Silicone rubber vulcanization tabletting device and forming method

Abstract

The invention provides a silicone rubber vulcanization tabletting device and a molding method. The silicone rubber vulcanization tabletting device comprises a frame body, a split mold and a jacking assembly, the split mold comprises a frame and a cover plate, the bottom mold frame is connected to the frame body, the cover plate is detachably connected to the bottom mold frame, the bottom mold frame, the frame body and the cover plate are encircled to form a cavity for accommodating a silicon rubber raw material, and the cavity has a preset shape; and the jacking assembly is connected to the frame body and abuts against the cover plate so that the cover plate can be attached to the bottom die frame. The silicon rubber sheet forming device can realize compression forming of silicon rubber sheets with uniform thickness, and is high in forming quality, high in safety coefficient in the forming process and low in energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber molding equipment, and more specifically to a silicone rubber vulcanization tablet pressing device and a molding method, which can be further extended and applied to the preparation of resin casting bodies. Background Art

[0002] Silicone rubber is an elastomer formed by catalytic curing of organic siloxane, filler and vulcanizer at room temperature or under heating conditions. The molecular chain of silicone rubber is composed of -Si-O- repeating units, and the silicon atom is generally connected to two organic groups. Therefore, it combines the characteristics of inorganic and organic materials, has high and low temperature resistance, air permeability, oxidation resistance, electrical insulation and designability, and is widely used in aerospace, transportation, electronics, construction and other fields.

[0003] The main component of silicone rubber is high molar mass linear polysiloxane. According to the type of silicone rubber, it can be divided into four categories: polydimethylsiloxane (i.e. methyl silicone rubber), polymethyltrifluoropropylsiloxane (fluorosilicone rubber), polymethylvinylsiloxane (vinyl silicone rubber) and polymethylphenylvinylsiloxane (phenyl silicone rubber). The average molecular weight (g / mol) is usually between 400,000 and 800,000.

[0004] Silicone rubber is usually vulcanized into sheets for use, but due to its large molecular weight and high room temperature viscosity, it is difficult to press into sheets and is often accompanied by uneven thickness after sheeting. At present, silicone rubber is usually pressed into sheets using a mechanical press. Bars, baffles or other supports of the required thickness are placed on the table of the mechanical press to control the thickness of the pressed silicone rubber sheet. When silicone rubber is formed by a mechanical press, since the force applied by the mechanical press is only located at the center of the silicone rubber, it is easy to cause the thickness of the central area of ​​the silicone rubber to be inconsistent with the thickness of the surrounding areas. In addition, the mechanical press is prone to safety problems during operation, and the energy consumption of the operation is also high. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The technical problem to be solved by the present invention is that the thickness of silicone rubber produced by the existing method of forming silicone rubber by a press is uneven, safety problems are easily generated during the operation of the mechanical press, and the energy consumption is high.

[0007] (II) Technical solution

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] In the first aspect, the present invention provides a silicone rubber vulcanization pressing device, comprising a frame, a split mold and a top pressing assembly; the split mold comprises a frame and a cover plate, the bottom mold frame is connected to the frame, the cover plate is detachably connected to the bottom mold frame, the bottom mold frame, the frame and the cover plate together form a cavity for accommodating silicone rubber raw materials, and the cavity has a preset shape; the top pressing assembly is connected to the frame and abuts against the cover plate so that the cover plate fits the bottom mold frame.

[0010] Preferably, the frame body includes a base plate, a support frame and an upper beam plate, the base plate is fixedly connected to the support frame, the upper beam plate is fixedly connected to the support frame, the base plate and the upper beam plate are arranged opposite to each other, and the bottom mold frame, the base plate and the cover plate together form a cavity for accommodating silicone rubber raw materials.

[0011] Preferably, the side wall of the bottom mold frame is provided with at least one glue outlet hole, and the glue outlet hole is communicated with the mold cavity.

[0012] Preferably, the split mold further comprises a glue box, which is arranged in the bottom mold frame and detachably connected to the bottom mold frame, and a glue groove is arranged in the glue box, and the glue groove is communicated with the glue outlet hole.

[0013] Preferably, the pressing assembly comprises a screw and a compression spring, the screw is threadedly connected to the upper beam plate, and the compression spring is arranged at the end of the upper beam plate away from the upper beam plate.

[0014] Preferably, the pressing assembly further comprises a handle, and the handle is fixedly connected to the end of the screw rod facing away from the bottom plate.

[0015] Preferably, there are a plurality of the pressing assemblies, and the plurality of pressing assemblies are spaced apart along the length direction of the cover plate.

[0016] Preferably, the preset shape is a rectangle or a circle or other shapes designed according to requirements.

[0017] In a second aspect, the present invention further provides a molding method, using the silicone rubber vulcanization tableting device described in any one of the above technical solutions, the molding method comprising the following steps:

[0018] Covering the inner walls around the cavity with a demoulding material, and drying to remove the solvent;

[0019] Filling the silicone rubber raw material into the cavity;

[0020] Covering the bottom mold frame with a cover plate to close the mold cavity;

[0021] Driving the pressing assembly to press the cover plate so that the cover plate fits the bottom mold frame;

[0022] vulcanizing the silicone rubber raw material in the silicone rubber vulcanization and sheeting device;

[0023] After demoulding, a silicone rubber sheet with a preset shape is obtained.

[0024] Preferably, vulcanizing the silicone rubber raw material in the silicone rubber vulcanization sheeting device comprises the following steps:

[0025] The silicone rubber vulcanization tablet pressing device containing the silicone rubber raw material is placed at a preset temperature according to material specifications and vulcanized for a corresponding time.

[0026] (III) Beneficial effects

[0027] The above technical solution of the present invention has at least the following advantages:

[0028] 1. In the present invention, the bottom mold frame, the frame body and the cover plate are combined to form a cavity for accommodating the silicone rubber raw material, so that the shape and size of the silicone rubber raw material can be constrained, and then the top pressure component is used to apply pressure to the cover plate so that the silicone rubber raw material is fully compressed, and finally vulcanized and demolded to form a silicone rubber sheet with uniform thickness. The silicone rubber sheet molded in this way has a shape and size that meets the requirements, has high molding quality, and can reduce the scrap rate of production.

[0029] 2. In the present invention, pressure is applied to the cover plate by tightening the screw to squeeze the compression spring. Compared with the prior art method of using a high-speed mechanical press to press, the probability of causing harm to the health of the operator is smaller, and no electricity is required to drive the mechanical press to move, thereby reducing production energy consumption.

[0030] 3. In the present invention, a driving screw is used to move and squeeze the compression spring to achieve pressure on the cover plate. The screw is tightened to put the compression spring in a compressed state. The compression spring can produce adaptive elongation when the screw stress is relaxed to ensure that pressure is always applied to the cover plate during the entire silicone rubber pressing process, thereby achieving the molding of a silicone rubber sheet with uniform thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the structure of a silicone rubber vulcanization sheet pressing device provided in an embodiment of the present invention.

[0033] Figure 2It is a cross-sectional structural diagram of a bottom mold frame and a plastic box provided in an embodiment of the present invention.

[0034] The reference numerals in the figures are:

[0035] 1. Frame; 2. Split mold; 3. Top pressure assembly; 4. Cavity; 11. Bottom plate; 12. Support frame; 13. Upper beam plate; 21. Bottom mold frame; 22. Cover plate; 23. Glue box; 31. Screw; 32. Compression spring; 33. Handle; 211. Glue outlet hole; 231. Glue groove. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0038] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments:

[0040] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a silicone rubber vulcanization tablet pressing device, including a frame 1, a split mold 2 and a top pressing assembly 3; the split mold 2 includes a bottom mold frame 21 and a cover plate 22, the bottom mold frame 21 is connected to the frame 1, and the cover plate 22 is detachably connected to the bottom mold frame 21, and the bottom mold frame 21, the frame 1 and the cover plate 22 are surrounded to form a cavity 4 for accommodating silicone rubber raw materials, and the cavity 4 has a preset shape; the top pressing assembly 3 is connected to the frame 1 and abuts against the cover plate 22 so that the cover plate 22 fits the bottom mold frame 21. Specifically, the preset shape is rectangular or circular, or other shapes designed as needed. The size and shape of the cavity can be determined according to actual needs, that is, the shape of the cavity can be changed by changing the shape of the bottom mold frame 21. Further, the bottom mold frame 21 is detachably connected to the frame 1 to facilitate the replacement of the bottom mold frame 21. More specifically, a step should be provided on the top end surface of the bottom mold frame, and the circumferential size of the step corresponds to the size of the cover plate 22, so as to facilitate the placement of the cover plate 22, and at the same time, the circumferential side of the cover plate is limited to prevent the cover plate 22 from shifting during the vulcanization process of the silicone rubber. In this embodiment, the bottom mold frame 21 and the cover plate 22 are both made of metal materials, and stainless steel is preferred. Metal materials such as stainless steel have high material rigidity and are not easily deformed during the pressing process of the silicone rubber, thereby ensuring that the shape and size of the finally pressed silicone rubber meet the requirements.

[0041] In one embodiment, the frame 1 includes a bottom plate 11, a support frame 12 and an upper beam plate 13. The bottom plate 11 is fixedly connected to the support frame 12, and the upper beam plate 13 is fixedly connected to the support frame 12. The bottom plate 11 and the upper beam plate 13 are arranged relative to each other, and the bottom mold frame 21, the bottom plate 11 and the cover plate 22 are enclosed to form a cavity 4 for accommodating silicone rubber raw materials. Specifically, the bottom plate 11, the support frame 12 and the upper beam plate 13 are fixedly connected to each other to form a frame structure. The bottom plate 11 needs to be uniform in thickness and horizontally arranged to facilitate placement on a horizontal plane. The surface of the bottom plate 11 used to enclose the cavity 4 needs to be flat, smooth and high in finish. The upper beam plate 13 is used to fix the top pressure assembly. The surface of the cover plate 22 also needs to be flat, smooth, high in finish and uniform in thickness. The height of the bottom mold frame 21 needs to match the thickness of the silicone rubber to be molded, that is, the height of the bottom mold frame 21 needs to be no less than the thickness of the silicone rubber to be molded, and the distance between the lower surface of the cover plate 22 and the upper surface of the bottom plate 11 needs to be equal to the thickness of the silicone rubber to be molded.

[0042] In one embodiment, the side wall of the bottom mold frame 21 is provided with at least one glue outlet hole 211, and the glue outlet hole 211 is connected to the mold cavity 4. In order to ensure that the thickness of the pressed silicone rubber can meet the design requirements, the total amount of silicone rubber raw material filled into the mold cavity 4 is generally greater than the amount of raw material required for the silicone rubber to be molded. Therefore, in order to facilitate the discharge of excess silicone rubber raw material, a glue outlet hole 211 is provided on the bottom mold frame 21 for extruding excess silicone rubber raw material.

[0043] In one embodiment, the split mold 2 further includes a glue box 23, which is disposed in the bottom mold frame 21 and detachably connected to the bottom mold frame 21. A glue groove 231 is provided in the glue box 23, and the glue groove 231 is connected to the glue outlet hole 211. Specifically, the glue box 21 is used to hold the excess silicone rubber raw material squeezed out from the glue outlet hole 211, and the glue box 21 is detachably connected to the bottom mold frame 21 so as to replace and clean the glue box. Furthermore, the detachable connection between the glue box 23 and the bottom mold frame 21 can be achieved by bolts, that is, holes are set at corresponding positions on the glue box 23 and the bottom mold frame 21, and bolts are used to pass through the holes and nuts are tightened, thereby achieving the detachable connection between the bottom mold frame 21 and the glue box 23.

[0044] In one embodiment, the top pressing assembly 3 includes a screw rod 31 and a compression spring 32, wherein the screw rod 31 is threadedly connected to the upper beam plate 13, and the compression spring 32 is arranged at the end of the upper beam plate 13 away from the upper beam plate 13. Specifically, a threaded hole corresponding to the screw rod 31 is arranged on the upper beam plate 13, and the screw rod 31 is threadedly connected to the threaded hole, so that the screw rod can be tightened. In the process of tightening the screw rod 31, the compression spring moves toward the direction where the cover plate 22 is located and presses the cover plate 22, so that the cover plate 22 can be pressed and fitted on the bottom mold frame 21. After the screw 31 is tightened, the compression spring 32 is in a compressed state. The compression spring 32 can evenly apply the pressure generated by the tightening of the screw to the cover plate 22 to avoid uneven thickness of the finally pressed silicone rubber due to uneven pressure application. In addition, the silicone rubber can prevent stress relaxation during the silicone rubber pressing process, that is, when the threaded connection of the screw 31 becomes loose, the compression spring 32 can adaptively stretch to ensure that the pressure generated by the tightening of the screw can always be applied to the surface of the cover plate 22 during the pressing process.

[0045] In one embodiment, the pressing assembly 3 further includes a handle 33, which is fixedly connected to the end of the screw rod 31 away from the bottom plate 11. By rotating the handle 33, the screw rod 31 can be driven to rotate, thereby achieving loosening and tightening of the screw rod 31.

[0046] In one embodiment, there are multiple pressing assemblies 3, and the multiple pressing assemblies 3 are arranged at intervals along the length direction of the cover plate 22. In order to ensure uniform force on the cover plate 22, multiple pressing assemblies 3 can be arranged according to the size of the cover plate 22, and the multiple pressing assemblies 3 can apply pressure to different areas of the cover plate 22, so that the pressure can be evenly distributed in various areas of the cover plate, thereby facilitating the molding of silicone rubber with uniform thickness.

[0047] The embodiment of the present invention further provides a molding method, using any one of the silicone rubber vulcanization tableting devices in the above embodiments, the molding method comprises the following steps:

[0048] The inner walls around the cavity 4 are covered with a demoulding material, and then dried to remove the solvent; specifically, the demoulding material is a demoulding agent or a demoulding cloth.

[0049] Filling the silicone rubber raw material into the cavity 4;

[0050] Cover the cover plate 22 on the bottom mold frame 21 to close the cavity 4;

[0051] The pressing assembly is driven to make the pressing assembly 3 press the cover plate 22 so that the cover plate 22 fits the bottom mold frame 21;

[0052] Vulcanize the silicone rubber raw materials in the silicone rubber vulcanization and pressing device;

[0053] After demoulding, a silicone rubber sheet with a preset shape is obtained.

[0054] In one embodiment, vulcanizing the silicone rubber raw material in the silicone rubber vulcanization sheeting device includes the following steps:

[0055] The silicone rubber vulcanization tablet pressing device with the silicone rubber raw material is placed at a preset temperature for a corresponding vulcanization time according to the material specification requirements. Specifically, in one embodiment, the silicone rubber vulcanization tablet pressing device with the silicone rubber raw material can be placed at room temperature for 3 days; in another embodiment, the silicone rubber vulcanization tablet pressing device with the silicone rubber raw material can be placed in a drying oven at a temperature of 175°C for 10 minutes.

[0056] It should be noted that the silicone rubber vulcanization tableting device and molding method provided in this embodiment are not only suitable for the pressing of silicone rubber sheets, but also suitable for the preparation of tablets of other rubber products and high-viscosity products such as resin castings.

[0057] The following are several specific embodiments provided in this application:

[0058] Example 1

[0059] A bottom mold frame 21 with a silicone rubber thickness of 3 mm is selected, and a release agent is applied to the surrounding surfaces of the cavity 4 (i.e., the cover plate 22, the bottom plate 11, and the surrounding inner walls of the bottom mold frame 21). In this embodiment, the release agent is preferably Frekote 770-NC release agent. After the release agent is applied, the silicone rubber vulcanization sheet pressing device is placed in a blast drying oven and blown with hot air at 60°C for 30 minutes to remove the solvent.

[0060] Fix the rubber box 23 to the bottom mold frame 21 by bolts, and fix the bottom mold frame 21 to the bottom plate 11 by bolts. Mix 100g of EA-4700CV silicone rubber raw materials, place them in the bottom mold frame 21 and cover them with the cover plate 22. Place the compression spring 32 above the cover plate 22 and directly below the screw 31. Turn the handle 33 to drive the screw 31 to move and squeeze the compression spring 32 to compact the cover plate 22. According to the vulcanization conditions of the pressed silicone rubber, place the device with the pressed silicone rubber at room temperature for vulcanization for 3 days. After 3 days, turn the handle 33, loosen the screw 32, release the pressure, remove the cover plate 22, loosen the bolts, remove the bottom mold frame 21 and the rubber box 23, take out the pressed silicone rubber, and obtain a silicone rubber product with a uniform thickness of 3mm. Clean the silicone rubber vulcanization tablet pressing device for the next use.

[0061] Example 2

[0062] A bottom mold frame 21 with a silicone rubber thickness of 2 mm is selected, and a release agent is applied to the surrounding surfaces of the cavity 4 (i.e., the cover plate 22, the bottom plate 11, and the surrounding inner walls of the bottom mold frame 21). In this embodiment, the release agent is preferably Frekote 770-NC release agent. After the release agent is applied, the silicone rubber vulcanization sheet pressing device is placed in a blast drying oven and blown with hot air at 60°C for 30 minutes to remove the solvent.

[0063] The rubber box 23 is fixed to the bottom mold frame 21 by bolts, and the bottom mold frame 21 is fixed to the bottom plate 11 by bolts. 85g of GX-1240SD silicone rubber raw materials are mixed, placed in the bottom mold frame 21 and covered with the cover plate 22, and a compression spring 32 is placed above the cover plate 22 and directly below the screw 31. The screw 31 is driven to move and squeeze the compression spring 32 by turning the handle 33 to compact the cover plate 22. According to the vulcanization conditions of the pressed silicone rubber, the silicone rubber vulcanization tablet pressing device with silicone rubber is placed in a blast drying oven at a temperature of 175°C for vulcanization for 10 minutes. After cooling to room temperature, the handle 33 is turned, the screw 32 is loosened, the pressure is released, the cover plate 22 is removed, the bolts are loosened, the bottom mold frame 21 and the rubber box 23 are removed, and the pressed silicone rubber is taken out to obtain a silicone rubber product with a uniform thickness of 2mm. The silicone rubber vulcanization tablet pressing device is cleaned for the next use.

[0064] Example 3

[0065] A bottom mold frame 21 with a silicone rubber thickness of 5 mm is selected, and a release agent is applied to the surrounding surfaces of the cavity 4 (i.e., the cover plate 22, the bottom plate 11, and the surrounding inner walls of the bottom mold frame 21). In this embodiment, the release agent is preferably Frekote 770-NC release agent. After the release agent is applied, the silicone rubber vulcanization sheet pressing device is placed in a blast drying oven and blown with hot air at 60°C for 30 minutes to remove the solvent.

[0066] The rubber box 23 is fixed to the bottom mold frame 21 by bolts, and the bottom mold frame 21 is fixed to the bottom plate 11 by bolts. After mixing 220g of GX-1240SD silicone rubber raw materials, it is placed in the bottom mold frame 21 and covered with the cover plate 22. A compression spring 32 is placed above the cover plate 22 and directly below the screw 31. The screw 31 is driven to move and squeeze the compression spring 32 by turning the handle 33 to compact the cover plate 22. According to the vulcanization conditions of the pressed silicone rubber, the silicone rubber vulcanization tablet pressing device with silicone rubber is placed in a blast drying oven at a temperature of 175°C for vulcanization for 10 minutes. After cooling to room temperature, the handle 33 is turned, the screw 32 is loosened, the pressure is released, the cover plate 22 is removed, the bolts are loosened, the bottom mold frame 21 and the rubber box 23 are removed, and the pressed silicone rubber is taken out to obtain a silicone rubber product with a uniform thickness of 5mm. The silicone rubber vulcanization tablet pressing device is cleaned for the next use.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A silicone rubber vulcanization tableting device, characterized in that: include: Frame; A split mold, comprising a bottom mold frame and a cover plate, wherein the bottom mold frame is connected to the frame body, and the cover plate is detachably connected to the bottom mold frame, wherein the bottom mold frame, the frame body and the cover plate together form a cavity for accommodating a silicone rubber raw material, and the cavity has a preset shape; The pressing assembly is connected to the frame and abuts against the cover plate so that the cover plate fits the bottom mold frame.

2. The silicone rubber vulcanization tableting device according to claim 1, characterized in that: The frame body includes a base plate, a support frame and an upper beam plate, the base plate is fixedly connected to the support frame, the upper beam plate is fixedly connected to the support frame, the base plate and the upper beam plate are arranged opposite to each other, and the bottom mold frame, the base plate body and the cover plate together form a cavity for accommodating silicone rubber raw materials.

3. The silicone rubber vulcanization tableting device according to claim 1, characterized in that: The side wall of the bottom mold frame is provided with at least one glue outlet hole, and the glue outlet hole is communicated with the mold cavity.

4. The silicone rubber vulcanization tablet pressing device according to claim 3, characterized in that: The split mold also includes a glue box, which is arranged in the bottom mold frame and detachably connected to the bottom mold frame. A glue groove is arranged in the glue box, and the glue groove is communicated with the glue outlet hole.

5. The silicone rubber vulcanization tablet pressing device according to claim 2, characterized in that: The pressing assembly comprises a screw rod and a compression spring. The screw rod is threadedly connected to the upper beam plate. The compression spring is arranged at the end of the upper beam plate away from the upper beam plate.

6. The silicone rubber vulcanization tablet pressing device according to claim 2, characterized in that: The pressing assembly further comprises a handle, which is fixedly connected to the end of the screw rod facing away from the bottom plate.

7. The silicone rubber vulcanization tablet pressing device according to claim 1, characterized in that: There are multiple pressing assemblies, and the multiple pressing assemblies are arranged at intervals along the length direction of the cover plate.

8. The silicone rubber vulcanization tablet pressing device according to claim 1, characterized in that: The preset shape is a rectangle or a circle.

9. A molding method, characterized in that: Using the silicone rubber vulcanization tablet pressing device according to any one of claims 1 to 9, the molding method comprises the following steps: Covering the inner walls around the cavity with a demoulding material, and drying to remove the solvent; Filling the silicone rubber raw material into the cavity; Covering the bottom mold frame with a cover plate to close the mold cavity; Driving the pressing assembly to press the cover plate so that the cover plate fits the bottom mold frame; vulcanizing the silicone rubber raw material in the silicone rubber vulcanization and sheeting device; After demoulding, a silicone rubber sheet with a preset shape is obtained.

10. The molding method according to claim 9, characterized in that: The process of vulcanizing the silicone rubber raw material in the silicone rubber vulcanization sheeting device comprises the following steps: The silicone rubber vulcanization tablet pressing device containing the silicone rubber raw material is placed at a preset temperature and vulcanized for a corresponding time according to material specification requirements.

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