The unique synthetic elastomer known as silicone rubber is created from a cross-linked polymer that has silica added as reinforcement. Silicone rubber provides stability at both high and low temperatures, transparency and ease of coloring, a wide range of hardness, and a high level of sealing performance.
The silicone rubber mold manufacturing process uses soft tooling and an indirect mold-making procedure. These molds’ materials silicone rubber, epoxy resin, etc. Extruding molding, compression molding, transfer molding, and liquid injection molding are the four fundamental silicon rubber molding techniques.
The most common method of silicon rubber molding is liquid injection molding. You can use the 3ERP silicone rubber molding service because it can provide you with experienced engineers, affordable durability, and fast delivery service. To produce the most exact molding at the lowest feasible cost, 3ERP uses foreign and top-brand domestic injection molds.
What Are The Different Properties Of A Silicone Rubber Mold?
In addition to having exceptional electrical qualities and good chemical resistance, silicone rubber can be used at temperatures between -50°C and +200°C. Additionally, it is translucent and easily colored or can be resisted at high and low temperatures, in the sun, and aging. They have a uniform and fast mold setup.
Because of their beneficial qualities, including high and low-temperature stability, inertness (no smell or taste), low toxicity, color ability, and transparency, combined with good electrical properties, they are increasingly being utilized to replace organic rubbers. From 10-80 Shore A, the hardness range is broad (WP, 2006).
Methods Used For Silicon Rubber Molding
Liquid Injection Molding Of Silicon
This procedure commonly involves co-molding or over-molding an LSR after injection molding a thermoplastic substance like PBT or nylon. LSR is heated to between 160°C and 200°C and then vulcanized using three primary components: an injection molding machine, a metering/mixing system, and a mold created specifically to hold the material. The majority of LSR injection molding equipment utilizes a reciprocating screw injection unit.
Compression of Silicon Molding
A preform is positioned on one half of a heated mold during compression molding. Rubber is pressed into every portion of the mold cavity when the mold is closed and put under pressure in a press. Excess rubber runs into a flash groove around the mold cavity. You should apply enough pressure to get a fast enough flow of rubber into the mold.
Transfer of Silicon Molding
In transfer molding, the assembly is put in a press after the vulcanized rubber is deposited in a chamber (referred to as a pot), typically at the top of the mold. In order to clamp the mold’s two halves together and force the rubber to flow through one or more sprees and into the heated mold, the press exerts pressure on a piston-like plug in the open end of the pot.
Extrusion of Silicon Molding
By applying pressure to a formed aperture, silicone rubber is forced through to create molds. Before curing, the rubber is constantly pushed through a die to give it the correct cross-sectional size and shape. The extrusion of silicone rubber is best done at room temperature. In fact, the temperature shouldn’t be allowed to rise above 54°C while extruding because greater temperatures may result in the loss of the vulcanizing ingredient.
Calendaring of silicon rubber
By passing a sheet over two sets of heated wheels, a material is compressed and squeezed during the calendaring process. Calendars are the name for these sets of hard steel, double or multiple rolls. They are pressure-adjusted to make silicone rubber with a preset and consistent thickness, surface finish, and texture that might be shiny, matte, smooth, adherent, embossed, etc.
Conclusion
Silicone is excellent for custom-molded shapes and particular applications with particular requirements since it is simple to customize and mold. Different methods of molding silicon rubber are available on the market. The most common method of silicon rubber molding is liquid injection molding. The best services for molding silicon rubber are offered on the 3ERP website.
