Ultrasound-assisted 3D printing of continuous fiber-reinforced thermoplastic (FRTP) composites

Investigation of manufacturing continuous fiber reinforced thermoplastic polymer composites (CFRTPCs) through 3D printing technologies has attracted great attention in the past few years due to excellent properties of CFRTPCs, such as high strength-to-weight ratio and stiffness. It is found that the properties of CFRTPCs are affected not only by the properties of the individual parent materials but also by interfacial characteristics. Modification of the interface is a great method to improve the wettability between fiber and polymer and hence the mechanical properties of CFRTPCs. In this work, an ultrasound-assisted 3D printing device for CFRTPCs is developed. The changes of surface profile and chemical structure of carbon fiber and carbon fiber prepreg after ultrasonic treatment are studied. The effects of ultrasonic processing parameters on the microstructure and mechanical properties of CFRTPCs are provided. It is found that the tensile and flexural strength of composite materials are improved by 34% and 29%, respectively, compared with untreated material by using the ultrasonic amplitude of 40 μm, resin solution mass fraction of 10%, processing speed of 15 mm/s.