Injection molding method and mold for plastic product

Abstract

The invention relates to the technical field of injection molds, and provides an injection molding method and mold for a plastic product, the injection molding mold comprises a first positioning ring, a second positioning ring, a heat exchange mechanism and a demolding mechanism, an upper mold is slidably arranged in the second positioning ring, and the first positioning ring is detachably connected with the side, close to the first positioning ring, of the second positioning ring; the heat exchange mechanism is arranged on the side, away from the upper mold, of the lower mold and used for adjusting the temperature of the lower mold, and when the upper mold and the lower mold are in butt joint, a gap between the upper mold and the lower mold communicates with the gas injection through hole, and a demolding mechanism is arranged on the side, away from the lower mold, of the second positioning ring. The demolding mechanism is detachably connected with the gas injection through hole, and the demolding mechanism is used for separating the plastic product from the upper mold, and through the technical scheme, the problem that in the prior art, when the plastic product is formed in an injection molding mode, the temperature of the mold is repeatedly adjusted and controlled, and the production efficiency is low is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the intelligent manufacturing equipment industry, more particularly to the technical field of injection molding, specifically, to an injection molding method and mold for plastic products. BACKGROUND

[0002] When producing plastic products, the injection molding method is usually used, that is, molten plastic is injected between two molds, which are respectively arranged on an injection molding machine. After the liquid plastic is cooled, the surface of the plastic gradually solidifies. Then the injection molding machine drives the two molds to open, and the plastic product can be taken out for cooling to complete the injection molding.

[0003] The mold needs to maintain a certain temperature when injection molding. The temperature cannot be too low, but it is much lower than the melting temperature of the plastic. When the liquid plastic enters between the two molds, it gradually cools to solidify. The mold maintains a certain temperature to prevent the liquid plastic from quickly solidifying when it is injected between the molds, which causes it to fail to form the desired shape. However, the temperature of the mold may also slow down the cooling speed of the plastic product. At this time, the mold is cooled to accelerate the solidification of the plastic product. After solidification, the mold is opened to take out the plastic product, and then the mold is heated again. This process is repeated to continuously injection mold. However, repeated heating and cooling of the mold, and the need to maintain the temperature of the mold when injection molding at a relatively accurate temperature, make the production efficiency low due to repeated temperature adjustment of the mold during continuous production. SUMMARY

[0004] The present application provides an injection molding method and mold for plastic products to solve the problem of low production efficiency caused by repeated temperature adjustment of the mold when using the injection molding method to form plastic products.

[0005] The technical solution of the present application is as follows: An injection molding method for plastic products, comprising: Step 1: Injection molding preparation: heating the mold, and the injection molding machine pushing the two molds to abut; Step 2: Plastic injection molding: the injection molding machine injecting molten plastic into the two molds; Step 3: Plastic solidification: the molten plastic gradually cools and solidifies between the two molds, the heated part of the mold separates, and the part of the mold and the plastic part is cooled to accelerate the solidification of the plastic product; Step 4: Product demolding: the injection molding machine drives the two molds to separate, and injection is performed between the plastic product and the mold to demold the plastic product; Step 5: Cycle production: the injection molding machine drives the two molds to abut, and the heated part of the mold abuts and heats to injection mold again.

[0006] The injection molding mold of the plastic product cited above is used to realize steps three to five of the injection molding method of the plastic product, and comprises an injection molding machine, an upper mold and a lower mold, the upper mold and the lower mold are arranged on the injection molding machine, the injection molding machine can drive the upper mold to vertically ascend and descend above the lower mold, and further comprises a positioning ring one, a positioning ring two, a heat exchange mechanism and a demolding mechanism, the positioning ring one is fixedly arranged on the injection molding machine, the positioning ring one is sleeved on the lower mold, the positioning ring two is arranged on the injection molding machine, the upper mold is slidably arranged in the positioning ring two, the positioning ring one is detachably connected to the side of the positioning ring two close to the positioning ring one, the heat exchange mechanism is arranged on the side of the lower mold away from the upper mold, the heat exchange mechanism is used for adjusting the temperature of the lower mold, a gas injection hole is arranged on the upper mold, when the upper mold is connected to the lower mold, the gap between the upper mold and the lower mold is connected to the gas injection hole, the demolding mechanism is arranged on the side of the positioning ring two away from the lower mold, the demolding mechanism is detachably connected to the gas injection hole, and the demolding mechanism is used for separating the plastic product from the upper mold.

[0007] The heat exchange mechanism comprises a heat exchange groove, a driving cylinder one and a heat exchange block, the heat exchange groove is arranged on the side of the lower mold away from the upper mold, the driving cylinder one is provided with a plurality of driving cylinders, the plurality of driving cylinders are fixedly installed on the side of the injection molding machine close to the heat exchange groove, the heat exchange block is fixedly connected to the output end of the plurality of driving cylinders, the heat exchange block is slidably and detachably connected to the heat exchange groove, and the side of the heat exchange block close to the heat exchange groove is provided with a heating device.

[0008] The lower mold is provided with a heat exchange pipe, the heat exchange pipe is used for cooling the lower mold, when the driving cylinder one pushes the heat exchange block to slide into the heat exchange groove, the heat exchange block is attached to the inner wall of the heat exchange groove, before the lower mold is cooled by the heat exchange pipe, the output end of the driving cylinder one is shortened to separate the heat exchange block from the heat exchange groove.

[0009] A plurality of driving cylinders two are fixedly installed on the positioning ring two, the output end of the driving cylinder two is fixedly connected to the upper mold, and the upper mold is provided with an injection port.

[0010] The demolding mechanism comprises a bridge and a gas injection assembly, the bridge is fixedly connected to the positioning ring two, the gas injection assembly is fixedly connected to the bridge, each gas injection assembly is detachably connected to one of the gas injection holes, the gas injection assembly comprises a driving cylinder three and a gas injection pipe, the driving cylinder three is fixedly installed on the bridge, the gas injection pipe is fixedly connected to the output end of the driving cylinder three, the gas injection pipe can extend into the gas injection hole, the gas injection pipe is connected to an external air pump, a section of the gas injection hole close to the lower mold is semicircular, the shape of the gas injection pipe matches the gas injection hole, when the gas injection pipe extends into the gas injection hole and is attached to the upper mold, the gas outlet on the gas injection pipe is not connected to the upper mold.

[0011] When injection molding is performed, the positioning ring one is connected to the positioning ring two, and the output end of the driving cylinder two pushes the upper mold to approach the lower mold.

[0012] The side of the positioning ring one is provided with a plurality of butt joints, and the side of the positioning ring two is provided with a plurality of butt pins, the butt pins and the butt pins are detachably connected.

[0013] The working principle and beneficial effects of the present application are as follows: 1、In the present application, by setting the heat exchange mechanism, the temperature of the lower mold can be adjusted, by changing the volume of the heating and cooling part on the lower mold to speed up the heating and cooling speed, and then speed up the step cycle speed of repeated injection molding; 2、In the present application, by setting the demolding mechanism, the separation of the plastic product and the upper mold can be promoted by gas after the plastic product is roughly formed, by the separation and combination of the heat exchange block and the lower mold in the heat exchange mechanism, the volume of the lower mold is adjusted, and then the heating and cooling speed can be faster, and the heat exchange block can also be used for heating, thereby improving the efficiency of injection molding. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0015] Figure 1 It is a 3D physical diagram of the injection molding method and mold of a plastic product in the present application; Figure 2 It is a schematic structural diagram of the whole; Figure 3 It is another perspective schematic structural diagram of the whole in the present application; Figure 4 It is a schematic structural diagram of the cooperation of the heat exchange block and the heat exchange groove in the present application; Figure 5 It is a sectional view structural schematic diagram of the positioning ring two in the present application; Figure 6 Figure 1 is a schematic diagram of the internal structure of the injection hole and the injection tube in the present application.

[0016] Figure 1 is a schematic diagram of the internal structure of the injection hole and the injection tube in the present application. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor also fall within the scope of protection of the present application.

[0018] Embodiment one As shown in the figure, the injection mold of the present embodiment belongs to the intelligent manufacturing equipment industry, and proposes an injection molding method of plastic products, which comprises the following steps: Figures 1 to 6 Step one: injection preparation: heat the mold, and the injection machine pushes the two molds to be connected; Step two: plastic injection: the injection machine injects molten plastic into the two molds; Step three: plastic shaping: the molten plastic gradually cools and shapes between the two molds, the heated part of the mold is separated, and the part of the mold and the plastic is bonded and cooled to accelerate the shaping of the plastic product; Step four: product demolding: the injection machine drives the two molds to separate, and injection is performed between the plastic product and the mold to demold the plastic product; Step five: cyclic production: the injection machine drives the two molds to be connected, the heated part of the mold is heated, and injection is performed again.

[0019] ​In traditional injection molding, heating and cooling the mold both require temperature changes across the entire mold, resulting in slow heating and cooling rates. In this application, the heat exchange block 8 is separated from the lower mold 2 during cooling. This reduces the area requiring cooling and allows the heat exchange block 8 to enter the heat exchange tank 6 during heating, where its own temperature and the heating device 9 heat the mold 2 without needing to heat the heat exchange block 8 again. This also allows for faster temperature regulation. The upper mold 1 is also equipped with a heating device. During demolding, the side of the plastic product closest to the lower mold 2 cools faster, causing the plastic product to detach from the lower mold 2. The upper mold 1 and the positioning ring 4 lift the plastic product upwards. The demolding mechanism inflates the space between the upper mold 1 and the plastic product, and the gas forces the plastic product to separate from the upper mold 1, completing the demolding process.

[0020] Example 2 like Figures 1 to 6 As shown, an injection mold for a plastic product, employing the aforementioned injection molding method for a plastic product, is used to implement steps three to five. It includes an injection molding machine, an upper mold 1, and a lower mold 2. Both the upper mold 1 and the lower mold 2 are mounted on the injection molding machine, which can drive the upper mold 1 to move vertically above the lower mold 2. The mold also includes a first positioning ring 3, a second positioning ring 4, a heat exchange mechanism, and a demolding mechanism. The first positioning ring 3 is fixedly mounted on the injection molding machine and fitted onto the lower mold 2. The second positioning ring 4 is mounted on the injection molding machine, and the upper mold 1 is slidably mounted within the second positioning ring 4. The first positioning ring 3 and the second positioning ring 4 are detachably connected on the side of the first positioning ring 3 closest to it. The heat exchange mechanism is located on the side of the lower mold 2 away from the upper mold 1 and is used to regulate the temperature of the lower mold 2. The air injection hole 5 is located on the upper mold 1. When the upper mold 1 and the lower mold 2 are in contact, the gap between the upper mold 1 and the lower mold 2 is connected to the air injection hole 5. A demolding mechanism is provided on the side of the positioning ring 2 away from the lower mold 2. The demolding mechanism is detachably connected to the air injection hole 5. The demolding mechanism is used to separate the plastic product from the upper mold 1. The positioning ring 1 3 and positioning ring 2 4 in this application are used to position the upper mold 1 and the lower mold 2, and at the same time prevent the liquid plastic from overflowing. When demolding, the upper mold 1 slides in the positioning ring 2 4. The positioning ring 2 4 can also bend any excess edges that may exist on the edge of the plastic product, so as to facilitate subsequent cutting and cleaning. The heat exchange mechanism reduces the temperature adjustment time by adjusting the volume of the part that changes temperature during heat exchange.

[0021] like Figures 1 to 3As shown, the heat exchange mechanism includes a heat exchange tank 6, a drive cylinder one 7 and a heat exchange block 8, the heat exchange tank 6 is opened in the lower mold 2 away from the upper mold 1 side, the drive cylinder one 7 is provided with a plurality of, a plurality of drive cylinder one 7 is fixedly installed on the injection molding machine close to the heat exchange tank 6 side, the heat exchange block 8 is fixedly connected on the output end of the plurality of drive cylinder one 7, the heat exchange block 8 and the heat exchange tank 6 are slidably detachably connected, the heat exchange block 8 is provided with a heating device 9 on the side close to the heat exchange tank 6, the output end of the drive cylinder one 7 is elongated, so that the heat exchange block 8 is tightly attached to the heat exchange tank 6, the heat exchange block 8 also supports the lower mold 2 when the injection molding is carried out, the heat exchange block 8 is separated from the heat exchange tank 6 when the output end of the drive cylinder one 7 is shortened, the heating device 9 heats the lower mold 2 and the heat exchange block 8 simultaneously before injection, after separation, the temperature change of the heat exchange block 8 is small, when the heat exchange block 8 enters the heat exchange tank 6, the heat of the heat exchange block 8 itself can also drive the temperature of the lower mold 2 to rise.

[0022] As shown in Figures 1 to 3 The lower mold 2 is provided with a heat exchange pipe 10, the heat exchange pipe 10 is used for cooling the lower mold 2, when the drive cylinder one 7 pushes the heat exchange block 8 to slide into the heat exchange tank 6, the heat exchange block 8 is attached to the inner wall of the heat exchange tank 6, before the lower mold 2 is cooled by the heat exchange pipe 10, the output end of the drive cylinder one 7 is shortened, which can drive the heat exchange block 8 to separate from the heat exchange tank 6, the heat exchange block 8 is separated from the heat exchange tank 6 when the lower mold 2 is cooled, the liquid is introduced into the heat exchange pipe 10 to cool the lower mold 2, the temperature of the heat exchange block 8 is not affected, only the lower mold 2 is cooled, the cooling speed is also fast, when the temperature rises, the heat exchange block 8 enters the heat exchange tank 6, the heating wire heats the lower mold 2, the heat exchange block 8 contacts the lower mold 2 to drive it to rise in temperature, reduces the heating time and energy consumption.

[0023] As shown in Figures 1 to 5 A plurality of drive cylinder two 11 is fixedly installed on the positioning ring two 4, the output end of the drive cylinder two 11 is fixedly connected with the upper mold 1, the upper mold 1 is provided with an injection port 12, the injection is carried out through the injection port 12 during injection, when the injection is carried out, the positioning ring one 3 is connected with the positioning ring two 4, the output end of the drive cylinder two 11 pushes the upper mold 1 to move close to the lower mold 2, when the mold is removed, the drive cylinder two 11 can be shortened to pull the upper mold 1 to the positioning ring two 4, so that the positioning ring two 4 extrudes the edge of the plastic product, on the one hand, the burr on the edge of the plastic product is extruded to facilitate the removal of the burr, on the other hand, the extrusion of the edge can also drive the edge of the plastic product to separate from the upper mold 1, which helps to remove the mold.

[0024] As shown in Figures 5 to 6As shown, the demolding mechanism includes a bridge 13 and a gas injection assembly, the bridge 13 is fixedly connected to the positioning ring two 4, and the bridge 13 is fixedly connected with the gas injection assembly. Each gas injection assembly is detachably connected with one gas injection hole 5. The gas injection assembly includes a drive cylinder three 14 and a gas injection pipe 15. The drive cylinder three 14 is fixedly installed on the bridge 13, and the gas injection pipe 15 is fixedly connected to the output end of the drive cylinder three 14. The gas injection pipe 15 can extend into the gas injection hole 5, and the gas injection pipe 15 is in communication with the external air pump. A section of the gas injection hole 5 close to the lower mold 2 is semicircular in shape. The shape of the gas injection pipe 15 matches the gas injection hole 5. When the gas injection pipe 15 extends into the gas injection hole 5 and is in close contact with the upper mold 1, the gas outlet on the gas injection pipe 15 is not in communication with the upper mold 1. In the embodiment, two gas injection holes 5 and two gas injection assemblies are provided. The semicircular end of the gas injection hole 5 matches the gas injection pipe 15. After the gas injection pipe 15 is completely inserted into the gas injection hole 5, the gas outlet on the gas injection pipe 15 is arranged at the middle position. At this time, the gas outlet is in close contact with the inner wall of the gas injection hole 5 and cannot inject gas. At this time, the gas injection pipe 15 is also in close contact with the surface of the upper mold 1 and participates in injection molding together. After the basic shaping, the output end of the drive cylinder three 14 can be shortened to pull the gas injection pipe 15 to slide outward, so that a gap exists between the gas injection hole 5. At this time, the gas injection pipe 15 can be inflated by the external air pump. The gas enters the gap between the upper mold 1 and the plastic product through the gas injection hole 5, pushes the plastic product away from the upper mold 1, and at this time the plastic product is demolded.

[0025] The side of the positioning ring one 3 is provided with a plurality of butt joints 16, and the side of the positioning ring two 4 is provided with a plurality of butt pins 17. The butt pins 17 and the butt joints 16 are detachably connected. When the injection molding machine drives the positioning ring two 4 to move downward, the butt pins 17 are inserted into the butt joints 16 to align the positioning ring one 3 with the positioning ring two 4.

[0026] In the embodiment, when the injection molding of the plastic product is carried out, the lower mold 2 is heated by the heating device 9, and the upper mold 1 is heated by the heating device in the upper mold 1. After the temperature reaches the appropriate temperature, the injection molding is carried out between the upper mold 1 and the lower mold 2 through the injection port 12. The molten plastic is cooled and gradually shaped by the upper mold 1 and the lower mold 2. At this time, the output end of the driving cylinder 7 is shortened to pull the heat exchange block 8 downward to separate from the heat exchange groove 6. The lower mold 2 can be cooled by passing water into the heat exchange pipe 10, and the plastic product is cooled and shaped. At this time, the positioning ring 4 can be lifted upward by the injection molding machine, and the positioning ring 3 and the positioning ring 4 are separated. At this time, the output ends of the driving cylinder 2 and the driving cylinder 3 are shortened at the same time. The output end of the driving cylinder 2 pulls the upper mold 1 and the plastic product upward. The positioning ring 4 extrudes the burr of the plastic product. On the one hand, the burr is bent to facilitate taking out. On the other hand, the edge of the plastic product is separated from the upper mold 1. The output end of the driving cylinder 3 pulls the injection pipe 15 in the injection hole 5. The external air pump can inject gas into the injection hole 5 through the injection pipe 15 to separate the upper mold 1 and the plastic product.

[0027] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of injection molding a plastic article, characterized by, Comprise: S1: injection molding preparation: heating the mold, injection molding machine pushes two molds to interface; S2: plastic injection molding: injection molding machine melts the plastic into two molds; S3: plastic forming: melt plastic gradually cools down between two molds, mold heating part separates, mold and plastic part cooling part accelerates plastic product forming; S4: product demolding: injection molding machine drives two molds to separate, injection molding machine drives two molds to separate, and injection molding machine drives two molds to separate; S5: cycle production: injection molding machine drives two molds to interface, mold heating part is connected to heating, and injection molding is carried out again.

2. An injection molding mold of a plastic product, which refers to the injection molding method of a plastic product described in claim 1, for implementing the steps of S3-S5, comprising an injection molding machine, an upper mold (1) and a lower mold (2), the upper mold (1) and the lower mold (2) are arranged on the injection molding machine, the injection molding machine can drive the upper mold (1) to perform vertical lifting movement on the lower mold (2), characterized in that, Also includes: Positioning ring one (3) is fixedly arranged on the injection molding machine, the positioning ring one (3) is sleeved on the lower mold (2), the positioning ring two (4) is arranged on the injection molding machine, the upper mold (1) is slidably arranged in the positioning ring two (4), the positioning ring one (3) is detachably connected with the side of the positioning ring two (4) close to the positioning ring one (3); Heat exchange mechanism is arranged on the side of the lower mold (2) away from the upper mold (1), and the heat exchange mechanism is used for adjusting the temperature of the lower mold (2); Gas injection hole (5) is arranged on the upper mold (1), when the upper mold (1) and the lower mold (2) are opposite, the gap between the upper mold (1) and the lower mold (2) is communicated with the gas injection hole (5), the side of the positioning ring two (4) away from the lower mold (2) is provided with a demolding mechanism, the demolding mechanism is detachably connected with the gas injection hole (5), and the demolding mechanism is used for separating the plastic product from the upper mold (1).

3. The injection molding mold for plastic products according to claim 2, characterized in that, The heat exchange mechanism comprises: Heat exchange groove (6) is arranged on the side of the lower mold (2) away from the upper mold (1); A plurality of drive cylinders one (7) are arranged, and the plurality of drive cylinders one (7) are fixedly installed on the side of the injection molding machine close to the heat exchange groove (6); Heat exchange block (8) is fixedly connected on the output end of the plurality of drive cylinders one (7), the heat exchange block (8) is slidably and detachably connected with the heat exchange groove (6), and the side of the heat exchange block (8) close to the heat exchange groove (6) is provided with a heating device (9).

4. The injection molding mold for plastic products according to claim 3, characterized in that, The lower mold (2) is provided with a heat exchange pipe (10), and the heat exchange pipe (10) is used for cooling the lower mold (2), when the drive cylinder one (7) drives the heat exchange block (8) to slide into the heat exchange groove (6), the heat exchange block (8) is attached to the inner wall of the heat exchange groove (6).

5. The injection molding mold for plastic articles according to claim 4, characterized in that, Before the lower mold (2) is cooled by the heat exchange pipe (10), the output end of the drive cylinder one (7) is shortened, which can drive the heat exchange block (8) to separate from the heat exchange groove (6).

6. The injection molding mold for plastic articles according to claim 5, characterized in that, A plurality of drive cylinders two (11) are fixedly installed on the positioning ring two (4), the output end of the drive cylinder two (11) is fixedly connected with the upper mold (1), and the injection port (12) is arranged on the upper mold (1).

7. The injection molding mold for plastic articles according to claim 6, characterized in that, The demolding mechanism comprises: A bridge (13) is fixedly connected to the positioning ring two (4), and a gas injection assembly is fixedly connected to the bridge (13), and each gas injection assembly is detachably connected to one of the gas injection through holes (5); The gas injection assembly comprises: A driving cylinder three (14) is fixedly installed on the bridge (13); A gas injection pipe (15) is fixedly connected to an output end of the driving cylinder three (14), and the gas injection pipe (15) can extend into the gas injection through hole (5), and the gas injection pipe (15) is in communication with an external air pump.

8. The injection molding mold for plastic articles according to claim 7, characterized in that, A section of the gas injection through hole (5) close to the lower mold (2) is semicircular, the shape of the gas injection pipe (15) is matched with the gas injection through hole (5), when the gas injection pipe (15) extends into the gas injection through hole (5) and is attached to the upper mold (1), the gas outlet of the gas injection pipe (15) is not in communication with the upper mold (1).

9. The injection molding mold for plastic articles according to claim 8, characterized in that, When injection molding is performed, the positioning ring one (3) is connected to the positioning ring two (4), and the output end of the driving cylinder two (11) pushes the upper mold (1) to be close to the lower mold (2).

10. The injection molding mold for plastic articles according to claim 9, characterized in that, A plurality of butt joints (16) are arranged on the side of the positioning ring one (3), and a plurality of butt pins (17) are arranged on the side of the positioning ring two (4), and the butt pins (17) and the butt pins (17) are detachably connected.

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