A combination of polyurethane skin foam and thermoplastic films give hospital trolleys a robust but lightweight frame.
The compact Aurion Mini 400 and 600 trolleys from Italian-based GMP S.p.A. weigh just 37.5 lb (17 kg). They give nurses a place to transport everything from bandages to laptop-based patient-data capture systems. They also feature 24 16-in. drawers to hold individual doses of medication.
The modest weight of the trolleys come via GMP's new FPT/FFT production process. Foiled polyurethane technology and Foiled-fiber polyurethane technology combine the benefits of Baydur 60 RIM (reaction-injection-molding) polyurethane with the surfaces characteristic of thermoplastic films.
Side and rear panels, as well as shelves for the 39 35 23-in. "mini" trolleys are constructed from two thermoformed PVC films back-foamed with Baydur 60 polyurethane skinfoam from Bayer MaterialScience, Pittsburgh (bayermaterialscience.com). Space between the two rigid shells is then filled with Baydur 20 from Bayer's Italian subsidiary Deltapur. This filling is lightweight 12.5 lb/ft3 (200 kg/m3) and gives the panels and shelves additional stability. It also forms a permanent bond between the two film composites with no need for additional adhesives.
The trolley base is made of FFT (glassfiberreinforced Baydur and film) making it strong enough for mounting the four casters. According to GMP's Guido Furlanetto, the low-pressure molded parts are formed using less-expensive aluminum molds, and metal thread inserts are foamed in place helping to simplify assembly. To ensure panel surfaces withstand aggressive hospital-grade cleaning agents, the film comes with a special polymethyl methacrylate (PMMA) coating applied in the factory. "Parts require no further coating after removal from the mold, eliminating another processing step and contributing to the high cost-effectiveness of the FPT/FFT process," says Furlanetto.