Injection molding of plastic plates combined with boss features on superplastic Zn-22Al sheet
Journal
International Polymer Processing
Journal Volume
16
Journal Issue
4
Pages
412-420
Date Issued
2001
Author(s)
Abstract
This paper presents the development of a hybrid process combining forming of a superplastic zinc-aluminum sheet with injection molding. The product is a plastic part covered with a superplastic zinc-aluminum layer used mainly for electromagnetic interference (EMI) shielding. This paper investigates the moldability of Zn/Al sheet covered plates with various bosses. The effects on the moldability of various parameters, including: melt temperature, injection pressure, sheet thickness, various boss shapes and boss location in the mold, are investigated. It is found that bosses formed with thick Zn/Al sheet and located close to melt entrance exhibit good moldability. Among boss geometries, boss depth is the most critical parameter; a little increase in boss depth sharply lowers the mold-ability. Large angle improves moldability. To help interpret the effects of geometrical parameters, sheet deformation is observed by measuring the deformations in printed-grids and thickness. The base circle of the boss is found to be the most severely deformed region. The thickness reduction ratio in the center of base circle could help predicting moldability. © 2001 Walter de Gruyter GmbH, Berlin/Boston, Germany.
Other Subjects
Aluminum alloys; Binary alloys; Deformation; Electromagnetic pulse; Geometry; Injection molding; Plastic parts; Zinc alloys; Aluminum layers; Electromagnetic interference shielding; Hybrid process; Melt temperature; Moldability; Plastic plates; Plastics parts; Zinc aluminiums; Zinc-aluminum; Zn-22Al; Molds
Type
journal article