PA66注塑导线槽脆断问题浅析

Analysis on brittle fracture of PA66 injection molding wire slot

在塑料注塑生产中,零件脆断的问题时有发生,为找出根本原因并做出相应改善,本文以PA66材料的汽车电路保护导线槽零件为研究案例,从设备、模具、工艺、材料、吸水量等方面进行研究分析。结果表明,在合适的设备和工艺条件下,PA66材料内玻璃纤维含量高低直接影响注塑产品的韧性;注塑零件避空位置会形成熔接线,该位置强度较其他位置相对薄弱,受外力时容易发生脆断;内部玻纤含量过高将会导致产品吸水性下降,吸水后增加的韧性并不足以抵消粒子本身的物性缺陷。

In the plastic injection molding production,the problem of brittle fracture of parts often occurs.In order to find out the root cause and make corresponding improvement,this paper takes the PA66 material as the research case of the automobile circuit protection conductor slot parts,and conducts research and analysis from the aspects of equipment,mold,process,materials,water absorption,etc.The results show that the glass fiber content in PA66 directly affects the toughness of injection molded products under appropriate equipment and process conditions;The welding line will be formed at the void free position of the injection molding part,which is relatively weak compared with other positions,and is prone to brittle fracture under external force;Too high content of internal glass fiber will lead to the decrease of water absorption of the product,and the increased toughness after water absorption is not enough to offset the physical defects of the particles themselves.