Liquid Silicone Rubber (LSR) Injection Molding — Medical, Automotive & Electronics
SSP Precision delivers fully automated two-component liquid silicone rubber molding with FDA/USP Class VI compliance, ±0.003in dimensional tolerance, and temperature resistance from −70°C to +230°C — shipped from China to over 30 countries with complete ISO documentation.
What Is Liquid Silicone Rubber Injection Molding?
Liquid Silicone Rubber (LSR) injection molding is a highly automated manufacturing process in which two-component platinum-catalyzed silicone (Part A + Part B) is precisely metered, mixed at a 1:1 ratio, and injected into a heated mold — where it vulcanizes in under 30 seconds into a finished elastomeric part.
Unlike thermoplastic injection molding, LSR is processed at room temperature and vulcanizes in a heated mold — the inverse of conventional molding. This enables sub-30-second cycles with zero post-processing, exceptional biocompatibility, and dimensional consistency exceeding ±0.005mm across millions of production cycles.
SSP's Automated LSR Injection Molding Process — 8 Stages
A fully documented, ISO 13485-compliant 8-stage production workflow — from raw material verification through global delivery with complete quality documentation.
Material Verification
Incoming LSR compound lot testing — Shore hardness, viscosity, catalyst ratio, and biocompatibility traceability. Full material COC retained per ISO 13485.
DFM & Mold Design
LSR-specific DFM analysis: parting line, gate type (cold runner preferred), draft angles, vent placement, and mold flow simulation for uniform fill and cure.
Precision Tooling
S136 stainless steel molds for medical-grade LSR — polished to Ra ≤4μin, with conformal cooling and vacuum-vented cavities. Mold rated 1M+ cycles.
2-Component Metering
Precision dosing pumps deliver Part A and Part B at exactly 1:1 ratio (±0.5%) — zero contamination in a fully closed, automated material handling system.
Static Mixing & Injection
Disposable static mixer blends components completely before delivery to a cold runner system. Injection pressures 500–1500 bar with <0.01mm/s velocity control.
Vulcanization (Cure)
Heated mold (150–200°C) platinum-catalyzes rapid vulcanization in 15–30 seconds. Conformal cooling stabilizes shrinkage for dimensional consistency.
CMM Quality Inspection
100% first article dimensional verification by CMM (±5μm resolution). Shore hardness, tensile, tear strength, and biocompatibility testing per ASTM standards.
Certified Global Delivery
ISO 13485 traceability documentation, FAIR reports, COC, MSDS, sterilization validation data — worldwide delivery within committed lead times.
Real LSR Parts. Real Facilities. Real Results.
Click any image to explore detailed specifications, industry applications, and capabilities behind each LSR molding offering at SSP Precision.
LSR Grades & Dimensional Tolerances
SSP Precision processes the complete spectrum of LSR grades — from standard industrial silicones to medical-grade platinum-cure compounds — with documented tolerance compliance across every grade.
LSR Dimensional Tolerances
Shrinkage & Dimensional StabilityLSR exhibits predictable isotropic shrinkage of 2.5–3.5% (grade-dependent). SSP compensates with precision mold geometry and validated process parameters — achieving ±0.005mm dimensional consistency across full production runs, documented on SPC control charts.
LSR Molding Performance Specifications — Standard vs. Medical Grade
Industry-validated performance data for standard and medical/precision LSR grades — all parameters verified by ASTM-standard testing methods with independent laboratory documentation.
| Category | Parameter | Standard LSR Grade | Medical / Precision Grade | Test Method |
|---|---|---|---|---|
| Material | Tensile Strength | 8–12 MPa | 10–15 MPa | ASTM D412 |
| Tear Strength | 25–50 N/mm | 40–60 N/mm | ASTM D624 | |
| Elongation at Break | 400–600% | 600–800% | ASTM D412 | |
| Hardness (Shore A) | 20–70A | 30–80A | ASTM D2240 | |
| Thermal | Operating Temp Range | −60°C to +200°C | −70°C to +230°C | ASTM D1329 |
| Thermal Conductivity | 0.2–0.3 W/mK | 0.15–0.25 W/mK | ASTM E1461 | |
| Compression Set (22h/175°C) | 15–25% | 10–15% | ASTM D395 | |
| Dimensional | Positional Tolerance | ±0.010in | ±0.003in | CMM (5μm) |
| Surface Finish (Ra) | 32–64 μin | 16–32 μin | White Light Interferometry | |
| Min. Wall Thickness | 0.3 mm | 0.15 mm | Micro-CT Scanning | |
| Biocompatibility | FDA/USP Class VI | No | Yes | ISO 10993 |
| Cytotoxicity | — | Pass | USP <87> | |
| Sterilization | Autoclave (121°C) | 100 cycles | 300+ cycles | AAMI ST108 |
| EtO / Gamma / E-beam | Compatible | Validated | ISO 11135 | |
| Electrical | Volume Resistivity | 10¹⁴ Ω·cm | 10¹⁵ Ω·cm | ASTM D257 |
| Dielectric Strength | 18–22 kV/mm | 20–25 kV/mm | ASTM D149 |
Five Technical Advantages of LSR Injection Molding
Each advantage is quantified — SSP Precision provides the measurement data to support every claim in your engineering specification, regulatory submission, or supplier qualification audit.
China's LSR Molding Specialist — Global Standards, China Efficiency
SSP Precision combines 15+ years of LSR manufacturing expertise with ISO 13485-certified quality management, dedicated 2-component automated equipment, and a full metrology lab — delivering documented medical-grade LSR components to clients across 30+ countries.
LSR Injection Molding Applications by Industry
SSP Precision's LSR molding capability serves six primary industry verticals — each with distinct material certification, dimensional accuracy, and regulatory compliance requirements.
Medical Devices
Catheter seals, respiratory masks, implantable-grade components, diagnostic membranes, drug delivery device valves — FDA/USP Class VI, ISO 10993-compliant with full sterilization validation.
Electronics & Connectors
IP67/IP68 sealing gaskets, cable harness grommets, EMI shielding pads, keyboard membranes, and switch actuators — LSR's dimensional stability ensures repeatable seal performance.
Automotive
Under-hood seals (−40°C to +200°C), sensor housings, vibration dampeners, LED headlight optics, HVAC system components — LSR's thermal stability and chemical resistance meet OEM specifications.
Baby & Consumer Products
Infant bottle nipples, pacifiers, breast pump components, food contact seals, cookware — FDA food-contact compliant, BPA-free, phthalate-free, and EN 1400/ASTM F406 tested.
Wearables & Healthcare
Smartwatch skin-contact bands, hearing aid domes, continuous glucose monitor (CGM) patches, and wearable sensor housings — skin-safe, hypoallergenic, dermatologically tested LSR grades.
Optical & Lighting
LED lens arrays, automotive headlight lenses, optical fiber protective coatings — optical-grade transparent LSR with <2% haze, maintained over 10,000 hours UV aging per ISO 4892.
Medical-Grade LSR Made in China. Delivered Worldwide.
SSP Precision's China-based LSR facility combines ISO 13485 quality management with competitive China manufacturing costs — delivering certified medical and precision silicone parts to medical device OEMs, automotive Tier 1 suppliers, and electronics manufacturers in 30+ countries.
Complete Precision Manufacturing Portfolio from SSP
LSR molding is one specialized capability within SSP Precision's complete manufacturing portfolio. Explore our full range — all from one ISO-certified China-based supplier with global delivery.
Injection Molding
Custom thermoplastic molding — ABS, PC, PEEK, POM, and 150+ materials. Overmolding, insert molding, two-shot, and gas-assisted molding from the same ISO-certified facility.
Micro Molding
±5μm tolerance, sub-millimeter features, 0.005cm³ minimum shot volume — ISO 13485 certified micro molding for medical devices, microelectronics, and optical components.
Green Mold
ISO 14001 eco-friendly molding with biodegradable bioplastics (PLA, PHA, Bio-PP), all-electric machinery, and closed-loop recycling — −60% energy vs conventional molding.
Tooling Spare Parts
Precision LSR mold components — S136 stainless inserts, cold runner nozzle tips, ejector pins, and cavity components — rapid replacement to minimize production downtime.
Ready to Source Medical-Grade LSR Molded Parts from China?
Submit your LSR part drawing or specification. SSP Precision's application engineering team responds within 24 hours with material recommendations, DFM feedback, a competitive quote, and — for medical applications — a preliminary biocompatibility compliance summary at no extra charge.