Liquid silicone rubber (LSR) is a two-part, platinum addition-cured elastomer that can be injection molded for clean and consistent parts. It is used in a huge range of products from medical devices and infant items like bottle nipples to kitchen goods such as silicone baking pans and rubber spatulas.
It is highly durable and resists temperatures from minus 60 degrees Celsius to 180 degrees Celsius. It is also biocompatible, which makes it ideal for components that come into contact with the skin.
Liquid silicone rubber has a variety of key material properties that make it a great choice for products in the medical, baby, and consumer product industries. These include fast curing, low compression set, and chemical resistance.
Like other elastomeric materials, liquid silicone rubber must undergo a polymerization reaction to form molecular chains, which gives it its strength and flexibility. During this process, long polysiloxane backbones are cross-linked with peroxide and platinum catalysts.
This process creates a shear thinning fluid that can be injected into a mold to create finished parts. This allows designers to achieve the intricate shapes they want. Injection molding is also quick and easy, making it an ideal manufacturing process for high volume production.
Low compression set
Compression set is the decrease in thickness of a rubber after prolonged pressure stress at specific deflections and temperatures. It’s typically measured as a percentage and is tested to ASTM D395 Method B.
While the compression set values listed on elastomer datasheets are helpful, they do not fully capture the performance of a material in real life. For example, a gasket material’s compression set resistance also depends on its heat resistance and stress relaxation properties. Silicone and silicone foam and sponge are very resistant to heat and have good stress relaxation, making them a great choice for custom gasket manufacturing. Contact us for more information about selecting the right gasket material for your application.
Liquid silicone rubber (LSR) is a two-part, platinum-cured elastomer that can be injection molded into a heated mold. It offers low compression set and good stability compared to thermoplastic elastomers.
Its durability and ability to withstand high temperatures make it ideal for use in electrical insulation, voltage line insulators, automotive applications, and outdoor environments. It is also resistant to chemical solutions and can be sterilized using steam autoclaving, ethylene oxide, gamma radiation, or E-beam.
A conductive agent can be added to the formulation to provide EMI/RFI shielding. This can reduce static on the part and allow for better adhesion to glass filled nylons, stainless steel and aluminum.
Liquid silicone rubber is able to resist extreme temperatures without degrading, making it an ideal material for components that will be exposed to heat or outdoor conditions. Like all elastomers, molded silicone resists water and oxidation and can be sterilized with steam autoclaving, ethylene oxide (ETO), gamma and e-beam techniques.
In addition to its strength and durability, liquid silicone can also be made electrically conductive with the introduction of carbon or other conductive materials as powdered fillers. This property makes it a useful material for products such as voltage line insulators. In fact, it can be used across multiple industries to create a variety of finished products.
Liquid silicone rubber is resistant to a wide range of chemicals, including automotive and household products. It also resists corrosion and is not affected by extreme temperatures, making it a good choice for insulating applications.
LSR is inherently translucent and can be pigmented for a variety of colors. Its low viscosity allows it to flow easily during injection molding. This reduces cycle times and the amount of raw material handling, resulting in lower production costs.
In addition, most ELASTOSIL grades from Wacker can be over-molded with engineering plastics and metal to create a diverse set of finished products. To discover how liquid silicone can enhance your product, contact a H.M. Royal product expert today.
LSRs have higher electrical insulation properties than other elastomeric materials, even when subject to high-temperature conditions. This makes them an excellent material for insulators and parts that need to resist corona discharge.
LSR can be molded and cured in a wide variety of molds. This flexibility allows for complex shapes and accurate dimensions. It also supports short cycle time injection and trim-free manufacturing processes.
LSR can be molded into electrical and electronic devices. Its electrical properties are unaffected by temperature, so it is a great choice for applications in areas that have strict fire safety standards. It is also a good option for medical implants that will undergo mechanical motion.