Compressionmoulding, a method of rubber processing in which rubber raw materials are formed into products by heating and pressure in a closed mold cavity. The products that use the molding process are: miscellaneous parts, sealing rings, oil seals, etc.
Generally, the powder flake rubber block is first made into a blank with a similar shape to the product, placed in the cavity of the heated mold, and then closed and pressurized to make it molded and solidified or vulcanized, and then the product is obtained by demoulding, which is especially suitable for the molding and processing of thermosetting products.
Merit:
1. Can be made into any shape
2. High precision, the shape of the product is regular and beautiful
Shortcoming:
1. Generally only can be done with a length of less than 600 mm
2. Long production cycle and low efficiency
3. The production process will produce a lot of burrs and scraps
4. The mold cost is expensive and the development cycle is long.
Extrusion (Crowdingout), generally according to the type of polymer to be processed and the shape of the product or semi-finished product, select the extruder, head and die, as well as the corresponding auxiliary devices such as shaping and traction, and then determine the extrusion process conditions such as screw speed, head pressure, material temperature, shaping temperature, traction speed, etc. In the extrusion process, the material is generally plasticized, but the shaping method is different. Extruded plastics, for example, often need to be cooled and shaped to solidify, while semi-finished products of extruded rubber need to be further vulcanized. The products that use the extrusion process are: rubber sealing strips, hoses, and rubber sheathed cables.
Merit:
1. Can be wireless long
2. Fast production cycle and high capacity
3. Very little waste is generated
4. The mold is cheap, and the development is convenient and fast.
Shortcoming:
1. It can only be made into strips
2. The accuracy is a little worse, and some shapes are difficult to produce