Resin Infusion Between Double Flexible Tooling: Evaluation of Process Parameters

Manufacturers of lean weight vehicular structures are discovering the advantages of utilizing the high strength to weight ratios found in composite materials. However, traditional closed mold techniques require a long cycle time and relatively expensive tooling. This paper reports on a new technique called Resin Infusion between Double Flexible Tooling (RIDFT). In this innovative process, the resin infusion and resin-fiber wetting are finished between two flexible tools in a two dimensional flat shape and then the entire wetted reinforcement and flexible tooling is formed into a specified part shape by using a vacuum. This process avoids complex resin flow and mold filling issues and saves mold preparation and fiber stacking time. Using a RIDFT prototype, several components were produced. A larger industrial RIDFT machine was constructed to establish its viability for large component manufacture. An evaluation of production parameters, including infusion pressure, resin temperature, number of fiber layers and hardener content, ascertained their effect on mechanical properties and infusion times for the manufactured parts. The interaction between the hardener and fiber layers were found to directly affect tensile strength. The interaction between hardener and infusion pressure was also shown to affect tensile strength.