Investigation of the influence of multiple thermoforming processes on the properties of continuous fiber-reinforced thermoplastics to enable structural reuse

Abstract

AbstractFiber-reinforced plastics (FRP) are finding more and more applications in many industrial sectors. The growth in material use simultaneously leads to larger volumes of end-of-life materials and FRP are generally difficult to recycle. This also applies to FRP with a thermoplastic matrix. One possibility is the approach of structural reuse by reshaping continuous fiber-reinforced thermoplastics (organosheets). In this process, end-of-life (EOL) components are remelted and formed back into semi-finished products. However, the multiple thermal processes can damage the matrix. In addition, the frequent forming processes lead to fiber breaks and displacements of the reinforcement architecture. In order to assess the level and impact of matrix and fiber damage, various forming and reforming processes were performed on selected materials, which were then investigated using attenuated total reflectance (ATR) spectroscopy and tensile tests. The results of the ATR spectroscopy show no evidence of damage to the matrix. In contrast, slight to moderate decreases in the characteristic values as a result of multiple deformations can be observed in the results of the tensile tests. However, the experiments and material tests show the potential that this approach can produce high quality secondary materials. A comparison is made here with mechanically recycled and compounded injection molding materials.