Recycled plastic recycling injection mold

Abstract

The invention belongs to the technical field of plastic recycling, and particularly relates to a recycled plastic reusing injection mold which comprises an upper pressing mold and a lower pressing mold which are attached to each other. A plurality of exhaust passages are arranged on the upper pressing die, exhaust assemblies are arranged in the exhaust passages, one end of each exhaust assembly intermittently abuts against a contact switch, and the contact switch is electrically connected with a micro air pump through a wire; the lower pressing die is provided with a feeding channel and a forming groove. Air is supplied to the first air supply channel through the micro air pump, pressure loss is prevented in cooperation with the one-way valve, then the pressurizing block is pushed by the pressure rod to supplement buffer area excess materials to the forming groove, and the problems of leakage caused by liquidity fluctuation and low viscosity of recycled materials and pressure leakage caused by cooling shrinkage and sealing gap enlargement are solved; finally, full and compact filling of molten plastic is achieved, material shortage sink marks are avoided, the density and strength of a finished product are improved, the defect of performance of recycled materials is overcome, and stable product quality is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of plastic recycling technology, specifically a recycling injection mold for plastics. Background Technology

[0002] Patent application number CN202011195430.5 discloses an injection mold including a front mold and a rear mold. The front mold is provided with a slanted core-pulling mechanism, which includes a movable insert, a driving component, a slanted core-pulling guide component, and a slanted core-pulling rod. The movable insert can move linearly along the opening and closing direction of the injection mold, and a through-hole is formed on the movable insert. The slanted core-pulling guide component is provided on the front mold and has an inclined guide portion. One end of the slanted core-pulling rod is adapted to be inserted into the slanted core-pulling hole, and the other end is slidably guided with the inclined guide portion. When the injection mold opens, it drives the driving component to move, thereby driving the movable insert to move linearly towards the rear mold, so that the slanted core-pulling rod is pulled out of the undercut in one go. This solves the problems of the narrow applicability of the front mold core-pulling structure of the existing three-plate mold, the long injection cycle of the hydraulic cylinder driven front mold core-pulling, and the low injection cost.

[0003] The prior art, including the aforementioned patents, still has the following drawbacks: Recycled plastic injection molding technology is widely used, but the material characteristics of recycled mixed plastics and the pain points of the injection molding process seriously restrict the stability of finished product quality. Recycled materials are mostly composed of a mixture of multiple materials such as PP, PE, and PET. The fluidity of different batches fluctuates significantly. Some batches have low melt viscosity due to molecular chain breakage and high impurity content. This makes them prone to leakage through the mold parting surface and ejector pin gaps, causing pressure loss. Moreover, the volume shrinkage of the molten plastic during the cooling stage directly releases the injection pressure. Hard impurities in the recycled material will also continuously wear down the mold sealing structure, causing the sealing gap to gradually widen and further aggravating pressure leakage. This creates a vicious cycle of increased pressure loss due to seal wear and more finished product defects. Ultimately, this results in incomplete plastic filling in the molding tank, material shortage, irregular edges, shrinkage marks and depressions on the finished product surface, increased internal porosity, and insufficient density and mechanical strength, making it difficult to compensate for the performance defects of the recycled material itself. Furthermore, most existing injection molds are single-feed molding structures, lacking a dynamic pressure compensation mechanism for the characteristics of recycled materials. Traditional one-way sealing structures cannot reliably seal the feeding channel, failing to effectively solve the above-mentioned pressure loss problem. Summary of the Invention

[0004] The purpose of this invention is to provide an injection mold for recycling plastics. A micro-pump supplies air to the first air delivery channel, and a one-way valve prevents pressure loss. A pressure rod then pushes a booster block to replenish the buffer material in the molding tank. This solves the problems of leakage caused by fluctuations in the fluidity and low viscosity of recycled materials, as well as pressure leakage caused by cooling shrinkage and increased sealing gaps. Ultimately, it achieves full and compact filling of the molten plastic, avoids shrinkage marks due to insufficient material, improves the density and strength of the finished product, compensates for the shortcomings of recycled materials, and ensures stable product quality.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: This invention provides a recycling injection mold for plastics, comprising an upper mold and a lower mold that are fitted together. The upper mold has multiple venting channels, and each venting channel contains a venting component. One end of each venting component intermittently contacts a contact switch, and the contact switch is electrically connected to a miniature air pump via a wire. The lower mold has a feeding channel and a molding groove. One end of the feeding channel is connected to a one-way valve and a buffer zone. One side of the buffer zone is connected to a first air supply channel. One end of the first air supply channel has a T-junction and a third air supply channel. The third air supply channel is equipped with an automatic valve assembly and a cutting assembly.

[0006] According to some embodiments of the present invention, a plurality of exhaust channels are arranged symmetrically about the center of the mold. One end of the exhaust channel is provided with a conical groove and is located at the bottom of the upper mold. The other end of the exhaust channel is provided with an exhaust port located on the side wall of the upper mold. A push rod is inserted into the top of the conical groove and one end of the push rod intermittently contacts a contact switch.

[0007] According to some embodiments of the present invention, the exhaust assembly includes: a conical block connected to one end of the push rod, the conical block being located in the inner cavity of the conical groove, and the bottom end of the conical block being provided with an arc-shaped groove; a limiting block connected to the push rod, one side of the limiting block being provided with a spring, and the other end of the spring being provided on the inner wall of the exhaust passage.

[0008] According to some embodiments of the present invention, the micro air pump is installed on the side wall of the upper mold, and the output end of the micro air pump is provided with a second air delivery channel, the other end of the second air delivery channel penetrating the bottom of the upper mold; the top end of the first air delivery channel is provided with an insertion interface, the position of the insertion interface corresponding to the bottom opening position of the second air delivery channel.

[0009] According to some embodiments of the present invention, one end of the feeding channel is provided with a feeding port, the feeding port is located at the bottom end of the lower die, the other end of the feeding channel is connected to the inner cavity of the forming groove, and the top end of the forming groove is provided with an overflow hole connected to the venting channel.

[0010] According to some embodiments of the present invention, a pressure rod is inserted into one end of the first air supply channel that communicates with the buffer zone, and a pressure boosting block is provided at the other end of the pressure rod. A plurality of limiting rods are provided on one side of the pressure boosting block, and one end of each of the plurality of limiting rods is slidably inserted into the inner sidewall of the buffer zone. The sidewall of the pressure boosting block abuts against the sidewall of the buffer zone.

[0011] According to some embodiments of the present invention, the automatic valve assembly includes a brass valve body, one end of which is inserted into the inner cavity of a third air supply channel, and the inner cavity of the brass valve body is provided with high-temperature mineral oil.

[0012] According to some embodiments of the present invention, the cutting assembly includes a shearing rod movably inserted into the cavity of a third air supply channel, and the other end of the shearing rod is provided with a cutter.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention delivers gas to the first gas delivery channel via a micro air pump. Combined with the one-way sealing effect of the one-way valve, it can prevent pressure loss during the secondary injection molding process. At the same time, the pressure rod pushes the pressure booster block to squeeze the remaining plastic in the buffer zone and replenish the molding tank. This not only solves the leakage problem caused by the large fluctuation of the fluidity of recycled materials and the low viscosity of some batches, but also compensates for the pressure release in the molding tank caused by cooling and shrinkage, as well as the pressure leakage problem caused by the increased sealing gap due to mold seal and structural wear. This makes the molten plastic in the molding tank more fully filled and more tightly bonded, avoids material shortage and shrinkage defects, improves the density and strength of the finished product, compensates for the shortcomings of the recycled material itself, and ensures the stability of the molding quality of injection molded products. 2. This invention forms an efficient venting path through symmetrically arranged venting channels and overflow holes. Utilizing the gap design between the conical block and conical groove in the venting assembly, combined with the elastic support of springs, the mixed gas generated when molten recycled plastic flows in the molding tank can be quickly and smoothly introduced into the venting channels and discharged. This design avoids gas stagnation in the molding tank, preventing defects such as bubbles, scorch marks, and incomplete edges in the finished product. It improves the molding accuracy, appearance integrity, and structural density of recycled plastic injection molded products, ensuring product quality stability. Simultaneously, it provides the necessary conditions for subsequent filling and cooling processes, further optimizing the injection molding effect of recycled material reuse. 3. This invention, through the interconnection design of the overflow hole and the venting channel, combined with the temperature-sensing automatic valve assembly and the cutting assembly, realizes the automatic cutting triggering of the residual material end face during the cooling process. Utilizing the thermal expansion and contraction characteristics of high-temperature mineral oil with changes in mold temperature, the opening and closing of the third air supply channel is automatically controlled. When the molten plastic temperature is suitable, the cutter is pushed to complete the cutting of the residual material. No additional manual operation is required, saving time and increasing efficiency. The cutting action is carried out slowly in the hot stage, requiring low pressure and accurately conforming to the beveled surface of the reset baffle, maximizing the smoothness, flatness, and integrity of the residual material cutting surface, avoiding product defects caused by irregular cutting end face, residual burrs, etc., reducing the probability of defective products, and improving the appearance consistency and assembly adaptability of recycled plastic injection molded products.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 2 This is a schematic diagram of the external structure of the present invention; Figure 3 For the present invention Figure 1 Enlarged structural diagram at point A; Figure 4 This is a schematic diagram showing the positional relationship between the exhaust assembly and the contact switch of the present invention; Figure 5 This is a schematic diagram showing the positional relationship between the miniature air pump and the second air delivery channel of the present invention. Figure 6 For the present invention Figure 1 Enlarged structural diagram at point B; Figure 7 This is a schematic diagram showing the connection relationship between the automatic valve assembly and the cutting assembly of the present invention; Figure 8 This is a cross-sectional view of the automatic valve assembly of the present invention; Figure 9 For the present invention Figure 1 Enlarged structural diagram at point C; Figure 10 This is a schematic diagram of the booster block of the present invention; Figure 11 This is a schematic diagram of the structure of the tee of the present invention.

[0017] In the diagram: 1. Upper die; 11. Exhaust duct; 111. Conical groove; 112. Exhaust port; 12. Exhaust assembly; 121. Conical block; 122. Arc groove; 123. Limiting block; 124. Spring; 13. Contact switch; 14. Miniature air pump; 141. Second air supply channel; 15. Push rod; 2. Lower die; 21. Feed channel; 211. Feed inlet; 22. Forming groove; 221. Overflow hole; 23. One-way valve; 24. Buffer zone; 25. First air supply channel; 251. Plug interface; 252. Pressure rod; 253. Pressure booster block; 254. Limiting rod; 26. T-junction; 27. Third air supply channel; 28. Automatic valve assembly; 281. Brass valve body; 282. High-temperature mineral oil; 29. ​​Cutting assembly; 291. Shearing rod; 292. Cutter. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0019] like Figures 1-11 As shown, the present invention provides a recycled plastic injection mold, including an upper mold 1 and a lower mold 2 that are fitted together. The upper mold 1 is provided with a plurality of venting channels 11, and venting components 12 are provided in the plurality of venting channels 11. One end of the venting components 12 intermittently contacts a contact switch 13. The contact switch 13 is electrically connected to a micro air pump 14 through a wire. The lower mold 2 is provided with a feeding channel 21 and a molding groove 22. One end of the feeding channel 21 is connected to a one-way valve 23 and a buffer zone 24. One side of the buffer zone 24 is connected to a first air supply channel 25. One end of the first air supply channel 25 is provided with a three-way valve 26 and a third air supply channel 27. The third air supply channel 27 is provided with an automatic valve assembly 28 and a cutting assembly 29.

[0020] Multiple venting channels 11 are arranged symmetrically about the center of the mold. One end of each venting channel 11 has a conical groove 111 and is located at the bottom of the upper mold 1. The other end of each venting channel 11 has an exhaust port 112 located on the side wall of the upper mold 1. A push rod 15 is inserted into the top of the conical groove 111. One end of the push rod 15 intermittently contacts the contact switch 13. During injection molding, the mixed gas generated by the molten recycled plastic flowing in the molding tank 22 can enter the venting channel 11 through the overflow hole 221 and be discharged through the exhaust port 112. When the molten plastic fills the molding tank 22 and flows into the overflow hole 221, it will push the conical block 121 to move the push rod 15 upward, so that the push rod 15 contacts the contact switch 13, thereby starting the micro air pump 14.

[0021] Specifically, the exhaust assembly 12 includes: a conical block 121 connected to one end of the push rod 15, the conical block 121 being located in the inner cavity of the conical groove 111, and an arc-shaped groove 122 at the bottom end of the conical block 121; a limiting block 123 connected to the push rod 15, a spring 124 being provided on one side of the limiting block 123, and the other end of the spring 124 being provided on the inner wall of the exhaust channel 11; the elastic force of the spring 124 always maintains a gap between the conical block 121 and the inner wall of the exhaust channel 11, ensuring smooth gas passage; when the molten plastic contacts the bottom of the conical block 121 and pushes it upward, the outer wall of the conical block 121 will abut against the inner wall of the exhaust channel 11, thereby sealing the conical groove 111 and preventing the molten plastic from blocking the exhaust channel 11.

[0022] A miniature air pump 14 is installed on the side wall of the upper mold 1. The output end of the miniature air pump 14 is provided with a second air delivery channel 141, and the other end of the second air delivery channel 141 passes through the bottom of the upper mold 1. The top end of the first air delivery channel 25 is provided with a plug interface 251, and the position of the plug interface 251 corresponds to the bottom opening position of the second air delivery channel 141. After the miniature air pump 14 is started, the gas is delivered to the three-way valve 26 through the second air delivery channel 141 and the plug interface 251, and then dispersed to the third air delivery channel 27 and the first air delivery channel 25.

[0023] It should be noted that one end of the feeding channel 21 is provided with a feeding port 211, which is located at the bottom of the lower die 2. The other end of the feeding channel 21 is connected to the inner cavity of the molding groove 22. The top of the molding groove 22 is provided with an overflow hole 221 connected to the exhaust channel 11. The inner cavity of the overflow hole 221 is provided with a reset baffle, and one side of the reset baffle is provided with a beveled surface. During injection molding, the high-temperature recycled plastic that has been crushed, stirred, heated and melted is fed into the feeding channel 21 through the feeding port 211. The amount of material fed in at one time must be greater than 1 / 10 of the amount of material conveyed normally to ensure that the buffer zone 24 and the molding groove 22 are filled. The molten plastic flows and diffuses from the center of the bottom of the molding groove 22 to the surrounding area. The internal gas moves towards the overflow hole 221 and is discharged as it is extruded. The overflow hole 221 can ensure the maximum discharge of gas.

[0024] A pressure rod 252 is inserted into one end of the first air supply channel 25, which is connected to the buffer zone 24. A pressure boosting block 253 is provided at the other end of the pressure rod 252. Multiple limiting rods 254 are provided on one side of the pressure boosting block 253. One end of each limiting rod 254 is slidably inserted into the inner wall of the buffer zone 24. The side wall of the pressure boosting block 253 abuts against the side wall of the buffer zone 24. The gas entering the first air supply channel 25 increases the pressure in the channel. Under the limiting action of the limiting rods 254, the pressure rod 252 pushes the pressure boosting block 253 to squeeze the remaining plastic in the buffer zone 24 to replenish the molding tank 22. With the cooperation of the one-way valve 23, the feed channel 21 is closed in one direction to avoid pressure loss. This achieves secondary injection molding pressure boosting, which compensates for the pressure release caused by cooling contraction and the pressure leakage caused by the increase in sealing gap, making the molten plastic fill more compactly.

[0025] The automatic valve assembly 28 includes a brass valve body 281, one end of which is inserted into the inner cavity of the third air supply channel 27. The inner cavity of the brass valve body 281 is provided with high-temperature mineral oil 282. When the molten plastic just enters the mold, the mold temperature is high, and the heat is conducted to the brass valve body 281, causing the high-temperature mineral oil 282 to expand due to heat. The brass valve body 281 seals the third air supply channel 27, and the gas cannot contact the cutting assembly 29. When the mold temperature slowly decreases, the expansion effect of the high-temperature mineral oil 282 decreases, the brass valve body 281 contracts, and the third air supply channel 27 opens.

[0026] Correspondingly, the cutting assembly 29 includes a shearing rod 291 that is movably inserted into the inner cavity of the third air supply channel 27. The other end of the shearing rod 291 is provided with a cutter 292. One side of the cutter 292 is provided with an inclined surface that fits against the inclined surface of the reset baffle. After the third air supply channel 27 is opened, the pressure in the inner cavity increases, pushing the shearing rod 291, causing the cutter 292 to push the reset baffle into the overflow hole 221, cutting off the remaining material in the overflow hole 221. At this time, the temperature of the molten plastic is suitable, the cutting pressure is small, and the cutting surface can be kept smooth, improving the aesthetics and reducing the probability of defective products. This cutting action is automatically triggered with the mold temperature, without the need for complicated operation.

[0027] Working principle: When it is necessary to recycle plastic injection molding, the recycled material is crushed, stirred, heated and melted. The molten high-temperature plastic is fed into the feeding channel 21 through the feeding port 211 by the feeding equipment. The molten recycled mixed plastic enters the center of the bottom of the molding tank 22 and then flows and diffuses to the surrounding area. During the flow, the recycled plastic and the gas generated by the mixing of multiple materials inside the plastic will move towards the overflow hole 221 by extrusion. Moreover, the gas will flow towards the top first during extrusion. Therefore, setting the feeding channel 21 at the bottom of the molding tank 22 can more efficiently promote the internal gas to move towards the overflow hole 221. When gas enters the overflow hole 221, the elastic force of the spring 124 in the exhaust assembly 12 will always maintain a gap between the conical block 121 and the inner wall of the exhaust channel 11. Therefore, when gas enters the overflow hole 221, it will pass through this gap into the exhaust channel 11 and then be discharged through the exhaust port 112. After the internal gas and the internal gas of the recycled plastic are discharged, the product quality can be improved, and the gas will not be trapped inside the molding tank 22, which will cause bubbles, burn marks, or uneven edges in the finished product. It should be noted that during the above operation, the amount of molten plastic fed into the feed inlet 211 at one time should be greater than 1 / 10 of the amount of material normally conveyed, so as to ensure that the molten plastic can fill the buffer zone 24 and the forming tank 22 at the same time. After the gas inside the forming tank 22 is completely discharged, the molten plastic will flow into the overflow hole 221 through the forming tank 22. The overflow hole 221 can maximize the gas discharge. At this time, the molten plastic will contact the bottom of the conical block 121 and push the conical block 121 to move to the top to compress the spring 124 and push the push rod 15. At the same time, the outer wall of the conical block 121 will abut against the inner wall of the exhaust channel 11 to seal the conical tank 111 and prevent the molten plastic from entering the exhaust channel 11 and blocking the exhaust channel 11. Secondly, after the push rod 15 is pushed, the push rod 15 will abut against the contact switch, causing the micro air pump 14 to start. After the micro air pump 14 starts, it will deliver gas to the three-way valve 26 through the second air delivery channel 141. The gas is dispersed in the three-way valve 26, with part of it entering the third air delivery channel 27 and the other part entering the first air delivery channel 25. The gas entering the first air supply channel 25 will increase the pressure in the first air supply channel 25. Therefore, under the limiting action of the limiting rod 254 on the pressure block 253, one end of the pressure rod 252 will be pushed by the pressure and will push the pressure block 253 to squeeze the remaining plastic in the buffer zone 24 into the molding tank 22. With the one-way valve 23, the feeding channel 21 is closed in one direction to avoid pressure loss and secondary injection pressure. This avoids the problem of pressure loss in the molding tank 22 due to volume shrinkage during cooling after a single feeding, and the problem of pressure not meeting the standard. This makes the molten plastic in the molding tank 22 more compact and fuller, solving the problem of material shortage caused by insufficient feeding and shrinkage caused by insufficient internal pressure. In addition, the improved density and strength of the finished product can make up for the performance defects of recycled materials. Certain conditions are required for gas to enter the third gas delivery channel 27. The automatic valve assembly 28 automatically controls the opening and closing of the third gas delivery channel 27 based on temperature changes. When the molten plastic first enters the mold, the temperatures of the upper mold 1 and the lower mold 2 are both high. When the heat is conducted to the brass valve body 281 through the lower mold 2, the high-temperature mineral oil 282 inside the brass valve body 281 expands due to the heat. One end of the brass valve body 281 is inserted into the third gas delivery channel 27 to seal it, preventing the gas from contacting the cutting assembly 29. As the temperature slowly decreases, the expansion effect of the high-temperature mineral oil 282 inside the brass valve body 281 decreases, and one end of the brass valve body 281 slowly... During contraction, the third air supply channel 27 is opened, increasing the pressure inside the third air supply channel 27. This pushes the shearing rod 291, causing the cutter 292 to push the reset baffle into the overflow hole 221, cutting off the remaining material in the overflow hole 221. It should be noted that the temperature of the molten plastic at this time will not be too low, so the cutting pressure does not need to be too high. Furthermore, slow cutting during the hot phase can better maintain the smoothness of the cut surface, improve the aesthetics of the cut surface, and reduce the probability of product defects caused by cutting off the end face of the remaining material. In addition, this cutting action is automatically triggered when the current mold temperature drops to a certain value, requiring no complicated operation and saving time and effort.

[0028] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A recycling injection mold for plastics, characterized in that, It includes an upper mold (1) and a lower mold (2) that fit together. The upper mold (1) is provided with multiple exhaust channels (11), and an exhaust assembly (12) is provided in the multiple exhaust channels (11). One end of the exhaust assembly (12) intermittently contacts a contact switch (13), and the contact switch (13) is electrically connected to a micro air pump (14) through a wire. The lower die (2) is provided with a feeding channel (21) and a forming groove (22). One end of the feeding channel (21) is connected to a one-way valve (23) and a buffer zone (24). One side of the buffer zone (24) is connected to a first air supply channel (25). One end of the first air supply channel (25) is provided with a three-way valve (26) and a third air supply channel (27). The third air supply channel (27) is provided with an automatic valve assembly (28) and a cutting assembly (29).

2. The injection mold for recycling plastics according to claim 1, characterized in that, Multiple exhaust channels (11) are arranged symmetrically about the center of the mold. One end of each exhaust channel (11) is provided with a conical groove (111). One end of each exhaust channel (11) is located at the bottom of the upper mold. The other end of each exhaust channel (11) is provided with an exhaust port (112). The exhaust port (112) is located on the side wall of the upper mold. A push rod (15) is inserted into the top of the conical groove (111). One end of the push rod (15) intermittently contacts the contact switch (13).

3. The injection mold for recycling plastics according to claim 2, characterized in that, The exhaust assembly (12) includes: A conical block (121) is connected to one end of the push rod (15). The conical block (121) is located in the inner cavity of the conical groove (111). The bottom end of the conical block (121) is provided with an arc-shaped groove (122). A limiting block (123) is connected to the push rod (15). A spring (124) is provided on one side of the limiting block (123), and the other end of the spring (124) is provided on the inner wall of the exhaust channel (11).

4. The injection mold for recycling plastics according to claim 3, characterized in that, The micro air pump (14) is installed on the side wall of the upper mold (1). The output end of the micro air pump (14) is provided with a second air delivery channel (141), and the other end of the second air delivery channel (141) penetrates the bottom of the upper mold (1). The first air supply channel (25) has a plug-in interface (251) at its top end, and the position of the plug-in interface (251) corresponds to the position of the bottom opening of the second air supply channel (141).

5. The injection mold for recycling plastics according to claim 1, characterized in that, One end of the feeding channel (21) is provided with a feeding port (211), which is located at the bottom end of the lower die (2). The other end of the feeding channel (21) is connected to the inner cavity of the forming groove (22). The top end of the forming groove (22) is provided with an overflow hole (221) connected to the exhaust channel (11).

6. The injection mold for recycling plastics according to claim 5, characterized in that, A pressure rod (252) is inserted into one end of the first air supply channel (25) that is connected to the buffer zone (24). A pressure boosting block (253) is provided at the other end of the pressure rod (252). A plurality of limiting rods (254) are provided on one side of the pressure boosting block (253). One end of the plurality of limiting rods (254) is slidably inserted into the inner side wall of the buffer zone (24). The side wall of the pressure boosting block (253) abuts against the side wall of the buffer zone (24).

7. The injection mold for recycling plastics according to claim 6, characterized in that, The automatic valve assembly (28) includes a brass valve body (281), one end of which is inserted into the inner cavity of the third air supply channel (27), and the inner cavity of the brass valve body (281) is provided with high-temperature mineral oil (282).

8. The injection mold for recycling plastics according to claim 7, characterized in that, The cutting assembly (29) includes a shearing rod (291) that is movably inserted into the cavity of the third air supply channel (27), and the other end of the shearing rod (291) is provided with a cutter (292).

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