LSR and HCR Silicone Molding
Silicone molding is one of the most dependable ways to produce rubber components that can stand up to extreme temperatures, resist aging, and hold tight tolerances run after run. At Moldtech, we specialize in both liquid silicone rubber (LSR) and high-consistency rubber (HCR) molding, so you get the material and process that fits your part, not a one-size-fits-all solution. Whether you’re developing a new medical device, sourcing parts for an automotive program, or scaling up production for an industrial application, our team is ready to help. Reach out to our team for a quote.
What Is LSR and HCR Silicone Molding?
Liquid silicone rubber and high-consistency rubber are both silicone-based materials, but they behave very differently on the production floor, and that difference shapes how each one is molded.
HCR silicone has been the standard in rubber manufacturing for decades. It performs well across a wide temperature range, from about -50°C to +300°C, and holds up to repeated exposure to heat, chemicals, and aging better than most other elastomers. Because HCR has a higher viscosity, it’s typically processed through compression molding or transfer molding rather than standard injection molding. These methods are more labor-intensive, but they remain the right call for many high-performance parts.
LSR, by contrast, is a platinum-cured, two-part silicone rubber with much lower viscosity. That makes it easy to pump and inject, which is why liquid silicone rubber has become a popular choice for high-volume, tight-tolerance parts. Silicone injection molding with LSR also tends to mean shorter cycle times and more consistent part quality from shot to shot, since the material is metered and mixed automatically rather than worked by hand.
Both materials can be molded into precise, repeatable components, and choosing between them usually comes down to your part geometry, production volume, and end-use environment. Our team can help you weigh those factors before a single tool is cut.
LSR vs. HCR: Which One Is Right for Your Part?
| Trait | LSR (Liquid Silicone Rubber) | HCR (High-Consistency Rubber) |
| Viscosity | Low, flows easily | High, putty-like consistency |
| Typical Process | Silicone injection molding | Compression molding, transfer molding |
| Best For | High-volume runs, complex or tight-tolerance geometry | Large parts, lower volumes, thick cross-sections |
| Cure Method | Platinum-cured, two-part system | Peroxide or platinum-cured |
| Cycle Time | Generally faster | Generally slower |
If you’re not sure which process fits your application, that’s a normal place to start. A lot of our customers come to us with a part drawing and a performance requirement, not a material spec, and we help them work backward from there.
Applications for Silicone Molded Parts
Both LSR and HCR can be molded into tight-tolerance components across a wide range of shapes and functions, including:
- Boots and bellows
- Diaphragms
- Dampers and isolators
- Hoses and tubes
- Seals and gaskets
- Rollers and wheels
- Custom silicone parts built to your specifications
If your application calls for a part that isn’t listed here, reach out anyway. Custom silicone molding is a large part of what we do, and most of our tooling is built around parts that don’t fit a standard catalog.
Industries We Serve
Silicone’s resistance to heat, UV exposure, and chemical breakdown makes it a go-to material well beyond one or two industries. We regularly produce silicone molded parts for:
- Medical: Medical grade silicone is biocompatible and easy to sterilize, which makes it a common choice for seals, tubing, and device components.
- Aerospace: LSR and HCR parts hold their properties across extreme temperature swings and altitude changes.
- Automotive: From dampers to seals, automotive rubber injection molding relies on silicone’s durability under heat and vibration.
- Military: Mission-critical parts need materials that perform reliably in harsh, unpredictable conditions.
- Industrial: General-purpose seals, gaskets, and custom components built for demanding environments.
Why Choose Moldtech for Silicone Molding?
When you need a silicone rubber manufacturer you can count on, Moldtech has the experience and the facility to back it up. For decades, we’ve focused on rubber injection molding for complex, highly engineered parts, and we’ve built our operation around making that process smoother for the people who depend on us.
We’re located in Lancaster, NY, in a vertically integrated facility with close to 50,000 square feet of production space, including cleanroom and climate-controlled workspaces built for sensitive applications like medical molding. Because we handle design, manufacturing, and assembly in-house, you get one point of contact and far more control over your project than you would working with a broker or a multi-vendor supply chain.
Some of the biggest names in the world trust us with their parts, including Boeing, Bosch, Johnson & Johnson, and the U.S. military. When the part has to work the first time and every time, that’s the kind of track record worth looking for in a partner.
Get a Quote Today
Curious how silicone molding could fit into your next project? Contact us today for a quote.