Innovative Composite Products

Structural RIM takes on established composites

Reaction-injection-molded (RIM) polyurethanes haven't always been lumped in with conventional composite materials like polyester FRP and SMC. Yet with the addition of reinforcements, RIM materials can take on traditional composites in a variety of applications. According to Harry George, manager of Bayer Corp.'s specialty RIM business, reinforced RIM has several compelling advantages. These include styrene elimination, lower manufacturing costs, and light weight-reinforced RIM formulations typically have a 20-40% lower density than plastic or polyester composites for a given stiffness. At the Composite Fabricator Show, Bayer showed off several recent applications for reinforced RIM systems. Among them were an engine cover for Volvo trucks, which replaced SMC with two RIM systems: A mica-reinforced Bayflex 180 material forms a frame that bolts to the truck floor, while a reinforced structural foam covers the frame. Also on hand were examples of applications involving high-strength RIM systems that use long glass-fiber reinforcements. Freightliner has used this technology to produce eight sleeper cab interior trim pieces for its Century Class tractor trailers. "There are significant opportunities to utilize long fiber technology in a number of markets, including automotive, agricultural, and heavy-duty construction equipment," says George. Bayer Corp., www.rimmolding.com: Enter 630

SMC fights paint pops

A new sheet molding composite (SMC) from AOC addresses one of the nagging difficulties associated with automotive painting processes. Atryl TCA, which stands for "Tough Class A," targets the paint pops that can occur when SMC parts are assembled and finished on-line with metal body parts. The culprit: Solvents collect in micro-cracks at the edges of the parts and vaporize when the part temperature rises during e-coat processing and painting. Atryl TCA has been formulated with extra toughness to prevent much of the micro-crack formation, according to Mike Dettre, AOC business manager for closed molds. "Laboratory test results show at least a 90% reduction in the formation of paint pops," says Dettre." Atryl TCA has or will soon appear on various Ford Motor Company vehicles, including Explorer Sport fenders, Ranger hoods, and various body panels for the Navigator and Thunderbird. AOC, www.aoc-resins.com: Enter 631

TPU-based composite poised for new applications

Dow's FULCRUM, a thermoplastic composite technology for making pultruded continuous-fiber parts, has long offered some attractive strength and stiffness properties. "This thermoplastic polyurethane-based composite pairs the high strength and rigidity of traditional composites with the processability of thermoplastics," reports Chris Edwards, business development manager for FULCRUM. Until recently, the material has seen use mainly in construction applications, such as concrete reinforcements and window profiles. Recent advances in the technology now promise to open up some new markets. Edwards explains that new pultrusion dies can produce multiple profile geometries, allowing faster prototyping and ultimately speeding the development of application-specific components. As thermoplastic parts, FULCRUM components can also offer extra design freedom-for example, through a secondary thermoforming step or overmolding with colored elastomers. These advances have left FULCRUM poised for new applications outside of the building and construction world. Perhaps the most promising is in appliances as a replacement for aluminum or steel. Edwards reports that one FULCRUM processor will soon start making shelf brackets and other support components for a domestic appliance maker. Dow Plastics, www.dowfulcrum.com: Enter 632