Why is the nylon conveyor belt oxidized?

1. Oxygen: Oxygen reacts with the rubber molecules in the free radical chain, and the molecular chain is broken or over-crosslinked, resulting in changes in rubber properties. Oxidation is one of the important reasons for rubber aging.
2. The chemical activity of ozone and ozone is much higher than that of oxygen, and it is more destructive. It also breaks molecular chains, but the effect of ozone on rubber varies with the deformation of the rubber. When used as deformed rubber (mainly unsaturated rubber), there will be cracks perpendicular to the direction of stress, which is called "ozone crack"; when it acts on deformed rubber, only the oxide film will be formed on the surface without cracking .
3. Heat: Increasing the temperature will cause thermal cracking or thermal crosslinking of rubber. But the basic function of heat is activation. Improving the oxygen diffusion rate and activating the oxidation reaction to accelerate the rubber oxidation reaction rate is a common aging phenomenon - thermo-oxidative aging.
4. Light: The shorter the light wave, the greater the energy. The damage to the rubber is caused by high-energy UV rays. In addition to directly causing the breakage and crosslinking of rubber molecular chains, ultraviolet rays can also cause free radicals in rubber by absorbing light energy, thereby triggering and accelerating the oxidation chain reaction process. Ultraviolet light acts as a heating agent. Another feature of light effect (different from thermal effect) is that it mainly grows on the rubber surface. For samples with high colloid content, network cracks will appear on both sides, which are called "smooth outer layer cracks".
5. Mechanical stress: During the repeated action of mechanical stress and continuous friction with the roller, the conveyor belt will break the rubber molecular chain to generate free radicals, trigger an oxidation chain reaction, and form a mechanochemical process. Mechanical breaking of molecular chains and mechanical activation of oxidation processes. Which one dominates depends on its conditions. In addition, it is easy to cause ozone cracking under pressure.
6. Moisture: The role of moisture has two aspects: when the humid air is exposed to rain or soaked in water, the rubber is easily damaged, because the water-soluble substances and water groups in the rubber are extracted and dissolved by water. Caused by hydrolysis or absorption, etc. Especially under the alternating action of water immersion and atmospheric exposure, the damage of rubber will be accelerated. In some cases, however, water will not damage the rubber and even delay aging.
7. Others: chemical media, variable price metal ions, high-energy radiation, electricity, biology, etc. Also acts on rubber.