Simply put, liquid silicone is a form, and rubber silicone is a state. A more accurate comparison should be "liquid silicone" and "solid silicone (or high-temperature vulcanized silicone)."
1. Liquid Silicone Rubber
Liquid Silicone Rubber (LSR) is a two-component silicone rubber in liquid form (component A is a silicone base material + catalyst, and component B is a silicone base material + inhibitor). It is fluid at room temperature. Components A and B are mixed in a precise ratio using a dedicated injection molding machine, injected into a mold, and rapidly solidified within the heated mold cavity.
Features:
Environmentally friendly and non-toxic: Typically vulcanized with a platinum catalyst, it is odorless and non-toxic, meeting FDA, LFGB, and other food-grade and medical standards.
High transparency: Easily create products with high transparency and gloss.
High design freedom: Products with complex structures, undercuts, or embedded components can be molded in one go.
No secondary processing required: Virtually no flash is left after molding, eliminating the need for trimming.
Typical Applications:
Medical: Respiratory masks, pacifiers, endotracheal tubes, prostheses, etc.
Food: Laminating of cake molds, ice trays, spoons, and spatula handles.
Consumer Electronics: Soft rubber components of mobile phone cases, watch straps, and headphone covers.
Automotive: High-precision seals and cable connectors.
2. Solid Silicone (Rubber Silicone)
The "silicone products" we often refer to in our daily lives mostly refer to solid silicone (High Consistency Rubber, HCR). This material exists as a high-viscosity solid colloid. After mixing with vulcanizing agents, masterbatches, and other additives in a mixer, it becomes a green sheet material (hence the name "rubber compound"). The sheet is cut, placed into a mold, and then pressed into shape in a flat-plate vulcanizer under high temperature and high pressure.
Features:
Excellent physical properties: Typically offers improved tensile strength, tear strength, and abrasion resistance, making it more durable.
Cost-effective: For products with simple shapes and high demand, the unit cost is advantageous.
Requires secondary processing: After compression molding, the product will have a parting line (flash), which requires manual tearing or trimming.
Typical Applications:
Kitchen Utensils: Silicone spatulas, steamer mats, potholders, dishes.
Daily Uses: Various silicone wristbands, keychains, cutting boards.
Industrial Parts: Sealing rings, gaskets, shock absorbers.
Electronic Products: Keyboard keys, remote control buttons (early versions).
How can you easily distinguish them?
Look at the production process: If it's injected and molded like plastic, it's usually liquid silicone. If it's cut into a piece and inserted into a mold and pressed, it's solid silicone.
Look at product performance: Products that require extreme clarity, food or medical contact, or are very flexible are often liquid silicone. Products that require extreme wear and tear resistance (such as silicone spatulas) are often solid silicone.
Smell (new products): New solid silicone products sometimes have a slight odor (from the peroxide curing agent), while platinum-cured liquid silicone is completely odorless.
If you need...
Liquid Silicone Rubber (LSR) for high transparency, high precision, medical and food grade, and complex structures
Select...
Hydraulic Silicone Rubber (HCR) for high strength, high wear resistance, durability, cost-sensitive applications, and simple structures
