The function of each index of valve port bag in application
1. Specific surface area
The size of the white carbon black reinforcing effect, depending on its specific surface with the increase of specific surface area, the general rubber products of the various strength indexes, but resilience reduces, tear strength is reduced, and do not wear, mixing scattered difficult, high heat, rubber Mooney viscosity, scorch easily, therefore, different formula, different purposes, require specific surface area is different also, The effect of specific surface area on physical and mechanical properties of vulcanized rubber is not always consistent.
2. Oil absorption value
The size of oil absorption value reflects the level of structure, oil absorption value is large, the structure is small, the extension strength of vulcanized rubber is generally large, the tensile strength and hardness are large, especially the wear resistance is small, but the elongation is low.
3. 900℃ burning reduction
The performance is that when the surface hydroxyl is too much, it is easy to cause the structure of the rubber composite material, so that the material becomes brittle. Affect the processing performance, and vulcanizate easy to drop blocks, and the surface hydroxyl on the vulcanization accelerator has strong adsorption, prolong the curing time.
4. 105℃ heating reduction
Reflect the amount of free water in the particle gap. When it is too small, the structure of the rubber material is high and the mixing of rubber becomes difficult. If the heating reduction is zero, the white carbon black is useless, and it is generally controlled at about 6%.
5. PH
Generally about 7, PH value increases (acidity decreases), vulcanization speed up. ,
6. Soluble salt
Less is better, but less costs more.
