One-step forming process for sports ball inner bladder and sports ball inner bladder

Abstract

The application discloses a one-time forming method for an inner bag of a sports ball and the inner bag of the sports ball, relates to the technical field of the inner bag of the sports ball, and comprises the following steps: S1, raw material preparation and pretreatment, S2, melt blending, S3, preparation of a preformed pipe embryo, and S4, blow molding. Through the blending of polyether low-crystallization TPU and SEBS elastomer, the extrusion of the blended viscous flow material by a TPU plasticizing device, the preparation of the preformed pipe embryo by a pipe embryo forming device, and the one-time blow molding of the inner bag blank in a blow molding die, the whole forming process is continuously completed from the feeding of raw materials to the taking out of the blank, multiple dipping and drying or multiple splicing are not needed, the production cycle is greatly shortened, and the output per unit time is improved.

Description

Technical Field

[0001] This application relates to the field of sports ball inner lining technology, and more specifically, to a method for one-time molding of sports ball inner lining and a sports ball inner lining. Background Technology

[0002] Sports balls (such as soccer balls, basketballs, and volleyballs) typically consist of an inner bladder, a yarn winding layer, and an outer skin layer. The inner bladder is the core component, its function being to provide the necessary elasticity and roundness after inflation, and to maintain airtightness over a long period. The performance of the inner bladder directly determines the ball's bounce height, feel, flight stability, and lifespan. Therefore, the selection of materials, molding processes, and quality control of the inner bladder have always been key technical aspects in the manufacturing of sports balls.

[0003] Currently, the mainstream production processes for sports ball inner sleeves worldwide still rely on traditional methods, primarily including latex impregnation, rubber molding vulcanization, and high-frequency ultrasonic welding. Latex impregnation is the oldest inner sleeve manufacturing process. The process involves repeatedly immersing a ball sleeve mold in liquid natural latex, followed by drying, vulcanization, and demolding to gradually form a multi-layered ball sleeve structure, which is then inflated and molded. Rubber molding vulcanization involves calendering or molding mixed rubber compounds into two or more sheets, which are then joined together and vulcanized to form a complete inner sleeve.

[0004] The existing processes generally suffer from the following drawbacks: Taking the latex impregnation method as an example, a single inner bladder requires multiple impregnation and drying processes, often resulting in a production cycle of several hours or even longer, with an hourly output of less than 10 pieces per mold. Furthermore, the rubber compression molding and vulcanization method is environmentally unfriendly, generating sulfur-containing waste gas and volatile organic compounds during vulcanization, which adversely affects the health of operators and the environment. The high density and uneven distribution of rubber materials result in inner bladders with high basis weight and poor thickness uniformity, often requiring subsequent dynamic balancing processes such as adding counterweights, increasing manufacturing costs and weight. Therefore, there is an urgent need to develop a manufacturing method for sports ball inner bladders that uses superior materials, can be molded in one piece, and has uniform wall thickness, to replace traditional processes. Summary of the Invention

[0005] The main purpose of this application is to provide a method for one-time molding of the inner lining of sports balls and a sports ball, so as to solve the problems of long production cycle, poor environmental protection and need to achieve balance compensation of the inner lining in the market.

[0006] To achieve the above objectives, this application provides a method for one-time molding of the inner lining of sports balls, comprising the following steps: S1. Raw material preparation and pretreatment: Dry polyether-type low-crystallinity TPU particles and SEBS elastomer particles at 80±5℃ for 4-6 hours, controlling the moisture content to be ≤0.05%. The mass ratio of the polyether-type low-crystallinity TPU particles to SEBS elastomer particles is 88-90:10-12. S2. Melt blending: The dried TPU granules, SEBS granules and additives are mixed in proportion, and the blended granules are extruded through TPU plasticizing equipment to obtain a blended viscous flow. S3. Preparation of preformed tube blanks: The blended viscous material is transported to a tube blank forming device with tube wall thickness control. The wall thickness and length of different sections of the tube blank are adjusted by the tube blank forming device to obtain preformed tube blanks. S4. Blow molding: The pre-made tube blank is placed in a blow molding mold to form the inner bladder blank.

[0007] Optionally, in step S2, the additives include 0.02-0.03 parts of catalyst DBTDL, 0.2 parts of antioxidant 1010 and 168 compound, 0.3-0.5 parts of high molecular weight silicone masterbatch, and 0.3-0.5 parts of anti-hydrolysis agent.

[0008] Optionally, in step S2, the temperature of the feeding section of the TPU plasticizing equipment is 90±5℃, the pre-plasticizing section is 180±5℃, the plasticizing section is 180±5℃, the homogenizing section is 180±10℃, the die head section is 170±10℃, and the mold temperature is 40-50℃.

[0009] Optionally, in step S3, the tube preform forming device is a die head structure having a cup wall, a cup ring, and a cup core; the cup wall is connected to the extrusion port of the TPU plasticizing equipment; the cup ring is disposed inside the cup wall and has a trapezoidal cross-section for forming a preform; the cup core is movably disposed inside the cup ring, and the wall thickness of the preform is controlled by adjusting the annular gap between the cup core and the cup ring.

[0010] Optionally, the tube preform forming apparatus further includes a controller and an extrusion speed sensor, the controller being configured to: According to the preset wall thickness distribution curve, the opening of the annular gap between the cup core and the cup ring is adjusted in real time to control the wall thickness of different sections of the preformed tube blank.

[0011] Optionally, in step S4, the blow molding mold includes two mold bodies that can close to each other, and a blow molding device for blowing compressed air into the preformed tube blank, wherein the blow molding nozzle of the blow molding device can be inserted into the mold body.

[0012] Optionally, in step S3, the preformed tube blank is an integral hollow tubular structure formed by extrusion, which has a hollow cavity inside for injecting compressed air in step S4.

[0013] Optionally, after step S4, the following post-processing steps are also included: S5. Surface treatment: Trim and anneal the inner bladder blank to form a matte frosted layer on the inner bladder surface and coat it with a water-based rubber feel oil coating. Then install the rubber nozzle and perform hot-press sealing.

[0014] Optionally, the controller is further configured to: when the extrusion speed sensor detects a change in extrusion speed exceeding ±2%, according to the formula... Automatically compensates for and adjusts the displacement of the cup core, among which This is the amount of compensation for the cup core displacement. For calibration coefficients, For real-time extrusion speed, The extrusion speed is preset to maintain the uniformity of the axial and circumferential wall thickness of the preform.

[0015] A sports ball inner bladder with a diameter of 190±10mm, a wall thickness of 0.55±0.1mm, a weight of 65±3g, a thickness uniformity tolerance of ≤0.15mm, and a hardness of 50±5A.

[0016] The present invention provides a method for one-time molding of the inner lining of a sports ball and the sports ball inner lining itself. Compared with the prior art, its advantages are as follows: By blending polyether-type low-crystallinity TPU with SEBS elastomer, the resulting blended viscous material is extruded using TPU plasticizing equipment. This viscous material is then used to prepare a preform using a preform forming device, and finally, it is blow-formed into an inner bladder blank in a blow molding die in a single operation. The entire molding process, from raw material input to blank removal, is completed continuously, eliminating the need for multiple impregnation and drying processes or multi-piece splicing, significantly shortening the production cycle and increasing output per unit time.

[0017] In the preform preparation step, this invention involves conveying a blended viscous material to a preform forming device equipped with a preform wall thickness controller. This device adjusts the wall thickness and length of different sections of the preform. This results in differentiated wall thicknesses in various axial locations of the preform, matching the requirements of the final product. After blow molding, the inner bladder wall thickness distribution is more reasonable and uniform, ensuring spherical roundness and dynamic balance performance. This avoids the problem of requiring additional dynamic balancing compensation steps due to uneven wall thickness in traditional processes. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2This is a schematic diagram of the blow molding die of the present invention; Figure 3 This is a schematic diagram of the structure of the preformed tube blank of the present invention; Figure 4 This is a schematic diagram of the tube blank forming apparatus of the present invention; Figure 5 This is a flowchart of the one-step molding process of the present invention.

[0019] The components include: 1. TPU plasticizing equipment; 2. Tube preform forming device; 21. Cup wall; 22. Cup ring; 23. Cup core; 3. Mold body; 4. Blow molding machine; 5. Preformed tube preform. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be used interchangeably where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0023] Furthermore, some of the aforementioned terms, besides indicating location or positional relationships, may also have other meanings. For example, the term "above" may, in certain circumstances, indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0024] In addition, the term "multiple" should mean two or more.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figures 1-5 As shown, Preparation of raw materials The raw materials used in the following embodiments and comparative examples are described below: Polyether-type low-crystallinity TPU: Based on PTMEG 3000, liquefied modified MDI system, Shore hardness 65A, density 1.12g / cm³; SEBS elastomer: 30% styrene content, hydrogenation degree ≥98%, Shore hardness 45A; Catalyst DBTDL: purity ≥99%; Antioxidant 1010 and 168 compound: 1010 and 168 mass ratio 1:1; High molecular weight silicone masterbatch: silicone content 50%; Anti-hydrolysis agent: carbodiimide; Water-based rubber feel oil: solid content 35%.

[0027] Example 1 This embodiment investigated the effect of different ratios of TPU and SEBS on the performance of the inner capsule. The experiment was carried out according to the formulation shown in Table 1-1. Examples 1-3 represent the preferred ratio range of the present invention, while Examples 1-1, 1-2, 1-4, and 1-5 are comparative verifications within the ratio range.

[0028] Table 1-1 Raw material ratios (parts by mass) for each experimental group in Example 1 Each experimental group followed these steps: S1. Raw material preparation and pretreatment: Weigh each component according to Table 1-1, place TPU particles and SEBS particles in a hot air circulating drying oven and dry at 80℃ for 5 hours. The moisture content was measured to be 0.03% by a moisture analyzer.

[0029] S2. Melt Blending: The dried TPU granules, SEBS granules, and various functional additives are fed into a high-speed mixer and mixed at 1100 r / min for 6 minutes. Then, the mixture is fed into TPU plasticizing equipment 1. The temperatures of each section of TPU plasticizing equipment 1 are set as follows: feeding section 90℃, pre-plasticizing section 180℃, plasticizing section 180℃, homogenizing section 185℃, and die head section 175℃. The screw speed is 40 r / min. The blended viscous material is obtained by melt extrusion.

[0030] S3. Preparation of Preform 5: The blended viscous material is directly conveyed to the preform forming device 2. The preform forming device 2 is a die head composed of a cup wall 21, a cup ring 22, and a cup core 23. The feed inlet of the cup wall 21 is connected to the extrusion port of the TPU plasticizing equipment 1. The preform forming device 2 is equipped with a PLC controller and an extrusion speed sensor. Preset extrusion speed... The extrusion speed is 18.5 mm / s, and the calibration coefficient k = 1.8. The controller adjusts the annular gap between the cup core 23 and the cup ring 22 in real time based on a preset wall thickness distribution curve, such as 10 mm at the beginning and end, 0.90 mm in the middle section, and 0.55 mm in the main body section. When the extrusion speed change exceeds ±2%, the controller adjusts the annular gap according to the formula... The displacement of the cup core 23 is automatically compensated and adjusted. It is formed into a one-piece hollow tubular structure through extrusion, with a hollow cavity inside.

[0031] S4. Blow molding: While the preformed tube blank 5 is still hot, it is placed into the mold body 3. The blow molding machine 4 is inserted into the hollow cavity and 0.25MPa compressed air is introduced for 30 seconds. The blow molding mold is cooled by 0.25MPa cooling air for 15 seconds. The mold temperature is about 32℃. The mold is opened and the inner bladder blank is taken out.

[0032] S5. Surface Treatment: Trim the edges of the inner bladder blank, anneal at 45℃ for 3 hours, and then furnace cool to room temperature. Sandblast the outer surface to form a matte frosted layer, apply water-based rubber feel oil with a coating thickness of 0.015mm, and dry at 65℃ for 1.2 hours. Install the rubber air nozzle and heat-press seal.

[0033] S6. Inspection: Visual inspection, airtightness test after immersion in water for 30 minutes, mechanical properties and dimensional inspection.

[0034] Thirty samples were taken from each test group for performance testing, and the results are shown in Table 1-2.

[0035] Table 1-2 Results of Capsule Performance Tests with Different TPU / SEBS Ratios in Example 1 Results analysis: When the TPU / SEBS ratio is 88 / 12 (Examples 1-3), the overall performance is optimal: excellent melt strength, no tube collapse, good wall thickness uniformity, and best airtightness, while maintaining a rebound rate of 68% and a compression set of 20%, meeting the requirements for use in sports balls. Without SEBS (Examples 1-5), the melt strength is poor, the tube collapses significantly, and the wall thickness uniformity is poor. When the SEBS content reaches 15% (Examples 1-4), the hardness drops to 45A, becoming too soft, and the compression set increases to 28%. Therefore, the preferred TPU to SEBS mass ratio is 88-90:10-12 (corresponding to Examples 1-2 and 1-3).

[0036] Example 2 This embodiment investigates the effect of raw material drying temperature on product performance. The preferred formulations from Examples 1-3 (88 parts TPU, 12 parts SEBS) were used, with only the drying temperature in step S1 changed; the remaining steps were the same as in Example 1. The parameters and results for each group are shown in Table 2.

[0037] Table 2. Results of inner capsule performance tests under different drying temperatures. Results Analysis: At a drying temperature of 70℃, the moisture content remained at 0.08% after 6 hours of drying, and a small number of bubbles appeared on the surface of the tube blank, indicating a decrease in airtightness. Drying at 80-85℃ yielded ideal results. Therefore, the drying temperature was determined to be 80±5℃.

[0038] Example 3 This embodiment examines the influence of blow molding process parameters on the quality of the inner bladder. The preferred formulations of Examples 1-3 are used, and the closed-loop control scheme of Examples 1-3 is employed in step S3. Only the blowing pressure, blowing time, and cooling time in step S4 are changed; the remaining steps are the same as in Example 1. The parameters and results for each group are shown in Table 3.

[0039] Table 3. Inner bladder forming quality under different blow molding process parameters Results analysis: At an air blowing pressure of 0.15 MPa, the mold did not fit completely; 0.20-0.30 MPa resulted in good molding. Slight deformation occurred after demolding when air was blown for 20 seconds and cooled for 10 seconds (Examples 3-5). The preferred air blowing pressure is ≥0.2 MPa, air blowing for 30 seconds, and cooling for 15 seconds.

[0040] Example 4 This embodiment details the specific implementation process of the controller performing closed-loop compensation adjustment according to the formula.

[0041] The preferred formulations of Examples 1-3 are used, and steps S1 and S2 are the same as in Example 1.

[0042] Step S3: Pre-formed tube blank 5 is prepared by conveying the blended viscous material to the tube blank forming device 2. The tube blank forming device 2 is a die head with a cup wall 21, a cup ring 22 and a cup core 23. The cup wall 21 is connected to the extrusion port of the TPU plasticizing equipment 1. The cup ring 22 is located inside the cup wall 21 and has a trapezoidal cross section. The cup core 23 is movably located inside the cup ring 22.

[0043] The tube blank forming device 2 is also equipped with: a PLC controller, a melt pressure sensor installed in the internal flow channel of the cup wall 21, an extrusion speed sensor installed at the end of the screw of the TPU plasticizing equipment 1, and a servo motor that drives the cup core 23 to move axially.

[0044] The controller's preset parameters are as follows: Preset wall thickness distribution curve: 0.90mm wall thickness in the first 10mm section, 0.55mm wall thickness in the middle main section, and 0.90mm wall thickness in the last 10mm section; Preset extrusion speed = 18.5mm / s; Calibration coefficient = 1.8, obtained through prior experimental calibration. The calibration method is as follows: Using this as a baseline, the extrusion speed was manually changed by ±5%, and the relationship between the displacement of the cup core 23 and the wall thickness recovery was measured. The results were then obtained through fitting. value; Extrusion speed fluctuation allowable threshold: ±2% (i.e., allowable range 18.13-18.87 mm / s); Controller sampling period: 0.1 seconds.

[0045] Normal working status: At the start of extrusion, the extrusion speed sensor detects a real-time extrusion speed of v = 18.5 mm / s, consistent with the preset value. The controller calculates the target wall thickness corresponding to the axial position of the preform 5 at the current moment according to the preset wall thickness distribution curve, and outputs a command to drive the cup core 23 to move to the corresponding annular gap opening position via a servo motor. For example, if the target wall thickness of the middle main body section is 0.55 mm, the corresponding annular gap opening is set to 2.2 mm.

[0046] Fluctuation Compensation Example 1 At the 15-second mark of the extrusion process (when the middle main body section is being extruded), the extrusion speed sensor detected that the real-time extrusion speed v had increased to 19.2 mm / s. Calculated deviation: Deviation percentage = (19.2 - 18.5) / 18.5 × 100% = +3.78% When the deviation exceeds the allowable threshold of ±2%, the controller triggers an automatic compensation program. Cup core 23 displacement compensation amount Δx = 1.8 × (19.2 - 18.5) / 18.5 = 1.8 × 0.0378 = 0.068mm Physical explanation: When the extrusion speed increases, the amount of melt extruded per unit time increases. If the annular gap opening remains unchanged, the wall thickness of the tube blank will increase. To maintain a constant wall thickness, the annular gap opening needs to be increased, that is, the cup core 23 moves backward, widening the gap between the cup core 23 and the cup ring 22, so that the melt flows on a larger annular cross section, and the wall thickness is restored to the target value.

[0047] Therefore, the controller outputs a command to the servo motor: cup core 23 retracts by 0.068mm. After adjustment, the wall thickness is restored to the target value of 0.55mm.

[0048] Fluctuation Compensation Example 2: At the 28th second of the extrusion process, the extrusion speed sensor detected that the real-time extrusion speed v had dropped to 17.8 mm / s. Calculated deviation: Deviation percentage = (17.8 - 18.5) / 18.5 × 100% = -3.78% When the deviation exceeds the allowable threshold of ±2%, the controller triggers an automatic compensation program. Δx = 1.8 × (17.8 - 18.5) / 18.5 = 1.8 × (-0.0378) = -0.068mm A negative value indicates that the core 23 needs to advance, i.e., the annular gap opening needs to be reduced. When the extrusion speed decreases, the amount of melt extruded per unit time decreases. If the annular gap opening remains unchanged, the tube blank wall thickness will become thinner. To maintain a constant wall thickness, the annular gap opening needs to be reduced to restrict the melt flow space.

[0049] The controller outputs a command to the servo motor: advance the cup core 23 by 0.068mm. After adjustment, the wall thickness is restored to the target value of 0.55mm.

[0050] Fluctuation Compensation Example 3: At the 40th second of the extrusion process, the extrusion speed sensor detected v = 18.7 mm / s. Calculated deviation: Deviation percentage = (18.7 - 18.5) / 18.5 × 100% = +1.08% If the deviation is within the allowable threshold of ±2%, the controller will not trigger compensation adjustment, and the cup core 23 will maintain its current position. This design avoids servo motor oscillation and mechanical wear caused by frequent adjustments due to small fluctuations.

[0051] Steps S4 to S6: Same as in Example 1.

[0052] The influence of the controller on the uniformity of the inner capsule wall thickness was investigated. The preferred formulations of Examples 1-3 were used, and the remaining steps were the same as in Example 1.

[0053] Example 4-1 (with controller): Same as Examples 1-3, the controller adjusts the annular gap opening according to the wall thickness distribution curve and automatically compensates for the extrusion speed fluctuation.

[0054] Example 4-2 (without controller): The cup core 23 is fixed in a preset position, the annular gap opening is constant, and no adjustment is made during the extrusion process.

[0055] 100 pieces were produced continuously, numbered in chronological order, and one sample was taken from every 10 pieces to measure the wall thickness. The results are shown in Table 4.

[0056] Table 4: Does the controller affect wall thickness uniformity? Results Analysis: After adopting a controller to automatically compensate for and adjust the displacement of the cup core 23 based on extrusion speed fluctuations, the wall thickness uniformity was significantly improved. The standard deviation of wall thickness decreased from 0.068 mm to 0.025 mm, the deviation rate decreased from 14.6% to 1.2%, and no dynamic balancing compensation was required for any of the products.

[0057] Comparative Example To demonstrate the advantages of the overall technical solution of this invention, the following comparative examples are provided.

[0058] Comparative Example 1: The traditional latex impregnation method was used to prepare the inner bladder of a soccer ball. The process flow was as follows: mold impregnation with latex → drying → vulcanization → demolding → inflation test.

[0059] Comparative Example 2: Using high-frequency ultrasonic molding, two TPU films were welded together to form an inner capsule.

[0060] Thirty samples each from Examples 1-3 and 4-1 of the present invention and Comparative Examples 1 and 2 were taken for comparative testing, and the results are shown in Table 5.

[0061] Table 5. Comprehensive comparison of the capsule performance of the present invention and existing technologies. Results analysis: (1) Compared with the traditional latex impregnation method (Comparative Example 1), the weight of the inner bladder of the present invention is reduced by about 17%, the uniformity of wall thickness is greatly improved, the resilience rate is increased from 58% to 68-70%, the compression set is reduced from 35% to 19-20%, the airtightness is significantly improved, the production efficiency is increased by about 7 times, and the use of harmful substances such as ammonia is avoided.

[0062] (2) Compared with the high-frequency welding method (Comparative Example 2), the weldless structure of the present invention fundamentally eliminates the risk of weld leakage, has better wall thickness uniformity, better resilience, and avoids the problem of uneven touch caused by high hardness (70A) at the weld.

[0063] (3) Example 4-1, which uses a closed-loop controller, achieves optimal levels in terms of wall thickness uniformity and air tightness, and the finished product weight is highly consistent, requiring no dynamic balancing compensation process.

[0064] A sports ball inner bladder with a diameter of 190±10mm, a wall thickness of 0.55±0.1mm, a weight of 65±3g, a thickness uniformity tolerance of ≤0.15mm, and a hardness of 50±5A.

[0065] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for one-time molding of the inner lining of sports balls, characterized in that, Includes the following steps: S1. Raw material preparation and pretreatment: Dry polyether-type low-crystallinity TPU particles and SEBS elastomer particles at 80±5℃ for 4-6 hours, controlling the moisture content to be ≤0.05%. The mass ratio of the polyether-type low-crystallinity TPU particles to SEBS elastomer particles is 88-90:10-12. S2. Melt blending: The dried TPU granules, SEBS granules and additives are mixed in proportion, and the blended granules are mixed and extruded through TPU plasticizing equipment (1) to obtain a blended viscous material. S3. Preparation of preformed tube blank (5): The blended viscous material is transported to a tube blank forming device (2) with tube blank wall thickness control. The wall thickness and length of different sections of the tube blank are adjusted by the tube blank forming device (2) to obtain the preformed tube blank (5). S4. Blow molding: Place the preformed tube blank (5) into the blow molding mold to make the inner bladder blank.

2. The method for one-time molding of the inner capsule of a sports ball according to claim 1, characterized in that, In step S2, the additives include 0.02-0.03 parts of catalyst DBTDL, 0.2 parts of antioxidant 1010 and 168 compound, 0.3-0.5 parts of high molecular weight silicone masterbatch and 0.3-0.5 parts of anti-hydrolysis agent.

3. The method for one-time molding of the inner capsule of a sports ball according to claim 1, characterized in that, In step S2, the temperature of the feeding section of the TPU plasticizing equipment (1) is 90±5℃, the pre-plasticizing section is 180±5℃, the plasticizing section is 180±5℃, the homogenizing section is 180±10℃, the head section is 170±10℃, and the mold temperature is 40-50℃.

4. The method for one-time molding of the inner capsule of a sports ball according to claim 1, characterized in that, In step S3, the tube preform forming device (2) is a die head structure with a cup wall (21), a cup ring (22) and a cup core (23); the cup wall (21) is connected to the extrusion port of the TPU plasticizing equipment (1); the cup ring (22) is located inside the cup wall (21) and has a trapezoidal cross section, used to form a preform tube preform (5); the cup core (23) is movably located inside the cup ring (22), and the wall thickness of the preform tube preform (5) is controlled by adjusting the annular gap between the cup core (23) and the cup ring (22).

5. The method for one-time molding of the inner capsule of a sports ball according to claim 4, characterized in that, The tube preform forming apparatus (2) further includes a controller and an extrusion speed sensor, the controller being configured to: According to the preset wall thickness distribution curve, the opening of the annular gap between the cup core (23) and the cup ring (22) is adjusted in real time to control the wall thickness of different sections of the preformed tube blank (5).

6. The method for one-time molding of the inner capsule of a sports ball according to claim 1, characterized in that, In step S4, the blow molding mold includes two mold bodies (3) that can close to each other, and a blow molding device (4) for blowing compressed air into the preform (5), wherein the blow molding nozzle of the blow molding device (4) can be inserted into the mold body (3).

7. The method for one-time molding of the inner lining of a sports ball according to claim 1, characterized in that, In step S3, the preformed tube blank (5) is an integral hollow tubular structure formed by extrusion, and its interior has a hollow cavity for injecting compressed air in step S4.

8. The method for one-time molding of the inner capsule of a sports ball according to claim 1, characterized in that, Following step S4, the following post-processing steps are also included: S5. Surface treatment: Trim and anneal the inner bladder blank to form a matte frosted layer on the inner bladder surface and coat it with a water-based rubber feel oil coating. Then install the rubber nozzle and perform hot-press sealing.

9. The method for one-time molding of the inner lining of a sports ball according to claim 5, characterized in that, The controller is also configured to: when the extrusion speed sensor detects an extrusion speed change exceeding ±2%, according to the formula... Automatically compensates for the displacement of the cup core (23), of which For the displacement compensation of the cup core (23), For calibration coefficients, For real-time extrusion speed, The extrusion speed is preset to maintain the uniformity of the axial and circumferential wall thickness of the preform (5).

10. A sports ball capsule, characterized in that, The inner capsule, manufactured by the one-time molding method according to any one of claims 1 to 9, has a diameter of 190±10mm, a wall thickness of 0.55±0.1mm, a weight of 65±3g, a thickness uniformity tolerance of ≤0.15mm, and a hardness of 50±5A.

Images