Application displacements caused by shrinkage and warpage of the parts as they are withdrawn from the tool and cooled to ambient temperature. The LFT door was assembled on an articulated bus and is currently undergoing durability and road tests. LFT battery-box access door A thermoplastic polyolefin (TPO) bonded to a vacuumthermoformed AZDEL SuperLite glass mat ribbed interior replaced the aluminium-skin door that gets welded to a steel stringer featured on current buses (figure 5). This reduced the AC door weight from Fig. 5: Air-conditioning roof of articulated bus. (a) Articulated mass transit bus with roof in open position; (b) Thermoplastic TPO skin-glass mat reinforced ribbed core design, figure shows the part with and without the TPO skin to show rib details, and (c) Thermoplastic roof door mounted on bus with “step” and door in open position showing minimum free-standing deflection. 27 kg to 12 kg. Each bus has 12 such doors, so adopting thermoplastic composites technologies can reduce the roof weight by approximately 250 kg. The free-standing deflection of the thermoplastic composite door was 30% lower than the aluminium baseline. The glass mat was thermoformed on a ribbed tool and the TPO formed on a smooth curved tool. The glass-mat ribbed core was bonded to the TPO and the surface was easily painted to match the bus colour. More information: www.uab.edu/composites uvaidya@uab.edu No36 October - November 2007 / JEC Composites Magazinehttp://www.alcanairex.com http://www.uab.edu/composites