Preparation Method And Processing Technology Of Silicone Rubber

Silicone rubber is a widely used material due to its excellent properties, such as high thermal stability, good electrical insulation, and excellent resistance to weathering, chemicals, and aging. It is used in a wide range of applications, including automotive, medical, electrical, and consumer products.

The preparation of silicone rubber involves several steps, including compounding, mixing, and vulcanization.

Compounding is the process of preparing the silicone rubber material by blending various ingredients, such as fillers, crosslinkers, and additives, to achieve the desired properties. The ingredients are usually mixed in a two-roll mill or a Banbury mixer.

The two-roll mill consists of two parallel rolls, which rotate in opposite directions. The silicone rubber material is fed between the rolls and passes through them, undergoing shearing and mixing action. The process can be repeated several times until the desired level of mixing is achieved.

The Banbury mixer is another type of mixing equipment used for compounding silicone rubber. It consists of a large, cylindrical mixing chamber, which rotates at high speed. The ingredients are added to the mixer through a hopper, and a series of blades inside the chamber mix and blend the material.

Vulcanization is the process of crosslinking the polymer chains to give the material its final properties. This is achieved by heating the material at a high temperature, typically between 150°C and 200°C, for a certain period of time. The vulcanization process can be carried out using a hot press or a mold.

A mold is another common method used for vulcanizing silicone rubber. The material is placed in a mold, which is then heated to the desired temperature. The mold is typically made of metal and has a cavity in the shape of the desired final product. The silicone rubber material fills the cavity and is heated to crosslink the polymer chains.

In addition to these traditional processing methods, there are also some advanced technologies used in the production of silicone rubber.

Liquid injection molding (LIM) is a technology used to produce high-precision parts with complex shapes. It involves injecting a liquid silicone rubber material into a mold under high pressure. The material is then cured in the mold to produce the final part. LIM is often used in the medical and automotive industries for the production of parts such as gaskets, seals, and medical devices.

Rapid prototyping is a process used to quickly produce a physical model of a product using computer-aided design (CAD) data. It involves using a 3D printer to create a silicone rubber prototype, which can be used for testing and validation before final production. This technology has been widely used in product design and development.

These steps of the preparation and processing of silicone rubber can be carried out using various equipment and techniques, depending on the desired properties and final application of the silicone rubber material. Advanced technologies, such as liquid injection molding and rapid prototyping, are also used in the production of silicone rubber products.