Heavy Equipment with a Soft Interior. (Mechanical Enclosures & Fixtures).

Savvy employers are constantly looking for ways to enhance the work environment while cutting costs. Caterpillar Inc., Peoria, IL, now offers such service to heavy equipment operations. For their model 905, 966 and 980 front end loaders, they have started using the Baydur STR/F651 reinforced structural foam polyurethane RIM system to form HVAC enclosures.

In this application, the RIM system replaced polyester and fiberglass formed via resin transfer molding. The change reduced part weight by 50% and reduced cycle time significantly without sacrificing structural integrity. The Baydur composite is reinforced with 15% fiberglass mat, offering impact resistance, thermal stability to 200[degrees]F and increased design flexibility. As an added bonus, the material has a soft tactile feel that is similar to an automobile interior.

Tipping the scales at 9 lbs, the HVAC enclosure consists of two separately-molded pieces that are 19-in, deep by 24-in, long. Wall thickness is a consistent 1/2-in., with the exception of a slightly thicker area where the lunch tray is bolted on. Both front and back pieces are molded by PLA-MA USA, Owosso, MI. For the front piece, the company first sprays the mold with a release agent, then places the vinyl exterior skin into the mold and clamps it into place. After a vacuum pulls the vinyl into the mold cavity, an operator hand-tucks the vinyl into the mold's recess. Next, a pre-cut fiberglass mat is laid over the vinyl and secured. The Polyurethane is injected and the mold is closed for 10 minutes. Both pieces are water-trimmed, bonded together with adhesive and then sent to Caterpillar where accessories are installed.