How is liquid silicone molded?

We often hear customers ask if we have injection molded silicone, and we have liquid silicone. However, there is no liquid silicone that can be injection molded, only injection molded.

Thermoplasticity refers to the process of plasticizing a material into a liquid at high temperatures, allowing it to flow, which in turn facilitates molding. When it returns to room temperature, it becomes a solid again. If it is heated again, it can be plasticized, so it can be recycled repeatedly. This category of products mainly includes PVC, PE, ABS and other plastics. "Thermosetting refers to the transformation of a material from a liquid or paste crop into a solid at high temperatures, and its retention as a solid at low temperatures. At high temperatures, it will not become a liquid or paste, but will remain in its original solid state.". "Until high temperatures damage the structure of the product, causing it to undergo chemical reactions and decompose into other objects, materials such as rubber epoxy resins are thermosetting materials.".

The injection molded liquid silicone rubber itself is liquid or paste shaped, and its main components include vinyl silicone oil and hydrogen-containing silicone oil white carbon black, catalysts, retarders, and other materials. Under the action of the catalyst at high temperatures, the liquid silicone rubber undergoes a chemical cross-linking reaction and is solidified into silicone rubber. This is a chemical reaction that is irreversible.

Due to the reaction of liquid silicone rubber at high temperatures, the flow path system of its injection molding equipment requires the use of cold flow paths, which is the main difference from injection molding equipment. Due to the fact that the injection molding machine is a hot runner, liquid silicone rubber will solidify in the runner, so it is not possible to use the injection molding machine to process liquid silicone rubber.