Study On Structure And Properties Of Continuous Fiber Reinforced Thermoplastic Composites

In this topic, five sheets were made of continuous glass fiber reinforced polypropylene (PP) composite of two different structures. The composite were composed of face layer and core layer. All the face layers were continuous fibers fabric reinforced polypropylene composites. There were two types of core layer. The core layers were made of chopped glass fibers reinforced polypropylene, which consists of three samples with different mass ratios of face layer. These kinds of composite samples were signed as Al, A2 and A3.The other core layers were made of PP with continuous glass fiber mesh fabric in center, which consists of two different PP, the usual PP and the highly liquid PP. These kinds of samples were signed as B1, B2. By the analysis in the mechanical properties of stretching, bending and impact and the failure mode, conclusions are obtained as follows:1 The composites are of high performance and good appearance made with mixed fibers by hot pressing method.2. Among samples of type A, the one that with highest mass ratio of face layer is of greatest tensile strength. Among samples of type B in same mass ratio of face layer, the one with high liquid PP has better performance of tensile strength than that of the one with usual PP. The bending strength depends on the mass ratio of face layer. The sample with highest mass ratio of face layer is of greatest bending strength among five samples. The sample that is in similar mass ratio of face layer with that of core layer, has the greatest notch impact strength.3. In the tensile process, the face layer and the core layer break together in samples of type A. A delamination between continuous glass fiber mesh and matrix appears in samples of type B. Under bending load, samples of type B appear obvious delamination. Under notch impact load, in samples of type A, the energy gotten from pounding head spreads uniformly through fiber layers delamination and the fracture has obvious fold texture. In samples of type B, serious delamination between continuous glass fiber mesh and matrix appears under impact load.