JP3893080B2 - Thermoplastic resin molding method and molding apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a thermoplastic resin molding method and molding apparatus.
[0002]
[Background Art and Problems to be Solved by the Invention]
In the thermoplastic resin injection molding method generally known so far, the molten resin is injected and filled with the cavity closed by clamping. In this case, in particular, when an attempt is made to mold a molded product having a thin wall and a large surface area, the pressure difference in the resin becomes large between the molten resin filling port and the cavity end. At this time, in order to fill the molten resin up to the end of the cavity, it is necessary to increase the injection filling pressure of the molten resin. Along with this, the mold clamping pressure of the cavity that can withstand the filling pressure is required, but increasing the mold clamping pressure increases the flow resistance of the molten resin to be filled, which further increases the pressure difference in the cavity. It becomes. This has caused problems such as molecular orientation and distortion of the molded product.
[0003]
As a means for solving this problem, an injection compression molding method is known. In this injection compression molding method, when filling the cavity with the molten resin, the pressure inside the molten resin is kept low by temporarily increasing the cavity volume, and after filling the predetermined amount of the molten resin, The molten resin is pressurized and compressed using a fastening mechanism or the like. Thereby, generation | occurrence | production of the molecular orientation of resin can be suppressed and a molded article with few residual stresses can be obtained. However, in this method, when a fine mold pattern is transferred to the molten resin, the molten resin does not sufficiently enter the mold pattern, and sufficient transfer of the mold pattern to the molten resin cannot be obtained.
[0004]
An object of the present invention is to provide a thermoplastic resin molding method and a molding apparatus for suppressing molecular orientation and distortion inside the resin and transferring a fine mold pattern onto the resin surface.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a method of molding a thermoplastic resin by filling a mold with a molten resin,
CO ₂ Filling a molten resin in a mold container which is disposed in a chamber filled with an open top surface;
There is provided a method for molding a thermoplastic resin including pressurizing a molten resin filled in a mold container using a press mold.
[0006]
In the present invention, injection molding is performed in which molten resin is injected and filled into a mold. The molten resin is pre-CO 2 ₂ Is filled in a mold container having an open upper surface. Since the mold container has an open upper surface, the flow resistance when the molten resin is filled is extremely low, so that the pressure difference of the molten resin hardly occurs in the container. CO filled in the chamber in advance ₂ By functioning as a plasticizer for the molten resin, the viscosity of the molten resin is kept low. Due to the low flow resistance and low viscosity of the molten resin, the molten resin sufficiently spreads to the end of the mold, and the molten resin sufficiently penetrates into the molding pattern formed on the bottom surface of the mold container. Next, the mold container is clamped by closing the open surface of the mold container using a press mold and pressurizing the molten resin. When the surface of the molten resin is cooled and solidified by the mold container and the press mold, the mold pattern is transferred to the surface of the molten resin. The thermoplastic resin can be molded by cooling the molten resin in this state. In the present invention, the molten resin to be injected and filled is preliminarily pressurized CO. ₂ Is preferably impregnated. Pressurized CO pre-impregnated inside the molten resin ₂ However, since it functions as a plasticizer for the molten resin, the viscosity of the molten resin can be kept even lower.
[0007]
In the present invention, the step of pressurizing the molten resin with a press die is performed by CO. ₂ It may be carried out in a chamber filled with or may be carried out by transferring the mold container to another place.
[0008]
According to a second aspect of the present invention, a method of molding a thermoplastic resin by filling a mold with a molten resin,
CO ₂ Filling a molten resin in a mold container which is disposed in a chamber filled with an open top surface;
There is provided a method for molding a thermoplastic resin including rotating a mold filled with the molten resin.
[0009]
In the present invention, injection molding is performed in which molten resin is injected and filled into a mold. The molten resin is pre-CO 2 ₂ Is filled in a mold container having an open upper surface. Since the mold container has an open upper surface, the flow resistance when the molten resin is filled is extremely low, so that the pressure difference of the molten resin hardly occurs in the container. CO filled in the chamber in advance ₂ By functioning as a plasticizer for the molten resin, the viscosity of the molten resin is kept low. Due to the low flow resistance and low viscosity of the molten resin, the molten resin sufficiently spreads to the end of the mold, and the molten resin sufficiently penetrates into the molding pattern formed on the bottom surface of the mold container. Further, the mold container is rotated using a rotary stage or the like to make the thickness of the molten resin on the mold container uniform. By cooling the molten resin in this state, a thermoplastic resin thin film can be formed. In the present invention, the molten resin to be injected and filled is preliminarily pressurized CO. ₂ Is preferably impregnated. Pressurized CO pre-impregnated inside the molten resin ₂ However, since it functions as a plasticizer for the molten resin, the viscosity of the molten resin can be kept even lower.
[0010]
According to a third aspect of the present invention, an apparatus for molding a thermoplastic resin,
A mold container with an open top;
A chamber for containing the mold container;
CO in the chamber ₂ CO to supply ₂ A supply section;
CO ₂ An injection filling device for filling the molten resin into a mold container accommodated in the chamber supplied with
And a pressurizing device for pressurizing the molten resin injected and filled in the mold container. An apparatus for molding a thermoplastic resin is provided.
[0011]
In the molding apparatus of the present invention, CO ₂ In the chamber filled with the molten resin, the mold container is filled with the molten resin by the injection filling device. CO ₂ Functions as a plasticizer for the molten resin, so that the viscosity of the molten resin is kept low. Further, since the upper surface of the mold container is open, the flow resistance when the molten resin flows into the mold container is lowered. Therefore, the molten resin can be distributed very easily and quickly over the entire surface of the transfer pattern of the mold container. Thereafter, the molten resin is pressurized through the open surface of the mold container with a pressurizing device such as a press piston, and then cooled.
[0012]
In the present invention, it is desirable that the injection filling device and the pressurizing device are disposed in the same chamber. By arranging the injection filling device and the pressurizing device in the same chamber, the injection filling of the molten resin into the mold container and the molding by the pressure of the molten resin can be performed continuously. In addition, it is desirable that the chamber has a transfer device for transferring the mold container filled with the molten resin from the injection filling device to the pressurizing device. By using the transfer device in the chamber, the mold can be used both when the injection filling device and the pressurizing device are arranged in the same chamber and when the injection filling device and the pressurizing device are arranged in different chambers. A container can be efficiently moved between apparatuses. Furthermore, it is desirable to have a stamper at the bottom of the mold container. By exchanging the stamper, a molded product to which various patterns are transferred can be formed.
[0013]
According to a fourth aspect of the present invention, there is provided an apparatus for molding a thermoplastic resin,
A mold container with an open top;
A chamber for containing the mold container;
CO in the chamber ₂ CO to supply ₂ A supply section;
CO ₂ An injection filling device for filling the molten resin in a mold housed in the chamber supplied with
And a rotating device for rotating the mold container. An apparatus for molding a thermoplastic resin is provided.
[0014]
In the molding apparatus of the present invention, CO ₂ In the chamber filled with the molten resin, the mold container is filled with the molten resin by the injection filling device. CO ₂ Functions as a plasticizer for the molten resin, so that the viscosity of the molten resin is kept low. Further, since the upper surface of the mold container is open, the flow resistance when the molten resin flows into the mold container is lowered. Therefore, the molten resin can be distributed very easily and quickly over the entire surface of the transfer pattern of the mold container. Since the rotating device rotates the mold container filled with the molten resin, the thickness of the resin in the mold container can be made uniform.
[0015]
In the present invention, it is desirable that the injection filling device and the rotating device are disposed in the chamber. By arranging the injection filling device and the rotation device in the same chamber, it is possible to continuously perform injection filling of the molten resin into the mold container and molding by rotation of the molten resin.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
[0017]
【Example】
A molding apparatus for molding the thermoplastic resin used in the present invention will be described with reference to FIGS. As shown in FIG. 2, the present molding apparatus mainly includes a chamber 1, an injection filling unit 5, a mold clamping unit 4, a molded product extraction unit 21, and a moving mold preheating unit 22. FIG. 1 is a view showing a cross section taken along line A′-A ′ in FIG. 2.
[0018]
As shown in FIG. 2, the chamber 1 is formed in a cylindrical shape having a diameter of 1000 mm and a height of 200 mm. The interior of the chamber 1 is divided into four sub-chambers 11, 12, 13 and 14 by walls 15, 16, 17 and 18 extending radially to the outer periphery around the central axis AX of the cylinder. . Each of the walls 15, 16, 17 and 18 can be moved up and down by a mechanism (not shown) that moves up and down. For example, the sub chamber 11 is sealed when the walls 15 and 16 are raised. The chamber 1 is provided with a transfer device 19 for rotating the moving mold 20 around the central axis AX of the chamber 1. The transport device 19 includes a rotor 100 positioned on the central axis AX and four arms 101 extending radially from the rotor 100, and a movable mold 20 is held at the tip of each arm. A chuck (not shown) is provided. Only when the moving mold 20 moves between the sub-chambers due to the rotation of the rotor 100 (clockwise), when the corresponding wall is lowered to connect the atmosphere between the sub-chambers, and the movement of the moving mold 20 is completed, The corresponding wall rises and isolates the subchambers again. As shown in FIG. 2, the moving mold 20 sequentially moves through the sub-chambers 11 to 14 by the rotation of the rotor 100, and work is performed in each sub-chamber. In the subchamber 11, resin injection molding and mold clamping (compression) are performed on the movable mold 20. The sub-chambers 12 and 14 are standby chambers. In the sub-chamber 13, the molded product is taken out and the moving mold 20 is heated.
[0019]
Each moving mold 20 is a cylindrical metal container made of HPM 38 made by Hitachi Metals, which is a steel material for molds. As shown in FIG. 3, a stamper 23 on which a desired concavo-convex pattern is formed is installed on the bottom surface 20 a of the moving mold 20 via a stamper presser (not shown).
[0020]
As shown in FIGS. 1 and 2, an injection filling unit 5 and a mold clamping unit 4 are arranged above the sub chamber 11 in order in the clockwise direction. The injection filling unit 5 and the mold clamping unit 4 perform injection filling of the molten resin into the movable mold 20 and mold clamping in the sub chamber 11, respectively.
[0021]
In the sub-chamber 13 facing the sub-chamber 11 with respect to the central axis AX, a molded product take-out part 21 and a moving mold preheating part 22 are provided, and the inside of the sub-chamber 13 is maintained at atmospheric pressure. High-frequency induction heating, microwave heating, or the like is used as heating means in the moving mold preheating unit 22. By heating the moving mold 20 in advance, the temperature of the molten resin injected and filled on the moving mold 20 can be maintained at the glass transition temperature or higher.
[0022]
As shown in FIG. 1, the injection filling section 5 includes a molten resin plasticizing section 2, an injection section 3, and a stage 70. The plasticizing part 2 and the injection part 3 are constituted by a pre-plastic injection mechanism. The plasticizing part 2 is arranged so that the nozzle 2 ′ at the tip is obliquely downward with respect to the horizontal plane. The plasticizing unit 2 is mainly composed of a cylinder 33, a screw 37 and a heater 36. The screw 37 is disposed inside the cylinder 33 and plasticizes the molten resin filled in the cylinder 33. The heater 36 is disposed around the cylinder 33 and heats the cylinder 33 in order to maintain the plastic state of the molten resin plasticized in the cylinder 33. A first vent port 34 and a second vent port 35 are formed on the side surface of the cylinder 33. The first vent port 34 is used for exhausting the volatile gas such as the monomer component generated from the resin plasticized by the rotation of the screw 37 in the cylinder 33 to the outside using the vacuum pump 32. The second vent port 35 is a pressurized CO. ₂ CO ₂ Pressurized CO from the gas cylinder 38 ₂ It is used for filling the cylinder 33 through the generator 39.
[0023]
The injection unit 3 includes an injection cylinder 40 and a gate opening / closing cylinder 42. The injection cylinder 40 is disposed below the plasticizing part 2 and extends in the horizontal direction. An injection plunger 41 is disposed inside the injection cylinder 40, and the molten resin filled in the injection cylinder 40 is injected. The injection plunger 41 is disposed at a position retracted from a molten resin supply port 40 ′ formed near the tip of the injection cylinder 40. Depending on the position of the injection plunger 41, the amount of molten resin to be injected and filled into the movable mold 20 through the gate opening / closing cylinder 42 is determined. Further, the inside of the injection cylinder 40 and the nozzle 2 ′ of the plasticizing unit 2 communicate with each other through the molten resin supply port 40 ′ of the injection cylinder 40. The gate opening / closing cylinder 42 extends in the vertical direction adjacent to the distal end portion of the injection cylinder 40, and the distal end reaches the inside of the sub-chamber 11. A gate opening / closing piston 45 is disposed inside the gate opening / closing cylinder 42, and the molten resin filled in the gate opening / closing cylinder 42 is injected into the sub chamber by the gate opening / closing piston 45. Further, a band heater 43 is installed around the gate opening / closing cylinder 42, and the temperature control of the molten resin filled in the gate opening / closing cylinder 42 is performed by the band heater 43. The nozzle 40 ″ of the injection cylinder 40 communicates with the gate opening / closing cylinder 42 at a predetermined height position. The stage 70 is disposed in the sub chamber 11 below the gate opening / closing cylinder 42. It is installed on the motor 90 so as to be rotatable about the axis BX of the motor 90. On the upper surface of the stage 70, the moving mold 20 conveyed by the conveying device (19) is placed, and this moving mold is placed. 20 is injection-filled with molten resin.
[0024]
As shown in FIG. 1, the mold clamping unit 4 mainly includes a press stage 50, a stage driver 51, and a press cylinder 52. The press stage 50 is installed on the upper surface of the stage driver 51 inside the sub chamber 11. Further, on the upper surface of the press stage 50, the moving mold 20 conveyed by the conveying device (19) from the injection filling unit 5 is placed. By driving the stage driver 51, the movable mold 20 moves up and down via the press stage 50. The press cylinder 52 is installed in the upper part of the sub chamber 11. Inside the press cylinder 52, a press piston 53 that moves vertically in the cylinder is installed. A press die 54 is attached to the lower surface of the press piston 53. When the press die 54 is lowered, the press die 54 is fitted into the concave portion of the moving die 20 to compress the resin in the concave portion.
[0025]
Next, a method for molding a thermoplastic resin will be described with reference to FIGS. First, the injection filling process of the molten resin will be described. A pellet (molding material) made of polycarbonate is supplied to a hopper 30 of the plasticizing unit 2 in the injection filling unit 5 from a dryer (not shown). Next, the pellets are heated inside the hopper 30 by a heater 31 installed around the hopper 30, and drying is further promoted. At this time, the inside of the hopper 30 is deaerated by the vacuum pump 32. Next, the dried pellets are supplied to the cylinder 33 of the plasticizing unit 2. Volatile gas generated at the time of plasticization from the first vent port 34 is degassed by the vacuum pump 32, and the molten resin is starved. Next, pressurized CO is supplied from the second vent port 35 into the cylinder 33 to which the molten resin is supplied. ₂ At a pressure of 10 MPa.
[0026]
Pressurized CO in the cylinder 33 ₂ The molten resin filled with is filled into the injection cylinder 40 through the nozzle 2 ′ of the cylinder 33 as the screw 37 rotates. Next, by moving the injection plunger 41 of the injection cylinder 40 forward (extrusion), only the molten resin supplied into the injection cylinder 40 is supplied to the gate opening / closing cylinder 42 through the nozzle 40 ″ of the injection cylinder 40. In a state where the tip of the injection plunger 41 has moved to the nozzle 40 ″ of the injection cylinder 40, the molten resin supply port 40 ′ is blocked by the injection plunger 41. Thereby, the inside of the cylinder 33 of the plasticizing part 2 is closed. By rotating the screw 37 in the cylinder 33 in this state, the pressure of the molten resin existing in the cylinder 33 can be maintained high. Next, the temperature of the molten resin supplied to the gate opening / closing cylinder 42 is controlled by the band heater 43. Next, by raising the tip 46 of the gate opening / closing piston 45, the gate 47 of the gate opening / closing cylinder 42 is opened, and the movable mold 20 is filled with molten resin.
[0027]
FIG. 3 is an enlarged view of the portion A in FIG. From the gate 47 of the gate opening / closing cylinder 42, the molten resin RS is filled onto the stamper 23 installed on the moving mold 20. At this time, since the moving mold 20 is a container whose upper side is opened, the molten resin RS flows out onto the stamper 23 installed on the bottom surface 20a without restricting its flow path. Inside the sub-chamber 11 is CO ₂ Pressurized CO from the gas cylinder 38 ₂ CO supplied via the generator 39 ₂ Is pre-filled at a pressure of 10 MPa. This CO ₂ However, it functions as a plastic material for the molten resin RS. Thereby, the viscosity of injection-filled molten resin RS is kept low. This CO ₂ The pressurized CO impregnated in the molten resin RS ₂ Further, foaming due to volatilization of residual gas and foaming due to air or the like being taken into the molten resin can be suppressed. Furthermore, CO in the subchamber 11 ₂ By maintaining the pressure of the pressure constant, the pressurized CO pre-impregnated into the molten resin RS ₂ The change of content of can be suppressed. Thereby, even when a stamper having a fine pattern with a high aspect ratio is installed in the moving mold 20, the molten resin can be sufficiently infiltrated to reach the details of the pattern.
[0028]
Next, the process of transferring the mold pattern to the molten resin will be described with reference to FIG. First, the moving mold 20 filled with the molten resin in the injection filling unit 5 is moved onto the press stage 50 in the same sub-chamber using the transport device (19). Next, the press die 53 is pushed down in the vertical direction so that the press die 54 is fitted to the movable die 20. Thereby, the molten resin on the moving mold 20 is compressed. Since the surface of the exposed molten resin is compressed by the press die 54 with a substantially uniform pressure, the internal pressure difference of the molten resin hardly occurs. The surface of the press die 54 at this time is CO. ₂ It is desirable that the temperature is higher than the glass transition temperature of the molten resin impregnated with. Since the molten resin comes into contact with the die surface of the press die 54 with substantially equal pressure, the surface of the molten resin is uniformly cooled and solidified. Further, the molten resin is cooled in this state, and the inside of the molten resin is solidified, whereby the thermoplastic resin is molded.
[0029]
The resin molded product thus molded is moved in the order of the sub-chambers 12 and 13 by the transfer device (19). As shown in FIG. 2, when moving the movable mold 20 from the subchamber 11 to the subchamber 13, first, the wall 16 positioned between the subchambers 11 and 12 is lowered, and the atmosphere of the subchambers 11 and 12 is lowered. To communicate. Next, the moving mold 20 is transferred from the sub chamber 11 to the sub chamber 12 by the transfer device 19. With the moving mold 20 completely entering the sub-chamber 12, the wall 16 rises and the atmosphere of the sub-chambers 11 and 12 is isolated. Next, the wall 17 located between the subchambers 12 and 13 is lowered, and the atmosphere of the subchambers 12 and 13 is communicated. After the moving mold 20 is moved from the subchamber 12 to the subchamber 13 by the transfer device 19, the wall 17 is raised. By doing so, the movable mold 20 can be transferred from the sub-chambers 11 to 13 without directly communicating the sub-chambers 11 and 13.
[0030]
The moving mold 20 transferred to the sub-chamber 13 is positioned in the molded product takeout part 21. In the molded product take-out unit 21, the molded product solidified in the movable mold 20 is taken out of the apparatus from an unillustrated outlet. Next, the empty moving mold 20 is transferred to the moving mold preheating unit 22 by the transfer device 19. In the moving mold preheating part 22, the moving mold 20 is heated for the next injection molding.
[0031]
The moving mold 20 heated by the moving mold preheating unit 22 is moved by the transfer device 19 in the order of the sub chambers 14 and 11. First, the wall 18 located between the subchambers 13 and 14 is lowered, and the atmosphere of the subchambers 13 and 14 is communicated. Next, the moving mold 20 is transferred from the sub chamber 13 to the sub chamber 14 by the transfer device 19. With the moving mold 20 completely entering the sub-chamber 14, the wall 18 rises and the atmosphere of the sub-chambers 13 and 14 is isolated. Next, the wall 15 located between the subchambers 14 and 11 is lowered, and the atmosphere of the subchambers 14 and 11 is communicated. After the moving mold 20 is moved from the subchamber 14 to the subchamber 11 by the transfer device 19, the wall 15 is raised. In this way, the moving mold 20 can be transferred from the sub-chamber 13 to 11 without directly connecting the sub-chambers 13 and 11, and the heat generated in the moving mold preheating part 22 in the sub-chamber 13 is transferred to the sub-chamber. 11 is prevented from being transmitted.
[0032]
As described above, a series of molding operations is performed by moving the movable mold 20 between the operating parts of the molding apparatus. Since the conveying device 19 of the main molding apparatus is provided with the four arms as described above, the four movable molds can be simultaneously processed by the respective operation units. For example, in the injection filling unit, another moving mold 20 is heated by the moving mold preheating unit 22 as a preparation step for filling the molten resin while a certain moving mold 20 is being filled with the molten resin. . By performing such an efficient operation inside the apparatus, the throughput of the molded product is improved.
[0033]
[Modification]
A modification of the present invention will be described with reference to FIG. In the above embodiment, after the movable mold 20 is filled with the molten resin, the movable mold 20 is moved to the mold clamping unit 4 and the mold clamping unit 4 clamps the molten resin. After filling the movable mold 20 with the molten resin, the movable mold 20 is rotated by driving the motor 90 connected to the stage 70 in a state where the movable mold 20 is disposed below the injection filling unit 5. As the mold rotates, the molten resin injected and filled onto the moving mold 20 spreads over the entire mold surface due to the centrifugal force of the moving mold 20, and the film thickness becomes uniform. In this state, the thermoplastic resin can be formed by cooling using a cooling device (not shown) or the like embedded in the stage 70. By using this method, it is possible to mold a thin molded article having a thickness of about 0.1 mm without clamping.
[0034]
In the above examples and modifications, polycarbonate was used as the pellet (molding material). However, the present invention is not limited to this. For example, polyethylene, polystyrene, polyolefin, polyacetal, polycarbonate, polyphenylene oxide, polymethylpentene, polyetherimide, ABS Resins or the like or copolymers thereof can be used. In particular, CO ₂ A thermoplastic resin in which the glass transition temperature is lowered by dissolving is desirable.
[0035]
In the above-described embodiments and modifications, the molten resin is filled from one gate, but a plurality of gates may be provided and the molten resin may be filled from these gates. When the molten resin is filled from a plurality of gates, the molten resin is filled more uniformly into the moving mold 20 than when the molten resin is filled from a single gate and cooled uniformly. You may adjust suitably the position which arrange | positions a 1 or several gate according to the shape of a molded article. Thereby, the molten resin can be more efficiently filled into the moving mold according to the shape of the molded product.
[0036]
In the above-described embodiments and modifications, the moving mold 20 is preheated in the sub-chamber 13 different from the sub-chamber 11, but the heater 71 built in the stage 70 on which the moving mold 20 is placed is used to The moving mold 20 may be heated in the chamber 11. Further, in the above embodiment, in the mold pattern transfer process, the temperature of the surface of the molten resin is controlled by bringing the molten resin into contact with the press mold 54. However, the press piston 53 and the moving mold in which the press mold 54 is installed are controlled. You may control temperature using the heater 75 and the cooling device 76 which were each incorporated in the press stage 50 in which the type | mold 20 is mounted. By controlling the temperature of the press mold 54 and the moving mold 20 using the heater 75 and the cooling device 76, the molten resin is prevented from being rapidly cooled. Thereby, generation | occurrence | production of the cooling nonuniformity and foaming of the molten resin surface can be suppressed. As the cooling device 76, the cooling water may be refluxed. In addition, by operating the solenoid valve 77, CO in the chamber ₂ May be allowed to escape from the chamber, thereby lowering the glass transition temperature of the molten resin and promoting cooling.
[0037]
After the molten resin is solidified or with the press mold 54 and the moving mold 20 fitted, the CO in the sub-chamber ₂ May be replaced. This replacement is performed by the following operation. After the sealed sub-chamber 11 is opened to the atmosphere via the electromagnetic valve 60, the electromagnetic valve 61 is operated to rapidly reduce the pressure by the vacuum pump 32. Next, by operating the solenoid valve 62, the pressurized CO ₂ Pressurized CO from the generator 39 to the subchamber 11 ₂ Supply. Thereby, excess oxygen generated in the sub-chamber, volatile components from the resin, residual gas in the fine pattern, and the like can be exhausted completely.
[0038]
In the above embodiment, the movable mold 20 is moved in the sub-chamber to perform the injection filling of the molten resin and the transfer of the mold pattern. However, the movement mechanism of the injection filling section 5 and the mold clamping section 4 is provided and moved. The injection filling and mold pattern transfer may be performed by moving the injection filling unit 5 and the mold clamping unit 4 while the mold 20 is fixed. Furthermore, the injection filling unit 5 and the mold clamping unit 4 may be installed in independent chambers to perform injection filling and mold pattern transfer.
[0039]
【The invention's effect】
In the present invention, since the mold is filled with the molten resin having a uniform and low viscosity, it is particularly suitable for molding using a molding material having low fluidity. In addition, since the molten resin is filled in a state where the mold is opened in the chamber, even when manufacturing a large molded product, the filling pressure of the molten resin and the pressure at the time of mold clamping can be lowered. The structure of the injection molding apparatus can be simplified. Furthermore, after injection filling with molten resin, it is possible to produce a molded product with a uniform thickness by rotating the mold without performing mold pattern transfer in the mold clamping process. Can be
[0040]
Further, in the present invention, when the molten resin is injected and filled, a high filling pressure and a mold clamping pressure are not required, so that the mold can be made thin. This mold has a smaller heat capacity and better heat conduction efficiency. Therefore, it is easy to control the temperature of the mold, and it is possible to suppress the heat of the molten resin from being rapidly taken away by the mold, and thus it is possible to manufacture a molded product having a very stable structure inside the resin.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an injection filling part, a mold clamping part, and a sub-chamber located below the injection filling part of a thermoplastic resin molding apparatus used in the present invention.
FIG. 2 is a schematic plan view of a chamber in the thermoplastic resin molding apparatus used in the present invention.
FIG. 3 is a view schematically showing a state of filling a molten resin in a thermoplastic resin molding apparatus used in the present invention.
[Explanation of symbols]
1, 11, 12, 13, 14 Chamber
2 Plasticization part
3 Injection part
4 Clamping part
5 Injection filling part
15, 16, 17, 18 walls
20 Moving mold
21 Molded product removal part
22 Moving mold preheating part
23 Stamper
33 cylinders
40 Injection cylinder
41 Injection plunger
42 Gate open / close cylinder
50 Press stage
53 Press piston
54 Press mold
90 motor

Claims (9)

A method of molding a thermoplastic resin by filling a mold with a molten resin,
Filling a molten resin in a mold vessel disposed in a chamber filled with CO ₂ and having an open top surface;
A method for molding a thermoplastic resin, comprising pressurizing a molten resin filled in a mold container with a press mold. The method for molding a thermoplastic resin according to claim 1, wherein the step of pressurizing the molten resin is performed in the chamber. A method of molding a thermoplastic resin by filling a mold with a molten resin,
Filling a molten resin in a mold vessel disposed in a chamber filled with CO ₂ and having an open top surface;
Molding a thermoplastic resin comprising the molten resin to mold containers filled, to bicycles around a predetermined rotation axis of the mold container. An apparatus for molding a thermoplastic resin,
A mold container with an open top;
A chamber for containing the mold container;
And CO ₂ supply unit for supplying the CO ₂ into the chamber;
An injection filling device for CO ₂ is filled with the molten resin in the stowed the mold container in the supplied the chamber;
And a pressurizing device for pressurizing the molten resin injected and filled in the mold container. The apparatus for molding a thermoplastic resin according to claim 4, wherein the injection filling device and the pressurizing device are arranged in the chamber. 6. The apparatus according to claim 4, further comprising a transfer device in the chamber for transferring the mold container filled with the molten resin from the injection filling device to the pressurizing device. The apparatus according to claim 4, further comprising a stamper at the bottom of the mold container. An apparatus for molding a thermoplastic resin,
A mold container with an open top;
A chamber for containing the mold container;
And CO ₂ supply unit for supplying the CO ₂ into the chamber;
An injection filling device for CO ₂ is filled with the molten resin in the stowed the mold container in the supplied the chamber;
A rotary device having a predetermined rotation axis, around the rotation axis, the mold container and the rotating device. Used to bicycles; apparatus for molding a thermoplastic resin characterized by having a. 9. The apparatus for molding a thermoplastic resin according to claim 8, wherein the injection filling device and the rotating device are disposed in the chamber.

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