Zhao Runtian, Li Xiaodong, Wang Zhihui, Wu Ting, Liang Jianguo
College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, No. 79, Yingze West Street, Taiyuan 030024, China.
Advanced Forming and Intelligent Equipment Research Institute, Taiyuan University of Technology, No. 79, Yingze West Street, Taiyuan 030024, China.
Polymers (Basel). 2025 May 6;17(9):1264. doi: 10.3390/polym17091264.
SCF/PA6 composites have gained extensive industrial applications due to their superior processability and moldability, with long-fiber pellet injection molding being the predominant manufacturing technique. However, systematic investigations into injection molding parameter optimization and its mechanistic impacts on tensile strength remain scarce. This study employed the Taguchi method to investigate the effects of four critical process parameters-injection pressure, melt temperature, mold temperature, and injection time-on the tensile strength of short-carbon-fiber-reinforced nylon 6 (SCF/PA6), while elucidating their underlying mechanisms. The optimal parameter combination within the experimental range was determined to be an injection pressure of 100 bar, a melt temperature of 280 °C, a mold temperature of 100 °C, and an injection time of 2 s. Under these optimized conditions, the tensile strength reached 184.33 MPa, representing an 8.05% enhancement over baseline values. Mechanistic analysis revealed that melt temperature and injection time (essentially reflecting injection velocity) primarily govern fiber orientation distribution. Notably, melt temperature additionally regulates molecular chain orientation in the amorphous matrix regions. Injection pressure predominantly influences process-induced defect formation and material densification. Mold temperature exhibits a negligible impact on tensile strength.
由于具有优异的加工性能和成型性，短碳纤维增强尼龙6（SCF/PA6）复合材料在工业上得到了广泛应用，长纤维粒料注塑成型是其主要制造技术。然而，对注塑成型参数优化及其对拉伸强度的作用机理进行系统研究的仍很匮乏。本研究采用田口方法，研究了注塑压力、熔体温度、模具温度和注塑时间这四个关键工艺参数对短碳纤维增强尼龙6（SCF/PA6）拉伸强度的影响，并阐明其潜在机理。实验范围内的最佳参数组合确定为：注塑压力100巴、熔体温度280℃、模具温度100℃、注塑时间2秒。在这些优化条件下，拉伸强度达到184.33兆帕，比基线值提高了8.05%。机理分析表明，熔体温度和注塑时间（主要反映注塑速度）主要决定纤维取向分布。值得注意的是，熔体温度还会调节非晶基体区域的分子链取向。注塑压力主要影响加工过程中缺陷的形成和材料致密化。模具温度对拉伸强度的影响可忽略不计。
