限定加热管布局的快速热循环注塑成形模具电加热系统优化

Optimization of RHCM Mould Electric Heating Systems for Constrainted Heating Pipe Layout

针对管道布局、最大允许能耗给定条件下快速热循环注塑成形(RHCM)注塑模具型腔表面快速均匀加热的问题,提出以单根加热棒热流密度为设计变量,以模具型腔表面升温效率和温度分布均匀性为目标,结合有限元模拟、响应面设计以及多目标粒子群优化技术来优化RHCM模具电加热系统。与优化前相比,加热系统优化后,模具型腔表面最大温差降低63.4%,加热系统总能耗降低9%。对比了不同注塑成形工艺条件下成形的平板塑件表面质量,结果表明,相对传统注塑成形(CIM)工艺,RHCM工艺将制品表面粗糙度Ra从320 nm降低到118 nm,并有效抑制了制品表面熔接痕、缩痕等缺陷;发现制品表面粗糙度与型腔表面对应点温度成负相关,说明优化后的型腔表面温度分布更有利于提升制品表面质量。

Under the constraints of given heating pipe layout and the maximum allowable energy consumption,aiming to achieve rapid and uniform heating of the RHCM mould cavity surfaces,with the heat flux density of the single heating rod as the design variable,a method combining the finite element simulation,response surface design and multi-objective particle swarm optimization(MOPSO)technology was proposed to optimize the RHCM mould electric heating systems.After optimization,the maximum temperature difference of the mould cavity surfaces and the energy consumption of the heating systems are reduced by 63.4%and 9%respectively.The surface quality of flat plastic parts molded was compared with that under the conventional injection molding and RHCM processes respectively.The results show that the product surface roughness Ra may be reduced from 320 nm to 118 nm,and the surface defects such as weld marks and shrink marks also may be effectively suppressed by RHCM processes.It is also found that the product surface roughness has a negative correlation with the temperature of the cavity surfaces at the same location,indicating that the optimized cavity surface temperature distribution is more conducive to improve the product surface quality.