Liquid Injection Molding Explained

Rubber Molding

There are a variety of types of rubber molding options available. Each molding option is ideal for certain products and uses. You can mold rubber by injection molding, transfer molding, or compression molding. One of the most precise and elegant methods of rubber molding is the process of liquid injection molding.

Liquid injection molding melts the rubber under high heat and injects it into a mold. Usually, this process is used with liquid silicone rubber, which is one of the highest quality rubbers available. Liquid silicone rubber is bio-compatible, which makes it a popular choice for food and medical applications.

In the liquid injection molding process, two rubber components are heated until the rubber has the consistency of toothpaste. The two components are mixed together and forced under high pressure into the mold. While in the mold, the rubber is cured or vulcanized, which causes the rubber to become hard and take on the shape of the mold.
After curing, the rubber is removed from the mold, cooled, and packaged. The entire injection molding process is very clean and actually is one of the fastest processes for transforming rubber into usable materials. Because the process is so fast, it is possible to create large orders of injection-molded rubber, making it ideal for use with industries where large quantities of materials are necessary. The process of liquid injection molding is fully automated, which makes all products created using this method consistent and eliminates mold errors due to human interaction. However, some inconsistencies can still occur when there is a problem with the mold or the rubber mixture. Usually, these problems are easy to address and do not cause problems for long.

Due to the advantages and benefits of liquid injection molding listed above, many factories choose to use this molding style whenever possible, in spite of the potential for higher expense.