摘要
研究了工艺参数如保压压力、熔融温度、螺杆转速、背压值对长玻纤(LFT)增强聚丙烯(PP)复合材料的力学性能的影响。通过测试发现,保压压力对PP/LFT复合材料整体的力学性能影响不明显,可以适当增大。熔融温度升高,导致熔体黏度降低,LFT受到的剪切力减小,LFT保留长度随温度升高呈上升趋势。PP/LFT复合材料的缺口冲击强度与拉伸强度整体都呈现上升趋势。熔融温度从190℃上升到250℃,缺口冲击强度提高了50%,拉伸强度提高了21.4%,应使熔融温度高于物料熔点。缺口冲击强度和拉伸强度受螺杆转速的影响较大,都是随螺杆转速的增大而增大,而后下降,控制螺杆为中等转速较佳;缺口冲击强度和拉伸强度敏感于背压值,背压越大,两者都会逐步下降,背压要减小。PP/LFT复合材料注塑加工较优的工艺参数组合为:保压压力为5 MPa,熔融温度为250℃,螺杆转速为50 r/min,背压值一般为零。
The influence of process parameters,such as holding pressure,melt temperature,screw speed and back pressure,on the mechanical properties of length of glass fiber(LFT)reinforced polypropylene(PP)composites were studied.It is found that the effect of holding pressure on the mechanical properties of PP/LFT composites is not obvious and can be increased appropriately.As the temperature of the melt increases,the viscosity of the melt decreases,and the shear force of the glass fiber decreases,and the re-tention length of the glass fiber increases with the temperature.The notch impact strength and tensile strength of PP/LFT composites show an increasing trend.When the melt temperature rises from 190℃to 250℃,the notch impact strength increases by 50%and the tensile strength increases by 21.4%.The melt temperature should be higher than the melting point of the material.The notch impact strength and tensile strength are greatly affected by the screw speed,both of which increase with the increase of the screw speed,and then decrease at the turning point.The medium speed of the control screw is better.The notch impact strength and tensile strength are sensitive to the value of back pressure.With the increase of back pressure,both will gradually decrease,and the back pressure can be reduced.The optimal process parameters of LFT/PP composites injection molding are as follows:the holding pressure is 5 MPa,the melt temperature is 250℃,the screw speed is 50 r/min,and the back pressure value is generally zero.
作者
李伟
童俊
胡满凤
王少坤
胡余良
陈开源
Li Wei;Tong Jun;Hu Manfeng;Wang Shaokun;Hu Yuliang;Chen Kaiyuan(College of Mechanical and Electrical Engineering and Automation,Foshan University,Foshan 528000,China;Guangdong Shunde Weasi Robot Co.,Ltd.,Foshan 528303,China;Foshan Vocational and Technical College,Foshan 528000,China)
出处
《工程塑料应用》
CAS
CSCD
北大核心
2022年第8期59-65,共7页
Engineering Plastics Application
基金
2019年佛山市促进高校科技成果服务产业发展若干扶持政策资助项目(2019XCC04)
广东省基础与应用基础研究基金区域联合基金项目(2020A1515111200,2020A1515110461)。
关键词
复合材料
在线配混
螺杆结构
玻纤断裂及分布
螺杆一线式
composite
online mixing
screw structure
glass fiber fracture and distribution
screw line type
