Effect of Processing Parameters on the Widths and Thicknesses of Thermoplastic Composites Made by Automated Fiber Placement

Abstract

The advent of Automated Fiber Placement (AFP) machine has expanded the capacities to manufacture engineering structures using thermoplastic composites. Structures of cylindrical shapes, flat and curved panels can be easily made using this technique. As more applications and more studies have been made on this technique for thermoplastic composites, many issues have come up. One issue of importance is the variation of the width and thickness of the tow as it is deposited. As the melted thermoplastic composite tow is being pressed under the compression force of the roller, the material flows. This changes the width and the thickness of the tow. The values of the width and thickness depend on many parameters such as the properties of the substrate, the temperature of the material, and the applied pressure. This variation in width and thickness of the individual tow being deposited has an influence on the development of laps and gaps between the deposited tows. This paper presents some of the results on an investigation on the above topic. Widths and thicknesses of carbon/PEEK tows processed using an Automated Fiber Placement machine with a hot gas torch were examined. Preliminary results show that there is significant variation in the width and thickness of the tows upon deposition.