Different from other plastic machinery, the calender consists of a frame, a pressing roller and its adjustment device, a transmission system and a heating system. Supporting roller bearings, shaft cross or roller pre-bending devices, roller adjusting devices, lubricating devices and other auxiliary devices. The pressure roller is made of chilled cast iron and cast steel, and its aspect ratio is selected according to the bending strength of the pressure roller material, which is about 2.6 to 3.5. In order to compensate for the defect of uneven thickness of the product caused by the bending deformation caused by the force of the pressure roller, the pressure roller is mostly made into a waist drum shape, and the roller cross device and the roller pre-bending device can also be used to eliminate the uneven thickness of the product. Each pressing roller is driven by a separate motor. Steam or superheated water is generally used to heat the pressure roller, and the temperature difference between the two ends is required not to exceed 1°C. Each pressure roller has an independent automatic heating system. Modern calenders use roller bearings instead of traditional plain bearings to save energy, improve bearing life and product thickness accuracy.
