Molded Parts


Compression Mold

“Molded Parts” is a term to describe parts that are molded into the shape that is practical for an application. In this article, we will focus on parts that are transfer molded, and molded by compression. When a part is molded, it is molded because, it is the most effective way for the part to be manufactured. Also, because it could not be converted into that shape or because it could not be fabricated to become that shape. Sometimes, a part needs to be molded and then fabricated to provide the most effective price structure and solution. Rubber can not typically be machined so a lot of parts are either fabricated to the shape desired or molded to the shape needed.

NEDC is extremely familiar with compression and transfer molding. NEDC can provide a wide selection of materials that may be molded including fluorosilicone, EPDM, Neoprene®, silicone, butyl rubber, polyurethane, and others. There are many factors that play into molding rubber, including shrink rates, amount of flash and other considerations.

Compression molding is usually the cheapest way to mold rubber. This is because the rubber is easily placed into the forming structure of the mold and relies on the tried and true hydraulic press. People quip about the hydraulic press being one of the machines that run forever. The determination whether or not to use a compression mold is determined by the number of parts that need to be run, the limitations of equipment on hand, and the complexity the part. NEDC provides parts that are manufactured by compression molding, such as its MIL-G-83528 materials, or electrically non-conductive materials like fluorosilicone rubber, butyl rubber, silicone rubber, EPDM rubber and many others.

Transfer molding is another step up in the price structure of molds, they typically cost a bit more than a compression mold but offer a few benefits over compression molding, such as lower shrink rates, less flash, higher repeatability, and better ability to manufacture more complex parts. NEDC uses transfer molding for many of the parts it does. Parts can be manufactured from many materials including fluorosilicone rubber, Neoprene® rubber, nitrile rubber, and many others.

You can count on NEDC to provide the best molded product possible; NEDC is considered a leading supplier of quality molded parts. For more information on NEDC’s molded parts please contact Inside Sales at