The roll forming of the roll forming machine equipment is the same as the spinning forming, which can adopt the male mold roll and the female mold roll. The male mold rolling uses the roller head to determine the shape and size of the male surface (external surface) of the blank. It is suitable for forming flat, wide-mouthed utensils and products with patterns on the inner surface of the blank.
The female mold rolling system uses a roller head to form the inner surface of the blank. It is suitable for forming products with small diameter and deep concave. When the male mold is rolled, the speed of the plaster model (that is, the rotation speed of the main shaft) cannot be too fast, otherwise the blank is easily thrown off, so the blank is required to have less moisture and better plasticity.
When the belt mold is dried, the green body is supported by the model, and the demolding is more difficult but the deformation is less. When the female mold is rolled, the spindle speed can be higher, the mud moisture can be higher. And the plasticity requirement can be slightly lower, but the mold is easy to deform when drying, and the model is often buckled on the pallet for drying to reduce deformation.
In order to prevent the roller head from sticking to mud, the hot rolling of the roller forming equipment can be used, that is, the roller head is heated to a certain temperature (usually about 1200°C). When the roller head contacts the wet mud, a steam film is formed on the surface of the roller head, which can prevent the mud from sticking to the roller head. The roller head heating method is to use a certain type of resistance wire coiled in the roller head cavity and electrified to heat.
When hot rolling is used, the requirements for mud moisture are not strict and the adaptability is wide, but the temperature of the roller head must be strictly controlled, and auxiliary equipment must be added, which often requires maintenance and is troublesome to operate. Some porcelain factories use cold rolling, in order to prevent sticking of the roller head, the mud is required to have a lower moisture content and better plasticity, and hydrophobic materials can be used as the roller head.
The forming of the roll forming machine relies on the roll press head to exert force. Therefore, whether the design of the roll press head is appropriate or not is a key issue for roll forming.
1) It can form the required shape and size of the product, and it is not easy to produce defects.
2) Roll forming machine equipment is conducive to the spreading of mud and the discharge of residual mud during rolling.
3) It has long service life, proper surface hardness and smoothness.
4) It is convenient to manufacture, maintain, adjust, assemble and disassemble.
5) Roll forming machine equipment has easy source and low price for rolling materials.