HTV high-temperature vulcanized silicone rubber is a type of organic silicon product that has excellent resistance to high and low temperatures, UV rays, radiation, weather, electrical insulation, high breathability, physiological inertness, low compression permanent deformation, and fatigue resistance. Therefore, HTV high-temperature vulcanized silicone rubber is widely used in aviation, aerospace, electronic and electrical, light industry, machinery, construction, chemical, medical, daily necessities, and other fields, Below, we will provide a detailed explanation of three molding processes for high-temperature vulcanized silicone rubber.

According to the current types of high-temperature silicone rubber on the market, one is solid silicone and the other is liquid silicone. The molding of solid silicone can be divided into compression molding and extrusion molding, while liquid silicone is mostly injection molding.

1、 Molding
Mold pressing, also known as hot pressing, is the process of placing a mixture of silicone vulcanizing agents (Double 25 or Double 24) into a high-temperature mold and applying pressure through a flat vulcanizing machine to achieve high-temperature vulcanization.

The molding process is the production process of solid silicone, which uses a combination of upper and lower modules with a mold core placed in the middle, hence it is called molded silicone rubber. The main production process of molded silicone rubber products is the silicone processing process in which silicone rubber raw materials are formed into products through heating and pressure in the closed mold cavity. Usually, the raw materials are evenly stirred into a mixed rubber through a mixer, and the mold is then moved into a 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 processing thermosetting materials.

The hardness of molded silicone is usually between 30-70A (Shore hardness). In the process of producing mixed rubber in the silicone factory, the first step is to add raw rubber to a double roll rubber mixer or a closed kneading machine, gradually adding white carbon black, silicone oil, and other additives to repeatedly refine it. The performance of silicone varies depending on the added fillers and additives.

This process is relatively low-cost, high-yield, and widely used. It is mostly used for monochromatic silicone products. It can also be applied to dual color dual hardness products or multi color multi hardness products, but the structure of the product is not flexible and limited. It can also be applied to plastic and metal wrapping, but it is also structurally inflexible and has temperature requirements for the wrapped object. Generally, the wrapped object is required to withstand 180 degrees Celsius without deformation.

The shape of the molding process determines the shape of the molded silicone product, which is currently the most widely used type in the silicone industry. Mainly used for silicone industrial accessories, buttons, silicone gifts, silicone wristbands, silicone watches, keycases, phone cases, silicone kitchenware, silicone pads, ice grids, cake molds, and so on.

2、 Extrusion molding
Extrusion molding is like squeezing toothpaste, and the extruder head is also the cross-sectional shape of the product, with a certain length. Under the action of force and temperature, the product produced by the extruder head has been vulcanized and formed. The products formed by this process are generally rectangular products, and the product cross-sections can be various. For example, rectangular strips, circular silicon tubes, etc.

Extruded silicone products are usually formed by extruding silicone using an extrusion machine, which is a continuous molding process suitable for the production and processing of solid silicone or platinum sulfide catalyzed liquid silicone. It is a process in which silicone rubber is continuously produced into various shapes of semi-finished products through the interaction of the silicone extruder barrel and rotating screws. It can be used to process silicone tubes, insulation sleeves for silicone wires and cables, and other silicone products.

3、 Injection molding
The equipment required for injection molding process includes a silicone injection machine and a pressing machine. Its raw materials are two-component liquid viscous. Its principle is to use a press to mix the raw materials of components A and B in a 1:1 ratio into the material barrel of the injection machine, and then mix them thoroughly through a static mixer. After injection into the injection tube, it is then produced by injection molding.. This process has a relatively low molding temperature, which is 130 degrees Celsius. It can be used for plastic encapsulation molding that is not very heat-resistant, which has advantages over solid-state hot pressing molding.

Liquid silicone machines are widely used in the fields of pharmaceuticals, food, silicone pacifiers, baby products, diving products, electrical insulation accessories, cable accessories, and other liquid silicone products.

The above three are common molding processes for high-temperature vulcanized silicone rubber.