Today's marketplace requires that the rubber molding and fabricating shop provide a wide range of capabilities through equipment and resources. Among those should be the ability to handle a 50-piece run from a single-cavity compression mold to a 250,000 piece run from an injection molding process.

A multifunction shop provides the following operations:

• Injection molding of silicone rubber with quick changeover techniques.

• Compression and transfer molding of virtually any elastomer. Presses are used from 14" x 14" to models rated to 400 tons and 30" x 30".

• Lamination of pressure-sensitive adhesives onto solid and sponge rubber sheets.

• High-volume and low volume die cutting with automatic systems.

• Conductive coatings onto silicone sponge rubber.

• Lamination of films, conductive fabrics and elastomers onto sponge rubber.

Custom fabrication, adhesive lamination and die cutting involve the use of silicone rubber, neoprene, EPDM, Buna-N, PORON cellular urethanes, fluorelastomers, fluorsilicone, electrically and thermally conductive silicones. Note that die cutting large gaskets may waste material since the center and web are usually discarded. However, a molded gasket provides full utilization of material. Additionally, production runs of as few as 200 pieces may offset the one-time tooling charge.

The Liquid Silicone Rubber (LSR) injection molding process gives customers the benefit of cure cycles, quick changeover and lower tooling costs. This process is suited to components requiring low durometer and thin cross sections down to 0.030". Fine cross sections such as rectangular or side-by-side O-rings can also be made. The properties of LSRs are low-temperature flex, high-temperature stability, excellent weatherability and UV resistance.

The creation of working prototypes fills an important role in arriving at a final design. The following operations can reduce time and cost in prototyping:

• Hand fabrication of prototypes employs die cutting and lamination.

• Tooling designs with mold insert systems to cut mold costs.

• Single cavity tooling designs machined into larger production capacity mold plates.

Silicone sponges with conductive coatings can be made in soft, firm and medium grades in thicknesses to 1". Silicone rubber gaskets with conductive surfaces used to seal door closures and other areas can greatly reduce static buildup by providing a convenient ground. Extra thin silicone sponge gasketing (0.032" and 0.062") are made in density ratings from 0.009 to 0.028 lb/in³. They are optionally available with pressure sensitive adhesive backings for sealing out dust and moisture.

The products made through the methods described herein have application in equipment such as instruments, controls, scanners, sensors and diagnostic equipment. Production should be reinforced with documentation, lot traceability, material certification and test reports.