JP2010173120A - Mold for molding thin plate moldings, injection molding machine, and injection molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding thin plate moldings in which at least two cavities are arranged between a fixed mold and a movable mold, and a gate is formed at the end of each cavity and which, when a plurality of the thin plate moldings are molded simultaneously, can mold each of the thin plate moldings in a good condition by a simple adjustment, an injection molding machine, and an injection molding method. <P>SOLUTION: In the mold 11 in which at least two cavities 14a and 14b are arranged between the fixed mold 13 and the movable mold 12, and the gate P3 is formed at the end of each cavity 14a, or 14b, blocks 17, 22, and 42 which constitute cavity-forming surfaces 23 and 43a and can be exchanged or repaired and molten resin flow control parts 19a and 19b which intercept or adjust the passage of a molten resin to the cavities 14a and 14b are provided, and the molten resin flow control parts 19a and 19b are controlled individually. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a molding die for a thin plate molded product, an injection molding machine, and an injection molding method used when simultaneously molding a plurality of thin plate molded products.

As a molding die for simultaneously molding a plurality of thin plate molded products such as a light guide plate using an injection molding machine, the one described in Patent Document 1 is known. However, when simultaneously forming a plurality of thin plate molded products such as a light guide plate and a diffusion plate using the molding die of Patent Document 1, the thicknesses of the thin plate molded products molded in both cavities are not uniform or uniform. There was a problem that it was very difficult to adjust. One reason for this is that in the case of optical molded products such as light guide plates and diffuser plates, a gate is provided at the end of the cavity, and the ratio of the plate thickness to the flow length in the cavity is greater than that of the disk substrate. Since the plate thickness is small and extremely thin, the plate thickness is not uniform due to a slight error in the cavity, resulting in insufficient filling. Conventionally, in correspondence with them, the plate thickness is mainly adjusted by sandwiching a thin plate such as a shim on the back surface of the core block. However, in order to sandwich the shim between the back of the core block, it is necessary to disassemble the mold, and it is unlikely that a good light guide plate can be formed equally in both cavities with a single adjustment. However, it was necessary to adjust the shim many times, and it took a very long time to adjust.

The disk substrate molding dies described in Patent Document 2 and Patent Document 3 can individually control the gates of the respective cavities when simultaneously molding a plurality of disk substrates. However, in the case of molding a disk substrate, the standards for the thickness of the disk substrate and the groove on the signal surface are standardized, and the cavity is formed by the corresponding mirror plate and stamper, so the thickness of each cavity is adjusted. There was almost no necessity, and the thickness difference and molding error of the disk substrate to be molded were small. In the case of molding the disk substrate, the molten resin is injected radially from the center of the cavity, and the ratio of the plate thickness to the flow length is relatively large, so it is relatively easy to make the plate thickness difference within the specification. .

JP 2008-307882 A (0021, FIG. 2) Japanese Patent No. 3483810 (Claim 2, FIG. 2) JP 2001-179780 A (Claim 1, FIG. 1)

In the present invention, in view of the above problems, there is provided a molding die for a thin plate molded product in which at least two cavities are disposed between a fixed die and a movable die, and a gate is provided at an end of the cavity. When using a plurality of thin sheet molded products at the same time, a plurality of thin sheet molded products can be molded in good condition by simple adjustment, a molding die for a thin sheet molded product, an injection molding machine, and An object is to provide an injection molding method.

The molding die for a thin plate molded product according to the present invention is a molding die for a thin plate molded product in which at least two or more cavities are disposed between a fixed mold and a movable mold, and a gate is provided at an end of the cavity. The mold is provided with a block that forms a cavity forming surface and is replaceable or modifiable, and a molten resin flow control unit that blocks or adjusts the flow path of the molten resin to the cavity. It is controlled.

According to another aspect of the present invention, there is provided an injection molding machine for a thin sheet molded product, wherein the molten resin flow control unit is a hydraulic cylinder operated by a servo valve. Alternatively, it is individually driven by a servo motor, and at least one of the position at the start of injection of the molten resin flow control unit, the timing of advancement, and the advancement speed can be adjusted.

The thin plate molded product injection molding method according to the present invention is the thin plate molded product injection molding method using the molding die according to claim 1, wherein the molten resin flow control unit is positioned at the start of injection, and the advance start timing. , And at least one of the forward speeds is individually controlled for each molten resin flow control unit to control the amount of molten resin flowing into each cavity or the amount of molten resin flowing out from each cavity.

In the molding die, injection molding machine, and injection molding method of the present invention, at least two cavities are disposed between the stationary die and the movable die, and a gate is provided at the end of the cavity. A block that can be exchanged or modified to form a cavity forming surface, and a molten resin flow control unit that blocks or adjusts a flow path of the molten resin to the cavity. Since the injection molding is performed using the molding die controlled to the above, a plurality of thin plate molded products can be molded in good condition, and the adjustment at that time is easy.

FIG. 1 is a horizontal sectional view of a molding die for a thin plate molded product of Example 1, and shows a state before the gate cutter advances. FIG. 2 is a horizontal sectional view of the molding die for the thin plate molded product of Example 1 and shows a state after the gate cutter advances. FIG. 3 is a horizontal sectional view of the main part of FIG. FIG. 4 is a front view of the main part of the movable mold in the molding die of the thin plate molded product of the first embodiment. FIG. 5 is a chart showing the injection molding method of the thin plate molded product of Example 1.

A molding die for a thin plate product to be attached to an injection molding machine (including injection compression molding and an injection press in one field thereof) has at least two cavities between a stationary die and a movable die of the molding die. It is supposed to be formed. The cavity forming surface of the molding die is configured by a replaceable or modifiable block, and can cope with a shape change of the light guide plate to be molded. Accordingly, when changing the shape or size of the thin plate molded product or adjusting the brightness of the surface, the block is exchanged, the processing of the block surface is corrected, the shim is inserted into the back surface of the block, and the like. At the end of each cavity, a gate which is a flow path of the molten resin is provided, and a molten resin flow control unit such as a gate cutter for blocking or adjusting the gate is provided. The molten resin flow control unit such as the gate cutter is individually controlled by a separate driving mechanism. The portion to be blocked or adjusted in the flow path of the molten resin is not limited to the gate portion, but is a runner (at least one of a hot runner or a cold runner), and the gate and the runner are attached to the thin plate product and taken out. It may be. Moreover, although it is assumed that the molding die of the present invention is distributed without a block such as a core block, the molding die without a block in that case is also an object of the mold invention. The drive mechanism of the molten resin flow control unit may be on either the molding die side or the injection molding machine side. Therefore, if the molten resin flow control unit of the molding die can be individually controlled, even if there is a drive mechanism on the injection molding machine side, it is an object of the mold invention. The present invention is also directed to an injection molding method using the molding die and the injection molding machine.

The light guide plate molding die 11 which is a molding die of the thin plate molding shown in FIGS. 1 to 4 will be described. The light guide plate molding die 11 includes a movable die 12 as a first die and a fixed die 13 as a second die. Two cavities 14a and 14b with variable volume and thickness are formed. The movable mold 12 includes a mold body 15 (mother mold), a core block 16, a movable frame block 17, a center block 18, and gate cutters 19a and 19b projecting pins 20.

The core block 16 that is a block constituting the mold is fixed to the main body 15, and the movable frame block 17 is attached to the main body 15 via a spring. Therefore, the position of the core block 16 and the movable frame block 17 can be relatively changed in the mold opening / closing direction. The core block 16 includes a spacer block 21 on the main body 15 side and a cavity forming block 22 (block) on the front side. The cavity forming block 22 has a cooling medium flow path through which a cooling medium flows, and a cavity forming surface 23 formed of a mirror surface on the surface. The thickness of the cavities 14a and 14b may be adjusted by forming a metal plating layer on the back surface of the cavity forming block 22 or sandwiching a thin plate such as a shim. Alternatively, the core block may be individually controlled and moved forward by a hydraulic cylinder or the like provided individually in the molding die 11. The movable frame block 17 may also be replaceable depending on the light guide plate P to be formed, and the light incident surface forming block 17a may be provided independently and replaced.

A center block 18 that forms a runner forming surface on the movable mold 12 side is integrally fixed to the main body 15. At the center of the center block 18, a protruding pin 20 is provided so as to be able to advance and retract, and a hydraulic cylinder 27, which is a driving mechanism for the protruding pin, is provided in the movable plate 26. In the first embodiment, the position of the center block 18 may be relatively changed by a spring with respect to the core block 16 as in the case of the movable frame block 17.

In the clearance between the core block 16 and the center block 18, gate cutters 19a and 19b, which are molten resin flow control units, are provided so as to freely advance and retract, respectively. The gate cutter 19b will be described. The cutter 28b of the gate cutter 19b is formed of a hard metal different from the core block 16 of the molding die 11, and the surface thereof is coated with a hardening material such as tungsten carbide. . As shown in FIG. 4, the gate P3 of the molding die 11 is a film gate, and the cutter 28b is a thin plate having a rectangular cross section suitable for cutting the film gate and having a predetermined length in the depth direction. is there. The front surface of the cutter 28b is composed of a flat gate forming surface 28c, and the corner of the gate forming surface 28c on the cavity 14b side is a blade 28d. The shape of the cutter 28b may be other shapes depending on the shape of the gate P3, or may have a sharp tip.

The cutter 28b of the gate cutter 19b is engaged with a plate 29 disposed in the space in the main body 15. A spring 30 is disposed around the base of the cutter 28b so that the cutter 28b and the plate 29 are urged toward the movable platen 26 side. Therefore, the initial position of the cutter 28b is adjusted such that the gate forming surface 28c, which is the front surface of the cutter 28b, is located at the same position (same height) as the cavity forming surface 23 of the cavity forming block 22. Further, a guide pin 32 guided by a rolling ball 31 is connected to the plate 29, and the rear end surface of the guide pin 32 abuts or slightly contacts the front end surface of the rod 34 of the hydraulic cylinder 33b as a drive mechanism. It is held across a gap.

The hydraulic cylinder 33 b that drives the gate cutter 19 b is provided in the movable plate 26 of the injection molding machine 24. The hydraulic cylinder 33b is closed-loop controlled for its forward position and forward speed by a position sensor, servo valve, controller, and the like (not shown). The hydraulic cylinder 33b may be one that detects and controls the pressure generated by receiving the elastic force of the opposing spring 30 or the resin pressure to control the forward position and forward speed of the cutter 28b, and is controlled using a servo valve. It is desirable but not necessary. The drive mechanism of the gate cutter 19b may be a combination of an air cylinder, a servo motor to which a rotary encoder is attached, a ball screw and a ball nut.

A hydraulic cylinder 33a controlled by another servo valve for driving the other gate cutter 19a is disposed in the movable plate 26. Therefore, the gate cutters 19a and 19b are individually controlled to block the flow path of the molten resin to the cavities 14a and 14b. The hydraulic cylinders 33a and 33b may be provided in the molding die 11.

Next, the fixed mold 13 of Example 1 will be described. As shown in FIGS. 1 and 2, the fixed mold 13 attached to the fixed platen 34 includes a main body 35 (mother mold), a core block 36, a contact block 37, a mescutter 38, an insert block 39, and a sprue bush 40. Etc. The core block 36, the contact block 37, the insert block 39, and the like are fixed to the main body portion 35. The core block 36 which is a block constituting the molding die 11 includes a spacer block 41 and a cavity forming block 42 (block) constituting a cavity forming surface. A nickel phosphorus plating layer 43 as a surface treatment layer is formed to a thickness of about 0.3 mm on the surface of stainless steel as a base material of the cavity forming block 42, and a transfer surface 43a is carved on the nickel phosphorus plating layer 43. Yes. When the mold 11 is closed, the front surface of the movable frame block 17 of the movable mold 12 and the front surface of the contact block 37 of the fixed mold 13 are brought into contact with each other. The cavities 14 a and 14 b are constituted by the cavity forming surface 23 of 22, the inner surface of the movable frame block 17 (including the light incident surface forming block 17 a), and the transfer surface 43 a of the cavity forming block 42 of the fixed mold 13. It has become. Although not shown, a guide pin provided in one of the molds is inserted into a guide hole of the other mold.

The surface treatment layer such as the metal plating layer 43 may be formed also on the cavity forming surface 23 of the movable mold 12. In addition to the metal plating layer, the surface treatment layer may be a heat insulating layer formed by metal spraying, ceramic, or the like, a surface protective layer made of Tin, DLC, WCC, or the like, or a combination thereof. Further, in addition to the transfer surface 43a of the metal plating layer 43, a transfer surface may be directly formed on the base material of the cavity forming block 42, or a stamper on which the transfer surface is formed may be attached. The surface treatment layer may be formed on the cavity forming block 22 of the movable mold 12. Further, both of the cavity forming blocks 22 and 42 may be mirror surfaces. In the first embodiment, the molten resin flow control unit such as the gate cutters 19a and 19b is provided in the movable mold 12. However, the molten resin flow control unit may be provided in the fixed mold 13. It is also assumed that a hot runner gate valve or the like is adopted.

An injection molding machine 24 to which the light guide plate molding die 11 of Example 1 is attached is a molding machine capable of injection compression molding (including an injection press in one field), and includes a fixed platen 34 and a movable platen 26. The mold clamping device 25 and the injection device 44 are configured. The mold clamping device 25 can control the position of the movable plate 26 and the pressure (clamping force) of the mold clamping cylinder with high accuracy. The injection device 44 can be controlled with high accuracy by high-speed injection (as an example, 200 to 1000 mm / sec).

Next, an injection molding method of the light guide plate P by the injection molding machine 24 to which the light guide plate molding die 11 is attached will be described with reference to FIG. In Example 1, a light guide plate P for a mobile phone having a diagonal size of 3.5 inches and a plate thickness of 0.3 mm is formed. In the present invention, the plate thickness is 0.15 to 0.5% of the diagonal size, for example, the diagonal size is 8 inches, the plate thickness is 0.5 mm, and the diagonal size is 14 inches and the plate thickness is 0.7 mm. This is particularly effective for a thin plate molded product having a transfer surface such as a light guide plate P or a light diffusion plate. As described in the “Background Art” section, the light guide plate P is extremely thin, so that even if there is even a dimensional error in the cavity forming block 22, it is formed by the two cavities 14a and 14b. In many cases, a difference in thickness, uneven thickness, sink marks, and the like occur in the light guide plate P. Therefore, initially, the injection molding machine 24 is operated in the state where the retreat stop positions of the cutters 28a and 28b of both the gate cutters 19a and 19b of the molding die 11 are in a fixed position (the same position as the cavity forming surface 23). The cutters 28a and 28b are advanced at the same timing, and the light guide plate P is test-molded. (Note that the method of forming the test piece of the light guide plate P is substantially the same as the description of the main forming of the light guide plate P after adjustment of the gates and the like, and will be described in detail later.)

When the test pieces of the light guide plate P are formed in both the cavities 14a and 14b of the molding die 11, the formed light guide plate P is taken out, and the thickness unevenness, internal stress, brightness, Etc. are measured. If the light guide plate P formed in one cavity 14a has a good thickness and the light guide plate P formed in the other cavity 14b is too thick, as shown in FIGS. The backward stop position of the cutter 28b on the thicker side is set to a position slightly protruding toward the fixed mold 13 by the protrusion amount T1. As a result, the gap G1 of the gate P3 to the other cavity 14b is narrowed, and the thickness of the light guide plate P formed by the cavity 14b is in a favorable range. In addition, when the light guide plate P formed by one cavity 14a has a good thickness and the light guide plate P formed by the other cavity 14b is too thin, the side with the good thickness (compared to the other) The retreat stop position of the cutter 28a on the thick side) is set to a position slightly protruding toward the fixed mold 13 side. Then, the mold clamping device 25 of the injection molding machine 24 is controlled, and the stop positions of the movable plate 26 and the movable mold 12 are slightly changed to the rear before the start of injection. As a result, the cross-sectional area of the gate P3 to the one cavity 14a is hardly changed from the previous one, and the cross-sectional area of the gate P3 to the other cavity 14b can be increased and the plate thickness of the cavity 14b can be increased.

The flow rate of the molten resin to the cavities 14a and 14b is most commonly adjusted by adjusting the backward stop positions (positions at the start of injection) of the cutters 28a and 28b to control the inflow amount. In addition, the position at the start of injection may be the same, the start timing and the forward speed may be different, and either the inflow amount or the outflow amount may be controlled. Further, it may be adjusted by combining at least one of the position at the start of injection, the timing of starting forward, and the forward speed. Further, when the internal stress is defective, the position at the start of injection of both gate cutters 19a and 19b may be adjusted. Regarding the adjustment, conditions such as the stop position of the movable mold 12 before the start of injection, the mold clamping speed at the time of re-clamping, the mold clamping pressure, the injection speed, the injection pressure, and the temperature of the molding mold 11 are also involved. Adjust them as needed.

Further, when the brightness balance and internal stress of the light guide plate P are not good and cannot be dealt with only by correcting the molding conditions including the control of the gate cutters 19a and 19b, the cavity forming blocks 22 and 42 of the core blocks 16 and 36 and the movable frame Replacement or correction of the block 17 is performed. Specifically, the brightness balance is corrected by polishing the metal plating layer 43 to make it flat once and then forming a pattern again. If there is unevenness in the plate thickness, the metal plating layer 43 is corrected, the cavity forming blocks 22 and 42 are replaced, and a thin plate such as a shim is inserted on the back of the block. By performing the adjustment, the thickness of the cavities 14a and 14b when the mold clamping is completed is changed. Therefore, the fine adjustment is performed by the gate cutters 19a and 19b which are the molten resin flow control units.

Next, the case where the main molding (continuous molding) of the light guide plate P is performed by an injection press will be described with reference to FIG. In the first test piece molding of the light guide plate P, the thickness of the light guide plate P formed by the other cavity 14b is too thick and the cutter 28b of the gate cutter 19b is slightly advanced to narrow the cross-sectional area of the gate P3. A case where adjustment is performed will be described. First, fine adjustment of the position (retraction stop position) at the start of injection of the gate cutter 19b according to the thickness of the light guide plate P is performed to search for a range in which the thickness of the light guide plate P is good. At this time, the position of the gate cutter 19a at the start of injection is not changed. When the adjustment is completed, the light guide plate P is formed. As shown in FIG. 5, when the mold clamping device 25 of the injection molding machine 24 is driven and the mold is closed, the cavity spacing between the cavities 14a and 14b before the completion of mold clamping is slightly opened (the cavity volume is slightly small). The movable platen 26 and the movable mold 12 are temporarily stopped at a position enlarged to (1). (Alternatively, the movable mold 12 may be moved forward to the mold clamping completion position and then retracted to the stop position.) The mold clamping force at that time is a relatively low value, and the movable plate 26 and the like are clamped. Oil is sealed in the mold clamping cylinder of the mold clamping device 25 so as not to move in both the direction and the mold opening direction. Alternatively, in a mold clamping device using a servo motor, a servo lock state is set. Then, the screw of the injection device 44 of the injection molding machine 24 is advanced, and the molten resin is injected toward the cavities 14a and 14b via the sprue P1, the runner P2, and the gate P3.

At that time, the gate P3 to the cavity 14b is controlled at the position where the cutter 28b is controlled by using a servo valve and a position sensor and advanced by the projection amount T1, and is adjusted to the gap G1 of the gate P3. The amount of molten resin flowing into 14b is optimally controlled. In the first embodiment, since the gate P3 is a film gate, the inflow amount of the molten resin is significantly adjusted and changed by moving the cutter 28b slightly. In the case of injection press molding, the position of the movable mold 12 at the start of injection may be changed to change the gap G1 between the cavities 14a, 14b and the gate P3, and the movable mold 12 stops at the mold clamping completion position. In the case of injection compression molding in which injection is performed, the mold clamping force may be changed to adjust the distance by which the movable mold 12 and the gate cutters 19a and 19b are retracted by the injection pressure.

Then, the timing at which a part of the molten resin flows into the cavities 14a and 14b by the injection is detected from the advance position of the screw, and the mold clamping device 25 is re-driven (high-speed pressurization). Then, the core block 16 of the movable mold 12 is advanced toward the core block 36 of the fixed mold 13 to compress the molten resin in the cavities 14a and 14b, and the molten resin is end far from the gate P3 of the cavities 14a and 14b. Extend to the club. During this injection process (filling process), the molten resin is supplied into the cavities 14a and 14b through the gate P3 and the like by advancing the screw. However, when the injection process (filling process) is completed and the process proceeds to the pressure holding process and the pressure from the injection device 44 side is rapidly reduced, the compression of the molten resin by the mold clamping device 25 is still continued. This time, the molten resin flows backward from the cavities 14a and 14b through the gate P3 to the runner P2. The backflow start is not constant depending on the cavity volume, such as injection speed, injection pressure, holding pressure, holding pressure switching timing, clamping speed, clamping force, and clamping start timing. This is performed from the time immediately before switching until the completion of pressurization of the mold clamping device. Further, when the molten resin in the cavities 14a and 14b is compressed, the gate cutters 19a and 19b and the center block 18 are also moved forward together with the core block 16, so that the runner P2 and the gate P3 are also compressed in thickness. In other words, when the initial injection is started, the cross-sectional areas of the runner P2 and the gate P3 are widened, so that the molten resin can be satisfactorily filled into the cavities 14a and 14b.

When the timer detects that a predetermined time has elapsed from the start of injection or mold clamping, the drive mechanisms of the gate cutters 19a and 19b are activated and the gate P3 is disconnected. In the first embodiment, the gate P3 is cut when the blades 28d of the cutters 28a and 28b intersect with the mescutter 38. However, the gate P3 may be crushed or may remain thin. The forward movement of the gate cutters 19a and 19b may be started by detecting the position of the movable mold 12 or the movable platen 26.

When the molten resin flows out from the cavities 14a and 14b to the runner P2 side, the gate cutters 19a and 19b are advanced to shut off the molten resin, so that the thickness difference of the light guide plate P can be further reduced. This is because, in general, in an ultra-thin molded product such as a light guide plate, a phenomenon is seen in which the plate becomes thicker near the gate of the cavity. Even when the gate cut is performed when the molten resin flows into the cavities 14a and 14b, the light guide plate P that is thicker in the vicinity of the gate P3 is often formed as described above. However, when the molten resin flows out from the cavities 14a and 14b to the runner P2 side, the light guide plate P having a uniform thickness can be formed because the molten resin in the vicinity of the gate P3 is flowing out to the runner P2 side. It becomes. Then, the molten resin is cooled in both cavities 14a and 14b, and light guide plates P and P having good thickness accuracy are respectively formed.

The molten resin flow control unit used for the molding die may be one that adjusts the cross-sectional area of the gate by exchanging the cutter of the gate cutter or the like. In addition to the gate cutter, the molten resin may partly block the flow of the molten resin. Furthermore, a molten resin flow control unit is provided in the hot runner or cold runner branched to each cavity other than the gate so that the amount of molten resin flowing into each cavity or the amount of molten resin flowing out of each cavity is controlled. May be. Even in such a case, the runner may be completely cut off, or the partially blocked flow rate may be adjusted. The molten resin flow control unit may protrude from the gate or runner at the timing after the start of injection to adjust the flow of the molten resin.

In the first embodiment, a type called a flat die in which the position of the movable frame block 17 can be changed relative to the core block 16 has been described. However, the convex portion of one mold is the concave portion of the other mold. The present invention can also be applied to a type called an inlay mold in which a cavity having a variable volume is formed therebetween. In the first embodiment, the molding die attached to the injection molding machine in which the mold is opened and closed in the horizontal direction has been described. However, the mold may be opened and closed in the vertical direction.

In addition to the light guide plate, the present invention is a molding metal for simultaneously molding a plurality of thin plate molded products of any kind, such as a light diffusion plate, a lens, a resin glass, a vehicle resin window material, an SD card case, a battery case, and a resin separator. It is used for all types of molds and is not limited as long as the number of cavities is two or more. In addition, the thin plate molded product is not limited to a plate having a uniform thickness, and the length (longest portion) is about 5 times or more the plate thickness (maximum thickness portion). Furthermore, materials for forming thin plate molded products are resin materials such as polycarbonate, acrylic and various olefin polymers for optical molded products, and resin materials suitable for molding for other molded products. Metal materials such as magnesium and aluminum, and other organic and inorganic materials are selected.

11 Light guide plate mold (thin plate mold)
12 Movable mold 13 Fixed mold 14a, 14b Cavity 16, 36 Core block (block)
17 Movable frame block (block)
19a, 19b Gate cutter (molten resin flow control unit)
22, 42 Cavity forming block (block)
24 Light guide plate injection molding machine (thin plate molding product injection molding machine)
25 Clamping device 28a, 28b Cutter 33a, 33b Hydraulic cylinder (drive mechanism)
43 Metal plating layer (surface treatment layer)
P3 gate T1 protrusion

Claims (4)

In a molding die for a thin plate molded product in which at least two or more cavities are disposed between a fixed die and a movable die, and a gate is provided at an end of the cavity,
An exchangeable or modifiable block comprising a cavity forming surface;
A molten resin flow control unit for blocking or adjusting a flow path of the molten resin to the cavity, respectively,
A molding die for a thin plate molded product, wherein the molten resin flow control unit is individually controlled. 2. The molding die for a thin plate molded product according to claim 1, wherein the block has a surface treatment layer formed on a base material. In an injection molding machine for a thin plate molded product to which the molding die according to claim 1 is attached,
The molten resin flow control unit is individually driven by a hydraulic cylinder or a servo motor operated by a servo valve, and at least one of a position at the start of injection of the molten resin flow control unit, a start timing of advance, and a forward speed An injection molding machine for thin sheet molded products, characterized in that it can be adjusted. In the injection molding method of a thin plate molded article using the molding die according to claim 1,
At least one of the injection start position, the advance start timing, and the advance speed of the molten resin flow control unit is individually controlled for each molten resin flow control unit, and the amount of molten resin flowing into each cavity or from each cavity An injection molding method for a thin plate molded product, characterized in that the flow rate of molten resin is controlled.

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