Forming die for liquid silica gel

Abstract

The utility model provides a liquid silica gel forming mold, and belongs to the technical field of silica gel forming equipment. The problem that when an existing liquid silicone rubber mold is heated, liquid silicone rubber in a flow channel is easily solidified, and the flow channel is blocked is solved. The liquid silica gel forming mold comprises an upper mold and a lower mold, a plurality of cavities are defined by the upper mold and the lower mold, runners communicated with the cavities are formed in the upper mold, the upper mold comprises a runner plate assembly and a mold core located below the runner plate assembly, and a heat insulation plate is arranged between the runner plate assembly and the mold core. And a needle valve type nozzle for opening and closing the runner and injecting glue into the cavity is arranged at an outlet of the runner. The heating plate is arranged, the runner can be closed during heating, liquid silica gel in the runner is prevented from being solidified, and the production efficiency is higher.

Description

TECHNICAL FIELD

[0001] The utility model belongs to silica gel forming equipment technical field relates to a kind of forming mould of liquid silicone. BACKGROUND

[0002] Silica gel products have the advantages of high temperature resistance, easy cleaning, long service life, softness and comfort, so that silica gel products are more and more widely used in daily life.

[0003] At present, silica gel products are mainly divided into solid silica gel forming and liquid silica gel forming according to different forming processes. In the solid silica gel forming, the mixed silica gel raw material is put into the mold, and it is vulcanized by heating and pressurizing. In the liquid silica gel forming process, the mold is injected by the injection molding machine, and then vulcanized by heating. Although the solid silica gel forming process has lower cost, the liquid silica gel forming process has better flowability, higher plasticity, and more detailed finished products, which cannot be replaced by the solid forming process.

[0004] For example, a mold for liquid silicone disclosed in Chinese patent application (application number: 201821869043.3) includes an upper mold, a middle mold, and a lower mold. The middle mold has a plurality of base piece lower cavities. The lower mold has a plurality of base piece lower cavities corresponding to the base piece upper cavities. The base piece upper cavities have a first glue injection hole and a second glue injection hole. The first glue injection hole and the second glue injection hole are in communication with the silicone flow channel groove on the upper surface of the middle mold. After the mold is closed and liquid silicone is injected into the cavity, it needs to be heated to solidify. Since the mold is made of steel material, it has good thermal conductivity. Heating the silicone in the cavity will cause the temperature of the middle mold to rise and the liquid silicone in the silicone flow channel groove to solidify, thereby blocking the flow channel. After the mold is opened, the silicone flow channel groove and the flow channel need to be cleaned, which increases the operation steps of the workers and greatly reduces the production efficiency. SUMMARY

[0005] The utility model aims at the above-mentioned problems existing in the prior art and provides a forming mold for liquid silicone. The technical problem to be solved by the utility model is how to avoid the solidification of liquid silicone that has not entered the cavity and improve the production efficiency of silica gel products.

[0006] The purpose of the utility model can be achieved by the following technical scheme. A forming mold for liquid silicone includes an upper mold and a lower mold. The upper mold and the lower mold form a plurality of cavities. The upper mold is provided with a flow channel in communication with the cavities. The upper mold includes a flow channel plate assembly and a mold core located below the flow channel plate assembly. A heat insulation plate is arranged between the flow channel plate assembly and the mold core. A needle valve type nozzle is arranged at the outlet of the flow channel for opening and closing the flow channel and injecting glue into the cavity.

[0007] The upper die is designed in a split type, a heat insulation plate is arranged between a die core and a runner plate assembly provided with a runner, a needle valve type nozzle is arranged in the runner, and the die core is injected with glue through the needle valve type nozzle, the runner is closed after glue injection, heat insulation protection is formed between the runner and the die core, the temperature of liquid silica gel in the runner is prevented from being too high to solidify, and the mold is convenient for glue injection production again after demolding.

[0008] In the molding die for liquid silica gel, the runner comprises a glue injection port, a runner groove communicated with the glue injection port, and a plurality of glue inlet channels communicated with the runner groove and the cavity, each of the glue inlet channels is provided with the needle valve type nozzle, the needle valve type nozzle comprises a pipe body, a valve needle inserted into the pipe body, and a piston connected with the valve needle, two ends of the pipe body are communicated with the runner groove and the cavity respectively, a plurality of limiting holes corresponding to the needle valve type nozzles are arranged in the runner plate assembly, the piston is slidingly arranged in the limiting hole and divides the limiting hole into two chambers, and each chamber is communicated with a pneumatic pipeline.

[0009] In the molding die for liquid silica gel, the runner plate assembly comprises a pressing plate, a nozzle limiting plate and a runner plate arranged in sequence from top to bottom, the glue injection port is arranged on the upper surface of the pressing plate, the limiting hole is arranged on the nozzle limiting plate and is closed by the pressing plate, and the runner groove is arranged on the runner plate. In this way, the needle valve type nozzle is convenient to install, and the runner is convenient to maintain in the later period.

[0010] In the molding die for liquid silica gel, the valve needle is sleeved with a sealing ring, and the sealing ring is located between the nozzle limiting plate and the runner plate.

[0011] In the molding die for liquid silica gel, the pipe body comprises an outer pipe body and an inner pipe body, the inner pipe body is inserted into the outer pipe body, two ends of the inner pipe body are fixedly connected with the outer pipe body, and a gap is formed between the middle part of the inner pipe body and the outer pipe body. In this way, the heat insulation effect of the inner pipe body can be further improved, and the liquid silica gel in the inner pipe body is prevented from solidifying.

[0012] In the molding die for liquid silica gel, a plurality of annular shoulders are arranged on the outer circumferential surface of the outlet of the lower end of the inner pipe body, an annular groove is formed between adjacent annular shoulders, and a sealing ring is arranged in the annular groove. In this way, the liquid silica gel is prevented from leaking between the inner pipe body and the outer pipe body, the sealing effect is improved, and the heat insulation effect is further improved.

[0013] In the finished mold of the liquid silicone rubber above, the lower surface of the mold core is provided with a plurality of upper cavities; the upper surface of the lower mold is provided with a plurality of lower cavities corresponding to the upper cavities one by one, the outlets of the glue feeding channels are located in the middle part of the mold core, the upper cavities are respectively located on both sides of the glue feeding channels, the outer edge of the upper surface of the lower mold is further provided with an exhaust groove arranged along the circumference of the lower mold, the exhaust groove surrounds all the lower cavities and is in communication with adjacent lower cavities, the edge of the mold core has a gap with the edge of the lower mold and forms an exhaust port in communication with the outside, and the exhaust port is in communication with the exhaust groove. In this way, after the upper mold and the lower mold are closed, when the glue is injected into the cavity, the liquid silicone rubber will diffuse from the middle part to the periphery, so that the air in the cavity flows to the exhaust groove in the periphery and is discharged from the exhaust port, avoiding air holes in the molded silicone rubber products, and the quality is more stable.

[0014] Compared with the prior art, the utility model has the following advantages:

[0015] 1、 the upper mold of the utility model adopts the split type structure, makes the runner part and the mold core for forming to be separated by the heat insulation plate, and sets up the needle valve type nozzle at the runner mouth, can close the runner and insulate when the mold is heated and solidified, avoids the liquid silicone rubber in the runner to solidify, thereby simplifies the processing flow, improves the processing efficiency.

[0016] 2、 the glue feeding channel outlet of the utility model is arranged in the middle part of the mold core, and the exhaust groove is arranged on the edge of the lower mold, when injecting glue, the liquid silicone rubber can diffuse from the center to the periphery, and the air in the cavity is discharged, avoiding air holes in the molded silicone rubber products, and improving the yield. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the structure schematic diagram of the utility model;

[0018] Figure 2 It is the structure schematic diagram of the lower mold;

[0019] Figure 3 It is the structure schematic diagram of the upper mold;

[0020] Figure 4 It is the structure explosion drawing of the upper mold;

[0021] Figure 5 It is the sectional view of the utility model;

[0022] Figure 6 It is Figure 5 The local enlarged view of A part in;

[0023] Figure 7 It is Figure 5 The local enlarged view of B part in;

[0024] Figure 8 It is the structure schematic diagram of the needle valve type nozzle.

[0025] In the diagram, 1. Upper mold; 11. Pressure plate; 11a. Injection port; 12. Nozzle limiting plate; 12a. Limiting hole; 13. Runner plate; 13a. Runner groove; 14. Heat insulation plate; 15. Mold core; 1a. Upper cavity; 2. Lower mold; 2a. Lower cavity; 2b. Venting groove; 3. Cavity; 4. Injection channel; 5. Needle valve nozzle; 51. Tube body; 511. Outer tube body; 512. Inner tube body; 513. Sealing ring; 52. Valve needle; 53. Piston; 54. Sealing ring; 6. Pneumatic pipeline; 7. Venting port. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] A molding die for liquid silicone, such as Figures 1-3 As shown, the mold includes an upper mold 1 and a lower mold 2. The lower surface of the upper mold 1 is provided with a plurality of upper cavities 1a, and the upper surface of the lower mold 2 is provided with a plurality of lower cavities 2a corresponding to the upper cavities 1a. When the upper mold 1 and the lower mold 2 are closed, the upper cavities 1a and the lower cavities 2a surround each other to form a cavity 3 for molding silicone products. The upper mold 1 includes a runner plate assembly and a mold core 15 located below the runner plate assembly. A heat insulation plate 14 is provided between the runner plate assembly and the mold core 15. A needle valve nozzle 5 is provided at the outlet of the runner for opening and closing the runner and for injecting silicone into the cavity 3. When the upper mold 1 and the lower mold 2 are closed and the liquid silicone in the cavity 3 is heated and cured, the needle valve nozzle 5 closes the runner and, under the action of the heat insulation plate 14, prevents the liquid silicone in the runner from overheating and curing.

[0028] Specifically, such as Figure 4 , Figure 5 As shown, the runner plate assembly includes a pressure plate 11, a nozzle limiting plate 12, and a runner plate 13 arranged sequentially from top to bottom. The runner includes a glue inlet 11a on the upper surface of the pressure plate 11, a runner groove 13a on the runner plate 13 communicating with the glue inlet 11a, and several glue inlet channels 4 connecting the runner groove 13a to the cavity 3. The glue inlet channels 4 are located between the runner plate 13 and the mold core 15. Each glue inlet channel 4 is equipped with a needle valve nozzle 5, and each needle valve nozzle 5 can open or close its corresponding glue inlet channel 4. Figure 6 , Figure 8As shown, the needle valve nozzle 5 includes a tube body 51, a valve needle 52 and a piston 53, the tube body 51 is inserted into the glue feeding channel 4, and the upper end of the tube body 51 is communicated with the flow channel groove 13a, the lower end of the tube body 51 is located at the outlet of the glue feeding channel 4 and communicated with the cavity 3, the valve needle 52 is inserted into the tube body 51, the piston 53 is fixedly connected to the upper end of the valve needle 52, a plurality of limiting holes 12a corresponding to the needle valve nozzle 5 are formed in the nozzle limiting plate 12, the upper end of the limiting hole 12a is closed by the pressing plate 11, the piston 53 is slidingly arranged in the corresponding limiting hole 12a, and the limiting hole 12a is divided into an upper cavity and a lower cavity, the upper cavity and the lower cavity are respectively communicated with the pneumatic pipeline 6, the upper cavity and the lower cavity are filled with air through the pneumatic pipeline 6, the piston 53 and the valve needle 52 are driven to move up and down, so as to open or close the outlet of the tube body 51.

[0029] Further, as shown in the drawings, Figure 6 In this embodiment, the tube body 51 adopts a double-layer structure, including an outer tube body 511 and an inner tube body 512, the inner tube body 512 is inserted into the outer tube body 511, the two ends of the inner tube body 512 are fixedly connected with the outer tube body 511, and there is a gap between the middle part of the inner tube body 512 and the outer tube body 511, further improving the heat insulation effect. Moreover, three annular shoulders are arranged on the outer circumferential surface of the lower end outlet of the inner tube body 512, two annular grooves are formed between the three annular shoulders, and a sealing ring 513 is arranged in each annular groove.

[0030] Further, a sealing ring 54 is further sleeved on the valve needle 52, the sealing ring 54 is located between the flow channel plate 13 and the nozzle limiting plate 12, and is used to close the channel between the limiting hole 12a and the flow channel groove 13a, so as to avoid leakage.

[0031] As shown in the drawings, Figure 2 , Figure 7 The outlets of the glue feeding channels 4 are located at the middle part of the mold core 15, and the upper cavities 1a are located on both sides of the glue feeding channels 4, respectively, the outer edge of the upper surface of the lower mold 2 is further provided with an exhaust groove 2b arranged along the circumference of the lower mold 2, the exhaust groove 2b surrounds all the lower cavities 2a and is communicated with the adjacent lower cavities 2a, the edge of the mold core 15 has a gap with the edge of the lower mold 2 and forms an exhaust port 7 communicated with the outside, and the exhaust port 7 is communicated with the exhaust groove 2b, which is convenient for exhausting during glue injection, avoids air holes in the finished silicone product, and ensures the quality.

[0032] The working principle of the utility model is as follows: after the upper die 1 and the lower die 2 are closed, liquid silicone is injected into the runner groove 13a, and the needle valve nozzle 5 is opened, so that the liquid silicone enters the cavities 3 between the upper die 1 and the lower die 2 from the plurality of glue inlet channels 4, the liquid silicone gradually spreads from the middle to the periphery to each cavity 3, and the air originally in the cavities 3 gradually flows to the exhaust grooves 2b around and is discharged from the exhaust port 7 between the core 15 and the lower die 2, so that the liquid silicone fills all the cavities 3; then the needle valve nozzle 5 is closed, and the lower die 2 is heated, so that the liquid silicone in the cavities 3 is solidified; due to the arrangement of the heat insulation plate 14 and the evaporative nozzle, heat is concentrated between the core 15 and the lower die 2, so that the temperature of the runner groove 13a and the glue inlet channel 4 is not too high to cause the liquid silicone to solidify.

[0033] The specific embodiments described herein merely exemplify the spirit of the utility model. Those skilled in the art to which the utility model belongs can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the utility model or exceed the scope defined by the appended claims.

[0034] Although the terms such as the upper die 1, the pressing plate 11, the nozzle limiting plate 12, the runner plate 13, the heat insulation plate 14, the core 15, the lower die 2, the needle valve nozzle 5, the sealing ring 54 and the like are used frequently herein, the possibility of using other terms is not excluded. These terms are used only for the convenience of describing and explaining the essence of the utility model; any kind of additional limitation by interpreting them is contrary to the spirit of the utility model.

Claims

1. A molding die for liquid silicone, comprising an upper die (1) and a lower die (2), wherein the upper die (1) and the lower die (2) together form a plurality of cavities (3), and the upper die (1) is provided with flow channels communicating with the cavities (3), characterized in that, The upper mold (1) includes a runner plate assembly and a mold core (15) located below the runner plate assembly. A heat insulation plate (14) is provided between the runner plate assembly and the mold core (15). A needle valve nozzle (5) for opening and closing the runner is provided at the outlet of the runner. The runner includes a glue inlet (11a), a runner groove (13a) communicating with the glue inlet (11a), and several glue inlet channels (4) communicating with the runner groove (13a) and the cavity (3). Each glue inlet channel (4) is provided with the aforementioned needle valve nozzle (5). The valve nozzle (5) includes a tube body (51), a valve needle (52) inserted in the tube body (51), and a piston (53) connected to the valve needle (52). The two ends of the tube body (51) are respectively connected to the flow channel groove (13a) and the cavity (3). The flow channel plate assembly is provided with a number of limiting holes (12a) corresponding to the needle valve nozzle (5). The piston (53) is slidably disposed in the limiting hole (12a) and divides the limiting hole (12a) into upper and lower chambers. Each chamber is connected to a pneumatic pipeline (6).

2. The molding die for liquid silicone according to claim 1, characterized in that, The flow channel plate assembly includes a pressure plate (11), a nozzle limiting plate (12), and a flow channel plate (13) arranged sequentially from top to bottom. The glue injection port (11a) is located on the upper surface of the pressure plate (11), the limiting hole (12a) is located on the nozzle limiting plate (12) and is closed by the pressure plate (11), and the flow channel groove (13a) is located on the flow channel plate (13).

3. The molding die for liquid silicone according to claim 2, characterized in that, A sealing ring (54) is fitted on the valve needle (52), and the sealing ring (54) is located between the nozzle limiting plate (12) and the flow channel plate (13).

4. The molding die for liquid silicone according to claim 1 or 2, characterized in that, The tube body (51) includes an outer tube body (511) and an inner tube body (512). The inner tube body (512) is inserted into the outer tube body (511). Both ends of the inner tube body (512) are fixedly connected to the outer tube body (511), and there is a gap between the middle part of the inner tube body (512) and the outer tube body (511).

5. The molding die for liquid silicone according to claim 4, characterized in that, The outer circumferential surface at the lower end outlet of the inner tube (512) is provided with a number of spaced annular shoulders, and an annular groove is formed between adjacent annular shoulders. A sealing ring (513) is provided in the annular groove.

6. The molding die for liquid silicone according to claim 1 or 2, characterized in that, The lower surface of the mold core (15) is provided with several upper cavities (1a); the upper surface of the lower mold (2) is provided with several lower cavities (2a) that correspond one-to-one with the upper cavities (1a); the outlet of the glue injection channel (4) is located in the middle of the mold core (15); the upper cavities (1a) are located on both sides of the glue injection channel (4); the outer edge of the upper surface of the lower mold (2) is also provided with an exhaust groove (2b) arranged circumferentially along the lower mold (2); the exhaust groove (2b) surrounds all the lower cavities (2a) and communicates with the adjacent lower cavities (2a); the edge of the mold core (15) and the edge of the lower mold (2) have a gap and form an exhaust port (7) communicating with the outside; the exhaust port (7) is connected to the exhaust groove (2b).

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