聚乙烯电话线缆绝缘料高速挤出包覆性能研究

High Speed Extrusion and Coating Property of PE for Telephone Cable Insulation Material

本文分析了聚乙烯 (PE)熔体在圆形口模及挤压式电话线缆包覆机头中的流动情况 ,并根据实验数据提出了高速挤出包覆时熔体的流动模型 ,分析了影响机头表压及芯线表面光滑程度的材料自身参数 。

High speed extrusion and coating for telephone cable core wire is generally used.The speed of the conducting wire through the crosshead is about 1500~2400m/min.So there are something quite different from the ordinary extrusion.The harshness requirment for materials and extrusion coating technology should be improved.The effects of the PE melt condition in round and pressure dies on extrusion and coating behaviour of wire and cable was analysed in this paper.The torsional moment of round die was determined by the apparent viscosity of PE melt,while the apparent pressure of the crosshead for wire and cable in high speed extrusion coating was determined by the rate of expansion of PE melt.Using bigger mold sheath results in lower apparent pressure.These has been verified by the experiment dates.In accordance with the experiment dates,the smooth level of the coated core wire is influenced by the melt flow ratio(MRI 21.6 /MRI 2.16 ).So the rate of expansion and the melt flow ratio are two main parameters,which influence the high speed extrusion and coating property of PE melt and are used as controlling indexes for production of the PE insulation materials,A flow model for PE melt in the crosshead is put forward in this paper.