In the production process of rubber products, a process in which various shapes and sizes are different in advance by using a calender or an extruder is called molding. The molding methods mainly include the following.
1.Calendering
It is suitable for the manufacture of simple sheet and plate products. It is a method of pressing a rubber compound into a certain shape and a certain size by a calender, which is called calender molding. Some textile products such as tires, tapes, hoses, etc. must be coated with a thin layer of glue on the fibers. The glue or glue is usually applied to the calender. The purpose of the fiber material to be dried and dipped before calendering is to reduce the water content of the fiber material so as not to evaporate the water and increase the temperature of the fiber material to ensure the quality of the calendering process. Dipping is a necessary process before the glue is applied to improve the bonding properties of the fiber material and the rubber compound.
2. Extrusion molding
For more complex rubber products such as tire tread, hose, wire surface coating, it needs to be manufactured by extrusion molding. It is a method of continuously molding a mixture of plastics with certain plasticity into the hopper of the extruder under the extrusion of the screw through various mouth shapes (also called templates). Before the extrusion, the rubber must be preheated to make the rubber soft and easy to extrude to obtain a rubber product with smooth surface and accurate size.
3. Molding
It is also possible to use a molding method to manufacture certain rubber articles having complicated shapes such as cups and seals, and to place the rubber in the mold by means of a molded female and male mold.
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