1. The roller should have sufficient rigidity to ensure that the bending deformation does not exceed the allowable value under the effect of heavy load.

2. The surface of the roller should have sufficient hardness, generally required to reach HRC50 degrees or more, with strong corrosion resistance. The coating has anti-shedding ability to ensure that the working surface of the roller has good wear resistance and corrosion resistance.

3. The surface of the roller should be finely processed to ensure the dimensional accuracy and surface roughness. The roughness should be above Ra0.16 without pores or grooves. The wall thickness of the working surface of the roller should be uniform, otherwise the temperature of the roller surface will be uneven, which will affect the quality of the product.

4. The material of the roller should have excellent thermal conductivity. Generally, chilled cast iron is used. In special cases, cast steel or molybdenum-chromium alloy steel is used. Whether it is heating or cooling, it can achieve rapid and uniformity.