Liquid silicone injection molding uses a two-component liquid silicone rubber (LSR) system. The components are metered, mixed and injected into a heated mold, where chemical crosslinking produces a solid elastomer.
LSR is thermosetting: it cures rather than solidifying by cooling a thermoplastic melt. Temperature control in the feed and injection system helps prevent premature curing before the material reaches the heated mold. Processing conditions must follow the material supplier’s instructions for the selected grade.
Key Comparisons with Traditional Compression Molding
1. Material feeding: Compression molding commonly starts with a preformed piece of high-consistency silicone rubber (HCR) placed in an open mold. The mold closes under pressure and the material cures before demolding. This differs from injecting a metered liquid material into a closed cavity.
2. Production comparison: LSR injection molding supports automated dosing and injection. Compression molding uses different material preparation and loading arrangements. Compare cycle time, labor, tooling cost and material use for the actual part, compound, cavity count and production volume; a universal cost or speed advantage should not be assumed.
3. Process control: Automation does not eliminate defects. For LSR, assess dosing and mixing, mold temperature, filling, venting and flash control during process qualification. Vacuum assistance, where required, is a tooling and process decision rather than a guarantee of defect-free production.
To discuss a suitable setup with MINHUI, provide the silicone grade, part drawing and weight, mold dimensions, cavity count, expected output and automation requirements. Confirm equipment compatibility and sample results for your application before making a purchasing decision.
