Compression vs. Injection Molding for Custom Molded Rubber Seals
When you need precision-molded rubber seals that can withstand demanding environments, choosing the right molding process makes a difference. Compression and injection molding are two of the most common methods for producing custom rubber components. However, they work very differently.
Understanding how each molding method works can help you minimize waste, improve performance, and ensure your seals meet exact specifications. In this blog, we’re breaking down the steps and benefits of both compression and injection molding. By the end, you’ll be confident enough to make a decision for your business.
What is Compression Molding?
In the compression process, thermoplastic material is loaded into one half of a metal mold. The other half then clamps down, forcing the heated material to take the mold’s shape. Once the cure time is complete, the mold is opened and the finished rubber seal is removed. Any flash is then removed, and the part undergoes secondary finishing if needed.
Compression molding is highly advantageous for low-to-medium volume runs. It has lower tooling costs and shorter setup times, which offer great benefits for a range of businesses. However, there are some considerations to keep in mind. This process has longer cycle times than rubber injection molding. It may also include more manual labor and have a bigger potential for dimensional variation between parts. It’s still an ideal molding process for a variety of use cases. An experienced rubber molder can help you understand if it’s right for you.
What is Rubber Injection Molding?
Rubber injection molding involves injecting a rubber mixture into a mold under high pressure. The rubber compound is fed into an injection barrel, where it is pre-heated. From there, it’s injected through nozzles into the closed mold cavity under high pressure. The heat and pressure cause the rubber to cure and take its final form. Once cooled, the mold opens and the finished part is ejected.
There are several advantages of using rubber injection molding for custom molded rubber seals. It offers excellent consistency and precision for complex, tight-tolerance parts as well as high production efficiency for large volumes. Additionally, it reduces waste because it uses precise material metering.
Though there are significant advantages, there are also considerations to keep in mind. This process often will have higher upfront tooling costs and longer lead times to develop molds. It’s also great for high-volume production, but not as suitable for lower volumes. An experienced rubber molder can help you make the right call for your business.
Work with Moldtech for High-Quality Custom Molded Rubber Seals
If you’re not sure whether compression molding or injection molding is right for your rubber components, we can help. For decades, we’ve been providing high-quality rubber molding services for companies in a range of industries. We’re ready to take on your next project.
Our Lancaster, NY, facility is vertically integrated with close to 50,000 square feet of production space. This includes cleanroom and climate-controlled workspaces. With our extensive experience, we can design, manufacture, and assemble your parts in-house. Trust us to give you maximum control over the process.
Some of the biggest companies in the world trust us to create tight-tolerance components. Boeing, Johnson & Johnson, and the U.S. military all rely on us for their needs. Contact us to learn how we can help you meet your goals.