The color rubber-coated lead ball is composed of an inner layer of glue and an outer layer of rubber covering a solid iron core or iron sand core, with a smooth and elastic surface, which can give people a better feel when holding and throwing; The elastic coating has a large cushioning capacity, which can alleviate the impact force of the lead ball on the ground when it lands, reduce the injury to the human body when accidentally touching the human body, and improve the safety of use. The inner layer of the color glue covered lead ball generally uses natural rubber as the main raw material, and the appropriate amount of reclaimed rubber is mixed to reduce the cost of raw materials.
1. The performance requirements of the inner layer of the color glued lead ball
The inner layer of the colored glued lead ball mainly plays a cushioning role, and the rubber material is required to have good elasticity and flexibility, and can withstand the impact force when the lead ball is thrown; It has a certain tensile strength and tensile elongation at break, and will not be easily broken or damaged during use; When using a multi-rubber compound system based on natural rubber (NR) to prepare the inner layer of color glue covered lead balls, an appropriate amount of reclaimed rubber and reasonable design of the formula can further improve the quality of the finished product while reducing costs.
2. The inner layer of the color glue covered lead ball is mixed with reclaimed rubber vulcanization formula
100 parts of natural rubber/styrene-butadiene rubber/reclaimed rubber, 5 parts of zinc oxide, 2.5 parts of stearic acid, 1.5 parts of paraffin, 10 parts of silica, 70 parts of ultrafine calcium carbonate, 20 parts of clay, 0.5 parts of triethanolamine, 1.3 parts of promoting CZ, 2.2 parts of sulfur; A total of 213 copies.
3. The inner layer of the color glue covered lead ball is mixed with reclaimed rubber formula design
(1) Vulcanization system design
Natural rubber/styrene-butadiene rubber/reclaimed rubber blended to prepare the inner layer of color glue covered lead balls, when the ball core and the inner layer of rubber vulcanize, the vulcanization speed needs to match the outer layer of glue, requiring low Mooney viscosity, short induction period, good flatness and other characteristics, generally using sulfur-accelerator system, using accelerator CZ with sulfur, sulfur dosage is controlled among 2-2.5 parts, accelerator CZ dosage is controlled among 1-1.5 parts, vulcanized rubber comprehensive performance is better.
(2) Filling system design
Carbon black can significantly improve the tensile strength, wear resistance and hardness of rubber compounds; Silica can not only strengthen rubber, but also improve the processing performance and aging resistance of rubber compounds. When choosing carbon black reinforcement for the inner layer rubber of natural rubber/styrene-butadiene rubber/reclaimed rubber for the production of color covered lead balls, it is recommended to use carbon black varieties with moderate particle size and high structure, such as N330 carbon black, and reasonably control the amount of carbon black (30-50 parts); Considering the color requirements of the compound, silica (10-20 parts) or light-colored reinforcing agent can be partially used.
Calcium carbonate is the most commonly used filler in the rubber products industry, and the light calcium carbonate has a small particle size and a relatively good reinforcing effect; Heavy calcium carbonate costs less; Ultrafine calcium carbonate has smaller particle size, E4LYY930 specific surface area, good dispersion, good reinforcing performance and more stable chemical properties. The calcium carbonate in the inner layer of the colored glued lead ball (20-50 parts) can be selected according to actual needs and cost considerations. Talcum powder (10-30 parts) has good lubricity and electrical insulation, which can improve the processing performance of rubber compounds; Clay (10-30 parts) can improve the hardness and wear resistance of the rubber.
When using natural rubber/styrene-butadiene rubber/reclaimed rubber to produce the inner layer of colored rubber-coated lead balls, softeners and plasticizers, such as naphthenic oil, can also be used appropriately to improve the processing performance and flexibility of the rubber; Choose the right antioxidant, such as antioxidant 4010NA, antioxidant RD, etc., to improve the aging resistance of the rubber compound and prolong the service life of the lead ball. In the follow-up, Xiaobian will continue to share with you the raw material selection skills and production process points of the inner layer rubber of reclaimed rubber for the production of colored glue covered lead balls.
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