Moldings

Rubber moldings include seals, gaskets and other custom-molded rubber products made from elastomers that provide high durability and elasticity. Precision-molded rubber products are ideal for indoor and outdoor sealing because they can withstand a wide temperature range and return to their original shape after being distorted.

Examples of industrial molded rubber products include:

• · Aircraft gaskets
• · Automotive seals
• · Bellows
• · Chemical resistant seals
• · Grommets
• · Industrial gaskets
• · Window seals

Molding Rubber Capabilities

NWRE produces custom molded rubber products through a variety of processes, including compression, injection, transfer, and fabric-reinforced molding, as well as rubber-to-metal bonding. We can custom-mold numerous materials, from natural rubber and chloroprene/Neoprene® to phenyl silicone, fluorocarbons, and many others. Our molding line accommodates molds up to 32 inches square.

Compression Rubber Moldings

Raw rubber materials or compounds, known as pre-forms, are placed into molds with a top plate and bottom plate. As the plates are pressed together, the rubber fills the mold cavity with excess flowing into overflow grooves. Once molding is complete the parts are taken out and the excess flash is removed.

• Suitable for smaller production runs
• Lower tooling costs than other methods
• Best suited to medium-hardness compounds
• Requires deflashing

Injection Rubber Moldings

Heated rubber is injected into a mold containing a series of cavities. The process reduces the need for pre-formed rubber and shortens cycle time. It is ideal for complex designs because the heated material flows easily into intricate cavities.

• Suitable for medium- to high-volume production
• Ideal for complex shapes and intricate designs
• Shorter production time

Transfer Rubber Moldings

Similar to compression molding, but pre-forms are placed into the “pot” portion of the mold. As the mold closes, rubber is compressed and forced through a sprue into the cavity. Once formed, parts are deflashed and excess rubber is discarded.

• Suitable for medium- to large-volume runs
• High cavity counts; cost-effective
• Allows tight tolerances; can be used for overmolding

Rubber-to-Metal Bonded Moldings

Metal inserts are coated in adhesive and placed into a mold. Heated rubber flows around the insert and bonds to the adhesive. Used for applications requiring both flexibility and stability — and viable for both large and small components.

Material Options for Precision Molded Rubber Products

• · Blends
• · Chloroprene (Neoprene®)
• · EPDM
• · Fluorocarbon
• · Fluorosilicone
• · General-purpose rubber
• · High-strength rubber
• · Natural rubber
• · Nitrile (Buna N)
• · Phenyl silicone
• · SBR
• · Silicone

View our Elastomeric Material Selection Guide to learn more about the advantages and disadvantages of each rubber molding material.

Industry Specifications

• · AMS (Aerospace Material Specifications)
• · ASTM D-2000
• · BMS (Boeing Material Specifications)
• · FDA
• · FMVSS
• · Mil-Specs
• · ZZ-R-765