Film covering process for butyl rubber plug

Abstract

The invention relates to a film covering process of a butyl rubber plug, which belongs to the technical field of butyl rubber plug preparation and is characterized in that during processing, in the same way as the prior art, a bonding surface of a film belt used for being bonded with a mixed rubber sheet needs to be activated, and then the bonding surface of the film belt is bonded with one side surface of an unvulcanized mixed rubber sheet; the film belt covers and is fixed on the mixing rubber sheet in an adhesion manner, and the key point is that in the covering and fixing process, the film belt is conveyed forwards in a manner of floating on a flowing liquid surface, and is attached and fixed with the mixing rubber sheet above the film belt in the conveying process, so that the film belt is prevented from being pulled by a conventional belt similar to a belt in belt transmission; and the film belt is prevented from being torn and damaged. The film laminating process can prevent the film belt from being torn due to mechanical traction and pulling as much as possible, and the processing process is convenient and reliable.

Description

Technical Field

[0001] This invention relates to the field of butyl rubber stopper production technology, specifically to a coating molding method in the butyl rubber stopper processing. Background Art

[0002] Butyl rubber stoppers are a commonly used medical rubber stopper, serving as a component of sealing devices for pharmaceuticals or blood samples. They frequently come into direct contact with liquids such as pharmaceuticals, significantly impacting the quality and stability of the drugs. Therefore, an inert film is needed to coat their surface to improve their performance.

[0003] Currently, the main methods for manufacturing butyl rubber stoppers include integral molding. This involves first activating the surface of the membrane using common chemical or physical methods, typically on one side only—the side in contact with the rubber itself. Then, the activated surface of the membrane material is brought into contact with and fixed to the uncured rubber sheet. At this point, the rubber sheet, usually a compounded rubber sheet, already has an inert film covering it. Therefore, when a specific shape of rubber stopper is required, this sheet can be directly vulcanized and molded to obtain the desired stopper.

[0004] Another method is the separate molding method, which also involves directly bonding the inert film layer. This process typically involves first preparing a rubber stopper to obtain a semi-finished product, namely the blank structure of the rubber stopper. Then, a layer of adhesive such as glue is applied to the surface of the blank structure. Simultaneously, the inert material film needs to be extruded into a shape suitable for the rubber stopper, directly bonding it to the rubber stopper blank, fitting it onto the rubber stopper, and pressing it tightly to achieve a fixed connection. The key to this technology lies in how evenly the adhesive is applied and pressed into a shape consistent with the rubber stopper blank. For example, if the thickness is uneven, there will inevitably be a mismatch between the pressed structure and the rubber stopper blank, making it difficult to fit onto the rubber stopper. This may result in defects such as film peeling and local wrinkles, thus affecting the overall shape of the butyl rubber stopper and directly impacting its use.

[0005] The above are two of the most common processing methods. It can be seen that both methods require covering the surface of the rubber stopper with an inert film material. The first existing technology mentions using an adhesive method, but it doesn't propose a convenient and efficient adhesive method. This leads to varying operations among manufacturers during the coating process. Often, the film strip and rubber sheet are transported separately and overlapped at a certain point to achieve adhesion. This is common for general bonding and fixing between two materials. However, the coating of butyl rubber stoppers is relatively thin, unlike some common methods where raw material plates can be directly bonded together. Due to the thinness of the film, it is easily damaged during transport under traction, directly affecting the coating quality. The other mainstream method mentioned above, because the two are formed separately, easily leads to the final rubber stopper semi-finished product not fitting smoothly with the extruded film preform, thus also affecting the coating effect. Summary of the Invention

[0006] The purpose of this invention is to provide a coating process for butyl rubber stoppers, which solves the technical problem that there is no convenient and reliable coating method for butyl rubber stoppers in the prior art.

[0007] To achieve the above objectives, the butyl rubber stopper coating process of the present invention includes first activating the bonding surface of the film strip to be bonded to the compound rubber sheet, and then covering and fixing the bonding surface of the film strip to one side surface of the uncured compound rubber sheet by adhesion. During the covering and fixing process, the film strip is conveyed forward by floating on the surface of the flowing liquid and is bonded and fixed to the compound rubber sheet above it during the conveying process.

[0008] Furthermore, when covering the compounded rubber sheet with the film tape, a layer of adhesive must first be applied to the surface of the compounded rubber sheet that mates with the bonding surface, and then the following steps should be taken: T1. A vertically installed liquid storage tower is set up. The top of the liquid storage tower is equipped with a liquid supply pipe. The bottom of the liquid storage tower is connected to the inlet of a liquid tank through an L-shaped liquid inlet pipe. The outlet of the liquid tank is always lower than the liquid level in the liquid storage tower. The liquid supply flow rate of the liquid supply pipe is always kept constant so that the fluid in the liquid tank always flows forward smoothly. T2. A roller is provided above the liquid tank. An activated membrane strip is wound on the roller. A section of the membrane strip is pulled out of the roller and floats on the surface of the liquid tank. It moves forward with the flow of the liquid surface, and the bonding surface of the membrane strip faces away from the fluid and does not contact the fluid. The mixed rubber sheet coated with an uncured adhesive is also provided on the liquid tank. The rubber sheet is wound from a first pulley to a second pulley. The first pulley is located above the second pulley, and in the direction of fluid flow in the liquid tank, the second pulley is in front of the first pulley. The adhesive coating surface of the mixed rubber sheet wound on the second pulley contacts the membrane strip floating on the liquid surface in a tangential manner, so that the floating membrane strip gradually adheres to the mixed rubber sheet.

[0009] Furthermore, the outlet of the liquid supply pipe is submerged below the liquid surface in the storage tower, and a nozzle is connected to the outlet. The nozzle has a spherical diverter with a raised top, and the edge of the diverter and the inner wall of the nozzle form an annular outlet channel.

[0010] Furthermore, the bottom of the storage tower is conical, with a vertical drain pipe connected to the tip of the cone. The bottom of the drain pipe is connected to the horizontal end of the inlet pipe, and the bottom of the liquid tank connected to the top of the vertical section of the inlet pipe is recessed downward to form a buffer tank. The opening of the buffer tank is connected to the drain channel of the liquid tank.

[0011] Furthermore, after the fluid enters the liquid tank from the buffer tank, it first passes through a rectifier and then flows under the membrane belt.

[0012] Furthermore, above the liquid tank in the direction of fluid flow, the roller, the first pulley, and the second pulley are arranged in sequence, and a tensioning wheel is provided between the two pulleys. The surface of the tensioning wheel is covered with a coating ring that can be dipped in the adhesive, and the tensioning wheel causes the mixed rubber sheet between the two pulleys to arch upwards, so that the mixed rubber sheet is coated with a layer of adhesive by the coating ring before entering the second pulley.

[0013] Furthermore, the tensioning pulley is located in a glue tank, and a glue receiving groove is provided below the glue tank. When adhesive occasionally drips from the compounded rubber sheet between the two pulleys, it falls directly into the glue receiving groove, and the bottom of the glue receiving groove has a groove to concentrate the output of the adhesive.

[0014] Preferred, as the second pulley rotates clockwise and the membrane belt moves forward with the fluid, the roller rotates clockwise accordingly to release the membrane belt synchronously.

[0015] Furthermore, the second pulley is vertically slidably installed. When the second pulley rotates once, it moves vertically upward by a distance equal to the sum of the thickness of the compounded film and the thickness of the film belt.

[0016] The coating process for the butyl rubber stopper of this invention leverages the thin and lightweight characteristics of the inert membrane material, allowing it to float on a steadily flowing liquid surface. The buoyancy and flow on the liquid surface are used for efficient transport, avoiding tearing of the membrane under rigid mechanical traction. This stable and reliable transport process solves the problem of inert membrane transport, enabling the butyl rubber stopper to be formed in one step, eliminating the difficulty in controlling the shape of the rubber stopper and membrane when forming a separate membrane sleeve. Furthermore, the entire process is automated; as the second pulley rotates, the coated rubber sheet is gradually compressed during the rotation of the second pulley. Attached Figure Description

[0017] The accompanying drawings used in the following description of the embodiments or prior art will be briefly introduced. The drawings in the following description are only some embodiments of the present invention and do not represent all specific structures or principles.

[0018] Figure 1 This is a schematic diagram illustrating the process principle of the present invention.

[0019] Component labeling: 1. Liquid storage tower, 2. Liquid supply pipe, 3. Diverter block, 4. Liquid outlet channel, 5. Liquid drain pipe, 6. Liquid inlet pipe, 7. Buffer tank, 8. Rectifier, 9. Liquid tank, 10. Roller, 11. Membrane belt, 12. First pulley, 13. Mixing rubber sheet, 14. Second pulley, 15. Tensioner, 16. Glue tank, 17. Glue receiving trough, 18. Groove, 19. Glue coating ring. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 The coating process for a butyl rubber stopper shown involves, similar to existing technologies, the activation treatment of the bonding surface of the membrane belt 11 to be bonded to the compound rubber sheet 13. Then, the bonding surface of the membrane belt 11 is covered and fixed to one side of the uncured compound rubber sheet 13 by adhesion. The key is that during the covering and fixing process, the membrane belt 11 is conveyed forward by floating on the surface of the flowing liquid, and is bonded and fixed to the compound rubber sheet 13 above it during the conveying process. This avoids the membrane belt 11 being pulled like a belt in a conventional belt drive, ensuring that the membrane belt 11 is not torn or damaged.

[0022] As a more specific implementation method, in this embodiment, when covering the membrane strip 11 onto the compounded film 13, a layer of adhesive needs to be applied to the surface of the compounded film 13 that mates with the bonding surface. Then, a vertically installed liquid storage tower 1 is set up. The liquid storage tower 1 can be a cylindrical tower. A liquid supply pipe 2 is provided at the top of the liquid storage tower 1. For example, the liquid supply pipe 2 injects water into the liquid storage tower 1, and the bottom end of the liquid storage tower 1 is connected to the inlet end of a liquid tank 9 through an L-shaped liquid inlet pipe 6. The liquid tank 9 can be installed horizontally or with a slight inclination to one end to facilitate fluid flow. Moreover, the outlet end of the liquid tank 9 is always lower than the liquid level in the liquid storage tower 1, and the liquid supply flow rate of the liquid supply pipe 2 is always kept constant so that the fluid in the liquid tank 9 always flows forward smoothly. Meanwhile, a roller 10 is provided above the liquid tank 9. The roller 10 is wound with an activated membrane strip 11. When the roller 10 is turned on, the membrane strip 11 is pulled out of the roller 10 and floats on the surface of the liquid in the liquid tank 9. The roller 10 continuously and gradually releases the membrane strip 11 in accordance with the flow rate of the fluid. That is, in combination with the flow of the fluid, the membrane strip 11 can move forward with the flow of the liquid surface in the liquid tank 9. The bonding surface of the membrane strip 11 faces away from the fluid and does not come into contact with the fluid, so as to be bonded to the compounded film 13. On the other hand, a compounded rubber sheet 13 coated with an uncured adhesive is also provided on the liquid tank 9. As shown in the figure, the rubber sheet is wound from the first pulley 12 to the second pulley 14. The first pulley 12 is located above the second pulley 14, and in the direction of fluid flow in the liquid tank 9, the second pulley 14 is in front of the first pulley 12. The adhesive coating surface of the compounded rubber sheet 13 wound on the second pulley 14 contacts the film strip 11 floating on the liquid surface in a tangential manner, so that the floating film strip 11 is gradually adhered to the compounded rubber sheet 13.

[0023] As a more specific implementation method, the outlet of the liquid supply pipe 2 is submerged below the liquid surface in the liquid storage tower 1. A nozzle is connected to the outlet. The nozzle has a spherical diverter block 3 with a raised top. The edge of the diverter block 3 and the inner wall of the nozzle form an annular outlet channel 4, so that the outflowing fluid is evenly distributed in the liquid storage tower 1, avoiding concentrated impact and causing greater internal fluid surge.

[0024] As shown in the figure, the bottom of the liquid storage tower 1 is conical, and a vertical drain pipe 5 is connected to the tip of the cone. The bottom of the drain pipe 5 is connected to the horizontal end of the liquid inlet pipe 6. The liquid tank 9 connected to the top of the vertical section of the liquid inlet pipe 6 has a bottom that is recessed downward to form a buffer tank 7. The opening of the buffer tank 7 is connected to the drain channel of the liquid tank 9, so that the fluid enters the liquid tank 9 by overflow and can flow relatively smoothly.

[0025] To make the fluid flow more stable, as shown in the figure, after the fluid enters the liquid tank 9 from the buffer tank 7, it is first rectified by a rectifier 8 and then flows under the membrane belt 11, which facilitates the smooth transport of the membrane belt 11.

[0026] More specifically, as shown in the figure, above the liquid tank 9 in the direction of fluid flow, a roller 10, a first pulley 12, and a second pulley 14 are arranged in sequence. A tensioning wheel 15 is provided between the two pulleys. The surface of the tensioning wheel 15 is covered with a glue-applying ring 19 that can be dipped in adhesive. The tensioning wheel 15 causes the mixed rubber sheet 13 between the two pulleys to arch upwards, so that the mixed rubber sheet 13 is coated with a layer of adhesive by the glue-applying ring 19 just before entering the second pulley 14, so as to facilitate subsequent bonding. The tensioning pulley 15 is located in a glue tank 16. The rotation of the tensioning pulley 15 causes the glue-applying ring 19 to continuously carry out adhesive. A glue-receiving groove 17 is also provided below the glue tank 16. When adhesive occasionally drips from the mixed rubber sheet 13 between the two pulleys, it can fall directly into the glue-receiving groove 17. The bottom of the glue-receiving groove 17 has a groove 18 to concentrate the output of adhesive and prevent a large amount of adhesive from flowing into the fluid.

[0027] In practice, for example, the second pulley 14 can be rotated clockwise. As the membrane belt 11 floats forward with the fluid, the roller 10 rotates clockwise accordingly to release the membrane belt 11 synchronously, allowing it to drift forward more smoothly and adhere to the compounded film 13. Simultaneously, the second pulley 14 is vertically slidable. With each rotation of the second pulley 14, it moves vertically upwards a distance equal to the sum of the thickness of the compounded film 13 and the thickness of the membrane belt 11. This ensures that a portion of the compounded film 13 remains in tangential contact with the floating membrane belt 11, thus adhering them together.

[0028] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A coating process for butyl rubber stoppers, comprising first activating the bonding surface of a film strip (11) for bonding with a compound rubber sheet (13), and then covering and fixing the bonding surface of the film strip (11) to one side surface of the uncured compound rubber sheet (13) by adhesion, characterized in that, During the covering and fixing process, the membrane strip (11) is conveyed forward by floating on the surface of the flowing liquid, and is attached and fixed to the compounded film (13) above it during the conveying process.

2. The coating process for butyl rubber stoppers as described in claim 1, characterized in that: When covering the compounded rubber sheet (13) with the film tape (11), an adhesive layer must first be applied to the surface of the compounded rubber sheet (13) that mates with the bonding surface, and then the following steps are performed: T1. Set up a vertically installed liquid storage tower (1), with a liquid supply pipe (2) at the top of the liquid storage tower (1). The bottom end of the liquid storage tower (1) is connected to the inlet end of a liquid tank (9) via an L-shaped liquid inlet pipe (6). The outlet end of the liquid tank (9) is always lower than the liquid level in the liquid storage tower (1). The liquid supply flow rate of the liquid supply pipe (2) is always kept constant so that the fluid in the liquid tank (9) always flows forward smoothly. T2. A roller (10) is provided above the liquid tank (9). An activated membrane strip (11) is wound on the roller (10). A section of the membrane strip (11) is pulled out of the roller (10) and floats on the surface of the liquid in the liquid tank (9). It moves forward with the flow of the liquid surface, and the bonding surface of the membrane strip (11) faces away from the fluid and does not contact the fluid. The mixed rubber sheet (13) coated with an uncured adhesive is also provided on the liquid tank (9). The film is wound from the first pulley (12) onto the second pulley (14). The first pulley (12) is located above the second pulley (14), and in the direction of fluid flow in the liquid tank (9), the second pulley (14) is in front of the first pulley (12). The adhesive coating surface of the compounded film (13) wound on the second pulley (14) contacts the film strip (11) floating on the liquid surface in a tangential manner, so that the floating film strip (11) gradually adheres to the compounded film (13).

3. The coating process for butyl rubber stoppers as described in claim 2, characterized in that: The outlet of the liquid supply pipe (2) is submerged below the liquid surface in the storage tower (1). A nozzle is connected to the outlet. The nozzle has a spherical diverter block (3) with a raised top. The edge of the diverter block (3) and the inner wall of the nozzle form an annular outlet channel (4).

4. The coating process for butyl rubber stoppers as described in claim 2, characterized in that: The bottom of the storage tower (1) is conical, and a vertical drain pipe (5) is connected to the tip of the cone. The bottom of the drain pipe (5) is connected to the horizontal end of the inlet pipe (6), and the bottom of the liquid tank (9) connected to the top of the vertical section of the inlet pipe (6) is recessed downward to form a buffer tank (7). The opening of the buffer tank (7) is connected to the drain channel of the liquid tank (9).

5. The coating process for butyl rubber stoppers as described in claim 4, characterized in that: After the fluid enters the liquid tank (9) from the buffer tank (7), it first passes through a rectifier (8) and then flows under the membrane belt (11).

6. The coating process for butyl rubber stoppers as described in claim 2, characterized in that: Above the liquid tank (9) in the direction of fluid flow, the roller (10), the first pulley (12), and the second pulley (14) are arranged in sequence. A tensioning wheel (15) is provided between the two pulleys. The surface of the tensioning wheel (15) is covered with a coating ring (19) that can be dipped in the adhesive. The tensioning wheel (15) causes the mixed rubber sheet (13) between the two pulleys to arch upwards, so that the mixed rubber sheet (13) is coated with a layer of adhesive by the coating ring (19) before entering the second pulley (14).

7. The coating process for butyl rubber stoppers as described in claim 6, characterized in that: The tensioning wheel (15) is set in a glue tank (16), and a glue receiving groove (17) is provided below the glue tank (16). When adhesive occasionally drips from the compounded rubber sheet (13) between the two pulleys, it falls directly into the glue receiving groove (17). The bottom of the glue receiving groove (17) has a groove (18) to concentrate the output of adhesive.

8. The coating process for butyl rubber stoppers as described in claim 6, characterized in that: As the second pulley (14) rotates clockwise and the membrane belt (11) moves forward with the fluid, the roller (10) rotates clockwise accordingly to release the membrane belt (11) synchronously.

9. The coating process for butyl rubber stoppers as described in claim 6, characterized in that: The second pulley (14) is vertically slidably installed. When the second pulley (14) rotates once, the second pulley (14) moves vertically upward by a distance, and the distance moved is equal to the sum of the thickness of the compounded sheet (13) and the thickness of the film belt (11).

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