Material Extrusion of Continuous Fiber Reinforced Plastics Using Commingled Yarn

At the University of Twente research has been executed on Additive Manufacturing using continuous fibers based material extrusion. A pultrusion based process has been developed to transform readily available commingled yarn to a polypropylene (PP) E-glass filament. A deposition device has been developed that among others includes a novel low cost fiber cutting device and a modified deposition strategy. Test samples were printed with a flexural modulus of 800% compared to 100% PP samples. Further void percentages up to 20% were found in the printed test samples. Future reduction of this void percentage will further increase the obtainable flexural modulus.