ABS衣架式模头的失效分析及其结构改进  

Failure Analysis and Structure Optimization of ABS Coat Hanger Die

作　　者：王和慧[1] 王军[1] 朱文敏[1] 陆磐谷[2] WANG Hehui;WANG Jun;ZHU Wenmin;LU Pangu(Sehool of Mechanical and Power Engineering, East China University of Science and Technology,Shanghai 200237, China;Gaoqiao Petro-Chamical Company, Shanghai 201208, China)

机构地区：[1]华东理工大学机械与动力工程学院,上海200237 [2]高桥石油化工公司,上海201208

出　　处：《塑料》2017年第6期118-125,共8页Plastics

摘　　要：利用有限元软件Polyflow对失效ABS棒材挤出模头的流道进行了数值模拟,得出压降过大是模头失效的主要原因。为降低模头压降提出改进方案:歧管的入口半径增大5 mm,模头压降降低了1.83 MPa,且出口速度分布更加均匀;扇形区的厚度增大2 mm,模头压降降低了2.06 MPa,但出口的速度变得更加不均匀;扇形区的厚度沿幅宽方向变化的模头改进相比对应的等厚度扇形区的模头压降降低了0.27 MPa,同时改善了模头出口速度的均匀性,但对压降与模头出口速度均匀性的改善效果并不明显;在歧管半径增大5 mm、扇形区厚度增大2 mm的改进基础上,双衣架模头的结构改进方法能将模头的压降降低了5.47 MPa。工艺改变特别是温度变化,对衣架式模头的正常挤出影响很大,当温度分别为260、240、225℃时,模头和分配器的总压降分别为5.9、10.7、14.2 MPa。通过对失效模头的各个关键参数进行改进模拟,定量地获得了各因素对模头压降与速度分布的影响规律和趋势,为类似衣架式模头的设计提供了思路和参考依据。In view of the failure of ABS steel extrusion die, Polyflow was used to simulate the die runner and the main reason of die failure was found that the pressure drop exceeds standard. In order to reduce the die pressure drop, improvement schemes were proposed. Firstly,the entrance radius of the manifold was increased by 3mm which resulted that the die pressure drop was decreased by 1.83 MPa and the outlet velocity distribution was more uniform. Secondly, the height of sector was increased by 2 mm which made the pressure drop decreased by 2.06 MPa but the speed of the export sector became more uneven. Thirdly, the design whose height of sector area was variable could improve the velocity uniform at the exit end, and reduce the pressure drop at the same time,but not obvious. Fourthly, based on the increase of radius 5 mm and 2 mm on the height, the new die which had double entrances made the pressure drop decreased by 5.47 MPa. The change of process especially the temperature had a great influence on the successful extrusion of the hanger die. When the temperature was 260, 240 and 225 ℃ , the total pressure drop of the die and distributor was respectively 5.9, 10. 7, 14. 2 MPa. Through these simulations, rules and the influence of various factors on pressure drop and velocity distribution were obtained quantitatively. Reference for the design of the similar coathanger die were provided.

关 键 词：衣架式模头 失效分析 结构改进 ICEM POLYFLOW 压力降 

分 类 号：TQ320.66[化学工程—合成树脂塑料工业]