Injection Molding
A screw extruder feeds the material "rubber" directly into a pot/ram injection chamber. This chamber injects the material, or rubber, through a series of flow channels, called a runner system directly into the mold cavity, or into a transfer pot and then into the cavities. There are many configurations and variations possible.
- Direct Injection
The screw extruder fills the injection chamber and the mold is closed under clamp pressure. The ram then comes forward, forcing the rubber through the runner system into the cavity, filling the part. Runner systems can be "hot" or "cold", or a combination of both.
- Injection Compression
The rubber material is injected into a slightly open cavity, then the mold is clamped shut. For all rubber parts, waste is similar to compression molding. Demolding can be easily automated.
- Injection Transfer (Hot or Cold)
The injection unit fills a pot unit with rubber. The mold and pot are then clamped under pressure to transfer rubber from the pot, through sprues, into the cavities. This doesn't require a complex runner system and allows for higher cavity density than straight injection.
Transfer Molding (Hot and Cold)
Rubber compound is forced (transferred) from a reservoir into a closed mold through a small opening (gate or sprue) to fill it, creating the desired shape. This is ideal for molding rubber-to-rubber or rubber-to-plastic inserts and for small parts with intricate details.
Compression Molding
A "preform" of a rubber compound is placed between two halves of an open mold and the desired rubber part is formed by closing the mold around the preform under pressure. This forces the preform to take on the shape of the cavity and forces out excess material (in the form of "flash"). This is the primary method of forming all molded rubber parts or rubber products.
Continuous Molded Rubber Strip
The continuous molding process is the result of a manufacturing process unique to Vernay. This process allows for the production of rubber and rubber-to-metal strip in a range of widths and thicknesses and held to close tolerances. The process offers the convenience of extrusion with the tolerances of molding. We offer continuous rubber strip in both EPDM and silicone that are used in some of the most demanding applications in industries worldwide. Strip width and thickness can be modified to provide the exact size to fit your cutting and assembly equipment, or we can provide individual pieces to suit your needs.