Liquid Silicone Rubber (LSR) Molding

Liquid Silicone Rubber (LSR) Molding Services in Canada

Liquid silicone rubber (LSR) molding is the precision process for producing silicone parts at scale. Two-component liquid silicone is metered, mixed, and injected into a heated mold where it cross-links into a finished elastomer part. LSR delivers the unique properties of silicone — biocompatibility, food safety, wide temperature range, chemical resistance, and consistent flexibility — in production quantities and tight tolerances. Canadian LSR capacity supports medical devices, infant care products, food and beverage equipment, and automotive sealing applications.

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Liquid Silicone Rubber (LSR) Molding in Canada

LSR molding is the production process for silicone parts that need to be precise, biocompatible, food-safe, and produced in quantity. The two-part liquid silicone material is metered, mixed inline, and injected into a heated mold where it cross-links from liquid to solid in seconds. The result: production-grade silicone parts with the geometric precision of injection molding and the unique properties of silicone elastomer.

Where LSR Wins

Medical devices. Surgical valves, respiratory components, infusion-pump seals, baby pacifiers and bottle nipples, dental aligners, hearing aid earpieces. USP Class VI-certified LSR enables Class II and III medical devices.

Food and beverage. Bakeware, kitchen utensils, ice molds, beverage seals, infant feeding bottles, baby pacifiers. FDA-compliant LSR is widely used in Canadian and US-bound food contact applications.

Automotive sealing. Wire harness seals, sensor housings, ignition components, and high-temperature gasket applications where conventional rubber would fail.

Consumer electronics. Waterproofing seals, button overlays, tactile interfaces, and integrated gaskets in connected devices.

Why LSR vs. Compression-Molded Silicone

FactorLSRCompression
ToleranceTighterLooser
Surface finishExcellentVariable
Cycle timeFast (seconds)Slow (minutes)
Tooling costHigherLower
Volume sweet spotHighLow

LSR wins for production. Compression remains useful for prototypes, very large parts, and very low volumes.

Canadian LSR Network

LSR capacity in Canada is densest in Quebec and Ontario, with ISO 13485-certified medical LSR molders supporting orthopedic, surgical, and dental customers. Food-grade and consumer-product LSR capacity supports kitchenware brands and infant-care manufacturers across the country.

Specifications

Liquid Silicone Rubber (LSR) Molding at a Glance

Certifications
  • ISO 9001:2015
  • ISO 13485 (Medical)
  • USP Class VI (Biocompatibility)
  • FDA Title 21 CFR 177.2600 (Food Contact)
  • IATF 16949 (Automotive)
Tolerances
Standard
+/- 0.1 mm
Precision
+/- 0.05 mm
Lead Times
Prototype
6–10 weeks (with tooling)
Production
3–5 weeks (after tooling)
Network
Closed Beta

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Available Materials

Standard LSR (Shore A 30–70) Medical-Grade LSR (USP Class VI) Food-Grade LSR (FDA-Compliant) High-Temperature LSR (up to 250°C) Optical-Grade LSR (Transparent) Self-Lubricating LSR Conductive / Antistatic LSR

Industries We Serve

Medical Devices
Infant Care & Baby Products
Food & Beverage
Automotive (Sealing)
Consumer Electronics
Industrial (Gaskets & Seals)

Frequently Asked Questions

How is LSR different from compression-molded silicone?
LSR is injected into a heated mold under pressure, producing parts with tighter tolerances, faster cycles, and better surface finish than compression molding. Compression molding remains common for very large parts or low volumes where tooling cost is hard to justify. For production-volume medical, food, and consumer silicone, LSR is the standard.
Is LSR biocompatible and food-safe?
Specific grades are. USP Class VI-certified LSR is biocompatible for implantable and skin-contact medical devices. FDA-compliant LSR (Title 21 CFR 177.2600) is food-safe for cooking and food-storage applications. Health Canada follows similar frameworks. Always specify the certification grade required for your end use.
Can LSR be overmolded onto plastic substrates?
Yes — LSR-on-plastic overmolding is common for medical valves, sealing interfaces on plastic enclosures, and integrated soft-touch components. Self-bonding LSR grades chemically bond to specific plastic substrates (PA, PBT, PC); non-bonding grades require mechanical interlocks. See our [overmolding page](/manufacturing/injection-molding/overmolding/) for the broader topic.
What are typical LSR durometer ranges?
Standard LSR durometers run from Shore A 5 (very soft, like a gel) to Shore A 80 (firm rubber). Most medical and consumer parts fall between Shore A 30 (soft seal) and Shore A 60 (firm gasket). LSR's durometer is set by formulation, not post-cure, so durometer is selected at material specification.

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