Resin supply device, molding device, resin supply method, and manufacturing method for molded product

Abstract

To supply a highly adhesive molten resin composition to a mold with high quantitative accuracy.SOLUTION: A resin supplying device (10) includes a moving mechanism section (6) having a moving mechanism for moving a mold (5) so as to increase a distance between a nozzle (31) and the mold (5), wherein the moving mechanism section (6) moves the mold (5) such that a thread diameter of the molten resin composition (11) discharged from the nozzle (31) to the mold (5) is controlled in less than φ 0.40 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a resin supplying device, a molding device, a resin supplying method, and a method for manufacturing a molded product. [Background technology]

[0002] A press molding method is known in which a thermoplastic resin is heated by an extruder or the like to prepare a molten resin composition, and the molten resin composition discharged from a discharge part of a resin supplying device is quantitatively supplied to a mold, and a product is manufactured by press molding. Usually, the molten resin composition has adhesiveness. Therefore, in the press molding method, when a quantitative supply of the molten resin composition is supplied to a mold, stringing of the molten resin composition occurs between the discharge part and the mold. And, the weight of the residue of the stringing molten resin composition between the discharge part and the mold differs for each resin supply, so there is a problem that the quantitative supply of the molten resin composition supplied to the mold is lost.

[0003] To address the above-mentioned problems, for example, Patent Document 1 discloses a technique for cutting the stringy portion of the molten resin composition between the discharge part and the mold with a cutter in a press molding method of a molten resin composition of a general-purpose resin such as a polyethylene-based resin or a polyolefin-based resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-078481 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional technology described in Patent Document 1 does not adequately cut the stringy portions of a molten resin composition made of a thermoplastic resin (e.g., a poly(3-hydroxyalkanoate)-based resin (hereinafter sometimes referred to as a "P3HA-based resin")), which is more viscous than the above-mentioned general-purpose resins, and there is room for improvement in terms of the quantitative supply of the molten resin composition to a mold.

[0006] One aspect of the present invention aims to provide a resin supplying device, a molding device, a resin supplying method, and a method for manufacturing a molded product that can cut the stringy parts between the discharge port and the mold and supply a molten resin composition of a thermoplastic resin having relatively high viscosity to the mold with high quantitative yield. [Means for solving the problem]

[0007] In order to solve the above problems, a resin supplying device according to one embodiment of the present invention includes a melting section that melts a resin composition containing a thermoplastic resin to produce a molten resin composition, a supplying section having a nozzle that supplies the molten resin composition to a mold, and a moving mechanism section having a moving mechanism that moves at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, and the moving mechanism section moves at least one of the nozzle and the mold so that the thread diameter of the molten resin composition ejected from the nozzle to the mold is less than φ0.40 mm.

[0008] In order to solve the above problems, a resin supplying method according to one embodiment of the present invention includes a melting step of melting a resin composition containing a thermoplastic resin to produce a molten resin composition, a supplying step of supplying the molten resin composition from a nozzle to a mold, and a moving step of moving at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, wherein the moving step includes a step of moving at least one of the nozzle and the mold so that the thread diameter of the molten resin composition extruded from the nozzle to the mold is less than φ0.40 mm. Effect of the Invention

[0009] For molten thermoplastic resin compositions having relatively high viscosity, the stringy portion between the discharge port and the mold can be cut off and the composition can be supplied to the mold with good quantitative accuracy. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a resin supplying device according to an embodiment of the present invention; [Diagram 2] 201 to 203 are diagrams illustrating the downward movement of a mold by a movement mechanism provided in the resin supplying device shown in FIG. [Diagram 3] FIG. 2 is a schematic diagram for explaining the distance between a hot air heater provided in the resin supplying device shown in FIG. 1 and a molten resin composition. [Figure 4] 401 and 402 are diagrams for explaining modified examples of the moving mechanism part provided in the resin supplying device shown in FIG. [Diagram 5] 1. FIG. 4 is a diagram showing a configuration of a modified example of the heating and cutting unit provided in the resin supplying device shown in FIG. [Figure 6] 3A to 3C are diagrams for explaining various steps of a resin supplying method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more, B or less." In addition, all documents described in this specification are incorporated herein by reference.

[0012] [Outline of one embodiment of the present invention] As described above, in the conventional press molding method, in order to quantitatively supply a molten resin composition to a mold, a technique is known in which the stringy portion of the molten resin composition between the discharge part (supply part) and the mold is cut with a cutter. However, the present inventors have found that when a molten resin composition of a thermoplastic resin having relatively high adhesion (e.g., P3HA-based resin, etc.) is used, the technique (a) causes the molten resin composition to adhere to the cutter, or (b) causes new stringiness between the cutter and the mold. As a result, it has been found that the above technique has a problem in that it is difficult to quantitatively supply a molten resin composition to a mold.

[0013] In order to solve the above problems, the inventors of the present application have developed a resin supplying device equipped with a heat-cutting unit that heats and cuts the molten resin composition between the nozzle unit and the mold instantaneously without contacting the composition. The heat-cutting unit allows the molten resin composition to be supplied to the mold with good quantitative accuracy. Furthermore, the inventors of the present application have worked hard to develop a technology that allows the heat-cutting unit to cut the stringy portion of the molten resin composition instantaneously without contacting the portion.

[0014] As a result, the inventors of the present application discovered that (1) providing a resin supplying device with a moving mechanism having a moving mechanism that moves at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, and (2) using the moving mechanism to make the thread diameter of the stringy portion of the molten resin composition less than φ0.40 mm, increases the reliability of the heating and cutting portion being able to heat and cut the stringy portion of the molten resin composition without contacting it and instantly. Thus, they arrived at the resin supplying device and resin supplying method of the present embodiment.

[0015] That is, the resin supplying device according to this embodiment includes a mold, a melting section that melts a resin composition containing a thermoplastic resin to produce a molten resin composition, a supplying section having a nozzle that supplies the molten resin composition to the mold, and a moving mechanism section having a moving mechanism that moves at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, and the moving mechanism section moves at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm. Hereinafter, the resin supplying device according to this embodiment may be referred to as the present resin supplying device.

[0016] The resin supplying method according to the present embodiment includes a melting step of melting a resin composition containing a thermoplastic resin to produce a molten resin composition, and a supplying step of supplying the molten resin composition from a nozzle to a mold, and includes a moving step of moving at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, and the moving step includes a step of moving at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm. Hereinafter, the resin supplying method according to the present embodiment may be referred to as the present resin supplying method.

[0017] According to this resin supplying device and this resin supplying method, at least one of the nozzle and the mold is moved so that the thread diameter of the molten resin composition extruded from the nozzle into the mold is less than φ0.40 mm, thereby increasing the reliability of the heating and cutting section being able to heat and cut the thread-like portion of the molten resin composition instantly without contacting it.

[0018] Furthermore, according to this resin supplying device and this resin supplying method, by using a biodegradable resin in the ocean (for example, P3HA-based resin, etc.), it is possible to suppress marine pollution due to disposal, which can contribute to the achievement of the Sustainable Development Goals (SDGs) such as Goal 12 "Ensure sustainable consumption and production patterns" and Goal 14 "Conserve and sustainably use the oceans and marine resources for sustainable development." The resin supplying device and this resin supplying method will be described in further detail below.

[0019] (Resin supply device) 1 is a diagram showing a schematic configuration of a resin supplying apparatus 10 according to this embodiment. As shown in FIG. 1, the resin supplying apparatus 10 includes an extruder 1, a transfer section 2, a discharge section 3 (supply section), a heat cutting section 4, and a movement mechanism section 6.

[0020] The extruder 1 corresponds to a melting section that melts a resin composition containing a thermoplastic resin to produce a molten resin composition 11. In the extruder 1, the resin composition is fed from an inlet 1a. The resin composition fed from the inlet 1a is melt-kneaded to produce a molten resin composition 11. The melting section is not limited to the extruder 1 shown in FIG. 1, and may be any section that can melt the resin composition.

[0021] The transfer section 2 transfers the molten resin composition 11 from the extruder 1 to the discharge section 3. In the transfer section 2, the molten resin composition 11 is transferred in a fixed amount to the discharge section 3. The transfer section 2 includes a fixed amount discharge section that discharges the molten resin composition 11 toward the discharge section 3, and a transfer section main body that transfers the molten resin composition 11 discharged from the fixed amount discharge section to the discharge section 3. Specifically, the transfer section 2 includes a gear pump 2a as the fixed amount discharge section, and a hot hose 2b as the transfer section main body. The gear pump 2a is connected to the extruder 1, and discharges the molten resin composition 11 toward the discharge section 3 in a fixed amount. The hot hose 2b is a hose that relays between the gear pump 2a and the discharge section 3. In the transfer section 2, the molten resin composition 11 is discharged in a fixed amount by the gear pump 2a, and is transferred to the discharge section 3 via the hot hose 2b. The fixed amount discharge section is not limited to the gear pump 2a, and any known device can be used as long as it is configured to discharge the molten resin composition 11 in a fixed amount. In addition to the gear pump, the constant volume discharge part may be, for example, a shot pump (note: a pump that repeats suction and discharge with a constant volume like a syringe), a manifold block, etc. In addition, the main body of the transfer part is not limited to the hot hose 2b, and any known member may be used as long as it is capable of transferring the molten resin composition 11.

[0022] In this manner, the resin supplying device 10 includes the transfer section 2 that transfers the molten resin composition 11 from the extruder 1 to the discharge section 3, and therefore the transfer from the extruder 1 to the discharge section 3 is smooth. Furthermore, the resin supplying device 10 includes the transfer section 2 that includes the gear pump 2a, and therefore the molten resin composition 11 can be discharged at a fixed amount toward the discharge section 3.

[0023] The discharge section 3 has a nozzle 31 that supplies the molten resin composition 11 to the mold 5. The mold 5 has a molding section 5a that constitutes a molding space of a molded product. The nozzle 31 of the discharge section 3 discharges the molten resin composition 11 to the molding section 5a of the mold 5. The nozzle 31 is provided at the tip of the discharge section 3. The molten resin composition 11 is discharged from the nozzle 31 to the mold 5 in a fixed amount. The discharge section 3 is not particularly limited as long as it has a configuration capable of discharging the molten resin composition 11, and a known device can be adopted. In addition, in the configuration shown in FIG. 1, one molding section 5a is formed for one mold 5. However, the mold 5 is not limited to the configuration shown in FIG. 1. Two or more molding sections 5a may be formed for one mold 5.

[0024] The thermal cutting unit 4 heats and cuts the molten resin composition 11 discharged from the nozzle 31 into the mold 5 in a non-contact and instantaneous manner. The thermal cutting unit 4 is equipped with a hot air heater 4a (hot air supply unit) that supplies hot air to the molten resin composition 11. According to the resin supplying device 10, even if the thermal cutting unit 4 cuts the stringy portion 11a of the molten resin composition 11 between the nozzle 31 and the mold 5, no new stringy portion is generated, and the molten resin composition 11 can be supplied to the mold 5 with good quantitative accuracy.

[0025] In the resin supplying device 10 shown in FIG. 1, the moving mechanism unit 6 has a lifting mechanism (moving mechanism, first mechanism) that lifts and lowers the mold 5 so as to increase the distance between the nozzle 31 and the mold 5, and a control unit 63 that controls the lifting mechanism. The lifting mechanism includes an electric cylinder 61 and a mounting unit 62, and the mounting unit 62 is configured to lift and lower. The electric cylinder 61 is a lifting member that lifts and lowers the mounting unit 62. The mounting unit 62 is a member for mounting the mold 5, and any configuration can be adopted as long as the mold 5 can be mounted so as to face the nozzle 31 from above and below. The control unit 63 controls the lifting mechanism of the mold 5 and controls the lowering operation of the mounting unit 62. The lowering operation of the mounting unit 62 controlled by the control unit 63 is, for example, the lowering timing, the lowering speed, etc. In addition, the control unit 63 specifically controls the operation of the electric cylinder 61. In the resin supplying device 10, the mold 5 can be raised and lowered by the lifting mechanism, whereas the nozzle 31 does not move upward or downward.

[0026] 1 includes an electric cylinder 61 as a lifting member for lifting the die 5, but the lifting member is not limited to the electric cylinder 61, and any conventionally known lifting member can be used as long as it can controllably lift the die 5. Examples of such a lifting member include an air cylinder and a hydraulic cylinder.

[0027] 201 to 203 in FIG. 2 are diagrams that show a schematic diagram of the lowering operation of the mold 5 by the moving mechanism 6. 201 in FIG. 2 shows a state at the start of the lowering operation of the mold 5 by the moving mechanism 6, and 202 and 203 in FIG. 2 show a state of the stringy portion 11a after the start of the lowering operation of the mold 5 by the moving mechanism 6. With reference to 201 and 202 in FIG. 2, according to the resin supplying device 10, the lowering operation of the mold 5 by the lifting mechanism of the moving mechanism 6 reduces the thread diameter of the stringy portion 11a of the molten resin composition 11 between the nozzle 31 and the mold 5. With the thread diameter of the stringy portion 11a shown in 202 in FIG. 2, the heating and cutting unit 4 cannot heat and cut it instantaneously without contact.

[0028] The state shown in 203 in Fig. 2 is the state of the stringy portion 11a when the mold 5 is further lowered from the state shown in 202 in Fig. 2. In the state of the stringy portion 11a shown in 203 in Fig. 2, the movement mechanism 6 moves the mold 5 so that the thread diameter of the molten resin composition 11 discharged from the nozzle 31 to the mold 5 is less than φ0.40 mm. In this way, the thread diameter of the stringy portion 11a of the molten resin composition 11 is less than φ0.40 mm, which increases the reliability of the heating and cutting unit 4 being able to heat and cut the stringy portion 11a instantaneously without contacting it.

[0029] The thread diameter of the stringy portion 11a of the molten resin composition 11 by the movement mechanism 6 may be less than φ0.40 mm, but is preferably φ0.30 mm or less, and more preferably φ0.15 mm or less. In other words, it is more preferable that the movement mechanism 6 moves the mold 5 so that the thread diameter of the molten resin composition 11 discharged from the nozzle 31 to the mold 5 is φ0.15 mm or less.

[0030] The thread diameter of the molten resin composition 11 between the nozzle 31 and the mold 5 can be measured by a laser displacement meter.

[0031] Here, in the operation of the discharge unit 3 supplying a fixed amount of the molten resin composition 11 to a plurality of molds 5, the discharge unit 3 performs intermittent discharge by alternately repeating execution and stop of the discharge operation so that the molten resin composition 11 can be supplied to each of the molds 5. The stringy portion 11a of the molten resin composition 11 occurs between the mold 5 and the nozzle 31 after the discharge operation of the discharge unit 3 is stopped. In order to more reliably supply a fixed amount of the molten resin composition 11 to the mold 5, it is preferable to reliably cut the stringy portion 11a that occurs after the discharge operation of the discharge unit 3 is stopped. Therefore, the timing of the expansion of the distance between the mold 5 and the nozzle 31 by the movement mechanism unit 6 is after the discharge operation of the molten resin composition 11 to the mold 5 by the discharge unit 3 is stopped. In other words, it is preferable that the control unit 63 controls the lifting mechanism of the mold 5 so as to expand the distance between the mold 5 and the nozzle 31 after the discharge operation of the molten resin composition 11 to the mold 5 by the discharge unit 3 is stopped. More preferably, after the control unit 63 stops the extrusion operation of the molten resin composition 11 into the mold 5 by the extrusion unit 3, the control unit 63 controls the lifting mechanism of the mold 5 so as to increase the distance between the mold 5 and the nozzle 31 without waiting for a while.

[0032] The timing for increasing the distance between the mold 5 and the nozzle 31 by the moving mechanism 6 is not limited to after the discharge operation of the discharge unit 3 has stopped. The timing may be any timing as long as the molten resin composition 11 can be supplied to the mold 5 with a good quantitative rate by cutting the stringy portion 11a by the heating and cutting unit 4.

[0033] The lowering speed of the mold 5 by the moving mechanism 6 may be any speed that can make the thread diameter of the stringy portion 11a less than φ0.40 mm. The lowering speed of the mold 5 is preferably 200 mm / s to 1000 mm / s, and more preferably 300 mm / s to 600 mm / s. If the lowering speed of the mold 5 is less than 200 mm / s, the thread diameter of the stringy portion 11a tends to become large, making cutting by the heating cutting unit 4 difficult. If the lowering speed of the mold 5 exceeds 1000 mm / s, the mold 5 may float from the stage (mounting unit 62) due to the law of inertia, which is not preferable. The lowering speed of the mold 5 that can make the thread diameter of the stringy portion 11a less than φ0.40 mm is, for example, 500 mm / s.

[0034] The distance by which the mold 5 is lowered by the moving mechanism 6 may be any distance that can make the thread diameter of the thread-drawing portion 11a less than φ0.40 mm. The distance by which the mold 5 is lowered is preferably 30 mm to 200 mm, and more preferably 50 mm to 100 mm. If the distance by which the mold 5 is lowered is less than 30 mm, the thread diameter is not thin enough to be cut by hot air, which is not preferable. If the distance by which the mold 5 is lowered is more than 200 mm, the thread-drawing portion 11a of the cut molten resin composition 11 tends to adhere to the periphery of the mold 5, and this thread-drawing portion 11a tends to become a foreign matter after molding, which is not preferable. The distance by which the mold 5 is lowered to make the thread diameter of the thread-drawing portion 11a less than φ0.40 mm is, for example, 100 mm.

[0035] In the heat cutting section 4, the air volume and hot air temperature of the hot air heater 4a are not particularly limited as long as the molten resin composition 11 can be cut by being heated instantaneously without contact. For example, the air volume of the hot air heater 4a is preferably 5 L / min or more, and more preferably 10 L / min or more. Furthermore, the hot air temperature of the hot air heater 4a is preferably 180°C or more, and more preferably 200°C or more. For example, a preferred embodiment of the air volume and hot air temperature of the hot air heater 4a is an air volume of 10 L / min and a hot air temperature of 200°C to 300°C.

[0036] FIG. 3 is a schematic diagram for explaining the distance L between the hot air heater 4a and the molten resin composition 11. As shown in FIG. 3, the distance L is the distance between the tip of the hot air heater 4a and the stringy portion 11a of the molten resin composition 11. The distance L can be set arbitrarily as long as the molten resin composition 11 can be cut by heating instantaneously without contact. The distance L is preferably 0.5 mm or more. In other words, the heat-cutting portion 4 is preferably separated by 0.5 mm or more from the strings (stringy portion 11a) of the molten resin composition 11 discharged from the nozzle 31 to the mold 5.

[0037] The upper limit of the distance L can be appropriately set according to the setting of the hot air heater 4a, the material and characteristics of the molten resin composition 11, and the like. For example, when the molten resin composition 11 is a melt of a resin composition containing a P3HA-based resin, in order to heat and cut the molten resin composition 11 instantaneously without contact, hot air of 100°C or more must be applied to the stringy portion 11a. When the air volume of the hot air heater 4a is set to 10 L / min to 20 L / min and the hot air temperature is set to 200°C to 400°C, the distance L is set to within 20 mm, preferably within 10 mm. More specifically, when the air volume of the hot air heater 4a is set to 10 L / min and the hot air temperature is set to 200°C, the distance L is set to within 10 mm. When the air volume of the hot air heater 4a is set to 10 L / min to 20 L / min and the hot air temperature is set to 300°C to 400°C, the distance L is set to within 20 mm.

[0038] In the resin supplying device 10 shown in FIG. 1, the moving mechanism 6 includes a lifting mechanism for lifting the mold 5. However, in the resin supplying device 10 according to the present embodiment, the moving mechanism may include a moving mechanism for moving at least one of the nozzle 31 and the mold 5 so as to increase the distance between the nozzle 31 and the mold 5. 401 and 402 in FIG. 4 are diagrams for explaining a modified example of the moving mechanism 6 shown in FIG. 1. As shown in 401 and 402 in FIG. 4, the moving mechanism 6A as a modified example includes a moving mechanism for moving the discharge unit 3 having the nozzle 31 so as to increase the distance between the nozzle 31 and the mold 5. More specifically, the moving mechanism 6A includes a lifting mechanism (second mechanism) for lifting the nozzle 31. In the lifting mechanism of the discharge unit 3, the lifting member for lifting the discharge unit 3 is not particularly limited, but the above-mentioned "lifting member for lifting the mold 5" can be adopted.

[0039] 3, by providing the moving mechanism unit 6A to the discharge unit 3, it becomes possible to change the distance between the nozzle 31 of the discharge unit 3 and the mold 5. For example, the distance between the nozzle 31 and the mold 5 can be changed depending on the adhesiveness of the thermoplastic resin used.

[0040] As shown in 301 in Fig. 3, if the stringy portion 11a of the molten resin composition 11 discharged from the nozzle 31 is thick, it may not be possible to instantaneously heat and cut the stringy portion 11a by the hot air heater 4a. In such a case, as shown in 302 in Fig. 3, the discharge part 3 can be raised by the movement mechanism part 6A, and the thread diameter of the stringy portion 11a can be made less than φ0.40 mm.

[0041] (Modification of the heating and cutting part) A modified example of the thermal cutting unit 4 shown in Fig. 1 will be described. Fig. 5 is a diagram showing the configuration of a modified example of the thermal cutting unit 4 provided in the resin supplying device 10 shown in Fig. 1. As shown in Fig. 5, the thermal cutting unit 4A differs from the thermal cutting unit 4 shown in Fig. 1 in that it is provided with a hot wire 4b. That is, the thermal cutting unit 4A is provided with a hot wire 4b that does not come into contact with the molten resin composition 11 and heats it instantaneously.

[0042] The hot wire 4b is a heat source, and is, for example, a metal wire heated by electrical heating. Even with the configuration of the thermal cutting unit 4A, the stringy portion of the molten resin composition 11 can be heated and cut instantaneously by radiant heat from the hot wire 4b. In the thermal cutting unit 4A, the settings of the temperature of the hot wire 4b and the distance between the hot wire 4b and the molten resin composition 11 are not particularly limited as long as the molten resin composition 11 can be heated and cut instantaneously without contacting the hot wire 4b.

[0043] (Molding device according to this embodiment) The molding device according to the present embodiment includes the resin supply device 10 described above. A suitable molding device is a press molding device. The press molding device includes a pair of dies, a lower die 5 to which the molten resin composition 11 is supplied, and an upper die paired with the die 5. In the press molding device, the pair of dies filled with the molten resin composition 11 are press molded, and the dies are opened to obtain a press molded product. The press molding device includes, for example, a heat press molding machine that performs heat pressing on the die 5, and a cooling press machine that cools and presses the heat-pressed die 5.

[0044] The above-mentioned hot press molding machine and cold press molding machine are not particularly limited as long as they are configured to be capable of hot pressing and cold pressing a pair of dies filled with the molten resin composition 11. The hot press molding machine and cold press molding machine can be conventionally known devices.

[0045] (Resin supply method) The resin supplying method includes a melting step of melting a resin composition containing a thermoplastic resin to produce a molten resin composition, a supplying step of supplying the molten resin composition from a nozzle to a mold, and a moving step of moving at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold. The moving step includes a step of moving at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm. This increases the reliability of the heating and cutting unit instantaneously and without contacting the thread-drawing portion of the molten resin composition.

[0046] The resin supplying method is not particularly limited as long as it includes the melting step, the supplying step, and the moving step, and may be, for example, a resin supplying method using the resin supplying device 10 described above. Fig. 6 is a process diagram showing an example of the resin supplying method. As shown in Fig. 6, the resin supplying method includes a melting step 101, a transporting step 102, a supplying step 103 (discharging step), a moving step 104, and a heat cutting step 105.

[0047] In the melting step 101, a resin composition containing a thermoplastic resin is melted to produce a molten resin composition. As a method for melting the resin composition, a conventionally known method can be adopted as long as it is a method capable of forming a molten resin composition containing a thermoplastic resin. Preferably, the melting step includes a melt-kneading step of melt-kneading the resin composition containing a thermoplastic resin.

[0048] The mode of the melt-kneading step is not particularly limited as long as a melt-kneaded resin composition can be obtained. Specific examples of the melt-kneading step include the following methods (a1) and (a2): (a1) A method in which a resin composition containing a thermoplastic resin is prepared by mixing or blending using a mixer or the like, and then the resin composition is supplied to a melt kneading device and melt kneaded; (a2) A method in which raw materials for a resin composition containing a thermoplastic resin are supplied to a melt kneading apparatus, and a resin composition is prepared (completed) in the melt kneading apparatus, and the resin composition is melt kneaded.

[0049] In the method (a1), the order in which the raw materials of the resin composition containing a thermoplastic resin are mixed or blended (dry blended) is not particularly limited. In the method (a2), the order in which the raw materials of the resin composition containing a thermoplastic resin are fed to a melt kneading device is not particularly limited.

[0050] In the method (a1), the mixing device is not particularly limited, and examples thereof include a ribbon blender, a flash blender, a tumbler mixer, and a super mixer.

[0051] In the above methods (a1) and (a2), the melt kneading device is not particularly limited, and examples thereof include an extruder, a kneader, a Banbury mixer, and a roll, etc. From the viewpoint of excellent productivity and convenience, the melt kneading device is preferably an extruder, and more preferably a twin-screw extruder.

[0052] In the melt-kneading step, for example, when the thermoplastic resin is a P3HA-based resin, the temperature at which the resin composition is melt-kneaded cannot be generally specified because it depends on the physical properties (melting point, weight average molecular weight, etc.) of the P3HA-based resin and the type of additive used. Regarding the temperature at which the resin composition is melt-kneaded, for example, the temperature of the molten resin composition discharged from the discharge part (hereinafter, sometimes referred to as the composition temperature) is preferably 140°C to 190°C, more preferably 150°C to 180°C, and even more preferably 160°C to 170°C. If the composition temperature is 150°C or lower, unmelted P3HA-based resin may be generated. On the other hand, if the composition temperature is 180°C or higher, the P3HA-based resin may be thermally decomposed.

[0053] In the transfer step 102, the molten resin composition is transferred to a discharge part (supply part) having a nozzle. The method of transferring the molten resin composition to the discharge part is not particularly limited, and a known transfer method can be adopted. Preferably, in the transfer step 102, the molten resin composition is quantitatively transferred to the discharge part. In addition, in this case, the transfer device may be any device capable of quantitatively transferring the molten resin composition, and examples thereof include a shot type pump (note: a pump that repeats suction and discharge in a constant volume manner like a syringe), a manifold block, and a gear pump. Among these, it is preferable to use a gear pump as the transfer device. That is, in the transfer step 102, it is preferable to transfer the molten resin composition to the discharge part using a gear pump. The gear pump is not particularly limited as long as it is capable of quantitatively transferring the molten resin composition to the discharge part, and a conventionally known device can be adopted.

[0054] In the transfer step 102, a transfer body may be provided between the transfer device and the discharge part, and the molten resin composition may be transferred from the transfer device to the discharge part via the transfer body. The transfer body is not particularly limited as long as it is configured to transfer the molten resin composition. The transfer body is preferably a hot hose. The hot hose is configured to transfer the molten resin composition having the above-mentioned composition temperature, and is composed of, for example, a heater, a heat-retaining layer, and an inner tube. Among these, from the viewpoints of pressure resistance and heat resistance, it is preferable that the material of the inner tube in the hot hose is Teflon (registered trademark).

[0055] In the supplying step 103, the molten resin composition is supplied from a nozzle to the mold. The method of supplying the molten resin composition from a nozzle to the mold is not particularly limited. From the viewpoint of mass productivity of the press molded article, a nozzle is preferably installed directly above the mold, and the molten resin composition is supplied to the mold by being discharged and dropped from the nozzle into the mold.

[0056] In particular, for a molten resin composition having a relatively high viscosity, it is preferable to intermittently discharge the molten resin composition in the supply step 103. This improves the quantitative supply of the molten resin composition to the mold. In the supply step 103, a nozzle capable of intermittently discharging the molten resin composition can be realized by, for example, an opening / closing mechanism that opens and closes an outlet. The nozzle intermittently discharges the molten resin composition by alternately opening and closing the outlet by the opening / closing mechanism.

[0057] In addition, the intermittent discharge of the molten resin composition may be performed by alternately starting and stopping the discharge operation periodically, or may be performed non-periodically. When the discharge operation is alternately and periodically started and stopped, the period of starting and stopping the discharge operation can be appropriately set according to the composition temperature, the adhesion of the molten resin composition, etc.

[0058] For example, when the thermoplastic resin is a P3HA resin, in the intermittent discharge of the molten resin composition, the discharge operation is preferably stopped every 1 to 30 seconds, more preferably every 1 to 15 seconds. The stop time of the discharge operation is preferably 1 to 15 seconds, more preferably 1 to 5 seconds. This has the advantage that the properties of the P3HA resin can be prevented from being deteriorated due to heat in the molten resin composition of the P3HA resin.

[0059] In the moving step 104, at least one of the nozzle and the mold is moved so as to increase the distance between the nozzle and the mold. The moving step includes a step of moving at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm. This increases the reliability of being able to heat and cut the thread-like portion of the molten resin composition in a non-contact and instantaneous manner in the heating and cutting step described below.

[0060] In the heat cutting step 105, the molten resin composition discharged from the discharge part into the mold is heated and cut instantaneously without contacting the composition. In this way, when the molten resin composition is supplied to the mold, the molten resin composition between the nozzle part and the mold is heated and cut instantaneously without contacting the composition, so that the molten resin composition can be supplied to the mold with good quantitative accuracy.

[0061] Here, "cutting by heating without contact" means that the molten resin composition is heated and cut without contacting the heat source for heating with the molten resin composition. The distance between the heat source and the molten resin composition is not particularly limited as long as the molten resin composition can be cut by instantaneously heating it. "Cutting by heating instantaneously" means that the molten resin composition is cut simultaneously with heating by the heat source. "Simultaneously with heating by the heat source" here means simultaneously within the measurement limit, and means within 3 seconds, preferably within 1 second, from heating by the heat source.

[0062] The method of cutting the molten resin composition in the heat cutting step 105 is not particularly limited as long as the molten resin composition can be cut by heating it instantaneously without contact. For example, the molten resin composition may be cut by heating it instantaneously without contact using radiant heat from a heat source. In this case, the molten resin composition may be cut by heating it instantaneously without contact using hot air. It is preferable to use a hot air heater as a heat source for supplying hot air to the molten resin composition. By adopting the heat cutting method using hot air in this way, new stringing phenomenon due to the cut molten resin composition is unlikely to occur. Therefore, the molten resin composition can be cut at the same place every time for each discharge operation. As a result, the effect of being able to quantitatively supply the molten resin composition to the mold is achieved.

[0063] Alternatively, the molten resin composition may be instantaneously heated and cut without contact using a hot wire (heated metal wire) in the thermal cutting step 105. In this case, the hot wire as a heat source is brought close to the molten resin composition without contact, and the molten resin composition is instantaneously heated and cut by radiant heat from the hot wire.

[0064] In this resin supplying method, the timing of the moving step 104 may be any timing as long as the molten resin composition can be supplied to the mold with a good quantitative quality by cutting in the heating and cutting step 105. However, when the molten resin composition is subjected to intermittent discharge in the supplying step 103 by alternately repeating the start and stop of the discharge operation, a stringy portion of the molten resin composition occurs between the mold and the nozzle after the discharge operation is stopped. Therefore, it is preferable to perform the moving step 104 after the discharge operation is stopped. More preferably, the moving step 104 is performed without a waiting time after the discharge operation is stopped in the supplying step 103.

[0065] (Method of manufacturing press-molded products) The method for producing a press-molded thermoplastic resin product according to the present embodiment includes the above-mentioned resin supplying method as one step. In the method for producing the press-molded product, a pair of dies is used, a lower die to which a molten resin composition is supplied by the resin supplying method, and an upper die that pairs with the lower die. The method for producing the press-molded product includes a press molding step of closing the pair of dies and performing press molding on the molten resin composition supplied to the die by the resin supplying method.

[0066] In the press molding step, the pair of dies is subjected to a heat press using a heat press molding machine. Then, the pair of dies after the heat press is cooled and pressed to perform press molding. After the press molding, the pair of dies are opened to obtain a press molded product.

[0067] The hot press molding machine and the cold press molding machine used in the press molding step are not particularly limited as long as they are configured to hot press and cold press the pair of dies to which the molten resin composition is supplied. Conventionally known devices can be used as the hot press molding machine and the cold press molding machine.

[0068] (thermoplastic resin) The resin composition used in the resin supplying device and the resin supplying method includes a thermoplastic resin. The thermoplastic resin is not particularly limited. Preferred thermoplastic resins include general-purpose resins such as polypropylene, polyethylene, polyvinyl chloride, polyvinyl acetate, polyacetal, polycarbonate, polyamide, acrylonitrile, butadiene, polystyrene, and acrylic polymers, as well as biodegradable resins such as P3HA resin, polylactic acid, polyglycolic acid, polybutylene succinate, polybutylene succinate adipate, polybutylene adipate terephthalate, polybutylene succinate terephthalate, and polycaprolactone. The molten resin composition of these resins may cause the above-mentioned stringing phenomenon when cut with a cutter, depending on the melting conditions of the resin composition. In addition, the resin composition used in the present manufacturing method preferably includes a thermoplastic resin that can be used in press molding.

[0069] In particular, the thermoplastic resin used in the resin supplying device and the resin supplying method is preferably a P3HA resin. In this specification, the term "P3HA resin" refers to a biodegradable aliphatic polyester (preferably a polyester that does not contain an aromatic ring). A P3HA resin is a 3-hydroxyalkanoic acid repeating unit represented by the general formula: [-CHR-CH2-CO-O-] (wherein R is C n H 2n+1 where n is an integer of 1 or more and 15 or less.) is a polyhydroxyalkanoate containing this as a repeating unit.

[0070] The P3HA resin also contains at least one copolymer of 3HB units and other hydroxyalkanoate units, and the 3-hydroxybutyrate units in the poly(3-hydroxyalkanoate) resin account for 94.5 to 98.5 mol %, preferably 95.0 to 98.5 mol %, more preferably 96.0 to 98.5 mol %, and even more preferably 96.5 to 98.0 mol %, of all repeating units (100 mol %).

[0071] When the composition ratio of the 3HB repeating unit is 94.5 mol% or more, the rigidity of the P3HA resin is improved, the crystallization speed is accelerated, burrs are reduced, and productivity tends to be improved. On the other hand, when the composition ratio of the 3HB repeating unit is 98.5 mol% or less, the melting point is lower than the thermal decomposition temperature, so stable and continuous production is possible. The monomer composition ratio of the P3HA resin can be measured by gas chromatography or the like (see, for example, International Publication No. 2014 / 020838).

[0072] More specifically, the P3HA-based resin is preferably one or more selected from the group consisting of copolymers of 3HB and other hydroxyalkanoates, such as poly(3-hydroxybutyrate) (P3HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P3HB3HV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P3HB3HH), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate).

[0073] In addition, P3HA resins produced by microorganisms (microorganism-produced P3HA resins) are usually P3HA resins composed only of D-form (R-form) polyhydroxyalkanoic acid monomer units. Among the microbially produced P3HA resins, P3HB, P3HB3HH, P3HB3HV, P3HB3HV3HH, and P3HB4HB are preferred, with P3HB, P3HB3HH, P3HB3HV, and P3HB4HB being more preferred, in terms of ease of industrial production.

[0074] Microorganisms that produce microbially produced P3HA resins are not particularly limited as long as they have the ability to produce P3HA resins. For example, the first P3HB-producing bacterium was Bacillus megaterium, discovered in 1925, and other natural microorganisms include Cupriavidus necator (formerly classified as Alcaligenes eutrophus and Ralstonia eutropha) and Alcaligenes latus. It is known that P3HB accumulates in the cells of these microorganisms.

[0075] Also, as bacteria that produce copolymers of hydroxybutyrate and other hydroxyalkanoates, Aeromonas caviae, which produces P3HB3HV and P3HB3HH, and Alcaligenes eutrophus, which produces P3HB4HB, are known. In particular, with regard to P3HB3HH, Alcaligenes eutrophus AC32 (FERM BP-6038) (T. Fukui, Y. Doi, J. Bateriol., 179, p4821-4830 (1997)) into which genes of P3HA resin synthesis enzyme group have been introduced is more preferable in order to increase the productivity of P3HB3HH, and microbial cells in which P3HB3HH has been accumulated in the cells by culturing these microorganisms under appropriate conditions are used. In addition to the above, genetically modified microorganisms into which various P3HA resin synthesis-related genes have been introduced may be used according to the P3HA resin to be produced, and culture conditions including the type of substrate may be optimized.

[0076] The molecular weight of the P3HA resin is not particularly limited as long as it shows substantially sufficient physical properties for the intended use. The weight average molecular weight of the P3HA resin is preferably in the range of 100,000 to 1,000,000, more preferably 150,000 to 700,000, further preferably 200,000 to 500,000, and particularly preferably 250,000 to 450,000. When the weight average molecular weight is 100,000 or more, appropriate mechanical strength is obtained. In addition, when the molecular weight is 1,000,000 or less, the increase in melt viscosity can be suppressed, and the moldability is excellent.

[0077] The weight average molecular weight can be measured by gel permeation chromatography (GPC) (Shodex GPC-101, manufactured by Showa Denko K.K.), using a polystyrene gel (Shodex K-804, manufactured by Showa Denko K.K.) as a column, and using chloroform as a mobile phase, and can be calculated as a molecular weight converted into polystyrene. In this case, a calibration curve is prepared using polystyrenes with weight average molecular weights of 31,400, 197,000, 668,000, and 1,920,000. As the column for the GPC, a column appropriate for measuring the molecular weight may be used.

[0078] The resin composition in the present manufacturing method may contain a second P3HA resin in addition to the P3HA resin. The second P3HA resin contains at least one copolymer of 3HB units and other hydroxyalkanoate units, and the amount of 3HB units in the poly(3-hydroxyalkanoate) resin is preferably 65.0 to 90.0 mol, more preferably 68.0 to 88.0 mol, and even more preferably 70.0 to 85.0 mol. When the resin composition further contains the second P3HA resin, the toughness of the molded product is excellent.

[0079] The second P3HA resin is not particularly limited as long as it is different from the P3HA resin. Examples of the second P3HA resin include the resins exemplified as the P3HA resin.

[0080] The content of the second P3HA resin is not particularly limited, but is preferably 50 parts by weight or less, more preferably 45 parts by weight or less, and even more preferably 40 parts by weight or less, relative to 100 parts by weight of the total P3HA resin. The lower limit of the content of the second P3HA resin is not particularly limited, and may be 0 parts by weight. The above-mentioned P3HA resin can be used as the second P3HA resin. In this specification, the term "total P3HA resin" refers to all P3HA resins contained in the resin composition in the present production method.

[0081] The resin composition may contain other resins other than the P3HA resin, as long as the effect of the present invention is not impaired. Examples of such other resins include aliphatic polyester resins such as polybutylene succinate adipate, polybutylene succinate, polycaprolactone, and polylactic acid, and aliphatic aromatic polyester resins such as polybutylene adipate terephthalate, polybutylene sebate terephthalate, and polybutylene azelate terephthalate. Only one type of other resin may be contained, or two or more types may be contained.

[0082] The content of the other resin is not particularly limited, but is preferably 50 parts by weight or less, more preferably 40 parts by weight or less, and even more preferably 30 parts by weight or less, relative to 100 parts by weight of the total P3HA resin. The lower limit of the content of the other resin is not particularly limited, and may be 0 parts by weight.

[0083] The resin composition does not need to contain an inorganic filler, but preferably further contains an inorganic filler. By containing an inorganic filler in the resin composition, the crystallization speed is improved, and effects such as reduction in burrs and improvement in the production cycle are achieved.

[0084] The inorganic filler is not particularly limited, but examples thereof include talc, diatomaceous earth, white clay, clay, calcium carbonate, manganese carbonate, magnesium carbonate, barium sulfate, mica, silica, alumina, zircon, iron oxide, zinc oxide, titanium oxide, silicon nitride, boron nitride, aluminum nitride, silicon carbide, graphite, carbon black, ferrite, graphite, quartz, glass fiber, glass particles, etc. These may be used alone or in combination of two or more kinds.

[0085] The content of the inorganic filler is, for example, 0 to 60 parts by weight, preferably 5 to 50 parts by weight, more preferably 10 to 40 parts by weight, and particularly preferably 15 to 35 parts by weight, based on 100 parts by weight of the total P3HA resin. When the content of the inorganic filler is within the above range, a sufficient crystallization rate and toughness can be achieved at the same time.

[0086] The resin composition may contain additives that can be used together with the P3HA resin, as long as they do not impair the effects of the present invention. Examples of such additives include colorants such as pigments and dyes, odor absorbents such as activated carbon and zeolite, fragrances such as vanillin and dextrin, plasticizers, antioxidants, weather resistance improvers, ultraviolet absorbers, crystal nucleating agents, lubricants, release agents, water repellents, antibacterial agents, and sliding property improvers. Only one type of additive may be contained, or two or more types may be contained. The content of these additives can be appropriately set by those skilled in the art depending on the purpose of use.

[0087] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0088] That is, one embodiment of the present invention is as follows.

[0089] <1> A resin supplying device comprising: a melting section that melts a resin composition containing a thermoplastic resin to produce a molten resin composition; a supplying section having a nozzle that supplies the molten resin composition to a mold; and a moving mechanism section having a moving mechanism that moves at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, wherein the moving mechanism section moves at least one of the nozzle and the mold so that the thread diameter of the molten resin composition extruded from the nozzle into the mold is less than φ0.40 mm.

[0090] <2> the moving mechanism moves at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is φ0.15 mm or less; <1> The resin supplying device according to claim 1 .

[0091] <3> The moving mechanism unit has at least one of a first mechanism for lifting and lowering the mold and a second mechanism for lifting and lowering the nozzle. <1> or <2> The resin supplying device according to claim 1 .

[0092] <4> The moving mechanism includes a control unit that controls the moving mechanism, and the control unit controls the moving mechanism so as to increase the distance between the mold and the nozzle after the supply unit stops supplying the molten resin composition to the mold. <1> ~ <3> 13. The resin supplying device according to claim 12 .

[0093] <5> A heating and cutting unit is provided which heats and cuts the molten resin composition discharged from the nozzle into the mold in a non-contact and instantaneous manner. <1> ~ <4> 13. The resin supplying device according to claim 12 .

[0094] <6> The heat cutting unit includes a hot air supply unit that supplies hot air to the molten resin composition, or a hot wire that heats the molten resin composition instantaneously without contacting the molten resin composition. <5> The resin supplying device according to claim 1 .

[0095] <7> The heat-cutting portion is spaced from the thread of the molten resin composition discharged from the nozzle to the mold by 0.50 mm or more. <5> or <6> The resin supplying device according to claim 1 .

[0096] <8> The moving mechanism of the moving mechanism unit includes an electric cylinder. <1> ~ <7> 13. The resin supplying device according to claim 12 .

[0097] <9> A transfer section is provided for transferring the molten resin composition from the melting section to the supply section, and the transfer section is provided with a gear pump. <1> ~ <8> 13. The resin supplying device according to claim 12 .

[0098] <10> The thermoplastic resin is a poly(3-hydroxyalkanoate)-based resin. <1> ~ <9> 13. The resin supplying device according to claim 12 .

[0099] <11> The poly(3-hydroxyalkanoate)-based resin is at least one selected from the group consisting of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate). <10> The resin supplying device according to claim 1 .

[0100] <12> <1> ~ <11> A molding apparatus comprising the resin supplying apparatus according to any one of claims 1 to 5.

[0101] <13> 1. A resin supplying method comprising: a melting step of melting a resin composition containing a thermoplastic resin to produce a molten resin composition; a supplying step of supplying the molten resin composition from a nozzle to a mold; and a moving step of moving at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, wherein the moving step includes a step of moving at least one of the nozzle and the mold so that a thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm.

[0102] <14> <13> A method for producing a press-molded product, comprising the resin supplying method according to claim 1 as one step. EXAMPLES

[0103] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0104] Example 1 Using an extruder (MFU25TW-60HG-NH manufactured by Technobel), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (sometimes referred to as P3HB3HH) (content of 3HB units in 100 mol% of all repeating units: 5.4 mol%, weight average molecular weight Mw: 400,000) powder was melted at 145°C to produce a molten resin. Thereafter, in order to quantitatively discharge the molten resin, it was sent to a gear pump (KFP-1DH-2.4 manufactured by Kawasaki Heavy Industries) set at 155°C, and then, in order to transport it to the next process, it was sent to an automatic opening and closing nozzle (manufactured by Proceed, outlet diameter φ4.5) set at 155°C via a hot hose (CA13-1000L manufactured by Toyonaka Hot Laboratory). Then, the molten resin was discharged from the opening of the automatic opening and closing nozzle into a mold processed with Teflon (registered trademark).

[0105] After the molten resin had been discharged into the mold and the automatic opening / closing nozzle had closed, the mold was lowered vertically at 500 mm / sec to increase the distance between the automatic opening / closing nozzle and the mold, causing a stringy portion with a thread diameter of φ1.0 mm to form in the molten resin.

[0106] Then, a hot air heater (HKY-15L manufactured by Hibegg) capable of instantly heating air and blowing hot air was used to cut the resulting stringy parts of the molten resin. The hot air temperature was set at 300°C, the flow rate was 10L / min, and the distance between the stringy part of the molten resin to be cut and the tip of the nozzle of the hot air heater was 20mm.

[0107] The thread diameter φ of the stringy portion was measured by a laser displacement meter.

[0108] The molten resin was visually observed to see whether or not the stringy portions formed by the hot air heater had been cut, and was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.

[0109] <Evaluation criteria for the shape of extruded molten resin> Good: The stringy part is cut off. Defective: The stringy part is not cut.

[0110] (Examples 2 and 3, Comparative Examples 1 to 3) The same operation as in Example 1 was carried out, except that the thread diameter φ of the stringy portion was set to the diameter shown in Table 1, and the stringy portion of the molten resin generated by the hot air heater was visually observed and evaluated as to whether it was cut or not. The evaluation results are shown in Table 1.

[0111] [Table 1]

[0112] The results of the evaluation of the cutting of the stringy portions shown in Table 1 show that in Comparative Examples 1 to 3, in which the thread diameter was φ0.4 mm or more, the stringy portions could not be cut with the hot air heater. On the other hand, in Examples 1 to 3, in which the thread diameter was less than 0.4 mm, the stringy portions could be cut with the hot air heater.

[0113] From this, it was found that in Comparative Examples 1 to 3, the thread diameter of the stringy portion was too thick to be cut by the hot air heater, resulting in poor quantitative supply of resin. On the other hand, in Examples 1 to 3, the stringy portion had a thread diameter that could be cut by the hot air heater, so it was found that molten resin could be supplied to the mold with good quantitative supply. [Industrial Applicability]

[0114] The present invention can be suitably used in, for example, the field of production of press-molded articles using P3HA-based resins, and other fields. [Explanation of symbols]

[0115] 1 Extruder (melting section) 2 Transfer section 2a Gear Pump 3 Discharge section (supply section) 4, 4A heating cutting section 4a Hot air heater (hot air supply part) 4b Hot Wire 5. Mold 6, 6A Moving mechanism section 10 Resin supply device 11 Molten resin composition 11a Stringy portion (string of molten resin composition) 31 Nozzle 61 Electric Cylinder 101 Melting process 102 Transfer process 103 Supply process 104 Moving process 105 Heat cutting process

Claims

1. a melting section for melting a resin composition including a thermoplastic resin to produce a molten resin composition; A supply unit having a nozzle for supplying the molten resin composition to a mold; a movement mechanism unit having a movement mechanism that moves at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, The moving mechanism moves at least one of the nozzle and the mold so that the thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm.

2. The resin supplying device according to claim 1 , wherein the movement mechanism moves at least one of the nozzle and the mold so that a thread diameter of the molten resin composition discharged from the nozzle to the mold is φ0.15 mm or less.

3. The resin supplying device according to claim 1 , wherein the moving mechanism portion has at least one of a first mechanism for raising and lowering the mold and a second mechanism for raising and lowering the nozzle.

4. The moving mechanism unit includes a control unit that controls the moving mechanism, The resin supplying device according to claim 1 or 2, wherein the control unit controls the moving mechanism to increase the distance between the mold and the nozzle after the supply unit stops supplying the molten resin composition to the mold.

5. 3. The resin supplying device according to claim 1, further comprising a heating and cutting section that heats and cuts the molten resin composition discharged from the nozzle into the mold instantaneously without contacting the composition.

6. The resin supplying device according to claim 5 , wherein the heat cutting section comprises a hot air supplying section that supplies hot air to the molten resin composition, or a hot wire that heats the molten resin composition instantaneously without contacting the molten resin composition.

7. The resin supplying device according to claim 5 , wherein the heat cutting portion is spaced from the thread of the molten resin composition discharged from the nozzle to the mold by 0.50 mm or more.

8. The resin supplying device according to claim 1 , wherein the moving mechanism of the moving mechanism portion includes an electric cylinder.

9. A transfer section is provided for transferring the molten resin composition from the melting section to the supplying section, The resin supplying device according to claim 1 , wherein the transfer unit comprises a gear pump.

10. 3. The resin supplying device according to claim 1, wherein the thermoplastic resin is a poly(3-hydroxyalkanoate)-based resin.

11. The poly(3-hydroxyalkanoate)-based resin is one or more selected from the group consisting of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyoctanoate), and poly(3-hydroxybutyrate-co-3-hydroxydecanoate). The resin supplying device according to claim 10.

12. A molding apparatus comprising the resin supplying apparatus according to claim 1 or 2.

13. A melting step of melting a resin composition containing a thermoplastic resin to produce a molten resin composition; a supplying step of supplying the molten resin composition from a nozzle to a mold; a moving step of moving at least one of the nozzle and the mold so as to increase the distance between the nozzle and the mold, The resin supplying method, wherein the moving step includes a step of moving at least one of the nozzle and the mold so that a thread diameter of the molten resin composition discharged from the nozzle to the mold is less than φ0.40 mm.

14. A method for producing a press-molded product, comprising the resin supplying method according to claim 13 as one step.

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