What are the common molding processes in silicone products?
When exploring the common molding processes in silicone products, we have to delve into the unique physical and chemical properties of this material, as well as how it can be transformed into various forms and functional products through different processing methods. Silicone, as a highly elastic, high-temperature resistant, and aging resistant material, is widely used in various aspects such as daily life, industrial production, and medical fields.
1、 Molding
Compression molding is the most common and fundamental process in the production of silicone products. The core of this process lies in the use of molds, and the shape of the molds directly determines the shape of the final product. In the molding process, the solid silicone raw material with added vulcanizing agent needs to be placed into a high-temperature mold first, and then pressure is applied through a vulcanizing machine to vulcanize the silicone raw material into a solid state at high temperature. The hardness range of molded silicone is usually between 30 ° C and 70 ° C, and can be adjusted according to specific needs. This process is simple to operate and suitable for the production of various silicone products, such as silicone tableware, silicone gaskets, etc.
2、 Injection molding
The injection molding process has higher quality requirements. It combines the advantages of liquid silicone and plastic, making the product have excellent thermal stability, cold resistance, excellent electrical insulation performance, and will not produce toxic substances during combustion. This characteristic makes injection molded silicone products occupy an irreplaceable position in fields such as health products, automobiles, baby products, medical supplies, diving products, kitchen utensils, and seals. Injection molding involves injecting liquid silicone into a mold under high temperature and pressure, rapidly cooling it to form a product with high precision and smoothness.
3、 Extrusion molding
Extrusion molding is the process of using a silicone extruder to extrude silicone raw materials into shape. This process is commonly used to produce tubular silicone products with longer shapes that can be cut freely, such as silicone tubes, silicone strips, etc. The extrusion molding process is relatively simple, but has high production efficiency and is suitable for large-scale production. Silicone tubing has a wide range of applications in medical and mechanical equipment fields, such as infusion tubes, urinary catheters, etc. It is also used in packaging materials to serve as a buffer.
The molding process of silicone products
4、 Rolling forming
Rolling molding is the process of mixing silicone rubber with white carbon black, silicone oil, and other materials to create a mixed rubber, which is then rolled out into a sheet of a certain thickness using a rolling machine. The rolling effect is related to factors such as the composition of the compound, rolling temperature, and speed ratio, resulting in significant differences in the longitudinal and transverse physical and mechanical properties of the sheet. This process is suitable for producing larger products such as silicone film, silicone board, etc. They have excellent flexibility and elasticity, and are widely used in the production of soft silicone products such as silicone gloves and silicone foot pads.
5、 Pouring or casting mold forming
Pouring or casting molding is a process used to produce relatively smooth or simple products. This process involves pouring the silicone extracted from the vacuum pump directly into a model or product surrounded by a rubber or glass plate. After the silicone is dried and formed, it is removed to complete the mold production. This process is labor-saving and time-saving, and does not require mold lines, making it suitable for the production of products such as phone cases and luggage cases. The injection mold is generally made of silicone with relatively soft hardness to facilitate demolding without damaging the product.
6、 Other special molding processes
In addition to the common molding processes mentioned above, the production of silicone products also involves some special processes, such as hot pressing, vacuum molding, and drip molding. Hot pressing molding uses high-temperature heating and pressure to shape silicone raw materials, suitable for producing products with high density and strength requirements, such as silicone tableware, silicone milk bottles, etc. Vacuum forming is the process of applying silicone raw materials onto a mold and shaping it through vacuum forming, which can produce products with complex shapes and high surface smoothness. Drip molding is the process of dropping heated and melted silicone raw materials into a mold and forming them through cooling. It is suitable for making small silicone products, such as silicone pendants and silicone jewelry.
silicone injection molding
