Calender is a kind of precision general rubber machinery, which is mainly used in the rubber industry for rolling film, rubber sheet, gluing and rubbing of textile fabrics and steel cord fabrics. There are many types of rubber calenders, including two rollers, three rollers, four rollers, five rollers, etc., but three-roller and four-roller calenders are widely used. Three-roll calenders are used for sheet release, single-sided rubbing or gluing, or two in series for double-sided gluing. Tire factories widely use four rollers to make cord fabric double-sided tape, and five rollers are rarely used at present.

In the past, the specifications of the calender were expressed by the outer diameter and length of the rollers and the number of rollers, such as 230*635*4, not a four-roll calender with a roller diameter of 230mm and a roller length of 635mm. At present, the ratio of the diameter to the length of the calender has been specified (that is, the ratio of length to diameter is 2.6~3), so the specifications of the calender are only expressed by the length of the roller, and the type is indicated by a symbol in front of the length.

Calenders work on much the same principle as open mills. When a rubber material with a certain temperature and plasticity is fed between two opposing rotating rolls, the rubber material is pulled into the roll gap under the action of friction. As the cross-section of the roll gap gradually becomes smaller, the rubber material is strongly squeezed and stretched. Usually many calendering processes require pairs of rollers to work at a certain speed ratio to further mix, knead, plasticize, and then calender into a film of a certain thickness and width through a small roll gap. In addition to pressing the rubber into a film with a calender, some processes require pressing the film onto a textile fabric (gluing or wiping) or steel cord under the action of roller pressure, some need to be pressed into a certain pattern and shape (pressing), and some need to bond multiple layers of film together.

Ultra-photovoltaic glass is a type of flat glass manufactured by calendering. The mixture melts, clarifies, homogenizes at high temperatures to form a qualified molten glass, which enters the channel through the neck and flows into the calendering unit from the overflow port at about 1 150. The calender hydroforms the glass and then enters the annealing kiln via a movable roller table. Calender is an important equipment for the production of ultra-clear photovoltaic glass and a key equipment for glass molding. The performance and stability of the calender will directly affect the continuity of photovoltaic glass production, as well as the yield and quality of the product. Therefore, it is very important for enterprises to choose a calender with superior performance and good stability to produce ultra-white photovoltaic glass.

The main body of the calender consists of an upper roller, a lower roller, four auxiliary rollers, a cooling device and a corresponding adjustment device. Each calender has two stainless steel X20Cr13 main rollers with smooth surfaces. The net roll length is 2 800 mm, the total length is 3 000 mm, the outer diameter of the main roll is 280-320 mm, and the inner diameter is 180 mm.

The above are some knowledge points about calenders, I hope you can learn to understand the relevant knowledge carefully.