正交设计确定模压条件对HDPE/CB复合材料室温电阻率的影响

Study on the influence of compression molding parameters on resistivity of HDPE/CB composites by statistical design

采用塑炼混合法,在碳黑及其它辅助填料的含量一定时,用正交实验法研究了模压压力、温度、时间及模压后样品冷却时间对HDPE/CB复合材料室温电阻率的影响,发现模压温度、模压时间和冷却时间都对复合材料的室温电阻率影响显著。在最佳模压条件(模压压力为10Mpa,模压温度155℃,模压时间20min,模压后样品冷却到室温的时间40min)下得到HDPE/CB复合材料的室温电阻率为0.6Ω.m,PTC强度达8.41,电阻率负温度系数(NTC)效应仅为0.2.

At the conditions of plastication ,the content of carbon black and other fillers in the composites are ensured, orthogohal experiment with four factors and three levels is designed to confirm the influence of compression molding parameters on resistivity of HDPE/CB composites using statistical design. According to the statistical analysis of experimental results, the influence of compression molding parameters on the room temperature resistivity of HDPE/CB composites is in order of compression molding temperature 〉 cooling time 〉 compression molding time 〉 compression molding pressure. The optimum compression molding technics condition with least room temperature resistivity of HDPE/CB composite should be chosen as characteristic values of compression molding pressure 10 Mpa, compression molding temperature 155 ℃, compression molding time 20 minutes, cooling time 40 minutes. The positive temperature coefficient （PTC） intensity of specimens pressed under the optimum conditions is 8.41, room temperature resistivity is 0.6Ω·m, almost no negative temperature coefficient （NTC） effect.