TWI686283B - Thick plastic injection mould - Google Patents

Abstract

The invention relates to a plastic injection molding mold for thick parts, which is mainly used for molding plastic parts such as thick parts with a thickness of more than 4 mm. At least one preliminary embryo cavity and a finished cavity are simultaneously built in a molding die. The thickness of the initial embryo cavity must be less than the thickness of the finished part; and after the mold is opened, the initial embryo part must be moved from the initial embryo cavity into the finished cavity; then the initial cavity in the finished cavity The green parts and the initial embryo mold cavity are simultaneously fully covered and injection molded, and after the mold clamping pressure is maintained and cooled, the initial green parts and finished products are produced at the same time; by the above injection molding method, injection molding can be greatly shortened When the pressure is maintained and the cooling time, it can greatly reduce production costs and increase production capacity.

Description

Thick plastic injection mould

The invention relates to the technical field of optical plastic molding, in particular to the category of injection molding dies for plastic parts such as thick parts exceeding 4 mm in thickness.

According to the general plastic injection molding, at least one cavity, first-class channel and one injection port are injected into a pair of molding molds. After heating the granular plastic material into a fluid, the fluid plastic is injected in a spiral mechanism In the forming mold, that is, the fluid plastic must pass through the injection port and the flow channel, and finally reach and fill the mold cavity, and then cool the fluid in the mold cavity through a cooling water channel provided in the forming mold Plastic, after the fluid plastic is finally formed into a solid and then demolded, it is a finished plastic part, thus completing a cycle of plastic injection molding.

In addition, for plastic injection molding of thick parts, one injection machine is used in conjunction with a set of molds. One-step injection molding is used to maintain pressure to prevent shrinkage. After cooling and solidification, the mold is opened and taken out. Due to the thickness of the finished product, it must be used The long pressure holding time and cooling solidification time are used to avoid "shrink marks" on the surface of the product. Therefore, the entire injection molding cycle time is long, which makes the process cost of producing thick parts high, and the production volume is low, making thick plastic parts The unit price of finished products is high.

In view of the above-mentioned problems of the general thick plastic injection molding method, the inventor has exhausted his efforts to develop the thick plastic injection molding mold of the present invention. Therefore, the main purpose of the present invention is to provide a thick plastic molding product to use the same Injection molding machine with a set of innovative structural molds It has a design to achieve rapid production to reduce the cost of the mold; the secondary purpose of the present invention is: both fully automatic or semi-automatic thick plastic injection molding mold.

In order to achieve the above purpose, the thick plastic injection molding mold of the present invention uses the following technical means: A thick plastic injection mold of the present invention includes: a molding mold including a movable mold side and a static mold side, A groove is provided on the side of the movable mold, and an initial embryo cavity, a finished cavity, a flow path between the two cavity and a positioning cone are provided at the bottom of the groove; and a moving positioning mechanism , Including a bearing plate and two positioning holes, wherein the bearing plate must be sunk into the groove on the side of the movable mold, and a positioning hole can be sleeved into the positioning cone in the groove, and then on the bearing plate There are two supporting holes corresponding to the initial embryo cavity and the finished cavity.

The above-mentioned preforms and finished parts can be set as thermoplastic engineering plastics, and its polycarbonate (PC), polymethyl methacrylate (PMMA), acrylonitrile-butadiene-styrene copolymer (ABS), polymer Propylene (PP), polyethylene terephthalate (PET), high density polyethylene (HDPE), low density polyethylene (LHPE), thermoplastic rubber (TPE), thermoplastic polyurethane (TPU) , Polycarbonate + acrylonitrile-butadiene-styrene copolymer (PC/ABS), industrial liquid crystal polymer (LCP), polystyrene (PS), polyether ether ketone (PEEK) or polyether ballast (PES ) Of plastic materials; and the minimum thickness of the finished part is set to at least 4 mm.

One side of the groove on the side of the movable mold is the cavity of the initial embryo, and the other side is the cavity of the finished product that can be embedded in the initial embryo.

The above flow channel is set as a cold flow channel, which includes a vertical runner and a cross flow channel, and the cross flow channel is set to flow into the initial embryo cavity on one side, and into the finished mold cavity on the other side, and then flow to the There is a first flow adjustment device on the cross flow channel of the initial embryo cavity, and a second flow adjustment device is also provided on the cross flow channel of the other side flowing to the finished mold cavity.

The above-mentioned runner is set as a hot runner, which includes a hot runner (Hot runner) and a lateral thermal splitter (manifold), and the lateral thermal splitter flows into the direction of the initial embryo cavity after being connected to the hot runner After the channel is injected into the cavity of the initial embryo, the other side flows into the direction of the cavity of the finished product, and then the hot runner is connected to the cavity of the finished product.

The above-mentioned moving mold side is provided with the automation device, and the automation device includes a driving device and a rotating shaft, wherein the driving device must drive the rotating shaft, and the rotating shaft can be connected to the two provided in the groove. Between supporting holes.

The above-mentioned driving device may be configured to drive the rotating shaft and the bearing plate with an electric motor, a rotary cylinder, a gear and rack group or a gear and chain group.

A closed circulating cooling water channel is provided in the movable mold side and the static mold side, and each closed circulating cooling water channel can cool the cavity of the initial embryo mold, the finished mold cavity and the surroundings.

The thick plastic injection molding die of the present invention uses the following technical means:

1. The present invention uses the same injection molding machine and a new mold design device to split the original designed finished product thickness into a preliminary embryo and a finished product, and then design the preliminary embryo cavity and the finished cavity at the same time. The same set of molds can be used for injection molding of the initial embryo and the finished product at the same time. The thickness of the initial embryo is less than the thickness of the original designed finished product, which can greatly reduce the pressure holding and cooling time of the initial embryo during injection molding The production cost of injection molding of plastic parts and increase their production capacity, at the same time, can avoid "shrink marks" on the surface of the finished parts to improve product quality and yield.

2. According to the invention, one of the supporting holes can support the first green part after the first injection molding and curing, and after the mold is opened, the supporting plate is ejected and rotated by an automatic device, and then the The primary embryo part is moved into the finished cavity, and the second injection molding is performed, so that the primary embryo part is completely covered in the finished cavity, and Complete a finished part.

A: Thick plastic injection molding method

B: Thick plastic injection mold

1: forming mold

2: moving mold side

20: groove

21: Early embryo mold cavity

22: Finished cavity

24: positioning cone

3: Static mold side

31: Early embryo mold cavity

32: finished mold cavity

4: mobile positioning mechanism

41: bearing plate

410: bearing hole

411: positioning hole

42: Automation device

421: Drive

422: hinge

423: Rotary cylinder

5: Three-plate mold cold runner

50: Two-plate mold cold runner

500: hot runner

51: Vertical sprue

52: Cross flow

53: The first flow adjustment device

54: Second flow regulating device

6: Closed circulating cooling water circuit

7: Initial embryo

8: Finished parts

T0: The minimum thickness of the finished part

T1: The minimum thickness of the initial blank

T21, T22: coating thickness

Fig. 1 is a state diagram of the mold clamping state of the thick plastic injection molding die of the present invention.

Fig. 2 is a diagram of the mold opening state of the thick plastic injection molding die of the present invention.

Figure 3: It is the appearance of the original blank and finished parts and the combined sectional view of the finished parts.

Fig. 4 is a flow chart of the method for injection molding of thick parts of the present invention.

FIG. 5 is a schematic diagram of the three-plate mold cold runner of the thick plastic injection molding mold of the present invention.

FIG. 6 is a schematic diagram of the cold flow channel of the two-plate mold of the thick plastic injection molding mold of the present invention.

7 is a schematic diagram of the hot runner system flow path of the thick plastic injection molding mold of the present invention.

Fig. 8 is a schematic diagram of an automatic device for injection molding of thick plastic parts of the present invention.

FIG. 9 is a schematic diagram of another automatic device for thick plastic injection molding molds of the present invention.

First of all, please refer to FIG. 1 and FIG. 2, which is a thick plastic injection molding mold of the present invention. The embodiment includes: an optical finished product 8 to be manufactured by the present invention. It is divided into an initial embryo part 7 and a finished part 8 containing the initial embryo part 7. The forming mold 1 of the present invention is set as a group, one side is set as a static mold side 3 (also known as a female mold), and the other side is set as a movable mold side 2 (also known as a male mold), and the static mold side An initial mold cavity 31 provided by 3 corresponds to an initial mold cavity 21 provided by the movable mold side 2, and a finished mold cavity 32 provided by the static mold side 3 corresponds to the provided mold cavity 2 of the movable mold side 2.的一find mold cavity 22.

In addition, a three-plate mold cold runner 5 provided on the static mold side 3 of the molding die 1 of the present invention includes a vertical runner 51, and then branches off from the vertical runner 51 to provide a side flow to the initial embryo cavity 31 Crossing 52, and there is a first flow regulating device 53 on the cross flow channel 52 of the initial embryo cavity 31, and the other side flows to the cross flow channel 52 of the finished mold cavity 32, and the cross flow channel 52 of the finished mold cavity 32 is provided There is a second flow adjustment device 54. In particular, the flow channel can be designed for the three-plate mold cold runner 5 (see Figure 5), the two-plate mold cold runner 50 (see Figure 6) or the heat using the hot flow plate. Runner 500 system runner design (see Figure 7).

Please refer to FIG. 8 and FIG. 9 together, and a moving positioning mechanism 4 is provided on the movable mold side 2 of the mold. The moving positioning mechanism 4 includes a bearing plate 41 and an automation device 42, and the automation device 42 can be connected The support plate 41 is provided; the automation device 42 further includes a driving device 421 and a rotating shaft 422, and the power source of the driving device 421 can be set to "electric motor", "hydraulic hydraulic cylinder", "pneumatic cylinder drive" "Gear and chain set", "gear and belt set" or "electric motor" directly rotate. In particular, as shown in FIG. 9, the bearing plate 41 and the rotating shaft 422 are connected to a rotary cylinder 423.

If you want to turn the primary blank 7, you need to actuate the carrier 41, which supports the injection of the primary blank 7 to avoid falling off, and then push it out of its groove 20, and then rotate 180 degrees Going to the finished cavity 22 of the movable mold side 2, the bearing plate 41 is retracted into the groove 20, that is, the preliminary embryo 7 is inserted into the finished cavity 22 of the movable mold side 2; , A positioning cone 24 and a positioning hole 411 provided on the bearing plate 41 are provided near the initial mold cavity 21 of the movable mold side 2 for cooperative positioning, so as to avoid the finished cavity of the bearing plate 41 and the movable mold side 2 22 misplaced. The bearing plate 41 can be driven by the circular groove 20, rotated 180 degrees, retracted into the groove 20, etc., which can be done by the aforementioned automatic device 42, but it is not limited to the automatic device 42, but also by After artificially wearing heat-insulating gloves, the bearing plate 41 is rotated by 180 degrees with the hand, so that the preliminary blank 7 is inserted into the finished cavity 22 of the movable mold side 2.

Therefore, the molding die 1 of the present invention can be combined with a general single-shot injection molding machine to simultaneously mold the initial embryo part 7 and the finished part 8, the operation method of which is described in conjunction with FIGS. 2, 4, and 8 as follows:

Action 1: Close the mold. The bearing plate 41 of the movable mold side 2 is reset close to the initial cavity 21 and the finished mold cavity 22 of the movable mold side 2, and the movable mold side 2 of the molding die 1 moves to the static mold side 3 and closes and closes the mold. By mold clamping.

Action 2: Injection molding. Plastic is frictionally melted by a screw heated by the injection molding machine tube, and the molten plastic is extruded through the tube screw for quantitative injection, and the molten plastic flows through the vertical runner 51 of the static mold side 3 and then branches through the cross flow The channel 52 flows into the initial mold cavity 31 and the finished mold cavity 32 respectively, and the first flow regulator 53 on the cross flow channel 52 of the initial embryo mold cavity 31 and the finished mold cavity 32 can be used to flow in the initial few injection molding The second flow regulating device 54 on the channel 52 adjusts its flow balance accordingly.

Action 3: Keeping pressure and cooling. The screw of the injection molding machine maintains a certain pressure holding pressure to compensate for the cooling shrinkage of the plastic material until the molten plastic cools and solidifies. That is, a closed circulating cooling water channel 6 is provided in the movable mold side 2 and the static mold side 3, and each closed circulating cooling water channel 6 can accelerate the cooling of the initial embryo cavity, the finished cavity and its surroundings.

Action 4: Open the mold and take out the finished part 8. When the movable mold side 2 is away from the static mold side 3 side for mold opening, it will stop after returning to the original position. If the flow path of the static mold side 3 is designed as a three-plate mold cold flow path 5, the three-plate mold cold flow path 5 will be broken off and separated from the initial blank part 7 and the finished part 8. That is, after the movable mold side 2 is returned to the original position, the bearing plate 41 of the movable mold side 2 moves out of the groove 20 through the injection molding machine and the automatic device 42 or is manually taken out of the groove 20. The finished product 8 and the three-plate mold cold and cold runner 5 can be gripped or taken out by a manipulator on the injection molding machine.

After that, the bearing plate 41 of the movable mold side 2 is rotated by 180 degrees through the automation device 42 on the molding die 1, for example, using a rotary cylinder 423, an electric motor, or manually, and can be positioned through the positioning cone 24 and The holes 411 are positioned and matched so that the initial blank 7 is inserted into the finished cavity 22 of the movable mold side 2 Inside. After that, the bearing plate 41 of the movable mold side 2 is reset by the automatic device 42 of the injection molding machine, an electric motor, or manually so that the bearing plate 41 is close to the initial embryo cavity 21 and the finished cavity 22 of the movable mold side 2 , And then return to the initial position of action one.

According to the above actions one to four, the cyclic action can be repeated continuously to achieve the purpose of mass production.

Please refer to Fig. 3, because the thickness T0 of the finished product 8 to be manufactured is too thick, in order to obtain a perfect finished surface, reduce the surface shrinkage traces as much as possible, so that the maximum production time of thick plastic injection molded products is In the third operation, the holding pressure and cooling stroke, but the molding die 1 of the present invention is designed to dismantle the minimum thickness T0 of the manufactured finished part 8 into the initial thickness mold cavity of the minimum thickness T1 of the initial part 7 and the finished part 8 The finished mold cavity with the thickness T2 is coated with the thickness T2 equal to the sum of the thickness T21 plus the thickness of T22, so the minimum thickness T0 of the finished product 8 is equal to the sum of T1 plus T2, which makes the two different molds 1 of the invention The cavity can be cooled at the same time, which can greatly reduce the time of holding the pressure and cooling of the action three, thereby reducing the cycle time of the entire injection molding, reducing the production cost of thick plastic products and increasing the machine capacity.

In particular, in the foregoing embodiments, the base material of the thick plastic injection molded plastic parts may be general thermoplastic engineering plastics, which may be polycarbonate (PC), polymethyl methacrylate (PMMA), acrylonitrile-butadiene Enene-styrene copolymer (ABS), polypropylene (PP), polyethylene terephthalate (PET), high density polyethylene (HDPE), low density polyethylene (LHPE), thermoplastic rubber (TPE) , Thermoplastic polyurethane (TPU), polycarbonate + acrylonitrile-butadiene-styrene copolymer (PC/ABS), industrial liquid crystal polymer (LCP), polystyrene (PS), polyether Plastic raw materials such as PEEK or PES.

Therefore, the advantages and effects of the present invention can be summarized as follows: [1] The injection molding method of this thick plastic product separates the original design finished style into the initial embryo style and the finished style, so that the injection can be reduced The molding thickness of the molding can further reduce the holding pressure and cooling time, which can greatly reduce the injection molding process cost and increase the production capacity. [2] This thick part product injection molding mold device can design the initial embryo style and the finished style in the same set of molds at the same time. This mold can simultaneously injection mold the finished embryo and the finished plastic parts containing the initial embryo. This mold can be matched with a single The injection molding machine or the double injection molding machine can be used for production.

In summary of the above-mentioned embodiments, the present invention relates to a thick plastic injection molding mold, and its constituent elements have not been seen in various books or public use. To pray; if need to be clarified, the above are the specific embodiments of this patent application and the technical principles used. If the changes are made according to the concept of this patent application, the resulting functional effects have not yet If it exceeds the spirit covered by the specification and drawings, it should be included in the scope of this patent application.

B: Thick plastic injection mold

2: moving mold side

20: groove

21: Early embryo mold cavity

22: Finished cavity

24: positioning cone

4: mobile positioning mechanism

41: bearing plate

410: bearing hole

411: positioning hole

42: Automation device

421: Drive

422: hinge

Claims (6)

A thick plastic injection mold for manufacturing optical products includes: a molding mold including a movable mold side and a stationary mold side, and a groove is provided on the movable mold side and the bottom inside the groove It is provided with an initial embryo cavity, a finished cavity, a first-class channel between the two cavity and a positioning cone; and a moving positioning mechanism, which includes a bearing plate and two positioning holes, where The bearing plate must be sunk into the groove on the side of the movable mold, one of the positioning holes can be sleeved into the positioning cone in the groove, and there are two holes on the bearing plate corresponding to the initial embryo mold cavity and the finished mold cavity Supporting hole; one of the supporting holes can support the molded and cured initial embryo parts, and after the mold is opened, the supporting plate is sequentially ejected by an automatic device, rotated by 180 degrees, and moved backward continuously. After another positioning hole is inserted into the positioning cone, the preliminary embryo is moved into the finished mold cavity, and injection molding is performed again, so that the preliminary embryo is completely covered in the finished mold cavity, and the completion is completed A finished product; and the automatic device includes a driving device and a rotating shaft, wherein the driving device can drive the rotating shaft, and the rotating shaft can be connected between the two supporting holes provided in the bearing plate in the groove; The above components can greatly shorten the pressure holding and cooling time during injection molding, so the production cost can be greatly reduced, and the production capacity can be increased, and shrinkage marks on the surface of the finished part can be avoided. The thick plastic injection mold as described in claim 1, wherein the preliminary parts and finished parts can be set as thermoplastic engineering plastics, which can be set as polycarbonate (PC), polymethyl methacrylate (PMMA), acrylonitrile -Butadiene-styrene copolymer (ABS), polypropylene (PP), polyethylene terephthalate (PET), high density polyethylene (HDPE), low density polyethylene (LHPE), thermoplastic rubber (TPE), thermoplastic polyurethane (TPU), polycarbonate + acrylonitrile-butadiene-styrene copolymer (PC/ABS), industrial liquid crystal polymer (LCP), polystyrene (PS) , Polyether ether ketone (PEEK) or polyether sock (PES) plastic raw materials; in addition, the minimum thickness of the finished part is set to at least 4mm. The thick plastic injection mold according to claim 1, wherein the flow channel is set as a cold flow channel, which includes a vertical runner and a cross flow channel, and the cross flow channel is set to flow into the cavity of the initial embryo mold on one side and the other side Then it flows into the finished mold cavity, and there is a first flow regulating device on the cross flow channel flowing to the initial embryo mold cavity, and a second flow regulating device is also arranged on the cross flow channel flowing to the finished mold cavity on the other side. The thick plastic injection mold according to claim 1, wherein the runner is set as a hot runner, which includes a hot runner and a lateral thermal shunt plate, and the lateral thermal shunt plate flows into the direction of the initial embryo cavity Then, connect the hot runner to inject the cavity of the initial embryo, and the other side flows into the direction of the finished mold cavity, and then connect the hot runner to inject the finished cavity. The thick plastic injection mold according to claim 1, wherein the driving device may be set to use an electric motor, a rotary cylinder, a gear and rack group or a gear and chain group to drive the rotating shaft and the bearing plate. The thick plastic injection mold as described in claim 1, wherein the movable mold side and the static mold side are provided with a closed circulating cooling water channel, and each closed circulating cooling water channel can cool the initial embryo cavity, the finished cavity and the surrounding .

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