What is the effect of pressing speed on the quality of pressed semi-finished products? How should it be controlled?

Pressing out speed is another important factor in the operation of pressing out, pressing out speed, semi-finished products expansion and contraction rate is large, the surface is rough, the rubber temperature is high, easy to produce burnt; Pressing out speed is low is the rubber expansion and contraction rate is small, the surface is smooth. Pressing speed is determined by the rotational speed of the screw, the screw speed is fast, the pressing speed is fast, in the screw speed is certain, the plasticity of the rubber material with good fluidity, the pressing speed is fast, the pressing temperature is high when the pressing speed is fast. Pressing speed should depend on the specifications of semi-finished products, generally 3 ~ 20 m / min, screw speed is generally controlled at 30 ~ 50 rpm / min appropriate. The speed of the transportation belt of the pick-up device connected with the press-out machine should be matched with the speed of the press-out, otherwise it will result in the rough surface of the press-out material or inaccurate size of the cross-section.