Manufacturing Capabilities
LSR Injection Molding Services
Liquid Silicone Rubber (LSR) injection molding delivers high-precision, flash-free silicone parts at high volume. The gold standard for medical, infant care, and food-contact applications.
What Is LSR Injection Molding?
LSR (Liquid Silicone Rubber) is a two-part, platinum-cured silicone that is injected into a heated mold via a precision metering pump and static mixer. Unlike solid HTV silicone compression molding, LSR injection produces parts with near-zero flash and excellent dimensional stability.
LSR can achieve tight tolerances (±0.05 mm on small features), fill complex thin-wall geometries (down to 0.3 mm), and is the preferred material for medical, infant care, and cleanroom-sensitive applications due to its purity and platinum-cure chemistry.
Our LSR Process
Two-part LSR (A+B) stored in temperature-controlled drums. Pigments or functional additives dosed automatically via metering unit.
Mixed LSR injected into heated mold (150–200°C). Cycle time typically 30–120 seconds depending on part size and wall thickness.
Addition cure mechanism completes inside the mold. No byproducts, no post-cure required for most grades. Biocompatible from the start.
Robotic take-out or air ejection minimizes part handling. Critical for medical and infant-grade parts requiring minimal contamination.
100% visual inspection + dimensional checks. Cleanroom packaging (Class 7 / ISO 14644-1) available for medical and food-contact applications.
Technical Specifications
| Parameter | Capability |
|---|---|
| Shot Size (Max) | ~500 g per shot |
| Part Weight Range | 0.01 g – 200 g |
| Shore A Hardness | 10 – 80 Shore A |
| Dimensional Tolerance | ±0.05 – 0.15 mm |
| Mold Cavitation | 1 – 64 cavities |
| Cleanroom Class | ISO Class 7 (ISO 14644-1) available |
| Certifications | FDA 21 CFR 177.2600 · USP Class VI · ISO 10993 · LFGB · RoHS |
Typical Applications
Catheters, valve membranes, wearable sensor seals, respiratory mask components.
Baby bottle nipples, pacifiers, teething toys. FDA / LFGB compliant as standard.
Bakeware, food-contact gaskets, spatulas, beverage machine seals.
Waterproof seals (IP67/68), smartwatch straps, connector seals, wearable device interfaces.
EV battery seals, LED lighting gaskets, sensor connectors.
LSR vs. Compression Molding — Which to Choose?
| Factor | LSR Injection | Compression Molding |
|---|---|---|
| Flash | Near zero | Requires deflashing |
| Tolerance | ±0.05–0.15 mm | ±0.15–0.30 mm |
| Tooling Cost | Higher | Lower |
| Volume Suitability | High (10K+) | Low–medium |
| Cleanroom Suitability | Excellent | Limited |
DFM Considerations for LSR
- Wall Thickness: Uniform 0.5–3 mm. Avoid >5 mm (air traps) or <0.3 mm (incomplete fill).
- Draft Angle: 1–2° typically sufficient. Textured surfaces may require 3–5°.
- Undercuts: Soft LSR can snap-out small undercuts (<0.5 mm). Side-actions increase tooling cost 30–50%.
- Parting Line: Communicate critical surfaces early — avoid parting line on sealing edges or optical surfaces.
- Shrink Rate: LSR shrinks 2–4% (higher than HTV). Mold must be machined larger to compensate.
Need High-Precision LSR Parts?
Upload your CAD file or drawing. Our engineers will review and respond within 24 hours.