LSR injection. HTV compression. Medical + food grade.

LSR: fast cycle (30-90 seconds), best for high-volume small parts, expensive tooling ($15,000-50,000). HTV: slower cycle (2-10 minutes), cheaper tooling ($3,000-15,000), better for lower volumes or larger parts. Break-even: around 5,000-10,000 parts annually. For medical devices with FDA registration, LSR is increasingly standard (better process control, more consistent). For consumer and industrial silicone, either works.

USP Class VI: biocompatibility standard for medical devices. ISO 10993: broader international biocompatibility. Specific requirements: post-cure process to eliminate volatiles (essential for implantables), material traceability from approved suppliers (NuSil, Shin-Etsu, Wacker), documented manufacturing controls. Medical silicone tooling must be isolated from industrial — we maintain separate mold programs for medical work.

FDA 21 CFR 177.2600 covers silicone for food contact. Platinum-cured silicone (vs peroxide-cured) preferred — no peroxide residuals. Post-cure required to drive off volatiles. Approved color additives only. Regular testing for extractables. For food-contact applications, specify platinum-cured, post-cured silicone with documentation.

Silicone overmolds well onto specific substrate materials: PBT, PET, some polyamides (with primer). Requires specific LSR grades formulated for adhesion. Metal overmolding: brass, aluminum, stainless — all possible with appropriate primer. For overmolding where silicone must bond permanently, use specific chemistry. Not all silicones and substrates compatible — test bond strength before committing to production.

Silicone can be pigmented to any custom color. Black is standard (carbon-filled). Red, blue, green, yellow, clear translucent — all standard. Custom Pantone colors possible with dedicated pigment blending. Medical grades available in standard colors; custom medical colors require additional biocompatibility testing.

LSR tooling: 6-10 weeks. HTV tooling: 4-8 weeks. First article production: 1-2 weeks after tool. Ongoing production delivery: 1-4 weeks per order depending on volume. Rush programs: aluminum rapid tooling available (tool in 3 weeks, higher production cost per part). For very urgent programs, silicone casting from master pattern (2-3 weeks) bridges to production tooling.