The Development of Epoxy Resin Composite Laminates that are Thermoformable at Temperatures Below 200 Degrees C and Using Vacuum Pressure 950557
The development of a low cost, high production thermoformable fabric composite required a new approach to traditional resin systems. An epoxy resin was developed that allows the composite piece to be thermoformed. The material, supplied in cured board form, can be reshaped at temperatures less than 200C (392F) with only the application of vacuum pressure. This allows the user to design light weight, high strength composite structures without the normal processing constraints associated with traditional composite structures.
The driver behind the product development was an existing commercial application where material utilization and processing times were key factors to the success of the product. By prefabricating a cured flat sheet, net size parts can then be cut out with a waterjet, and the pieces are then thermoformed into their final shape. This method provided Hexcel, the manufacturer, with much better material utilization than the existing process did, thus allowing for reduced cost.
This paper discusses how the product was developed from theoretical DMTA curves in conjunction with mechanical testing to arrive at a product that processed well and was mechanically sound for the application.
Applications for the use of thermoformable composites are described.
Citation: Porter, J., Owen, T., and Hedges, W., "The Development of Epoxy Resin Composite Laminates that are Thermoformable at Temperatures Below 200 Degrees C and Using Vacuum Pressure," SAE Technical Paper 950557, 1995, https://doi.org/10.4271/950557. Download Citation
John H. Porter, Thomas K. Owen, Winston L. Hedges
International Congress & Exposition
Advances in Automotive Plastic Components and Technology-SP-1099, SAE 1995 Transactions: Journal of Materials and Manufacturing-V104-5