Special rubber conveyor belts work in special occasions for a long time. They have special performance requirements for conveyor belt covering rubber, including non-flammable conveyor belts, heat-resistant conveyor belts, conductive conveyor belts, acid and alkali conveyor belts, food conveyor belts, etc. Recycled rubber processed from waste rubber products can be used in special conveyor belt covering rubber to significantly reduce the cost of raw materials. However, it is necessary to match the types of compounding agents to ensure the performance and service life of special conveyor belts containing reclaimed rubber.
The nitrile reclaimed rubber, butyl reclaimed rubber and EPDM reclaimed rubber in the reclaimed rubber products can be used in the production of special conveyor belts, mainly including flame retardant conveyor belts, heat-resistant conveyor belts and acid-resistant conveyor belts.
1. Selection of compounding agents in the formulation of flame retardant conveyor belt containing reclaimed rubber
The most important characteristic of the flame-retardant conveyor belt is “flammable”. Generally, the non-flammable conveyor belt covered with polyvinyl chloride and nitrile rubber can be mixed with a small amount of nitrile reclaimed rubber. It needs to be combined with chlorinated paraffin. Flame retardant, such as antimony trioxide, zinc borate, aluminum hydroxide, etc., to ensure the flame retardancy of the flame retardant conveyor belt.
2. Selection of compounding agents in heat-resistant conveyor belt formulations containing reclaimed rubber
The heat-resistant conveyor belt naturally has high requirements on the heat resistance of the cover rubber. The rubber product manufacturer can mix the appropriate amount of EPDM reclaimed rubber in the heat-resistant conveyor belt formula, and use the effective vulcanization system and peroxide. Vulcanization system, resin vulcanization system, etc., improve the heat resistance of reclaimed rubber compound. For heat-resistant conveyor belt covering rubber with high mechanical strength, low-sulfur compound or peroxide vulcanization can be selected; heat-resistant conveyor belt with reclaimed rubber N330 carbon black and aeration furnace black can be used to improve the hardness of the regenerative rubber heat-resistant conveyor belt while preventing high-temperature cracking; together with paraffin oil, coal tar, solid coumarone, chlorinated paraffin, etc. with high decomposition temperature, Improve the viscosity and heat resistance of heat-resistant rubber containing reclaimed rubber.
3. Selection of compounding agents in the formula of acid-base conveyor belt containing reclaimed rubber
The acid-base conveyor belt is in contact with acid and alkali for a long time, and the acid and alkali corrosion resistance of the rubber compound is extremely high. Chloroprene rubber and butyl rubber are ideal. In the acid-base conveyor belt cover rubber compound produced by butyl rubber, an appropriate amount of butyl reclaimed rubber can be used, and the active hard carbon black such as N330 and barium sulfate can be used to improve the acid and alkali resistance of the rubber compound.
The special rubber conveyor belt covering rubber has strict requirements on the performance of the rubber compound. The content of the reclaimed rubber in the rubber coating formula must be reasonably controlled. The selection of the compounding agent in the special conveyor belt covering rubber compound containing reclaimed rubber must be cautious.