There are many application scenarios for heat-resistant conveyor belts, because the requirements for conveyor belts have certain special characteristics, so it is necessary to have no aging for a long time under high temperature conditions, high adhesion to rubber compounds, and heat shrinkage deformation. Small and other characteristics.
The biggest problem of the heat-resistant conveyor belt nitrile rubber tableting is that the shrinkage is severe and the surface is rough, so it is difficult to calender. However, if the rubber compound formula is properly adjusted and the heat-refining time is extended, the smooth operation can be ensured, and the formula should use soft carbon black. Such as semi-reinforcing or thermal cracking furnace black 100 parts, can also be used with active calcium carbonate, etc., and add about 50 parts of plasticizer at the same time, the roller temperature should be 10 ° C lower than natural rubber, and the middle roller temperature is low In the upper roll, some technical literature recommends a temperature range of 60-75 ° C for the upper roll, 35-50 ° C for the middle roll, and 50-60 ° C for the lower roll. The roll temperature is appropriately increased when the transfer belt adhesive roll is encountered. Reduce the tendency of the sticky roller. The fluororubber heat-treating temperature should be 40-50 ° C, the thickness of the conveyor film is 2-3 mm, and the high-temperature rolling and lower roll cooling are used. The polysulfide rubber should be calendered at a low temperature. The suitable temperature range is: upper roller 45 ° C, middle roller 40 ° C, lower roller room temperature, film thickness not exceeding 0.8 mm, and the rolling speed is constant.
In the production process of heat-resistant conveyor belt, the factors affecting the operation of tableting and the overall quality are roller temperature, roll speed, rubber compounding characteristics, rubber content and plasticity. By increasing the rolling temperature, the shrinkage rate of the semi-finished product can be reduced, and the surface of the belt film is smooth. However, if the film is too high, bubbles and scorch are easily generated, the roll temperature is too low, the flowability of the rubber is poor, the surface of the rolled semi-finished product is rough, the shrinkage rate is increased, and the roll temperature is determined. The type of raw rubber and the characteristics of the formula, the plasticity of the rubber and the gelatinization rate are determined. Usually, the formula has a higher gel ratio, a lower plasticity of the rubber compound or a higher elasticity, and the calender roll temperature should be appropriately increased, and vice versa.
In addition, in order to facilitate the smooth transfer of the rubber tape between the rolls, it is also necessary to maintain a proper temperature difference between the rolls, such as a natural rubber easy to pack hot roll, when the film is transferred from one roll to another, and the other The temperature of the roller should be increased appropriately. The synthetic rubber is just the opposite. The temperature difference between the rollers is generally 5-10 °C. The plasticity of the heat-resistant conveyor belt is large, the flowability is good, the shrinkage of the semi-finished product is low, and the surface is smooth. However, the plasticity is too large and it is easy to cause a sticking roller phenomenon, which affects the operation.