Rubber molding is a widely used rubber manufacturing technique, with applications in countless industries and virtually limitless options for customization. From heavy-duty equipment and automotive components to sanitary food service equipment parts, rubber-molded goods are found in virtually every major industry.
There are three primary types of rubber molding techniques:
- Rubber injection molding
- Rubber transfer molding
- Rubber compression molding
All three rubber molding processes have unique advantages in terms of design, production, and costs. Understanding each rubber molding process is key for manufacturers when making decisions about production.
Rubber Injection Molding
Rubber injection molding is a popular rubber molding method with many applications. Raw rubber is heated and melted to a liquid consistency then injected into a mold under high pressure. The heated rubber flows into the mold’s cavities to create the desired shape.
Advantages & Best Uses
One of the greatest advantages of rubber injection molding is its precision. Rubber injection molding is excellent for tiny or complex shapes, parts with internal features, and any project with tight tolerances. This rubber molding method is fast and well-suited for automation, making it an efficient option for high-volume production.
Rubber Transfer Molding
The rubber transfer molding process begins by placing preformed rubber inside a specialized chamber located above the mold rather than the mold itself. The mold is heated, and then a plunger forces the preformed rubber through specialized channels and into the heated mold. The part is cured while still inside the mold.
Advantages & Best Uses
Because rubber transfer molding allows manufacturers to control the quantity of material in the mold, this method can generate less rubber molding material waste. This method also offers tremendous design flexibility when compared to other types of rubber molding, partially because it allows for molds with a high cavity count. Transfer molding is one of the best rubber molding techniques for components that will undergo secondary processes, such as further assembly, the addition of fasteners, tape, adhesive, or retail packaging of any kind.
Rubber Compression Molding
Rubber compression molding is widely thought to be the oldest type of rubber molding, dating back to the 1850s. A technician places preformed, uncured rubber inside a mold, then closes the mold. The mold is heated and pressurized, which pushes the rubber into the desired shape. The rubber compression molding process can be loosely compared to pouring batter into a waffle iron and closing it to cook the batter.
Advantages & Best Uses
Rubber compression molding is a fairly simple process, requiring less machinery than other rubber molding methods. Rubber compression molding is also more economical in many cases since the tooling costs of this method are low. This particular method is excellent for simple shapes, such as o-rings, seals, and gaskets, as well as large pieces. Rubber compression molding is great for low to medium production volumes.
Injection Mold vs. Transfer Mold vs. Compression Mold
Need a quick rundown for when to use which rubber molding process? Here’s a quick overview of the types of production each kind of molding process is best suited for:
- Injection mold: Best for high-volume applications that require high levels of precision and efficiency
- Transfer mold: Ideal for applications with more complex designs and/or secondary processes
- Compression mold: Great for simple, low-volume runs or prototype production
Trust UP&R for Your Rubber Molding Projects
The experts at UP&R can help you choose the right rubber molding process for your part or application. We’ll work closely with you to understand the service environment and performance expectations of your final product, as well as your goals and your budget, so we can advise you on the best manufacturing method.
UP&R is a trusted tier supplier, offering quicker lead times and industry-leading consistency with every rubber molding project. You can streamline your entire supply chain, from materials sourcing to logistics services when you partner with our US-based team.
On spec, on time, every time: Talk to UP&R to get your rubber molding project started today.