Processing Technology of Silicone Rubber

1. Molding

The molding process is mainly a production process formed by pressing molds in related machines, such as the production of silicone mobile phone cases, silicone ice trays, etc. The main production process is the silicone processing of silicone raw materials or rubber raw materials that are formed into products by heating and pressurizing in a closed mold cavity. Usually, the raw materials are uniformly mixed into a mixed rubber through a mixer , and the mold is moved into the vulcanization molding machine. Then the mold is closed and pressurized to form and solidify or vulcanize, and then demolded to obtain silicone products. This process is suitable for the processing of thermosetting materials.

2. Injection

This process requires relatively high quality, and is a combination of liquid silicone and plastic. Its products show good thermal stability, cold resistance , excellent electrical insulation properties, and no toxic substances are produced when burning. Therefore, it has become an irreplaceable material in the production design of health products, automobiles, baby products, medical products, diving products, kitchen utensils and seals.

3. Extrusion

Extrusion molding, extruded silicone products are usually formed by extruding silica gel through an extrusion machine. Generally , the shape of the silicone extrusion is long, and the tubular shape can be cut at will. The shape of the extruded products is relatively simple, mostly strip. Silicone tubes are widely used in the fields of medical and mechanical equipment. It can also be used as a buffer in the packaging material.

4. Calendering

The silicone rubber is kneaded and kneaded by adding silica, silicone oil, etc. to make a mixed rubber, and then the sheet is calendered. The film produced by calendering has obvious difference in physical and mechanical properties in the longitudinal direction and the transverse direction. This phenomenon is called the calendering effect. The specific performance is that the longitudinal tensile strength of the film is greater than the transverse direction, the transverse elongation at break of the film is greater than the longitudinal direction, and the longitudinal shrinkage rate of the film is greater than the transverse direction. The calendering effect is the result of the orientation of macromolecules and needle-like and flake-like compounds in the rubber compound along the calendering direction during the calendering process. The size of the calendering effect is related to the composition of the rubber compound, the calendering temperature, the speed, and the speed ratio. For larger products, such as silicone sheets, silicone plates.

5. Perfusion

The operation method of filling or pouring mold: pouring mold or pouring mold is used for relatively smooth or simple products, no mold line saves manpower and time, i.e. the product or model you want to reproduce is surrounded by rubber or glass plates, through vacuum pump The outgoing silica gel is poured directly into the product. After the silica gel is dried and formed, the product is taken out to form a mold (Note: The perfusion mold is generally made of silica gel with relatively soft hardness, so that it is easier to demould and will not damage the products in the silicone mold). It belongs to solid-liquid combination and is used in mobile phone sets, luggage sets and other products.

6. Coating

Fast vulcanization; strong adhesion; good fluidity and easy defoaming. The catalyst of platinum complex is non-toxic and tasteless, and has good air permeability, heat resistance and certain tensile strength after molding (use temperature -60℃～200℃). Excellent non-slip properties; no pollution; low hardness; strong adhesion. High tear; high transparency; good tensile properties. Wear resistance, washing resistance, high temperature resistance; high three-dimensional level, smooth, soft, good elasticity. Resistant to water washing and dry cleaning. Suitable for fabrics, with anti-aging effect, such as silicone gloves, rain boots, etc.