Nitrile reclaimed rubber is a high-resistance reclaimed rubber product processed from waste nitrile rubber products such as nitrile water, sub-brand nitrile rubber and nitrile gloves. Replacing nitrile rubber to produce rubber products can significantly reduce raw material costs. The hardness of nitrile reclaimed rubber processed by different raw materials is different. Among them, high hardness nitrile reclaimed rubber is used to produce various oil resistant hoses, rubber rollers, glue sticks, rubber strips, etc., among which high hardness nitrile reclaimed rubber products processing technology and use Performance is directly related to formulation design. How to design the hardness of nitrile reclaimed rubber products?
1, raw material selection
Nitrile rubber butadiene and acrylonitrile are polymerized by emulsion polymerization. The hardness of nitrile rubber prepared at different polymerization temperatures is very different. It is mainly divided into hot polybutyronitrile and cold poly soft nitrile. When nitrile reclaimed rubber is used to produce high hardness NBR products, manufacturers should choose high hardness nitrile reclaimed rubber when selecting raw materials. When using nitrile rubber together, it is necessary to add hot polybutyronitrile to ensure the hardness of high hardness nitrile reclaimed rubber products. related requirements.
2, vulcanization system design
When using nitrile reclaimed rubber to produce high-hardness nitrile rubber products, it is best to use a sulfur vulcanization system in combination with an aldehyde amine and a thiourea organic accelerator, in which sulfur and limb sulfur are precipitated in a high-hardness nitrile reclaimed rubber compound. The dispersion speed and dispersion uniformity are better than ordinary sulfur, and the vulcanization speed is slightly faster; when the high hardness nitrile reclaimed rubber product selects sulfur vulcanization system, it is necessary to properly control the amount of sulfur to avoid scorching due to excessive sulfur consumption and affecting normal process operation. The problem arises and the amount of accelerator is determined based on the amount of sulfur used.
3, filling system design
Filler can reduce the cost of rubber compound and improve the processing technology of rubber compound in the production of rubber products. In the formula of high-hardness nitrile reclaimed rubber products, iron oxide can not only improve the plasticity of the rubber compound in the rubber compound mixing process, but also improve the rubber compound. The tensile strength, impact strength and softening temperature of nitrile reclaimed rubber, viscosity and high hardness nitrile products; high hardness nitrile rubber can increase the tensile strength and softening temperature of nitrile rubber and improve the processing of rubber compound Process, especially for extrusion-type high-hardness nitrile products; calcium carbonate can improve the softening temperature and reduce the cost of rubber compound while improving the impact strength of the rubber; asbestos powder and clay can also be used in the processing of high-hardness nitrile reclaimed rubber products. However, the physical and mechanical properties of clay are poor, and the uniformity of dispersion should be paid attention to when mixing asbestos powder.
4, softening system
The softener can increase the viscosity of the rubber compound while improving the rubber mixing process, the extrusion process and the molding process. When selecting the softener, the high hardness of the nitrile reclaimed rubber product should pay attention to selecting the non-volatile product to avoid the occurrence of pores due to the volatilization of the softener. : Dibutyl cresol can improve the tensile strength, impact strength and viscosity of the rubber compound, but it will reduce the softening temperature of the high-hardness nitrile reclaimed rubber product; the dimerized oil can improve the tensile strength and impact strength of the rubber; coal tar and turpentine can Improve the softening temperature of the nitrile reclaimed rubber; ester plasticizers such as dibutyl phthalate and dibutyl cresol, coal tar, coumarone can significantly improve the rubber processing technology.
In addition to the above-mentioned compounding agent, the high-hardness nitrile reclaimed rubber product is inseparable from the compounding agent such as reinforcing agent and coloring agent in the production process, and the plasticizing temperature, the timing of adding the compounding agent, and the mixing operation are also required in the processing. , vulcanization time, vulcanization temperature, etc., will be discussed with you later.