Product use
In plastic machinery, the calender is usually a complete calender production line with pilot devices such as material conveying, screening, measuring, kneading and plasticating, subsequent devices such as pulling, drawing, embossing, cooling, thickness measurement, winding and cutting, as well as transmission, monitoring and heating devices, to produce soft and hard films, sheets, artificial leather, wallpaper and floor coverings.
Product classification
There are many types of calender classification in plastic machinery, and the number of press rolls is divided into two rolls, three rolls, four rolls and five rolls. The arrangement of rollers can be divided into F, Z, S and L.
Internal composition
Unlike other plastic machinery, the calender consists of a frame, a press roll and its regulating device, a transmission system and a heating system. The frame is usually made of cast iron and is directly mounted on both sides of the cast iron or cast steel frame to support pressure roll bearings, shaft crossing or press-bending devices, press roll regulating devices, lubrication devices and other auxiliary devices. The press roll is made of chilled cast iron and cast steel, and its length-diameter ratio is selected according to the bending strength of the press roll material, which is about 2.6 ~ 3.5. In order to compensate for the bending deformation caused by the force of the roller, the roller is made into a waist drum shape, and the roller crossing device and the roller pre-bending device can also be used to eliminate the thickness of the product. Each press roll is driven by a separate motor. Roller heating generally uses steam or superhot water, requiring that the temperature difference between the two ends does not exceed 1ºC. Each roll has its own automatic heating system. Modern calenders use roller bearings instead of traditional plain bearings to save energy, improve bearing life and product thickness accuracy.