At the same time, different hollow roller heating methods suitable for the pressure delay of the non-woven fabric calender machine are designed, and a hollow roller suitable for steam heating and a peripheral drilling roller suitable for oil heating and water heating are respectively designed. Through the production practice, the heating methods of the two types of holes can meet the requirements of the process for the temperature fluctuation error of the roll surface.
In terms of material selection, we use alloy chilled cast iron material with good wear resistance and rigidity. The hardness of the working face of the roll reaches HS72-75. However, the alloy chilled cast iron rolls are often necessary for the special treatment of the roll surface due to casting defects and the corrosion of the additives in the pellets.
Special treatments mainly include surface-spraying wear-resistant materials and hard chrome plating. We use the latter. In order to enhance the bonding strength between hard chrome and alloy chilled cast iron, nickel plating is required before chrome plating, and the thickness of chrome plating after grinding is generally 0.05-0.08 mm.