A method for making tennis racket strings using pig intestine casings

Abstract

This invention belongs to the field of sports equipment manufacturing technology, specifically relating to a method for making tennis racket strings using pig intestine casings. The method includes the following steps: (1) selecting qualified pig intestine casings, cutting off the small intestine portion to obtain pig small intestine; (2) pre-treating the pig small intestine; (3) soaking the pre-treated pig small intestine in an alkaline solution followed by ultrasonic treatment, and then bleaching to obtain bleached pig intestine casings; (4) soaking the bleached pig intestine casings in a potassium chloride solution to completely remove the fat, then twisting seven fat-free pig intestine casings together into a twisted thread; (5) drying, grinding, polishing, and coating the twisted thread to obtain the finished tennis racket string. The method for making tennis racket strings using pig intestine casings in this invention combines alkaline soaking with ultrasonic treatment, achieving a degreasing rate of 99%, and significantly improving wear resistance through a specific manufacturing process.

Description

Technical Field

[0001] This invention belongs to the field of sports equipment manufacturing technology, specifically relating to a method for making tennis racket strings using pig intestines. Background Technology

[0002] Gut casings can be made into gut strings, which are used as racket strings. Tennis strings were originally made entirely of gut. Elasticity is a unique advantage of natural gut; to date, no synthetic string can match the elasticity of pure natural gut, which is why natural gut has always existed. Furthermore, the elasticity of natural gut increases with stress, typically between 55 and 70 pounds, while other synthetic strings begin to lose elasticity as tension increases.

[0003] Despite years of improvements and changes in tennis racket materials, natural gut has consistently held an irreplaceable position in the tennis string industry. Natural gut has always been the benchmark for many tennis string materials. It allows the string bed of the racket to perform exceptionally well throughout a match, providing players with an excellent feel, which increases product added value and has a promising market prospect. Of course, natural gut also has the problem of being easily worn. Natural gut is extremely prone to wear, and it is also very expensive to produce. A single string requires the gut casings of three cows, and high-quality tennis racket strings made from natural gut may require the gut casings of more than ten cows to produce just one string. Furthermore, the fat and collagen in the gut and other animal tissues are tightly bound together, making removal difficult. The presence of fat severely affects the quality of the gut, causing the surface to yellow and containing numerous fat deposits, reducing the tensile strength of the gut.

[0004] Therefore, there is an urgent need in the existing technology to provide a tennis racket string made from natural gut that is lower in cost, less prone to wear, and has more thorough fat removal. Summary of the Invention

[0005] The purpose of this invention is to provide a method for making tennis racket strings using pig intestines. Compared with the prior art, this method replaces the commonly used cow intestines with pig intestines. Furthermore, through a specific preparation process, the resulting tennis racket strings are not only lower in cost and have more thorough fat removal, but are also less prone to wear.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a method for making tennis racket strings using pig intestine casings, comprising the following steps:

[0008] (1) Select qualified sausage casings, cut off the small intestine to obtain pig small intestine;

[0009] (2) Pre-treat the pig small intestine;

[0010] (3) The pretreated pig small intestine was soaked in an alkaline solution and then subjected to ultrasonic treatment, followed by bleaching to obtain bleached pig casing.

[0011] (4) After bleaching, the pig casings are soaked in potassium chloride solution to completely remove the fat from the pig casings. Then, seven fat-free pig casings are twisted together on the twisting thread and twisted into a twisted thread.

[0012] (5) The twisted strands are dried, ground, polished and coated with paint to obtain the finished tennis racket string.

[0013] Furthermore, in step (2), the pretreatment involves washing the surface and inner wall of the pig small intestine with clean water, immersing it in a sodium bicarbonate aqueous solution with a mass concentration of 2-4% for 6-10 hours, and maintaining the temperature at 42-47℃; washing away the sodium bicarbonate with water, and then scraping off the serous membrane and other attachments in the pig small intestine with a knife to initially remove the fat and impurities in the pig small intestine, thus obtaining the pretreated pig small intestine.

[0014] Furthermore, in step (3), the soaking in the alkaline solution involves immersing the pretreated pig small intestine in a container filled with sodium carbonate at a pH of 9.5-10.5 for 1-3 hours.

[0015] Furthermore, in step (3), the parameters of the ultrasonic treatment are ultrasonic oscillation at 42-47℃ for 0.4-0.8h and an oscillation frequency of 45-55kHz.

[0016] Furthermore, in step (3), the bleaching is the bleaching and decolorization of pig small intestine in a 35-39 wt% hydrogen peroxide solution until it is transparent and colorless.

[0017] Furthermore, in step (4), the soaking in potassium chloride solution is soaking in a 16-18% potassium chloride solution for 13-20 minutes.

[0018] Furthermore, in step (5), the coating is an coating of animal collagen and a waterproof paint.

[0019] The beneficial effects of this invention are as follows:

[0020] The method for making tennis racket strings using pig intestines in this invention combines alkaline soaking with ultrasonic treatment, achieving a degreasing rate of 99%. This invention significantly improves the tensile strength of the gut strings through a specific treatment process, reaching up to 169 MPa. Furthermore, this invention enhances the wear resistance and fatigue resistance of the tennis racket strings by soaking and coating them with a coating, making them less prone to wear. Moreover, this invention significantly reduces the production cost of natural gut tennis racket strings by using pig intestines to make the strings. Detailed Implementation

[0021] The following experimental examples are used to further illustrate the present invention, but are not limited to the present invention. Example 1

[0022] This solution provides a method for making tennis racket strings using pig intestine casings, including the following production steps:

[0023] (1) Select qualified casings and cut off the small intestine to obtain pig small intestine;

[0024] (2) Wash the surface and inner wall of the pig small intestine with clean water, soak it in a 2% sodium bicarbonate aqueous solution for 6 hours, and keep the temperature at 42℃. Wash away the sodium bicarbonate with water, and then scrape off the serosal and other attachments in the pig small intestine with a knife to initially remove the fat and impurities in the pig small intestine and obtain the pretreated pig small intestine.

[0025] (3) The pretreated pig small intestine was soaked in a container of sodium carbonate with pH 9.5 for 1 hour. Then the container was placed in an ultrasonic device and ultrasonically oscillated for 0.4 hours at a frequency of 45 kHz and a temperature of 42°C to further remove fat from the pig small intestine. The pretreated pig small intestine was then bleached and decolorized in a 35 wt% hydrogen peroxide solution until it was transparent and colorless, and the bleached pig casing was obtained.

[0026] (4) Soak the bleached pig casings in a 17% potassium chloride solution for 20 minutes to completely remove the fat from the pig casings and obtain fat-free pig casings.

[0027] (5) Twist the 7 fat-free pig intestines together on the twisting thread to form a twisted thread;

[0028] (6) Place the twisted strands on a drying rack and air dry them under conditions of 60% humidity and natural wind speed;

[0029] (7) The dried stranded wire is first polished on a polishing machine, and then animal collagen is coated on the surface of the polished stranded wire. After drying, the tennis string semi-finished product is obtained.

[0030] (8) Coat the semi-finished tennis racket string with waterproof paint to obtain the finished tennis racket string. Example 2

[0031] This solution provides a method for making tennis racket strings using pig intestine casings, including the following production steps:

[0032] (1) Select qualified casings and cut off the small intestine to obtain pig small intestine;

[0033] (2) Wash the surface and inner wall of the pig small intestine with clean water, soak it in a 3% sodium bicarbonate aqueous solution for 8 hours, and keep the temperature at 45℃; wash away the sodium bicarbonate with water, and then scrape off the serous membrane and other attachments in the pig small intestine with a knife to initially remove the fat and impurities in the pig small intestine and obtain the pretreated pig small intestine.

[0034] (3) Soak the pretreated pig small intestine in a container containing sodium carbonate with pH 10 for 2 hours. Then place the container in an ultrasonic device and vibrate it for 0.6 hours at a frequency of 50 kHz and a temperature of 45°C to further remove fat from the pig small intestine. Then bleach and decolorize the pretreated pig small intestine in 37 wt% hydrogen peroxide solution until it is transparent and colorless.

[0035] (4) Soak the bleached pig casings in a 16% potassium chloride solution for 15 minutes to completely remove the fat from the pig casings and obtain fat-free pig casings.

[0036] (5) Twist the 7 fat-free pig intestines together on the twisting thread to form a twisted thread;

[0037] (6) Place the twisted strands on a drying rack and air dry them under conditions of 60% humidity and natural wind speed;

[0038] (7) The dried stranded wire is first polished on a polishing machine, and then animal collagen is coated on the surface of the polished stranded wire. After drying, the tennis string semi-finished product is obtained.

[0039] (8) Coat the semi-finished tennis racket string with waterproof paint to obtain the finished tennis racket string. Example 3

[0040] This solution provides a method for making tennis racket strings using pig intestine casings, including the following production steps:

[0041] (1) Select qualified casings and cut off the small intestine to obtain pig small intestine;

[0042] (2) Wash the surface and inner wall of the pig small intestine with clean water, soak it in a 4% sodium bicarbonate aqueous solution for 10 hours, and keep the temperature at 47℃. Wash away the sodium bicarbonate with water, and then scrape off the serous membrane and other attachments in the pig small intestine with a knife to initially remove the fat and impurities in the pig small intestine and obtain the pretreated pig small intestine.

[0043] (3) Soak the pretreated pig small intestine in a container of sodium carbonate with pH 10.5 for 3 hours. Then place the container in an ultrasonic device and vibrate it for 0.8 hours at a frequency of 55 kHz and a temperature of 47°C to further remove fat from the pig small intestine. Then bleach and decolorize the pretreated pig small intestine in 39 wt% hydrogen peroxide solution until it is transparent and colorless.

[0044] (4) Soak the bleached pig casings in an 18% potassium chloride solution for 13 minutes to completely remove the fat from the pig casings and obtain fat-free pig casings.

[0045] (5) Twist the 7 fat-free pig intestines together on the twisting thread to form a twisted thread;

[0046] (6) Place the twisted strands on a drying rack and air dry them under conditions of 60% humidity and natural wind speed;

[0047] (7) The dried stranded wire is first polished on a polishing machine, and then animal collagen is coated on the surface of the polished stranded wire. After drying, the tennis string semi-finished product is obtained.

[0048] (8) Coat the semi-finished tennis racket string with waterproof paint to obtain the finished tennis racket string.

[0049] Comparative Example 1

[0050] This comparative example provides a method for making tennis racket strings using cow intestines, including the following production steps:

[0051] (1) Select qualified bovine casings and cut off the small intestine to obtain bovine small intestine;

[0052] (2) Wash the surface and inner wall of the small intestine with clean water, soak it in a 0.2% sodium bicarbonate aqueous solution for 24 hours, and keep the temperature at 30°C; wash away the sodium bicarbonate with water, and then scrape off the serous membrane and other attached substances in the small intestine with a knife.

[0053] (3) Bleaching and decolorizing the pretreated bovine small intestine in a 39wt% hydrogen peroxide solution until it is transparent and colorless;

[0054] (4) Twist the 7 bleached bovine small intestines together on the twisting thread to form a twisted thread;

[0055] (5) Place the twisted strands on a drying rack and air dry them under conditions of 60% humidity and natural wind speed;

[0056] (6) The dried stranded wire is first polished on a polishing machine to obtain a semi-finished tennis string;

[0057] (7) Coat the semi-finished tennis racket string with waterproof paint to obtain the finished tennis racket string.

[0058] Effect test

[0059] The measured results of the examples and comparative examples are shown in Table 1:

[0060]

[0061] This invention utilizes alkaline cleaning agents and bleach to remove odors and decolorize sausage casings, while simultaneously enhancing the performance of the sutures; seven sutures are twisted together into one suture and coated with varnish to maintain strong elasticity.

[0062] 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 it. 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 be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for making tennis racket strings using pig intestine casings, characterized in that, Includes the following steps: (1) Select qualified sausage casings, cut off the small intestine to obtain pig small intestine; (2) Pre-treat the pig small intestine; (3) The pretreated pig small intestine was soaked in an alkaline solution and then subjected to ultrasonic treatment, followed by bleaching to obtain bleached pig casing. (4) After bleaching, the pig casings are soaked in potassium chloride solution to completely remove the fat from the pig casings. Then, seven fat-free pig casings are twisted together on the twisting thread and twisted into a twisted thread. (5) The twisted strands are dried, ground, polished and coated with paint to obtain the finished tennis racket string; In step (2), the pretreatment involves washing the surface and inner wall of the pig small intestine with clean water, immersing it in a sodium bicarbonate aqueous solution with a mass concentration of 2-4% for 6-10 hours, and maintaining the temperature at 42-47℃; washing away the sodium bicarbonate with water, and then scraping off the serosal deposits in the pig small intestine with a knife to initially remove the fat and impurities in the pig small intestine, thus obtaining the pretreated pig small intestine. In step (3), soaking in alkaline solution means immersing the pretreated pig small intestine in a container containing sodium carbonate with a pH of 9.5-10.5 for 1-3 hours; In step (3), the parameters of the ultrasonic treatment are ultrasonic oscillation at 42-47℃ for 0.4-0.8h and oscillation frequency of 45-55kHz. In step (3), the bleaching is the bleaching and decolorization of pig small intestine in a 35-39 wt% hydrogen peroxide solution until it is transparent and colorless; In step (4), the soaking in potassium chloride solution is soaking in a 16-18% potassium chloride solution for 13-20 minutes.

2. The method for making tennis racket strings using pig intestine casings according to claim 1, characterized in that, In step (5), the coating is an coating of animal collagen and a waterproof paint.

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