Process optimizationof injection mold for large plastic parts of automobile dashboard based on Moldflow

doi:10.19491/j.issn.1001-9278.2021.12.020

Abstract

Abstract:

Taking a large plastic car dashboard as an example， the CAE analysis software Moldflow was used to analyze the optimal gate position of multiple gates. The orthogonal experiment scheme was established with the warpage deformation as a main analysis index， and the optimal process combination was obtained through analysis and comparison. Based on the simulation analysis of the analysis model， the excessive warpage deformation and welding marks on the surface were found to become the main defects. The uneven shrinkage， orientation effect， and uneven cooling were considered as the main reasons for the excessive warpage deformation. Through using a sequential valve gate technology， the gating system， cooling system， and related process parameters were optimized， the obvious weld marks on the appearance surface were basically eliminated， and the amount of warping deformation could meet the production requirements of enterprose. Finally， the optimized process parameters and mold structure were obtained. The research results indicated that the use of Moldflow for the CAE analysis of large plastic parts could effectively shorten the design cycle， improve the molding quality of large plastic parts， and reduce production costs.

Key words: dashboard, orthogonal experiment method, weld line, optimization design, warpage, cooling system, hot runner, valve gate

CLC Number:

TQ320.66⁺2

WU Junchao. Process optimizationof injection mold for large plastic parts of automobile dashboard based on Moldflow[J]. China Plastics, 2021, 35(12): 121-128.

Figures/Tables 19

Fig.1. Car dashboard

Fig.2. Properties of the Lustran ABS 1146 resin

Fig.3. Meshing result

Fig.4. Gap error warning

Fig.5. Renumber units and nodes

Fig.6. Set restrictive gate node

Fig.7. Gate setting and gate position analysis of car dashboard plastic parts

Fig.8. Single layer cooling water circuit used in analysis

水平

浇口个数

（A）

模具温度

（B）/℃

熔体温度

（C）/℃

保压时间

（D）/s

240

260

280

Tab.1. Factors and levels table

试验号	A	B /℃	C /℃	D/s	翘曲变形总量/mm
1	6	70	240	20	30.28
2	6	75	260	25	25.26
3	6	80	280	30	24.65
4	8	70	260	30	16.68
5	8	75	280	20	15.22
6	8	80	240	25	14.86
7	9	70	280	25	17.02
8	9	75	240	30	16.88
9	9	80	260	20	15.98
均值1	26.730	21.327	20.673	20.493
均值2	15.587	19.120	19.307	19.047
均值3	16.627	18.497	18.963	19.403
极差	11.143	2.830	1.710	1.446

Tab.2. Orthogonal table and test results

Fig.9. Effect curves

Fig.10. Determined gating system and cooling system

Fig.11. Holding pressure and holding time

Fig.12. Moldflow analysis results of instrument panel plastic parts

Fig.13. Schematic diagram of valve gate

Fig.14. Analysis of warping deformation

Fig.15. The casting system， cooling water way setting and valve gate setting of instrument panel plastic parts

Fig.16. CAE analysis results of instrument panel optimization scheme

Fig.17. Freezing factor at gate and filling time

References 9

1	战仕海．汽车仪表板的设计与分析研究［D］．大连：大连理工大学，2013.
2	任海民. 汽车车身材料应用现状与发展趋势［J］. 电子世界，2014（10）：411.
3	马清，刘仁辰，刘岩.等. 单晶α-Al₂O₃纤维规模化制备及应用进展［J］. 耐火材料，2019（4）：4.
	MA Q， LIU R C， LIU Y，et al. Mass production and applicati⁃on of single crystal α⁃Al₂O₃fiber［J］. Refractories，2019（4）：4.
4	郭文博，刘泓滨，车应田，等．飞机支线架注塑成型缺陷分析和多目标优化［J］．轻工机械，2019，37（5）：77⁃83.
	GUO W B， LIU H B，CHE Y T，et al.Injection molding defect analysis and multi⁃objective optimization of aircraft branch frame［J］．Light Industry Machinery， 2019，37（5）：77⁃83.
5	张林，张会，刘睿.等.基于Moldflow的电池盒工艺参数优化及注塑成型研究［J］.陕西理工学院学报，2015（5）： 5⁃10.
	ZHANG L， ZHANG H， LIU R，et al. Study on battery cover molding and optimization based on Moldflow［J］．Journal of Shaanxi Shaanxi University of Technology （Natu⁃ral Science Edution），2015（5）： 5⁃10.
6	曾令琴. 注塑件熔接痕的改善措施及数值模拟D］．山西.太原科技大学，2009.
7	黄先.大型精密注塑模具熔体充模流动CAE优化分析［D］.成都：四川大学，2007.
8	吴俊超. 复杂薄壁注塑件翘曲变形及注塑工艺参数的优化与研究D］．南昌：南昌大学，2012.
9	周香. A、B面壳类注塑件成型工艺优化［D］.合肥：合肥工业大学，2015.

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