Tear strength is an important indicator to measure the ability of rubber products to resist damage. The tearing of rubber is the phenomenon of damage caused by the rapid expansion and cracking of cracks or cracks in the material under stress. Nitrile reclaimed rubber has the basic performance characteristics of nitrile rubber, excellent oil resistance, good heat resistance and wear resistance. It can be used alone or in combination with nitrile raw rubber to produce various nitrile rubber products, reducing the cost of raw materials. When nitrile reclaimed rubber is used as the main raw material to produce rubber products, the formula design of rubber products directly affects the tear strength of vulcanized rubber, which is reflected in the following aspects.
1. The design of the vulcanization system of the nitrile reclaimed rubber product affects the tear strength of the vulcanizate
The tear strength of rubber increases with the increase of the crosslinking density of the rubber. After reaching the maximum value, the crosslinking density continues to increase and the tearing strength decreases. When improving the tear strength of nitrile reclaimed rubber 2ELYY816 products, due to the high tear strength of polysulfide bonds, it is recommended to use the traditional sulfur-accelerator system as much as possible, the amount of sulfur should be controlled 2-3 parts, and the use of accelerator DM, accelerator CZ and other accelerators with moderate activity and good flatness are blended.
2. The formulation and filling system design of nitrile reclaimed rubber products affects the tear strength of vulcanizate
The particle size of carbon black decreases, and the tear strength increases; to improve the tear strength of nitrile reclaimed rubber products, it is recommended to use low-structure carbon black. Isotropic reinforcing fillers are used in the formulation and filling system of nitrile reclaimed rubber products, such as carbon black, white carbon black, Bai Yanhua, lithopone, zinc oxide, etc., and the tear strength of nitrile reclaimed rubber vulcanizate is better; Avoid the use of anisotropic fillers, such as clay, magnesium carbonate, etc., which cannot achieve high tear strength.
3. The softening system design of nitrile reclaimed rubber products affects the tear strength of vulcanizate
The use of softeners will reduce the tear strength of vulcanized rubber; not only softeners but also plasticizers are used in nitrile reclaimed rubber or nitrile rubber/reclaimed rubber; The tear strength of nitrile reclaimed rubber vulcanizates is reduced. Nitrile reclaimed rubber is recommended to use high aromatic oil with aromatic content higher than 50%-60%, and avoid using paraffin naphthenic oil.
In actual production, many rubber product manufacturers will use nitrile reclaimed rubber and nitrile raw rubber together, and the variety and amount of nitrile rubber will also affect the tear strength of vulcanizate to a certain extent. Do you have any other good ways to improve the tear strength of nitrile reclaimed rubber vulcanizates? I look forward to discussing this issue with you.
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