Neoprene recycled rubber is made of waste rubber products with high neoprene content, such as cable sheath, which has the characteristics of weather resistance, ozone resistance, good adhesion, etc., and can be used alone or combined with neoprene, nitrile rubber, etc. to produce rubber products, such as transmission belts, conveyor belts, wires and cables, rubber seals and other products, effectively reducing the cost of raw materials. When using neoprene reclaimed rubber to produce rubber products, a reasonable design of rubber product formula can further optimize product quality while reducing costs.
1. Key points of design of vulcanization system for neoprene rubber products
When producing rubber products with neoprene reclaimed rubber as the main raw material, sulfur can not be used as a vulcanizing agent, magnesium oxide and zinc oxide systems are commonly used, MgO and ZnO are used in accordance with the ratio of 4:5, the vulcanization rate is fast, the vulcanization flatness is good, the processing safety is high, and the vulcanized rubber has good heat resistance. Magnesium oxide can play the role of a stabilizer in the mixing of neoprene reclaimed rubber to prevent early cross-linking and cyclization of neoprene compound; Zinc oxide is mainly used as a vulcanizing agent, which can speed up the initial vulcanization, improve heat resistance and aging resistance.
Mercury oxide, barium oxide, calcium oxide, iron oxide, titanium dioxide, etc. have vulcanization effects on neoprene and neoprene reclaimed rubber. NA-22 is a commonly used accelerator in the vulcanization system of chloroprene reclaimed rubber products, which gives the reclaimed rubber good heat resistance, tensile stress and compression set, but the vulcanization rate is fast and easy to scorch. When the neoprene material is vulcanized at low temperature, it is recommended to use the accelerator DETU/DM/DOTG together; Anti-scorching agents can be used in an appropriate amount to prevent scorching.
2. Key points of the design of the reinforcing filling system for neoprene rubber products
Neoprene and neoprene reclaimed rubber products are filled with 20-40 parts of carbon black, which can improve the tensile stress and tear strength of the rubber compound; Most of the white reinforcing fillers have little effect on the strength and elongation E4LYY1217 of neoprene reclaimed rubber vulcanized rubber, among which silica can make the rubber material compression deformation small, water resistance, acid and alkali resistance and natural aging; Clay can give neoprene vulcanized rubber high strength and tear resistance, improve the extrusion performance of the rubber, make the rubber shrinkage small, smooth surface, and the dosage in the extrusion product is among 30-50 parts.
3. Key points of design of softening and plasticizing system for neoprene recycled rubber products
The plasticizers commonly used in the production of neoprene recycled rubber products include ester plasticizers such as dibutyl phthalate and dioctyl phthalate, which can reduce the embrittlement temperature of vulcanized rubber, and the commonly used amount is 10-15 parts; petroleum-based softening plasticizers such as engine oil, transformer oil, spindle oil and petroleum jelly; Coumaron resin can increase viscosity and plasticity; Stearic acid has the effect of preventing sticking rollers, the general dosage is 0.5-2 parts, if more than 2 parts have a delayed vulcanization effect; The use of oil paste as a compatibilizer can improve the process performance of the rubber compound, reduce the sticky roller, reduce the shrinkage, and make the rolling surface smooth, but can reduce the physical properties.
4. Key points of the design of the anti-aging system of neoprene recycled rubber products
The commonly used antioxidants for neoprene reclaimed rubber products include antioxidants RD, A, DNP, 4020, 4010NA, AW, MB, SP, SP-C, etc.; Antioxidants RD and A can be used if heat and oxygen resistance is required; When ozone resistance is required, antioxidants 4020, 4010NA, AW, etc. can be used, and 1~2 parts of paraffin wax can be added to combine with other antioxidants.
The design of the formula of neoprene reclaimed rubber products needs to be combined with the use scenarios, performance requirements and cost budget of rubber products, and comprehensively consider the vulcanization system, reinforcing filling system, softening and plasticizing system and anti-aging system. In the future, Xiaobian will continue to share with you the specific application of neoprene reclaimed rubber in various rubber products.
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