A holistic recycling procedure to use different fractions of dry carbon fiber production waste in filled bulk moulding compoundsDonnerstag (06.07.2017) 17:20 - 17:40 Uhr Bestandteil von:
The increasing demand for composites leads to a growing amount of end-of-life material and production waste. The latter consists of a large fraction of unimpregnated fiber waste which is not sufficiently reprocessed using conventional textile processing procedures as they are either too expensive or their mechanical performance is too low.
Using pieces of dry non-crimp fabrics (patches) in a Bulk Moulding Compound process (BMC) displays a straightforward route of fabric recycling. By adding fillers to the resin-fiber mixture, the compound's thermal, electrical and mechanical properties can be adjusted. Furthermore, fillers are often used to lower the price of the material. The most commonly used filler in the BMC process is calciumcarbonate (chalk) which is investigated here. Furthermore, a filler on basis of carbon fiber waste grinded to dust-like carbon fiber powder is used. In this way, all kind of dry fiber wastes can be reused in one process: Larger offcuts are chopped to smaller rectangular patches whereas waste fractions of small offcuts are processed to carbon fiber powder as filler. Numerous grinding technologies are analyzed in order to select the most energy efficient production process.
The filled material is further compared to materials without filler and to the competing process for new unfilled materials (Sheet Moulding Compound, SMC).
Material performance and quality is evaluated by means of tensile properties, thermal gravimetric analysis (TGA) and optical investigations.
As the fiber material is recycled and as the process is straightforward, the height of investment is very low to comparable recycling concepts. As a consequence, component costs are estimated to be low compared to SMC material.