Three-dimensional numerical simulation for plastic injection-compression molding

doi:10.1007/s11465-018-0490-1

Frontiers of Mechanical Engineering

2018, Vol. 13

Issue (1): 74-84 https://doi.org/10.1007/s11465-018-0490-1

本期目录

Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG¹(

), Wenjie YU¹, Junjie LIANG¹, Jianlin LANG², Dequn LI¹

¹. State Key Laboratory of Material Processing and Die & Mold Technology, Huazhong University of Science and Technology, Wuhan 430074, China
². Beijing Institute of Aeronautical Materials, Beijing 100095, China

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Abstract：

Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian-Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.

Key words： injection-compression molding simulation injection molding melt flow cavity pressure

收稿日期: 2017-04-29 出版日期: 2018-01-23

Corresponding Author(s): Yun ZHANG

引用本文:

. [J]. Frontiers of Mechanical Engineering, 2018, 13(1): 74-84.
Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI. Three-dimensional numerical simulation for plastic injection-compression molding. Front. Mech. Eng., 2018, 13(1): 74-84.

链接本文:

https://academic.hep.com.cn/fme/CN/10.1007/s11465-018-0490-1
https://academic.hep.com.cn/fme/CN/Y2018/V13/I1/74

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Parameter	Value	Parameter	Value
$τ ∗$ /Pa	720887	$C p$ /(J·kg^-1·K^-1)	1880
$n ˜$	0.17	$k$ /(W·m^-1·K^-1)	0.24
$A 1$	38.724	$b 1$ /(m³·kg^–1)	8.65e–4 (melt), 8.61e–4 (solid)
$A ˜ 2$ /K	51.6	$b 2$ /(m³·kg^–1·K^-1)	4.83e–7 (melt), 5.85e–8 (solid)
$D 1$ /(Pa·S)	5.95e15	$b 3$ /Pa	1.74e+8 (melt), 3.43e+8 (solid)
$D 2$ /K	417.15	$b 4$ /K^-1	4.39e–3 (melt), 2.27e–3 (solid)
$D 3$ /(K·Pa^-1)	0	$b 5$ /K	415.98 (melt, solid)
$ρ$ /(kg·m^-3)	1034.7

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