Paper making rubber roller is a large thick walled rubber roller used in various parts of paper machines. According to different functions, it can be divided into press rollers and various auxiliary rollers driven by press rollers. Today, let's learn about the material preparation and forming process of paper making rubber rollers.
1、 Preparation of rubber material
For paper making rubber rollers, rubber mixing is a crucial step. There are more than 10 types of rubber materials used for rubber rollers, ranging from natural rubber, synthetic rubber to special materials. The rubber content is 25%~85%, the hardness is 0~90 degrees, and the span is very large. Therefore, how to mix these compounds evenly has become a big problem. The traditional method is to use an open mill to mix and process various types of raw materials. In recent years, enterprises have increasingly turned to meshing internal mixers to prepare rubber materials through segmented mixing.
After the rubber material is mixed evenly, it should be filtered through a rubber filter to eliminate impurities in the rubber material. Then, use calendering machines, extruders, and laminating machines to manufacture bubble free and impurity free films or tapes for forming paper making rubber rollers. Before forming, these films and adhesive strips should undergo strict visual inspection to limit parking time, maintain surface freshness, and prevent adhesion and compression deformation. Due to the fact that most rubber rollers are non molded products, once there are impurities and bubbles in the surface rubber, sand holes may appear when polishing the surface after vulcanization, leading to excessive repair or even scrapping of the entire rubber roller.
2、 Rubber roller forming process
The molding of paper making rubber rollers mainly involves pasting and coating rubber on a metal core, including coating method, extrusion method, molding method, injection method, and injection method. At present, mechanical or manual bonding molding is mainly used in China, while most foreign countries have already achieved mechanical automation. Large and medium-sized rubber rollers are mostly produced by imitation extrusion, with continuous bonding of extruded film or continuous winding of extruded rubber strips. At the same time, during the molding process, the specifications, dimensions, and appearance shape are automatically controlled by a microcomputer, and some can also be extruded through the right angle and irregular shape of an extruder.
The above molding method can not only reduce labor intensity, but also eliminate possible bubbles. In order to prevent deformation and the generation of bubbles and sponges during the vulcanization process of paper making rubber rollers, especially for rollers formed by winding method, flexible pressing method should be used on the outer side. Usually, several layers of cotton or nylon cloth are wrapped around the surface of the rubber roller, and then fixed and pressed with steel wire or fiber rope. Although this process has been mechanized for a long time, a "cecum" process is formed after vulcanization, making the manufacturing process more complex. Moreover, the use of bandages and wrapping ropes is limited and consumes a lot, resulting in waste.
In summary, the paper making rubber rollers currently used in production have formed a product series with unique processes. Although traditional products are still the mainstay in China, the technological content is constantly improving, and many products have entered the high-tech field, with increasing added value, becoming another economic highlight in industrial rubber products.
Editor: Chihiro
