Basketball rubber skin anti-bulging processing method

Abstract

The application discloses a basketball rubber skin anti-bulging processing method and belongs to the technical field of sports product processing. The method comprises four core steps of cutting piece preparation, punching treatment, ball wrapping forming and vulcanization setting. A plurality of exhaust holes are pre-processed on the rubber skin cutting piece, the cutting piece is wrapped outside the ball bladder with a yarn bladder layer and is subjected to vulcanization treatment. In the vulcanization heating and pressure increasing process, the gas retained between the rubber skin and the yarn bladder layer can be smoothly discharged outward through the exhaust holes, so that the defect that the skin is formed into a bulge due to the expansion of the interlayer gas caused by heating is fundamentally avoided. The process steps are simple, the method can be directly embedded into an existing basketball processing production line, equipment does not need to be greatly modified, the defective rate of finished products can be reduced, and the product yield and service life are improved.

Description

Technical Field

[0001] This invention relates to the field of sports equipment processing technology, and in particular to a method for processing basketball rubber skin to prevent bulging. Background Technology

[0002] Rubber basketballs are a mainstream ball product in mass sports scenarios. Their conventional structure consists of a rubber bladder, a yarn lining layer, and a rubber outer layer from the inside out. The existing mature processing flow is as follows: First, an inflatable rubber bladder is prepared. Then, high-strength yarn is wound around the outer wall of the bladder to form a yarn lining layer, which improves the structural strength and shape retention of the ball. Subsequently, pre-cut rubber outer layer pieces are wrapped and attached to the outside of the yarn lining layer piece by piece. Finally, the ball is sent to a vulcanization device for high-temperature and high-pressure vulcanization, which causes the rubber outer layer to undergo a cross-linking reaction to solidify and bond tightly to the inner yarn lining layer.

[0003] In actual industrial production, due to the limitations of the ball-bonding process, a small amount of air inevitably gets trapped between the inner surface of the rubber skin and the yarn core layer. After entering the vulcanization process, the internal temperature and pressure of the equipment gradually increase. The trapped air expands rapidly after being heated, and the rubber skin softens after being heated, further improving its airtightness. The internal expanding gas cannot diffuse outward and eventually pushes outward in a local area of ​​the skin, forming a visible bulge defect. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preventing bulging of basketball rubber skin. By pre-setting through-vent holes in the rubber skin, the gas that expands due to heat between layers during vulcanization can be directly discharged to the outside, eliminating the power source for gas to push up the skin, improving the production line yield, and reducing rework and scrap costs. The perforation process can be directly embedded into the existing processing flow, set between the cutting process and the ball wrapping process, without the need for structural modifications to the existing vulcanization equipment and ball wrapping equipment.

[0005] To achieve the above objectives, the present invention provides a method for preventing bulging of basketball rubber skin, comprising the following steps: S1. Preparation of cut pieces: Cut the rubber sheet according to the unfolded size of the basketball skin to obtain several independent skin cut pieces; S2, punching process: punch holes in each of the outer skin pieces obtained in S1 to form several vent holes on each outer skin piece. S3. Ball forming: The perforated outer skin pieces are sequentially attached and wrapped around the outer surface of the ball bladder with the lining layer. The edges of each outer skin piece are spliced ​​and aligned to form a complete basketball blank. S4. Vulcanization and shaping: The basketball blank obtained in S3 is placed in a vulcanization device for vulcanization treatment. During the vulcanization process, the gas between the rubber skin and the yarn lining is discharged outward through the exhaust hole. After vulcanization is completed, the finished rubber basketball is obtained.

[0006] Preferably, the vent hole is a through hole extending along the thickness direction of the outer skin piece, with the inner diameter facing the inner layer of the lining being larger than the outer diameter facing the outer surface of the sphere, and the whole is conical. The inner diameter of the vent hole is 0.6~1.5mm, the outer diameter is 0.2~0.5mm, and the taper of the channel is 1:5~1:10.

[0007] Preferably, the plurality of vent holes are evenly distributed along the outer contour of the skin piece, and the center-to-center distance between adjacent vent holes is 15-40 mm.

[0008] Preferably, in step S2, the punching process is performed using any one of laser punching, needle punching, or die punching.

[0009] Preferably, in step S2, after the drilling is completed, a ring-shaped reinforcing edge with a width of 1~2mm and a depth of 0.1~0.2mm is pressed around the inner opening of each of the exhaust holes.

[0010] Preferably, in step S2, an air-guiding groove is further processed on the inner surface of the outer skin piece facing the yarn core layer, and the air-guiding groove is connected to the exhaust hole.

[0011] Preferably, the cross-section of the air guide groove is trapezoidal, the depth of the air guide groove is 0.3~0.6mm, the groove width is 0.8~1.5mm, and the air guide grooves are distributed crisscrossingly along the inner surface of the skin piece.

[0012] Therefore, the present invention adopts the above-mentioned anti-bulging processing method for basketball rubber skin. By pre-setting through vent holes in the rubber skin, the gas that expands due to heat between layers during vulcanization can be directly discharged to the outside, eliminating the power source for gas to push up the skin, improving the production line yield, and reducing rework and scrap costs. The perforation process can be directly embedded into the existing processing flow, set between the cutting process and the ball wrapping process, without the need for structural modifications to the existing vulcanization equipment and ball wrapping equipment.

[0013] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0014] Figure 1 This is a flowchart (I) of the anti-bulging processing method for basketball rubber skin in this invention. Figure 2 This is a schematic diagram of the specific structure of the outer surface of the skin piece in this invention; Figure 3 This is a flowchart (II) of the basketball rubber surface anti-bulging processing method in this invention. Figure 4This is a schematic diagram of the specific structure of the inner surface of the skin piece in this invention.

[0015] Figure Labels 1. Outer fabric piece; 2. Vent hole; 3. Air guide groove. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Example 1 like Figure 1 and Figure 2 As shown, a method for preventing bulging of the rubber surface of a basketball, used to process a standard size 7 rubber basketball, includes the following specific steps: S1. Preparation of cut pieces: Select a natural rubber compound sheet with a thickness of 1.8mm, and cut it according to the unfolded pattern of the No. 7 basketball skin to obtain 8 skin cut pieces 1 with matching shapes. The edges of the skin cut pieces 1 are reserved for splicing.

[0019] S2. Perforation Processing: Each piece of skin fabric 1 is perforated using an ultraviolet laser perforation device to form several vent holes 2 that are completely through the thickness of the fabric piece. The vent holes 2 are truncated cones with an inner diameter of 0.8 mm and an outer diameter of 0.3 mm. The taper of the hole is 1:8. Each vent hole 2 is evenly distributed along the outer contour of the skin fabric 1 within the effective area of ​​the skin fabric 1, and the center-to-center distance between adjacent vent holes 2 is 25 mm. After perforation, a ring-shaped reinforcing edge with a width of 1.5 mm and a depth of 0.15 mm is pressed on the inner hole opening.

[0020] S3. Ball forming: First, pre-make the ball bladder with a yarn lining layer; then, lay the 8 perforated outer skin pieces 1 in sequence inside the ball forming machine, aligning and splicing the edges of each piece. After laying, connect the ball bladder to the air pump of the ball forming machine and place it inside the machine. The operator starts the ball forming machine, and the machine closes to make the outer skin pieces 1 fit and wrap around the outer surface of the yarn lining layer, finally obtaining a complete basketball blank.

[0021] S4. Vulcanization and Shaping: The basketball blank is fed into a vertical vulcanizing tank and vulcanized using a stepped temperature and pressure increase process. Low-temperature exhaust stage: Set the temperature to 95℃, the pressure inside the tank to 0.4MPa, and maintain the temperature and pressure for 10 minutes. Most of the gas trapped between layers will be discharged through the variable cross-section exhaust port 2.

[0022] Medium-temperature crosslinking stage: The temperature is raised to 120℃ at a uniform rate, and the pressure is raised to 0.9MPa simultaneously. The temperature and pressure are maintained for 18 minutes. The rubber gradually crosslinks, the outer pores gradually narrow, and the residual gas is continuously discharged.

[0023] High-temperature setting and sealing stage: Heat to 132℃, pressurize to 1.3MPa, hold for 8 minutes, the outer orifice is completely melted and sealed, and the rubber surface is fully cross-linked and set.

[0024] After vulcanization, the pressure is gradually released and the temperature is lowered. The ball is then removed, cooled, and shaped to obtain the finished rubber basketball.

[0025] Example 2 like Figure 3 and Figure 4 As shown, a method for preventing bulging of the rubber surface of a basketball, used to process a size 5 youth rubber basketball, includes the following specific steps: S1. Preparation of cut pieces: Select styrene-butadiene rubber synthetic sheet with a thickness of 2.0mm, and cut it with a die according to the unfolded size of the No. 5 basketball skin to obtain 6 independent skin cut pieces 1.

[0026] S2. Perforation treatment: The outer skin piece 1 is perforated using a needle punching device. At the same time, a crisscrossing air-guiding groove 3 is pressed into the inner surface of the outer skin piece 1 facing the yarn core layer using a pressing die. The depth of the air-guiding groove 3 is 0.4 mm, the groove width is 1.0 mm, and each vent hole 2 is located at the intersection of the air-guiding groove 3. The vent hole 2 is truncated cone-shaped with an inner diameter of 1.0 mm and an outer diameter of 0.4 mm. The center distance between adjacent vent holes 2 is 30 mm. The air-guiding groove 3 and all vent holes 2 are interconnected to form an air-guiding network.

[0027] S3. Ball forming: Pre-fabricate the ball bladder with a yarn lining layer; then, lay the outer skin pieces 1 with vent holes 2 and air guide grooves 3 in sequence inside the ball forming machine, aligning and splicing the edges of each piece, ensuring that one side of the air guide groove 3 faces the yarn lining layer. After laying, connect the ball bladder to the air pump of the ball forming machine and place it inside the ball forming machine. The operator starts the ball forming machine, and the ball forming machine closes so that the outer skin pieces 1 fit and wrap around the outer surface of the yarn lining layer, finally obtaining a complete basketball blank.

[0028] S4. Vulcanization and Shaping: The basketball blank is fed into a vertical vulcanizing tank and vulcanized using a stepped temperature and pressure increase process. Low-temperature exhaust stage: set the temperature to 92℃, the internal pressure to 0.35MPa, and maintain the temperature and pressure for 9 minutes.

[0029] Intermediate temperature crosslinking stage: Heat to 118℃ at a uniform rate, pressurize to 0.85MPa simultaneously, and maintain the temperature and pressure for 16 minutes.

[0030] High-temperature shaping and sealing stage: heat up to 130℃, pressurize to 1.25MPa, and maintain the temperature and pressure for 7 minutes.

[0031] During the vulcanization heating process, the interlayer trapped air expands due to heat, quickly diffuses laterally through the air guide groove 3 and gathers to the nearest exhaust hole 2, and then is discharged outward; the outer hole is automatically sealed in the later stage of vulcanization; after the vulcanization is completed, the pressure is gradually released and the temperature is reduced, and the sphere is taken out to cool and solidify.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for processing basketball rubber skin to prevent bulging, characterized in that, Includes the following steps: S1. Preparation of cut pieces: Cut the rubber sheet according to the unfolded size of the basketball skin to obtain several independent skin cut pieces; S2, punching process: punch holes in each of the outer skin pieces obtained in S1 to form several vent holes on each outer skin piece. S3. Ball forming: The perforated outer skin pieces are sequentially attached and wrapped around the outer surface of the ball bladder with the lining layer. The edges of each outer skin piece are spliced ​​and aligned to form a complete basketball blank. S4. Vulcanization and shaping: The basketball blank obtained in S3 is placed in a vulcanization device for vulcanization treatment. During the vulcanization process, the gas between the rubber skin and the yarn lining is discharged outward through the exhaust hole. After vulcanization is completed, the finished rubber basketball is obtained.

2. The method for preventing bulging of basketball rubber surface according to claim 1, characterized in that: The vent hole is a through hole extending along the thickness direction of the outer skin piece. The inner diameter of the vent hole facing the inner layer of the lining is larger than the outer diameter of the vent hole facing the outer surface of the sphere. The vent hole is conical in shape. The inner diameter of the vent hole is 0.6~1.5mm, the outer diameter is 0.2~0.5mm, and the taper of the vent hole is 1:5~1:

10.

3. The method for preventing bulging of basketball rubber surface according to claim 2, characterized in that: The ventilation holes are evenly distributed along the outer contour of the skin piece, and the center-to-center distance between adjacent ventilation holes is 15~40mm.

4. The method for preventing bulging of basketball rubber surface according to claim 3, characterized in that: In step S2, the drilling process is performed using any one of laser drilling, needle punching, or die punching.

5. The method for processing a basketball rubber surface to prevent bulging according to claim 4, characterized in that: In step S2, after the drilling is completed, a ring-shaped reinforcing edge with a width of 1~2mm and a depth of 0.1~0.2mm is pressed around the inner opening of each exhaust hole.

6. The method for processing a basketball rubber surface to prevent bulging according to claim 5, characterized in that: In step S2, an air-guiding groove is further processed on the inner surface of the outer skin piece facing the yarn core layer, and the air-guiding groove is connected to the exhaust hole.

7. The method for processing a basketball rubber surface to prevent bulging according to claim 6, characterized in that: The cross-section of the air guide groove is trapezoidal, the depth of the air guide groove is 0.3~0.6mm, the groove width is 0.8~1.5mm, and the air guide grooves are distributed crisscrossingly along the inner surface of the skin piece.

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