High speed impact cutting of continuous fiber reinforced thermoset plastics

Abstract

Abstract. Endless fiber-reinforced plastics are being used to an increasing extent as alternative materials for highly stressed or lightweight components instead of metallic materials. In order to achieve the geometric requirements, peripheral machining of the raw parts is necessary. Instead of the currently mainly used cutting processes, which are not suitable for clocked production, high-speed impact cutting (HSIC) was examined in the presented experiments. This technology is known as adiabatic cutting from the processing of metallic materials. Due to the high process energy which is released in a very short time resulting in high punch speed, the prevailing separation mechanism changes. Instead of bending the fibers due to the shear force the high-speed cutting experiments with a punch speed of 10 m/s lead to a brittle shearing of the glass fibers and a locally very limited heating and hence softening of the matrix material resulting in a clean surface of the cut specimen. The inter fiber breakage, meaning the separation between fibers and matrix called delamination, can be avoided or at least be sealed at the surface due to heat induced smearing of the matrix material. The resulting surface quality of the cutting edge is exceptionally good. However, the technically necessary cutting clearance leads to a jump in diameter within the cut surface.