LSR silicone injection molding — medical, food, electrical.

TPE and LSR look similar but serve different applications:

• Temperature: TPE maxes around 130 °C. LSR handles 200 °C continuous.
• Biocompatibility: Most TPE grades aren't medical-certified. LSR has long-established USP Class VI and ISO 10993 grades.
• Long-term durability: LSR is chemically stable for decades. TPE degrades faster under UV and heat.
• Chemistry resistance: LSR survives autoclaving, steam sterilization, acids, bases. TPE limited.
• Cost: LSR tooling and parts are 2–4× more expensive than TPE.

Rule of thumb: if the application is medical, long-life outdoor, or high-temperature, choose LSR. Otherwise TPE is cheaper and simpler.

LSR molding requires dedicated tooling — not compatible with thermoplastic tools:

• Cold runner system. LSR cures at mold temperature; runners must stay cool to prevent cure in the runner. Adds 15–25% to tooling cost.
• Heated mold. Mold held at 150–200 °C to cure the injected LSR.
• Vacuum venting. LSR releases hydrogen gas during cure. Trapped gas creates voids.
• Polished cavities. LSR replicates surface finish precisely. A2 or A1 polish standard for cosmetic parts.

Typical LSR prototype tool: $5,000–$12,000. Production: $15,000–$40,000.