Development of Low Density Glass Mat Thermoplastic Composites for Structural Applications

The need for lightweight, fuel efficient, environmentally friendly, affordable automobiles has spurred considerable development in the field of composites. Composites made from lightweight thermoplastics, glass and carbon fibers or low-density metal alloys inherently fit the industry trends. Glass Mat Thermoplastic (GMT) composites made from continuous strand or chopped glass fiber web have been used for over two decades in automotive structural applications such as bumper beams, skid plates, running boards etc. Typically GMTs weigh 4 to 5 Kg/m² and are flow-molded in a compression press. A low-density, lightweight GMT composite containing long chopped fiber strands was developed by AZDEL, Inc. for use in headliner and other automotive interior applications. The low density GMT weighs between 0.5 to 2Kg/m².

This paper presents further development of the low-density GMT for automotive structural applications. This new thermoformable material has several advantages over other traditional materials such as steel and thermoset composites. The low-density GMT offers:

• Design flexibility
• Low weight
• High rigidity
• Excellent energy absorption characteristics
• Faster molding cycle times
• A more environmentally-friendly manufacturing process

The design flexibility and application of these low-density GMT composites in automotive industry and the advantages of applying these composites over the other materials in structural and modular applications will be discussed