Liquid pumped. Gum compressed. Different volumes.

LSR tool: $15-50K. HTV tool: $3-15K. Tool cost difference ~$12-35K. Per-part LSR cost is lower (faster cycle, less labor, less waste). Typical breakeven: 5,000-15,000 parts depending on part complexity. Below: HTV wins. Above: LSR wins. For production programs expecting 50,000+ parts lifetime, LSR is nearly always right. For ≤5,000 parts, HTV usually right.

LSR: liquid is pre-mixed, injected into hot mold (160-200°C), cures rapidly (seconds). Small parts cycle 30-45 sec total. HTV: gum stock placed in mold, pressure applied, cure requires 2-5 minutes at temperature for crosslinking. Opening mold, removing part, cleaning, loading next takes additional 30-60 sec. Total cycle 3-10 min per part. For volume production, LSR efficiency advantage compounds.

LSR injection molding: precision comparable to thermoplastic injection. ±0.05mm on critical features, ±0.1-0.15mm overall. Consistent cavity-to-cavity in multi-cavity tools. HTV: ±0.15mm typical, can have more variation between parts. For precision parts (medical device seals, precision gaskets): LSR preferred. For general rubber parts where ±0.2mm is acceptable: HTV works.

Both available in medical grade (USP Class VI, ISO 10993). LSR preferred for medical volume production because of: automated processing, reduced handling contamination, consistent part quality, compatible with medical device quality systems. HTV medical grade available for lower-volume or larger specialty parts. Most newer medical silicone parts: LSR.

Yes — both processes support overmolding onto rigid substrates. LSR 2K molding: plastic first, silicone second in same machine. HTV insert molding: place pre-molded plastic in silicone mold. LSR overmolding is more automated and consistent; HTV is lower-volume option. For overmolded products, process choice depends on volume and precision needs.

LSR: tool fabrication 6-10 weeks. HTV: tool fabrication 4-6 weeks. Both: first-article production 1-2 weeks after tool. Overall programs: LSR 8-12 weeks from design to first production, HTV 6-10 weeks. HTV slightly faster for tool, LSR slightly faster for production.