Compression Molding: Processes, Industries Served, and Applications

There are several types of molding processes, one of which is compression molding. Compression molding is a process that utilizes compression and heat in the molding process. By using this combination of temperature and pressure, it allows the polymers to form and link into a strong permanent structure. 

First, a mold is created from machined metal to form the shape of the part. The mold press is prepped and preheated to the proper temperature. After the machine is prepared, a weighed out quantity of uncured rubber is inserted into each mold cavity for curing. As the press applies and heat to mold the product into the desired shape. During this process, the pressure can be between about 100 to 500 kilograms per centimeter squared with the heat being around 100°-200 celsius. After the curing is finished, the molded product is removed manually or automatically to be cooled,  cleaned, and inspected for inconsistencies before being packaged for shipment.

Compression molding is used in a variety of industries including medical, marine, and is particularly common in the automotive industry for engine components and exterior parts such as filters, gaskets, tires, handles, and bumpers. 

Some advantages of this type of molding as opposed to others is that compression molding can be more cost effective with relatively low capital and tooling costs in large batches, products have low residual stress, are very strong and retain their physical properties. Some downsides to this type of molding is that it is not cost effective in smaller orders that are not the same size, often secondary processing such as trimming is needed and the initial mold depth is limited during production. 

Request a quote on custom molded products for your application, or contact us to find out what we can do for you. We also provide value added services including hand building, part marking, deflashing, assembly, and more

NW Rubber Extruders