A type of injection mold for recycling plastics

Abstract

This invention relates to an injection mold for recycling plastics, applied in the field of injection mold technology. It includes a fixed base, a fixed mold, an injection cavity, an injection port, a cavity cover, an injection barrel module, a stirring shaft, and an inclined cone. In this invention, when using recycled plastics for injection molding, the injection barrel module delivers molten recycled plastic into the injection cavity. The stirring shaft uniformly mixes the molten recycled plastic entering the injection cavity, evenly distributing the melt pressure within the molten recycled plastic. The molten recycled plastic then enters the mold cavity of the fixed mold through the injection port, improving the flow effect of the recycled plastic melt during the injection molding process and effectively improving the quality of the injection molded product. Simultaneously, the stirring shaft drives the inclined cone to rotate, using the inclined cone to adjust and shield the injection port, cyclically adjusting the injection flow rate and effectively reducing the impact of multiple injection ports on the injection pressure. This achieves uniform injection of the recycled plastic melt into the mold, effectively improving the injection molding effect of recycled plastics.

Description

Technical Field

[0001] This invention relates to an injection mold, and more particularly to an injection mold for recycling plastics, applicable to the field of injection mold technology. Background Technology

[0002] Recycled plastics refer to the process of reprocessing waste plastic products or plastic waste into reusable plastic materials. Recycled plastics have significant characteristics and differences compared to virgin plastics in injection molding. These differences mainly stem from their source, the degradation process they undergo, and the recycling process. These differences directly affect the process parameters of injection molding, the performance of the final product, and the cost.

[0003] Chinese patent CN118269302A discloses a mold structure for improving plastic flowability. Through the cooperation of a fixed mold, a moving mold, a closed mold, and a sealing mechanism, it facilitates the uniform molding of plastic injection molded parts. Furthermore, the sealing and ejector mechanisms ensure uniform injection during edge retraction, effectively improving the uniformity of the molded parts' thickness. Chinese patent CN120056353A discloses a molding die for recycled plastic injection. A screw feeding unit transports the molten plastic from a heated mixing tank to the injection port. The molten plastic entering the injection port is continuously agitated and mixed by a second spiral groove, which can evenly distribute the melt pressure within the molten plastic, reducing localized high or low pressure areas and thus reducing pressure fluctuations. This helps improve the flow effect and stability of the molten plastic during injection molding.

[0004] Because recycled plastics undergo processing and degradation before recycling, the reduced molecular weight of recycled plastics usually leads to a decrease in melt viscosity. Furthermore, the presence of impurities, degradation products, and additives in the recycled plastic melt can interfere with rheological behavior, resulting in relatively weak fluidity of the melt. When filling the mold, uneven flow of the recycled plastic melt can easily affect the injection molding quality of plastic products. Summary of the Invention

[0005] The technical problem to be solved by the present invention in view of the above-mentioned prior art is that the fluidity of the melt after the recycled plastic is melted is relatively weak. When filling the mold, the uneven flow of the recycled plastic melt can easily affect the injection molding quality of the plastic products.

[0006] To solve the above problems, the present invention provides a recycling injection mold for plastics, including a fixed base, a fixed mold fixedly connected to one end of the fixed base, an injection cavity opened on the back of the fixed mold, injection holes distributed in a ring at the bottom end of the injection cavity, the injection holes communicating with the mold cavity of the fixed mold, a cavity cover fixedly connected to the outside of the injection cavity, and an injection cylinder module fixedly connected to the other end of the fixed base, the output end of the injection cylinder module being fixedly connected to the cavity cover.

[0007] A stirring shaft is rotatably connected between the injection chamber and the chamber cover. An inclined cone is fixedly connected to one end of the stirring shaft near the injection hole. The bottom of the inclined cone is movably connected to the injection hole. The axis of the bottom of the inclined cone is located between the stirring shaft and the injection hole, and the tip of the inclined cone is coaxial with the stirring shaft.

[0008] In the above-mentioned recycled plastic injection mold, the recycled plastic melt entering the injection cavity is uniformly mixed by a stirring shaft, and then enters the mold cavity of the fixed mold through the injection hole. At the same time, the stirring shaft drives the inclined cone to rotate, and the inclined cone is used to shield and adjust the injection hole, thereby cyclically adjusting the injection flow rate of the injection hole and effectively reducing the influence of multiple injection holes on the injection pressure. This achieves uniform injection of recycled plastic melt into the mold and effectively improves the injection molding effect of recycled plastic.

[0009] As a further improvement of this application, a servo motor is fixedly connected to the bottom of the fixed base. The end of the stirring shaft away from the fixed mold extends through the cavity cover, and the extended end of the stirring shaft is connected to the output end of the servo motor through bevel gear meshing. The servo motor drives the stirring shaft to rotate by bevel gear meshing, which facilitates the adjustment of the stirring shaft speed.

[0010] As a further improvement of this application, a filter screen is fixedly connected to the middle of the cavity cover, and the stirring shaft is rotatably connected to the middle of the filter screen. The filter screen is used to filter the recycled plastic melt, which effectively improves the purity of the recycled plastic melt and thus effectively improves the quality of the injection molded products made from recycled plastic.

[0011] As a further improvement of this application, a cleaning vane is fixedly connected to the outside of the agitator shaft. The cleaning vane slides in contact with the surface of the filter screen, and the cleaning vane rotates to clean the surface of the filter screen, effectively preventing the filter screen from clogging.

[0012] As a further improvement of this application, a drain pipe is fixedly connected to the bottom of the cavity cover. The upper opening of the drain pipe corresponds to the bottom of the end of the filter screen away from the injection cavity, and a sealing plug is inserted into the lower opening of the drain pipe. The drain pipe is used to discharge the recycled plastic melt containing impurities from the cavity cover, thereby cleaning the inside of the cavity cover. The sealing plug seals the drain pipe.

[0013] As a further improvement of this application, a collection tube is fixedly connected to the top of the sealing plug. The collection tube is sleeved with the drain pipe, and the recycled plastic melt entering the drain pipe is contained by the collection tube, effectively preventing leakage of the recycled plastic melt.

[0014] As a further improvement of this application, a connecting ring is fixedly connected to the upper opening of the excretion pipe, a sealing cap is movably connected to the middle of the connecting ring, and a bottom support ring is fixedly connected to the bottom of the sealing cap. The bottom support ring is clamped between the top of the storage tube and the bottom of the connecting ring. The storage tube abuts against and clamps the bottom support ring, realizing the lifting state of the sealing cap, thereby realizing the opening of the upper opening of the excretion pipe. A restoring spring is sleeved between the connecting ring and the bottom support ring. The elastic force of the restoring spring pushes the bottom support ring, causing the sealing cap to automatically descend to close the upper opening of the excretion pipe.

[0015] As a further improvement of this application, a spiral shaft is threadedly connected to the middle of the sealing plug, and a movable plug is rotatably connected to the top of the spiral shaft. The movable plug is movably connected to the collection cylinder, and the top of the movable plug is in close contact with the lower opening of the assembly ring. By rotating the spiral shaft, the movable plug is driven to descend, thereby drawing the recycled plastic melt containing impurities into the collection cylinder, which facilitates the extraction and recycling of the recycled plastic melt containing impurities.

[0016] In summary, when using recycled plastics for injection molding, the injection barrel module delivers molten recycled plastic into the injection cavity. A stirring shaft uniformly mixes the molten recycled plastic entering the injection cavity, evenly distributing the melt pressure within the molten recycled plastic. The molten recycled plastic then enters the mold cavity through the injection hole, improving the flow effect during the injection molding process and effectively enhancing the quality of the molded product. Simultaneously, the stirring shaft drives the inclined cone to rotate, using the inclined cone to adjust and shield the injection hole, cyclically adjusting the injection flow rate and effectively reducing the impact of multiple injection holes on the injection pressure. This achieves uniform injection of the recycled plastic melt into the mold, effectively improving the injection molding effect of recycled plastics. Attached Figure Description

[0017] Figure 1 This is a perspective view of the overall structure of the first embodiment of this application;

[0018] Figure 2 This is a three-dimensional enlarged structural view of the cavity cover according to the first embodiment of this application;

[0019] Figure 3 This is a three-dimensional structural diagram of the injection cavity according to the first embodiment of this application;

[0020] Figure 4 A cross-sectional perspective view of the mold for the first embodiment of this application;

[0021] Figure 5 This is a demonstration diagram of the first embodiment of this application, showing the oblique cone rotating to shield the injection hole;

[0022] Figure 6 This is a three-dimensional structural diagram of the stirring shaft and the oblique cone according to the first embodiment of this application;

[0023] Figure 7 This is a side cross-sectional view of the cavity cover according to the second embodiment of this application;

[0024] Figure 8 This is a cross-sectional perspective view of the cavity cover according to the second embodiment of this application;

[0025] Figure 9 This is a diagram illustrating the steps of replacing the sealing plug in the second embodiment of this application;

[0026] Figure 10 This is a three-dimensional structural diagram of the sealing cover, bottom support ring, and restoring spring according to the second embodiment of this application.

[0027] Explanation of the labels in the diagram:

[0028] 1. Fixed base; 101. Fixed mold; 102. Injection cavity; 103. Injection hole; 104. Cavity cover; 105. Stirring shaft; 106. Inclined cone; 107. Servo motor; 108. Bevel gear; 2. Injection cylinder module; 3. Filter screen; 301. Unclogging vane; 302. Drain pipe; 303. Sealing plug; 304. Storage cylinder; 4. Assembly ring; 401. Sealing cover; 402. Base ring; 403. Restoring spring; 404. Spiral shaft; 405. Movable plug. Detailed Implementation

[0029] The two embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0030] First implementation method:

[0031] Figures 1 to 4 The illustration shows a recycled plastic injection mold, including a fixed base 1, a fixed mold 101 fixedly connected to one end of the fixed base 1, an injection cavity 102 opened on the back of the fixed mold 101, an injection hole 103 distributed in a ring at the bottom end of the injection cavity 102, the injection hole 103 communicating with the mold cavity of the fixed mold 101, a cavity cover 104 fixedly connected to the outside of the injection cavity 102, and an injection cylinder module 2 fixedly connected to the other end of the fixed base 1, the output end of the injection cylinder module 2 being fixedly connected to the cavity cover 104.

[0032] When using recycled plastic for injection molding, the injection barrel module 2 delivers the molten recycled plastic through the cavity cover 104 into the injection cavity 102. The molten recycled plastic in the injection cavity 102 then enters the mold cavity of the fixed mold 101 through the injection hole 103, realizing the injection molding of recycled plastic. The annularly distributed injection holes 103 ensure that the molten recycled plastic is evenly injected into the mold cavity of the fixed mold 101, effectively reducing the impact of the low fluidity of the recycled plastic itself on the injection molding effect, thereby effectively improving the quality of recycled plastic injection molded products.

[0033] Figures 2 to 6 As shown, an agitator 105 is rotatably connected between the injection cavity 102 and the cavity cover 104. An inclined cone 106 is fixedly connected to one end of the agitator 105 near the injection hole 103. The bottom of the inclined cone 106 is movably connected to the injection hole 103. The axis of the bottom of the inclined cone 106 is located between the agitator 105 and the injection hole 103, and the tip of the inclined cone 106 is coaxial with the agitator 105. A servo motor 107 is fixedly connected to the bottom of the fixed base 1. The end of the agitator 105 away from the fixed mold 101 extends through the cavity cover 104. The extended end of the agitator 105 is connected to the output end of the servo motor 107 through a bevel gear 108. The servo motor 107 drives the agitator 105 to rotate by means of bevel gear 108, which facilitates the speed adjustment of the agitator 105.

[0034] The stirring shaft 105 uniformly mixes the recycled plastic melt entering the injection chamber 102, effectively and evenly distributing the melt pressure within the recycled plastic melt. The stirring shaft 105 also drives the inclined cone 106 to rotate, guiding the recycled plastic melt towards the injection hole 103 via the conical surface of the inclined cone 106. Simultaneously, the bottom of the inclined cone 106 partially obstructs the injection hole 103, cyclically adjusting the injection flow rate. Specifically, when the bottom of the inclined cone 106 obstructs the injection hole 103, the flow rate through the injection hole 103 is reduced, but the injection hole 103 is not completely blocked. Even when the injection holes 103 are not blocked, the minimum flow rate of the injection holes 103 still exists. Conversely, when the injection holes 103 are not blocked, the flow rate of the injection holes 103 is restored. That is, the flow rate of the ring-shaped injection holes 103 is adjusted in a cyclical manner. Since not all injection holes 103 are full flow, the recycled plastic melt is concentrated from a few high-flow injection holes 103 into the mold cavity of the fixed mold 101, which effectively reduces the influence of multiple injection holes 103 on the injection pressure. The injection pressure is maintained in the mold cavity of the fixed mold 101 through the injection holes 103, so as to achieve uniform injection of the recycled plastic melt and effectively improve the injection molding effect of recycled plastic.

[0035] Second implementation method:

[0036] Compared to the first embodiment, the main additions are a filter screen 3 and a drain pipe 302. The specific additions are as follows, while the remaining structures are the same as in the first embodiment.

[0037] Figure 7 and Figure 8 As shown, a filter screen 3 is fixedly connected to the middle of the cavity cover 104, and the agitator shaft 105 is rotatably connected to the middle of the filter screen 3. The filter screen 3 is used to filter the recycled plastic melt, removing impurities, mainly carbonized particles. Carbonized particles easily clog the injection hole 103 of the fixed mold 101, affecting the flow performance of the recycled plastic melt in the fixed mold 101, effectively improving the purity of the recycled plastic melt, and thus effectively improving the quality of the injection molded products made from recycled plastic. A cleaning blade 301 is fixedly connected to the outside of the agitator shaft 105 to clean... The clogging plate 301 slides in contact with the surface of the filter screen 3. The clogging plate 301 rotates to clean the surface of the filter screen 3, effectively preventing the filter screen 3 from clogging. The bottom of the cavity cover 104 is fixedly connected to the drain pipe 302. The upper opening of the drain pipe 302 corresponds to the bottom of the end of the filter screen 3 away from the injection cavity 102, and the lower opening of the drain pipe 302 is connected to the sealing plug 303. The drain pipe 302 is used to discharge the recycled plastic melt containing impurities inside the cavity cover 104, thereby cleaning the inside of the cavity cover 104. The sealing plug 303 seals the drain pipe 302.

[0038] The filter screen 3 is used to filter the recycled plastic melt, screen out the impurities in the recycled plastic melt, and effectively improve the purity of the recycled plastic melt. At the same time, the stirring shaft 105 drives the cleaning vane 301 to clean the surface of the filter screen 3, effectively maintaining the permeability of the filter screen 3. When the impurities in the cavity cover 104 reach the threshold, the recycled plastic melt with impurities in the cavity cover 104 is discharged through the drain pipe 302, realizing the internal cleaning of the cavity cover 104.

[0039] The threshold of impurities in the cavity cover 104 can be determined by using a pressure sensor, which is not shown in the attached figure. That is, when the filter screen 3 is affected by impurities, the pressure of the recycled plastic melt in the cavity cover 104 increases. The pressure of the recycled plastic melt reflects the threshold of impurities in the cavity cover 104.

[0040] Figures 8 to 10As shown, a receiving cylinder 304 is fixedly connected to the top of the sealing plug 303. The receiving cylinder 304 is sleeved with the drain pipe 302. The recycled plastic melt entering the drain pipe 302 is contained by the receiving cylinder 304, effectively reducing the leakage of the recycled plastic melt. A connecting ring 4 is fixedly connected to the upper opening of the drain pipe 302. A sealing cover 401 is movably connected to the middle of the connecting ring 4. A bottom support ring 402 is fixedly connected to the bottom of the sealing cover 401. The bottom support ring 402 is clamped between the top of the receiving cylinder 304 and the bottom of the connecting ring 4. The receiving cylinder 304 abuts against and clamps the bottom support ring 402, realizing the lifting state of the sealing cover 401, thereby realizing the opening of the upper opening of the drain pipe 302. A restoring spring 403 is sleeved between the connecting ring 4 and the bottom support ring 402. The restoring spring 403 can be made of nickel-based high-temperature alloy. The spring can withstand the high temperature environment of injection molding for a long time and maintain excellent mechanical properties at high temperatures of 650-1000℃. It has the characteristics of high tensile strength and outstanding fatigue resistance. The elastic force of the restoring spring 403 pushes the bottom support ring 402, which drives the sealing cover 401 to automatically descend to close the upper opening of the discharge pipe 302. The middle of the sealing plug 303 is threaded with a spiral shaft 404. The top of the spiral shaft 404 is rotatably connected to a movable plug 405. The movable plug 405 is movably connected to the collection cylinder 304, and the top of the movable plug 405 is in close contact with the lower opening of the assembly ring 4. By rotating the spiral shaft 404, the movable plug 405 is driven to descend, so as to draw the recycled plastic melt with impurities into the collection cylinder 304, which facilitates the extraction and recycling of the recycled plastic melt with impurities.

[0041] When cleaning impurities from the cavity cover 104, the rotating screw shaft 404 is rotated to lower the movable plug 405, thereby drawing the recycled plastic melt containing impurities into the collection cylinder 304, effectively reducing leakage of the recycled plastic melt. Then, the sealing plug 303 is released, and the collection cylinder 304 is removed, facilitating the extraction and recycling of the recycled plastic melt containing impurities. As the collection cylinder 304 separates from the drain pipe 302, the restoring spring 403 pushes the bottom support ring 402 with its elastic force, causing the sealing cover 401 to automatically descend and seal the upper opening of the connecting ring 4, effectively reducing leakage of the recycled plastic melt. Then, a new sealing plug 303 seals the drain pipe 302, and the collection cylinder 304 re-contacts the bottom support ring 402, causing the sealing cover 401 to rise. At this time, the movable plug 405 is at the top of the collection cylinder 304, and the movable plug 405 takes over from the sealing cover 401 to seal the lower opening of the connecting ring 4, also effectively reducing leakage of the recycled plastic melt.

[0042] In light of current practical needs, the above-described embodiments adopted in this application are not limited to these. Any changes made within the scope of knowledge possessed by those skilled in the art without departing from the concept of this application still fall within the protection scope of this invention.

Claims

1. A recycling injection mold for plastics, characterized in that: The device includes a fixed base (1), one end of which is fixedly connected to a fixed mold (101). An injection cavity (102) is provided on the back of the fixed mold (101). An injection hole (103) is provided at the bottom of the injection cavity (102) in an annular arrangement. The injection hole (103) communicates with the mold cavity of the fixed mold (101). A cavity cover (104) is fixedly connected to the outside of the injection cavity (102). An injection molding cylinder module (2) is fixedly connected to the other end of the fixed base (1). The output end of the injection molding cylinder module (2) is fixedly connected to the cavity cover (104). A stirring shaft (105) is rotatably connected between the injection cavity (102) and the cavity cover (104). An inclined cone (106) is fixedly connected to one end of the stirring shaft (105) near the injection hole (103). The bottom of the inclined cone (106) is movably connected to the injection hole (103). The axis of the bottom of the inclined cone (106) is located between the stirring shaft (105) and the injection hole (103). The tip of the inclined cone (106) is coaxial with the stirring shaft (105). A servo motor (107) is fixedly connected to the bottom of the fixed base (1). The end of the stirring shaft (105) away from the fixed mold (101) extends through the cavity cover (104). The extended end of the stirring shaft (105) is meshed with the output end of the servo motor (107) through a bevel gear (108).

2. The injection mold for recycling plastics according to claim 1, characterized in that: A filter screen (3) is fixedly connected to the middle of the cavity cover (104), and the stirring shaft (105) is rotatably connected to the middle of the filter screen (3).

3. The injection mold for recycling plastics according to claim 2, characterized in that: The stirring shaft (105) is externally fixedly connected to a cleaning blade (301), which slides in contact with the surface of the filter screen (3).

4. The injection mold for recycling plastics according to claim 2, characterized in that: The bottom of the cavity cover (104) is fixedly connected to a drain tube (302). The upper opening of the drain tube (302) corresponds to the bottom of the end of the filter (3) away from the injection cavity (102), and a sealing plug (303) is inserted into the lower opening of the drain tube (302).

5. The injection mold for recycling plastics according to claim 4, characterized in that: The top of the sealing plug (303) is fixedly connected to a storage tube (304), and the storage tube (304) is sleeved with the drain pipe (302).

6. The injection mold for recycling plastics according to claim 5, characterized in that: A connecting ring (4) is fixedly connected to the upper opening of the drain pipe (302). A sealing cover (401) is movably connected to the middle of the connecting ring (4). A bottom support ring (402) is fixedly connected to the bottom of the sealing cover (401). The bottom support ring (402) is clamped between the top of the storage tube (304) and the bottom of the connecting ring (4). A restoring spring (403) is sleeved between the connecting ring (4) and the bottom support ring (402).

7. The injection mold for recycling plastics according to claim 6, characterized in that: The sealing plug (303) is threadedly connected to a spiral shaft (404) in the middle. The top of the spiral shaft (404) is rotatably connected to a movable plug (405). The movable plug (405) is movably connected to the storage cylinder (304), and the top of the movable plug (405) is in close contact with the lower opening of the connecting ring (4).

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