http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Byunghyun Kang,Donguk Kim,Joo Seong Sohn,Nocheol Park,Kwangjoo Kim,Hyeong-Jun Kim,Youngdeog Koh,Byoung-Ho Choi 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.2
In this study, the change in the mechanical properties of glass fiber-reinforced thermoplastic (GFRTP) according to the recycled material content was evaluated. The recycled material was polypropylene, with short glass fiber reinforcement, dry blended with virgin polypropylene and additional glass fiber, and injected into its final shape. It is known that during the recycling process, the length of the glass fibers decreases, which leads to the deterioration of the mechanical properties. Therefore, to compensate for the fiber length shortening, long glass fibers were introduced, and changes of the length distribution of the glass fiber and mechanical properties were investigated. Variation of key short- and long-term mechanical properties by introducing long fibers was measured and investigated by performing tensile test, Izod impact test, essential work of fracture (EWF) test, and fatigue test. Most of the mechanical properties showed a linear relationship with the long glass fiber content, but the percent elongation at break and the resistance to the crack initiation were significantly improved immediately after the long fiber was introduced. In addition, the distribution of fiber length was measured and analyzed, and it was found that significant fiber breakage occurred during the injection process and the recycling process including the chopping of recycled material. Finally, through the observation of fracture surfaces, it was validated that the ductile-to-brittle fracture mechanism transition was mainly caused by the poor compatibility between virgin and recycled materials.