Rubber Molding Versus Silicone Rubber Injection Molding

When placing an order for rubber molding, there are several different options between manufacturers. The right type of rubber for the job will make all the difference in the finished product, but which is the right one for your project? Here is a quick reference guide for your next rubber injection molding job.

Rubber Molding with High Consistency Rubber

The most common association that people make to rubber is referred to as high consistency rubber, or HCR. It is available in different thicknesses and usually comes in high viscosity sheets. It is gummier in texture and gives products a flexible quality, much like you’d expect in rubber tubing. This material is not commonly used in injection molding because it has such a high viscosity and takes a long time to cure. The HCR is great for certain applications and takes a long time to produce. It is labor-intensive to produce a finished product, but it is ideal for tubing and cording.

The other problems that companies come across is the amount of waste produced during manufacturers. This usually results in higher costs for materials, extra space, and labor costs for the company that is passed on to the customer.

Injection Molding with Liquid Silicone Rubber

Liquid silicone rubber, or LSR, is liquid, as the name implies. This is a great material for injection molding because it is easy to inject into molds than the HCR form into different shapes.

LSR starts as two parts that become solid once mixed together. Before combining the two parts, additives can be added and then machinery mixes everything together in precise amounts. The mixture is then pushed into molds and left to cure inside them. There is a low viscosity to LSR so the process is fast and requires less labor. This helps keep this type of rubber molding less expensive because there is less time spent on each order. Since molds are used to create the final product, there is less material waste.

Another benefit to using LCR is that the results are consistent. With HCR, the rubber is harder to form and is created with pre-created sheets. Production might vary between parts, which requires an extra step for trimming and quality control. LCR is used in the same molds, producing the same results each cycle, even with complex shapes.

Some of the industries that benefit from rubber injection molding include automotive, appliances, military and defense, and the solar industry, among others.

The Right Rubber for the Job

If you have a job that requires custom rubber molding, consider the two main options. The HCR is still ideal for many rubber products, but custom or complex jobs require a forming of liquid rubber into molds. Consider the pros and cons of each job and talk to a high quality manufacturer like us, about what they would recommend.

For the best custom rubber molding services, our customer service agents are happy to discuss options for your job. Our machinery is equipped to handle many different materials, including natural rubber, nitrile, neoprene, Viton, EPDM, and SBR. We can do repeat jobs and handle any size order- large or small. Let us know how we can fulfill your orders and help your company succeed.