waste plastic raw material M in the container 110 may be omitted or simply performed.

As shown in FIG. 1, the apparatus 100 for manufacturing waste plastic molded products P includes a container 110, a transfer section 120, a communication section 130, and a cooling section 140.

(container)
The container 110 is a housing portion that can accommodate the waste plastic raw material M. The container 110 has a hopper 113 opened toward the Z direction on one end 111 side in the Y direction in FIG. Waste plastic raw material M is charged into the container 110 through the hopper 113. The waste plastic raw material M is kneaded and heated to 150° C. or higher inside the container 110.

If the heating temperature in the container 110 is less than 150° C., the waste plastic raw material M will not be sufficiently melted, and the surface side will not be sufficiently solidified in the molding process of the waste plastic molded product P, which will be described later. As a result, it is not possible to increase the density of the waste plastic molded product P. Furthermore, the fact that the waste plastic raw material M is heated to 150° C. or higher in the container 110 does not mean that it is heated to 150° C. or higher in all areas within the container 110; It is sufficient that the waste plastic raw material M, which is ready to be extruded in the vicinity of , is heated to 150° C. or higher. Specifically, the temperature inside the container 110 is measured by a temperature sensor 170 provided inside the face plate 117, which will be described later. Further, the temperature sensor 170 is provided within a range capable of detecting the heating temperature of the heater 151 provided in the face plate 117.

Furthermore, a part of a transfer section 120 is provided inside the container 110, and the waste plastic raw material M is transferred toward the other end 115 of the container 110 in the Y direction by the transfer section 120. A face plate 117 is provided at the other end 115 of the container 110. The face plate 117 is a plate-like member provided at the other end 115 of the container 110, and the face plate 117 is provided with a communication portion 130. Details of the communication section 130 will be described later. The thickness, shape, etc. of the face plate 117 may be appropriately set in consideration of the pressing force in extrusion molding, etc.

(transfer section)
The transfer unit 120 transfers the waste plastic raw material M in the container 110 toward the other end 115 of the container 110. Specifically, the transfer section 120 has a so-called twin-screw extrusion mechanism, as shown in FIG. As shown in FIGS. 1 and 2, the transfer unit 120 includes, for example, a pair of shafts 121 provided in the container 110 with the axial direction extending along the Y direction, and a pair of shafts 121 connected to the axial ends of the shafts 121. It has a speed reduction mechanism 123 and a drive source 125 that applies rotational force to the shaft 121 via the speed reduction mechanism 123.

A screw portion 127 having a spiral blade-like portion is provided on the outer circumferential surface of the pair of shafts 121 . With the rotation of the shaft 121, the screw portion 127 transfers the waste plastic raw material M from the one end 111 side of the container 110 to the other end 115 side. Further, by the rotation of the screw parts 127 provided on the pair of shafts 121, the waste plastic raw material M is kneaded and heated by friction. The rotation directions of the pair of shafts 121 may be the same direction or may be opposite directions, and are appropriately set according to the kneading, heating state, etc. of the waste plastic raw material M in the container 110.

Further, the pair of shafts 121 may be provided with a kneading disk portion 129. The kneading disk portion 129 is provided at the axial center of the shaft 121, as shown in FIG. By rotating the kneading disk parts 129 provided on the pair of shafts 121, the waste plastic raw material M is further kneaded and heated by friction.

(Communication part)
As shown in FIG. 1, the communication portion 130 is a cylindrical portion with a circular cross section provided at the other end of the container 110, and communicates the inside of the container 110 with the outside. The waste plastic raw material M is extruded through the communication portion 130 to be molded into a predetermined shape, and becomes a waste plastic molded product P.

As shown in FIG. 3, a plurality of communicating parts 130 are provided on the face plate 117 of the container 110. In particular, the communication portion 130 is provided in a circumferential manner at a position corresponding to the outer peripheral side of the screw portion 127 on the face plate 117 . Further, the communication portion 130 has a nozzle 131 protruding from the outer end surface 117A of the face plate 117. By having the nozzle 131, the distance that the waste plastic raw material M comes into contact with the inner circumferential surface 131A of the communication portion 130 becomes longer. Thereby, as will be described later, the molten surface of the waste plastic raw material M can be solidified by cooling due to heat radiation caused by contact with the communication portion 130 whose temperature is lower than a predetermined temperature.

Moreover, the moldability of the waste plastic molded product P is improved because the distance that the waste plastic raw material M contacts the inner circumferential surface 131A of the communication portion 130 becomes longer. That is, after extrusion molding, the waste plastic molded product P has a predetermined diameter. For example, the distance L of the nozzle 131 is set to 20 mm or more.

(cooling section)
The cooling unit 140 cools the communication unit 130 to 100° C. or lower. If the temperature of the communication section 130 is higher than 100° C. even by cooling by the cooling section 140, the surface of the molten waste plastic raw material M will not be sufficiently solidified. As a result, it is not possible to increase the density of the waste plastic molded product P. Furthermore, the fact that the communication part 130 is cooled to 100°C or less does not mean that all areas of the communication part 130 are cooled to 100°C or less; It is sufficient that the communication portion 130 in the necessary range is cooled to 100° C. or lower. Specifically, as shown in FIG. 1, the temperature of the communication section 130 is measured by a temperature sensor 131C provided in the communication section 130. Further, the temperature sensor 131C is provided directly below the water cooling nozzle 141, which will be described later, at a position where it can measure the temperature of the radially intermediate portion of the communication portion 130 (see FIG. 4A, which will be described later). An example of the temperature sensor 131C is a thermocouple.

Further, as the range to be cooled of the communicating part 130, for example, at least half of the distal end side of the communicating part 130 (outside side of the container 110) of the entire length of the communicating part 130 is cooled to 100 degrees Celsius or less. That's enough. In this case, the temperature sensor 131C is provided on the distal end side of the communication section 130 in the longitudinal direction of the communication section 130.

Further, preferably, the cooling unit 140 cools the communication unit 130 to 70° C. or lower. By setting the temperature of the communication portion 130 to 70° C. or lower, the surface of the molten waste plastic raw material M is more fully solidified. As a result, expansion of the waste plastic raw material M after extrusion molding is further suppressed, and high density of the waste plastic molded product P is realized.

In particular, the communication section 130 is cooled by heat removal by the cooling water W supplied by the cooling section 140. By performing cooling with the cooling water W having relatively high cooling efficiency, the molten surface of the waste plastic raw material M can be efficiently solidified.

As shown in FIG. 1, the cooling unit 140 includes a water-cooled nozzle 141 and a pump 143 that supplies cooling water W to the water-cooled nozzle 141. The tip of the water-cooled nozzle 141 is provided at a position facing the communication section 130, and cooling water W is sprayed from the tip of the water-cooled nozzle 141 to the outer peripheral surface 131B of the nozzle 131 of the communication section 130. As shown in FIG. 3, the cooling unit 140 has a plurality of water-cooled nozzles 141, and one water-cooled nozzle 141 is provided for each nozzle 131 of the communication unit 130. Note that the spraying of the cooling water W includes a form in which a water flow of the cooling water W flows out toward the communication part 130, and a form in which a mist-like cooling water W is injected into the communication part 130.

By spraying the cooling water W onto the outer circumferential surface 131B of the nozzle 131 of the communication section 130, the contact area between the cooling water W and the communication section 130 becomes larger than when the nozzle 131 is not provided. As a result, the efficiency of cooling by the cooling unit 140 becomes higher. In addition, by spraying the cooling water W onto the outer circumferential surface 131B of the nozzle 131, the cooling water W is prevented from directly splashing onto the waste plastic raw material M during extrusion molding, and unnecessary moisture contained in the waste plastic molded product P is suppressed. amount is reduced.

(heating part)
The apparatus 100 for manufacturing waste plastic molded products P has a heating section 150 that can adjust the temperature around the face plate 117. As shown in FIG. 1, the heating unit 150 is, for example, a resistance heating type heater 151 provided in the face plate 117. The heater 151 is connected to a heating power source 153 and heats the face plate 117 and its vicinity by generating heat inside the face plate 117. Heating by the heating unit 150 provided on the face plate 117 of the other end 115 of the container 110 suppresses the temperature drop of the waste plastic raw material M. That is, the molten state of the waste plastic raw material M in the communication section 130 is maintained until immediately before cooling by the cooling section 140.

(cutting part)
The apparatus 100 for manufacturing waste plastic molded products P has a cutting section 160. As shown in FIG. 1, the cutting section 160 includes, for example, a rotary blade 161, a drive source 163, and a cutting section shaft 165. The rotary blade 161 is a radially extending arm with a blade attached to the tip. One end of a cutting shaft 165 is provided at the center of the arm of the rotary blade 161 in the radial direction. A drive source 163 is attached to the other end of the cutting shaft 165. The drive source 163 applies rotational force to the rotary blade 161 via the cutting shaft 165. Due to the contact of the rotary blade 161, the waste plastic raw material M extruded from the communication portion 130 is cut and made into a waste plastic molded product P.

Furthermore, the cutting section 160 cuts the waste plastic raw material M that has been extruded in the communication section 130 whose temperature is below a predetermined temperature. Therefore, the outer circumferential surface of the waste plastic raw material M is solidified, and the outer shape of the waste plastic raw material M is maintained, making it easier to cut. Furthermore, compared to the case where the waste plastic raw material M is bent to an appropriate length under its own weight, or when the waste plastic raw material M whose outer peripheral surface is not solidified and expanded after extrusion molding is cut, the cutting location is better controlled. As a result, the shape and dimensions of the waste plastic molded product P are made uniform, and in addition to increasing the density of the waste plastic molded product P, an improvement in bulk density is realized.

As shown in FIG. 1, the waste plastic molded product P manufacturing apparatus 100 includes a temperature sensor 170 that can detect the temperature around the face plate 117. The temperature sensor 170 is, for example, a thermocouple inserted into the face plate 117.

Moreover, the manufacturing apparatus 100 for the waste plastic molded product P has a control section 180, as shown in FIG. The control unit 180 controls the molding process of the waste plastic molded product P in the waste plastic molded product P manufacturing apparatus 100. Specifically, during cooling by the cooling unit 140, the control unit 180 controls the amount and pressure of the cooling water W to be sprayed based on the output from the temperature sensor 131C. Further, the control unit 180 controls the heating around the face plate 117 by the heating unit 150 based on the output from the temperature sensor 170. Further, the control unit 180 controls the rotation speed of the drive source 163 of the cutting unit 160 and the drive source 125 of the transfer unit 120, etc. The function of the control unit 180 is realized, for example, by cooperation of a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The schematic configuration of the apparatus 100 for manufacturing waste plastic molded products P according to the present embodiment has been described above.

<2. Molding process of waste plastic moldings＞
Next, the process of molding the waste plastic molded product P according to this embodiment will be described with reference to FIGS. 4A, 4B, 5A, and 5B. FIG. 4A is a partial cross-sectional view schematically explaining the state of cooling according to this embodiment. Moreover, FIG. 4B is an AA' end view in FIG. 4A. FIG. 5A is an external view schematically illustrating the waste plastic molded product P according to the present embodiment. FIG. 5B is a BB' end view in FIG. 5A.

First, the waste plastic raw material M that has been kneaded in the container 110 and heated to 150° C. or higher is transferred inside the container 110 toward the other end 115 where the face plate 117 is provided. At this time, the waste plastic raw material M heated to 150° C. or higher is in a molten state at least on the outer surface within the container 110. Thereafter, as shown in FIG. 4A, the waste plastic raw material M passes through the communication portion 130 while being extruded. At this time, the temperature of the waste plastic raw material M decreases due to heat radiation caused by the contact between the waste plastic raw material M and the inner circumferential surface 131A of the communication portion 130. In particular, when the communicating portion 130 has the nozzle 131, the distance where friction occurs becomes longer, and the temperature of the waste plastic raw material M is further reduced.

Furthermore, the communication section 130 is cooled by the cooling section 140 at least while the waste plastic raw material M is being extruded. Here, the cooling unit 140 cools the communication unit 130 to 100° C. or lower, which is the temperature at which solidification of the molten waste plastic raw material M starts. Specifically, the cooling unit 140 sprays cooling water W onto the outer circumferential surface 131B of the communication unit 130. Therefore, while passing through the communication section 130, the waste plastic raw material M, which was in a molten state, solidifies from the outer circumferential side where it comes into contact with the communication section 130. That is, as shown in FIG. 4B, the waste plastic raw material M is extruded through the communication portion 130 while forming a solidified region M1 on the outer circumferential side thereof, and is molded as a waste plastic molded product P. Since a solidified region P1 is formed on the outer peripheral side of the waste plastic molded product P while passing through the communication portion 130, the waste plastic molded product P remains radially outward even after being pushed out from the communication portion 130. Expansion is suppressed.

As shown in FIG. 5A, the waste plastic molded product P according to this embodiment is a short, generally rod-shaped molded product that has a hard outer shell. Further, as shown in FIG. 5B, a solidified region P1 is formed in the waste plastic molded product P on the outer circumferential surface side in a cross-sectional view of the waste plastic molded product P. Compared to the waste plastic molded product Q in the case of not being cooled, whose outer shape is shown by a broken line in FIG. 5B, the waste plastic molded product P according to this embodiment has suppressed expansion in the radial direction. The process of molding the waste plastic molded product P according to the present embodiment has been described above.

<3. Method for manufacturing waste plastic molded products>
Next, a method for manufacturing the waste plastic molded product P according to the present embodiment will be described with reference to FIG. 6. FIG. 6 is a flowchart showing an example of the method for manufacturing the waste plastic molded product P according to the present embodiment. As shown in FIG. 6, first, waste plastic raw material M is put into the container 110 (S101). Subsequently, the waste plastic raw material M is kneaded and heated in the container 110 (S103). At this time, water may be sprayed into the container 110 in order to adjust the temperature inside the container 110.

Further, the waste plastic raw material M heated to 150° C. or higher is transferred toward the communication portion 130 provided at the end of the container 110 and communicating between the inside of the container 110 and the outside (S105). In step S105, the waste plastic raw material M is transferred to the end of the container 110, and the waste plastic raw material M is pushed out inside the communication part 130. At this time, the communication part 130 is cooled to 100° C. or lower at least while the waste plastic raw material M is being extruded through the communication part 130 (S107). Finally, the waste plastic raw material M is extruded from the communication part 130 and cut by the cutting part 160, and the waste plastic molded article P is molded.

Although step S103 and step S105 have been described as separate steps in the method for manufacturing waste plastic molded product P according to the present embodiment, these steps may be performed simultaneously. That is, the waste plastic raw material M may be transferred to the other end 115 of the container 110 while being kneaded and heated within the container 110. The method for manufacturing waste plastic molded product P according to one embodiment of the present invention has been described above.

(effect)
According to this embodiment, when extrusion molding is performed on the waste plastic raw material M heated to a predetermined temperature or higher to produce a waste plastic molded product P, the communicating portion 130 during extrusion molding is cooled to a predetermined temperature or lower. By doing so, the molten surface of the waste plastic raw material M can be solidified. As a result, expansion of the waste plastic molded product P during extrusion or after extrusion from the communication portion 130 is suppressed, and high density is achieved. Furthermore, by realizing higher density of the waste plastic molded product P, the transportation efficiency of the waste plastic molded product P is improved, and handling in subsequent processes becomes easier.

In particular, when the waste plastic moldings P are used for recycling chemical raw materials in a coke oven, the waste plastic moldings P may be required to have a high density from the viewpoint of efficient feeding into the coke oven. According to this embodiment, when manufacturing the waste plastic molded product P, the communicating part 130 during extrusion is cooled to a predetermined temperature or lower to solidify the molten surface of the waste plastic raw material M, thereby forming the waste plastic molding. High density of objects P is realized.

Furthermore, according to the present embodiment, the communication portion 130 is removed during extrusion molding, compared to the case where the waste plastic raw material M is molded, cut, and then cooled, which is a common process in molding the waste plastic molded product P. Since the outer surface side of the waste plastic raw material M is cooled through the cooling medium, the process is simplified. Furthermore, by setting the temperature of the communicating portion 130 to 100° C. or less, the expansion of the waste plastic raw material M immediately after being extruded from the communicating portion 130 is effectively suppressed, compared to the case where the temperature during extrusion molding is not specified.

Furthermore, according to the present embodiment, the temperature of the communication portion 130 during extrusion molding is set to a predetermined temperature or lower, so that the cooling water W is directly sprayed onto the waste plastic raw material M during extrusion molding or after molding. However, the cooling water is prevented from directly splashing on the waste plastic raw material M, and the amount of excess water contained in the waste plastic molded product P is reduced.

<Modification 1>
Next, some modifications of the embodiment of the present invention will be described with reference to FIGS. 7 to 9. Note that in some modified examples described below, descriptions of configurations common to the above embodiment may be omitted. FIG. 7 is a partial cross-sectional view schematically explaining the state of cooling according to a modified example of the embodiment of the present invention. In this modification, the cooling method by the cooling unit 140 is different from the above embodiment. As shown in FIG. 7, in this modification, the cooling section 140 is a water cooling mechanism provided within the communication section 130.

Specifically, cooling water W is supplied into a cylindrical space 145 provided in the communication portion 130 along the longitudinal direction (Y direction in FIG. 7) via a pump and piping (not shown). The space 145 only needs to be able to cool the communication portion 130, and its shape, arrangement, etc. are not particularly limited. For example, the space 145 may be a spiral pipe whose central axis runs along the longitudinal direction of the communication portion 130. According to this modification, the cooling water W is prevented from directly splashing on the waste plastic molded product P, and unnecessary moisture contained in the waste plastic molded product P is reduced. Furthermore, there is no need to provide drainage equipment for the cooling water W after it has been used for cooling.

<Modification 2>
Another modification of the embodiment of the present invention will be described with reference to FIG. 8. FIG. 8 is a partial cross-sectional view schematically explaining the state of cooling according to this modification. This modification is different from the above embodiment in that the communication section 130 does not include the nozzle 131. As shown in FIG. 8, the communication portion 130 does not have a nozzle 131 and is a through hole provided in the face plate 117 of the container 110. The cooling unit 140 cools the communication unit 130 by spraying cooling water W from the outer end surface 117A of the face plate 117. According to this modification, by not having the nozzle 131 protruding from the end surface 117A of the face plate 117, interference of the nozzle 131 with other members such as the cutting portion 160 can be suppressed.

<Modification 3>
Another modification of the embodiment of the present invention will be described with reference to FIG. 9. FIG. 9 is a side view of a manufacturing apparatus 100 for waste plastic molded products P according to this modification. This modification is different from the above embodiment in that the communication portions 130 are provided in a plurality of rows in an annular shape. As shown in FIG. 8, the communication portions 130 are provided in a figure 8 shape and are provided in multiple rows in the radial direction. That is, they are arranged in a triple ring shape, and two of the rings are adjacent to each other. According to this modification, the productivity of the waste plastic molded product P is improved by providing a plurality of rows of communicating portions 130 in the radial direction. Furthermore, by increasing the number of communication parts 130, it becomes possible to adjust the density of the waste plastic molded product P over a wider range.

In this modification, all of the communication parts 130 do not need to be used, and may be closed as necessary (see black circles in FIG. 9) and not used. Furthermore, one cooling unit 140 does not need to be provided corresponding to one communication unit 130, and one cooling unit 140 may cool a plurality of communication units 130. In this case, since the cooling unit 140 cools the plurality of communication units 130, the cooling efficiency is improved. Several modifications of the embodiments of the present invention have been described above.

In order to confirm the effects of the manufacturing method and manufacturing apparatus 100 for waste plastic moldings P according to this embodiment, the characteristics of waste plastic moldings P manufactured using the manufacturing apparatus 100 for waste plastic moldings P according to this embodiment was evaluated.

Specifically, as Comparative Examples 1 and 2, plastic molded products were manufactured in the waste plastic molded product manufacturing apparatus 100 according to the present embodiment without cooling the communication portion 130 by the cooling unit 140. Further, in Comparative Example 1, the heater temperature during molding was about 150°C. On the other hand, in Comparative Example 2, the temperature was about 250°C.

As an example, a waste plastic molded product P was manufactured using the waste plastic molded product P manufacturing apparatus 100 according to the present embodiment while cooling the communication portion 130 by the cooling unit 140. Specifically, the flow rate of the cooling water W during cooling was adjusted so that the temperature measured by the temperature sensor 131C provided in the communication portion 130 was 100° C. or less (for example, 60 to 70° C.). Further, in the example, the heater temperature during molding was about 250°C.

In addition, the average diameter and apparent density of the waste plastic moldings were measured as items for evaluating the characteristics of the waste plastic moldings. The measurement results will be explained below with reference to FIGS. 10 and 11.

FIG. 10 is a graph showing the measurement results of the average diameter of waste plastic moldings. As shown in FIG. 10, in both Comparative Example 1 and Comparative Example 2, the average diameter of the waste plastic molded products was larger than the diameter of the nozzle 131 serving as the communication portion 130. That is, after being extruded, the waste plastic molding expanded radially outward. Further, in Comparative Example 1 and Comparative Example 2, although the temperature of the heater, which is the heating section 150 provided on the face plate 117, was changed, no significant change was observed in the average value diameter.

On the other hand, as shown in FIG. 10, in the example, the average diameter of the waste plastic molded product P was almost the same as the diameter of the nozzle 131 as the communication part 130. That is, it is shown that the solidified region P1 was formed on the outer circumferential surface of the waste plastic molded product P by cooling the communication portion 130, so that the radially outward expansion of the waste plastic molded product P was suppressed. Ta.

FIG. 11 is a graph showing the measurement results of the apparent density of the waste plastic molded product P. As shown in FIG. 11, in Comparative Example 1 and Comparative Example 2, the waste plastic moldings expanded, so the apparent density became small. On the other hand, in the example, expansion of the waste plastic molded product P was suppressed by cooling the communication portion 130. As a result, the apparent density of the waste plastic molded product P was significantly increased compared to Comparative Examples 1 and 2. As described above, it has been shown that the waste plastic molded product P can be made to have a higher density by the method and manufacturing apparatus 100 for producing the waste plastic molded product P according to the present embodiment.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various modifications or applications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.

For example, in the above embodiment, an example of twin-screw extrusion molding having a pair of shafts was shown, but the present invention is not limited to such an example. For example, uniaxial extrusion molding using one shaft may be used.

Further, in the above embodiment, an example is shown in which the refrigerant is water, but the present invention is not limited to such an example. For example, cooling may be performed by air cooling using air as a refrigerant, or cooling using a liquid capable of cooling the communication portion 130 as a refrigerant (oil cooling, cooling with a polymer aqueous solution, etc.) may be performed.

100 Waste plastic molded product manufacturing apparatus 110 Container 117 Face plate 117A End surface 120 Transfer part 130 Communication part 131 Nozzle 131A Nozzle inner peripheral surface 131B Nozzle outer peripheral surface 140 Cooling part 150 Heating part M Waste plastic raw material P Waste plastic molded product W Cooling water

Claims (5)

a raw material input process of inputting waste plastic raw materials into a container;
a kneading and heating step of kneading and heating the waste plastic raw material in the container;
a transfer step of transferring the waste plastic raw material heated to 150° C. or higher toward a communication portion provided at an end of the container and communicating between the inside of the container and the outside;
a cooling step of cooling the communicating part to 100° C. or less while at least the waste plastic raw material is being pushed out inside the communicating part;
a cutting step of cutting the extrusion-molded waste plastic raw material in the communication portion to a predetermined length;
including;
Cooling of the communication portion in the cooling step is performed by removing heat from the communication portion using cooling water.
A method for manufacturing waste plastic molded products. a face plate is provided at the end of the container;
The communication portion has a nozzle protruding from an end surface of the face plate on the outer side of the container,
Cooling of the communication portion in the cooling step is performed by spraying cooling water on the outer peripheral surface of the nozzle.
The method for producing a waste plastic molded article according to claim 1 . a face plate is provided at the end of the container;
The communication portion has a nozzle protruding from an end surface of the face plate on the outer side of the container,
In the transfer step, the waste plastic raw material is heated by friction with the inner peripheral surface of the nozzle.
The method for producing a waste plastic molded product according to claim 1 or 2 . A heating part is provided at the end of the container,
In the transfer step, the waste plastic raw material is heated by the heating section,
The method for producing a waste plastic molded article according to any one of claims 1 to 3 . a container that stores waste plastic raw materials inside;
a transfer unit that transfers the waste plastic raw material kneaded in the interior of the container and heated to 150° C. or higher toward an end of the container;
a communication part provided at the end of the container and communicating between the inside of the container and the outside of the container;
a cooling section that cools the communication section to 100° C. or less;
a cutting section that cuts the extrusion-molded waste plastic raw material in the communication section to a predetermined length ;
Equipped with
The apparatus for manufacturing a waste plastic molded product , wherein cooling by the cooling part is performed by removing heat by cooling water from the communication part .