在线混炼注塑一步法成型设备及制品性能研究

Study on Equipment of Online Compounding Injection One-step Molding and Products Performance

研究了长玻纤增强聚丙烯复合材料的成型工艺对其各项性能的影响。结果显示:LFT-S在线混炼注塑一步法成型工艺制备的制品,其拉伸强度、弯曲强度、冲击强度达到了135.2MPa、196.6 MPa和34.3 kJ/m^2,相较于传统LFT-G先造粒再注塑成型工艺制备的制品,分别提高了17.8%、20.6%和56.6%。主要原因是在LFT-S工艺制品中,其长玻纤平均保留长度为5~8 mm,远大于玻纤增强复合材料中纤维临界长度(3.0 mm),长玻纤所形成的缠结网络结构能更好地承受各个方向上的应力。此外,通过扫描电子显微镜对断面的分析表明:纤维增强制品在断裂过程中,需要克服纤维与基体间的粘结力,随着大量玻纤从基体树脂中拔出,大量聚丙烯树脂残留在玻纤表面,证明玻纤与聚丙烯基体界面结合力较强。

To study the molding process influence the properties of long glass fiber reintfrced polypropylene composite. Results show that the LFT-S （online compounding injection one-step molding） products＇ tensile, bending, impact strength reached 135.2 MPa, 196.6 MPa and 34.3 kJ/m^2, comparing to traditional LFT-G （first granulation second injection molding ） products, increased by 17.8% , 20.6%, 56.6% , respectively. The main reason is that the LFT-S products reserved average length of long glass tiber reaches 5-8 mm, much longer than the critical tiber length （3.0 mm） in glass fiber reintfrced composites, which is formed entanglement network structure by the long glass fiber can better withstand stress in ditierent directions. In addition, analyzing the fracture surface by scanning electron microscopy, shows that tiber reinforced products in the process of fracture need to overcome the cohesive three between the fiber and matrix. As a large number of glass fiber pulling out from the matrix resin, a large number of polypropylene resin residues on glass fiber surface, proved that the glass fiber and polypropylene substrate interfhce bonding three is very strong.