1. The roller shall have sufficient rigidity to ensure that the bending deformation under heavy load does not exceed the allowable value.
2. The surface of the drum should have enough hardness, which is generally required to reach HRC50 degrees or above, and has strong corrosion resistance. The coating has anti-peeling ability, which ensures that the working surface of the roller has good wear resistance and corrosion resistance.
3. The working surface of the roller should be finely machined to ensure dimensional accuracy and surface roughness. The roughness shall be above Ra0. 16, and there shall be no air holes or grooves. The wall thickness of the roller working surface should be uniform, otherwise the temperature of the roller surface will be uneven, which will affect the product quality.
4, the material of the drum should have good thermal conductivity, usually using chilled cast iron, special circumstances using cast steel or molybdenum chromium alloy steel, whether heating or cooling, can achieve fast and uniform.
Rollers usually adopt seamless steel pipes, and some adopt aluminum alloy 606 1T5, 304L/3 16L stainless steel, 2205 duplex stainless steel, steel castings, solid forged alloy steel cores and other materials according to different technological requirements.
The production of roller is mainly composed of initial turning of roller body, initial static balance, interference assembly welding of shaft head, fine turning and fine dynamic balance. If roundness, cylindricity, straightness and other geometric tolerances are required to be below 0.2 mm, it is necessary to grind with a cylindrical grinder or a roll grinder after turning. If surface hardness is required, heat treatment process should be increased.
After the roll is formed, surface treatment or coating, such as painting, zinc plating, Teflon spraying, rubber coating, chromium plating, ceramic spraying and oxidation, is needed for rust prevention, corrosion prevention and support.
According to the size, there are large idlers for papermaking machinery (the length can reach 1 0m or more and the diameter 1500mm or more) and small flat idlers for belt conveying on automatic assembly lines (generally within1m and the diameter is within 159mm).
According to their functions, there are rollers on digital laser printers, calendering rollers on paper machines, supporting rollers with low dimensional accuracy requirements, rollers with heat exchange requirements, and rollers with heavy pressure filtration.
In order to prolong the service life of the drum, the maintenance of the drum must be done well.
1. Clean the dust and other foreign objects on the drum regularly.
2. Regularly check whether the welded joint between the drum shell and the end cover is firm.
3, good lubrication, reduce wear and tear.
4. Avoid overload operation and prolong the service life of the drum.