Types of rubber used for rubber rollers
Release time:
2020-10-20
The rise of polyurethane rubber. Polyurethane rubber has outstanding comprehensive properties. It has a wide range of hardness (from Shore A40 to Shore D80), machinery, (5-10 times that of ordinary rubber), oil resistance
1. The rise of polyurethane rubber. Polyurethane rubber has outstanding comprehensive properties. It has a wide range of hardness (from Shore A40 to Shore D80), machinery, (5-10 times that of ordinary rubber), oil resistance, good vibration absorption performance, and easy cutting and processing. Since the 1970s, it has been used for rubber rollers and has successively replaced many traditional ordinary rubbers, and has almost reached the point where it is almost equal to ordinary rubber. The current cold-rolled sheet steel unit has a linear speed of about 1000m/min. The line pressure also requires more than 80kg/cm, and ordinary rubber and nitrile rubber can no longer meet its requirements. Therefore, more than 66% of the installed rubber rollers, especially the tension rollers and pull-correction rollers, have been changed to cast polyurethane rubber rollers. Some steel rollers, such as measuring rollers and load-bearing rollers, are changed to mechanical polyurethane rubber rollers that are more flexible than steel rollers in order to reduce the marks on the steel plate. With the technological progress of papermaking rubber rollers, it is required that the linear pressure exceeds 150kg/cm, the linear velocity reaches 1800m/min, and the hardness reaches Shore D74-80. Although ordinary rubber can be made into hard rubber to achieve this level of hardness, it has poor toughness, poor impact resistance, and short grinding cycle. Large rubber rollers with a diameter of nearly 1m and a length of about 10m are often disassembled and repaired. Grinding is a very troublesome thing. Using high-hardness polyurethane elastomer material, the grinding period of the press roll can be extended by 3 months, and the service life is 4 to 5 times that of ordinary rubber.
Another valuable property of polyurethane rubber is that it swells in the fluid like other rubbers, but it can be restored to its original size after being taken out of the fluid, dried, and the solution is removed. This makes the low-hardness polyurethane rubber roll in the coating, It is widely used in paint coating operations.
The shortcomings of urethane rubber are large heat generation and limited heat resistance, especially humidity and heat resistance. However, there are many types of polyurethane elastomers, which can be synthesized according to processing requirements, and there is a lot of room for modification. Therefore, if the materials and processes are properly selected, the heat resistance, hydrolysis resistance, and degree of media performance will be great.
2, special rubber rollers came into being
Due to technological progress and increasingly demanding conditions, special rubber rollers with various requirements have emerged. The acid-base washing rubber roller with squeezing function is mainly used in the degreasing, pickling, chemical coating, squeezing and other stages of the steel sheet production line in the iron and steel metallurgical industry. For example, the lye for degreasing is 25g/L, and the temperature is 70℃-1gp. ℃. The acid wash is dilute sulfuric acid; the chemical coating is chromic acid; the stainless steel production line also uses hydrofluoric acid. The preferred choice that can adapt to these conditions is the chemical-resistant, weather-resistant chlorosulfonated polyethylene (Hypalon) rubber . Since the variety, concentration, temperature and all conditions of acid and alkali media are very different, the same chlorosulfonated polyethylene rubber formula can be considered and used together, and the appropriate compounding agent can be selected. The research potential of formula rubber is great.
As for the rubber rollers used for laminating color steel sheets and the rubber rollers used under high temperature conditions in the clothing and plastic industries, many domestic manufacturers know that they can be made of silicone rubber. However, due to the short service life, easy shelling, and bursting, it is required Large-scale silicone rubber rollers with a service temperature above 250°C and a service life of more than half a year still need to be organized to solve problems. Especially in the selection of silicone rubber, bonding system, molding and vulcanization process improvement, etc., we look forward to breakthroughs.
As for soft calender rolls and large glossy rolls for paper machines, hard rubber or a combination of rubber and resin are available. Conditions of use The large working line pressure is more than 300KN/m, the vehicle speed is about 1000m/min, and the adjacent steel rolls The temperature is between 120°C and 150°C, and the encapsulation hardness is above D90. Similar products are already available, and our country is still studying. In addition, a high-performance, high-hardness papermaking rubber roller that adjusts the camber of the roller surface by hydraulic pressure has also entered my country following the introduction of papermaking machinery.
Tag:
Previous
Next
Previous:
Next:
Recommended
Share
Yongcai Rubber Roller
Message