Thermoset Rubber Injection Molding
Thermoset rubber injection molding is the fastest, most cost-effective way to produce high-precision rubber parts at scale. It saves on labor and material costs while holding tight tolerances part after part, run after run, which is why it’s become the go-to process for manufacturers who need consistency they can count on.
Moldtech specializes in thermoset rubber injection molding for customers who can’t afford to guess. Whether you need a handful of prototypes or a continuous production run, our team builds the process around your part, not the other way around. Reach out to our team for an initial consultation.
What Is Thermoset Injection Molding?
Thermoset injection molding is an irreversible molding process. It starts with an uncured, malleable rubber compound, which is forced into a heated mold cavity under pressure. Inside the mold, the material permanently takes the shape of the cavity. That’s the “thermoset” part. Unlike thermoplastic materials, which can be melted down and reformed, a thermoset rubber part can’t be reshaped once it’s cured. That permanence is exactly what gives these parts their strength, chemical resistance, and long-term stability in demanding environments.
Compared to compression or transfer molding, injection molding typically means shorter cycle times, less material waste, and tighter, more repeatable tolerances, which is why it’s often the preferred rubber injection molding process for medium- to high-volume production of precision parts.
How the Thermoset Rubber Injection Molding Process Works
- Material preparation: Uncured rubber compound is fed into the injection barrel in continuous strip form.
- Injection: The barrel heats and pressurizes the material, then injects it through a nozzle into a closed, heated mold cavity.
- Curing (vulcanization): Heat and pressure inside the mold cross-link the rubber, permanently setting its shape.
- Demolding: Once cured, the mold opens and the finished part is ejected.
- Secondary operations: Parts are trimmed, inspected, and, if your project calls for it, bonded, coated, or assembled in-house.
Benefits of Thermoset Rubber Injection Molding
- Tight, repeatable tolerances, ideal for precision parts that have to perform the same way every time
- Faster cycle times than compression or transfer molding, which keeps per-part costs down at volume
- Less material waste, since the process meters exactly what each cavity needs
- Consistency at scale, from a handful of prototypes to continuous production runs
- Durability in demanding environments, thanks to the permanent cross-linking that gives thermoset rubber its chemical and heat resistance
Materials We Mold
Moldtech works with a wide range of thermoset elastomers, and we can help you select, or custom-formulate, the right compound for your application:
- EPDM: weather, ozone, and UV resistance for outdoor and automotive parts
- Nitrile (NBR): oil and fuel resistance for industrial and automotive seals
- Neoprene (CR): a balance of weather, chemical, and flame resistance
- FKM (Viton): high-temperature and chemical resistance for demanding environments
- HNBR: added durability and heat resistance beyond standard nitrile
- Natural rubber: excellent flexibility and tear resistance
Need a material that isn’t listed here? Our team can advise on the right compound, including custom formulations, based on your part’s performance requirements.
Why Choose Moldtech?
Moldtech is a highly experienced thermoset injection molding partner, built to deliver parts that meet your exact specifications. Our vertically integrated facility in Lancaster, NY, lets us manage the entire project in-house, from design through final shipment, so you retain full control over your product without juggling multiple vendors.
With nearly 50,000 square feet of production space, we operate 24 hours a day, five days a week, so we can respond quickly to urgent requests and get you to market faster. From single prototypes to large-scale production runs, we’ve got you covered, and if your project needs extra care, we offer cleanroom and climate-controlled workspaces.
With decades of experience, we’re ready to take on even the most challenging rubber molding projects. Our parts are trusted by some of the biggest names in the world, including Boeing, Bosch, Johnson & Johnson, and the U.S. military.
Request a Quote Today
Want to learn more about what we can do for you? Reach out to our team for a quote.