Composition and working principle of calender

The calender, in simple terms, is a kind of equipment used to improve the gloss of the paper surface, and is a kind of matte polishing process. Under normal circumstances, after the surface of the printed matter is coated, the gloss layer is dried, and the gloss, smoothness and gloss of the coating need to be improved again. At this time, calender is required. The gloss of the glaze can only reach about 655 to 85%, but the gloss after calender can reach 905 to more than 95%.

What are the types of super calender?

For writing paper, printing paper, coated paper and other cultural paper and coated paper, it is characterized by high requirements for gloss and smoothness; when the width is large and the speed is high, the line pressure is relatively low, and the heat roller temperature is low.

The calender with controllable partition is becoming popular, and this knowledge should be supplemented as soon as possible.

When the calender roller group of the papermaking machine is pressurized, because the roller group bears the uniform load generated by its own weight and the external load applied to the bearing, the bottom roller and the top roller will produce flexural deformation, and the maximum deflection will be generated in the middle of the bottom roller and the top roller, thus the pressure distribution of the whole pressure zone is uneven, with small middle and large sides. In order to solve this problem, controllable middle and high rollers are now widely used, such as swimming roller (swimming roll), controllable middle and high roller (controlled crown roll) and partition controllable roller (nip roll). This paper focuses on the design of the electro-hydraulic control system of the controlled roller.

The calendering effect of paper, what to do

When the paper passes through the calender, under the action of the line pressure, the polyurethane roller and the paper are deformed to form a deformed area. The pressure is distributed over this area. The width of the deformed area determines the amount of deformation of the polyurethane roller and the amount of reduction in the thickness of the paper. (The ratio of the line pressure to the width of the deformed area is called the specific pressure, and the unit is kPa/m2). The use of a polyurethane roll on a calender enables a wider deformation area to be formed, as with the use of a polyurethane roll in the press section.