<aside> 🔖 Discover what liquid silicone rubber (LSR) is, how it works, key properties, and types. Also, learn why injection molding outperforms other elastomers.
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Liquid silicone rubber (LSR) is a two-component thermoplastic elastomer that combines a base with a platinum-cured curing agent.
Think of it as a recipe with two ingredients that, when mixed, create a clear, strong, flexible rubber. It's commonly used in injection molding and sealing applications.
XYZ company injection molds LSR components in a Class 1000 cleanroom, producing parts that meet Production Part Approval Process (PPAP) standards for automotive, aerospace, and healthcare applications.
LSR is surprisingly simple: silicone (made from silicon, the same element you'll find at the beach) and platinum (yes, the expensive metal, but used as a catalyst here).
Mix them together and you get a thick liquid that can be molded into virtually any shape. Once it cures, you have flexible, durable rubber.
The material comes in different hardness levels, from squishy to firm, and handles temperatures from -155°F to 392°F. That's cold enough to survive an Arctic winter and hot enough to withstand your car engine on a summer day.
It's also resistant to oils, chemicals, and UV light while keeping its shape under pressure and heat.
LSR's structure is similar to other silicones you might know, like polydimethylsiloxane (PDMS).
The key difference? LSR gets its strength from specially treated silica added to long polysiloxane chains. The methyl-hydrogen siloxane acts as the glue holding everything together, while platinum makes sure the curing process actually works. Without platinum, you'd just have expensive goo.
Temperature Range: Functions between -155°F and 392°F. While other thermoplastic elastomers get brittle and crack in the cold, LSR stays flexible.
Chemical Resistance: Maintains its integrity when exposed to chemicals at extreme temperatures. Other thermoplastic elastomers can only handle chemicals in comfortable, room-temperature situations. LSR is tougher.
Environmental Durability: Resists UV damage and environmental wear, which means it won't fall apart after a few months in the sun. Great for outdoor applications and manufacturing processes that need consistency.
Precision Molding: The low viscosity (thickness) means LSR flows into thin walls and complicated shapes without throwing a fit. It fills every nook and cranny while staying consistently firm.