0957-4174/$ - see front matter © 2013 Elsevier Ltd。 All rights reserved。 doi:10。1016/j。eswa。2013。02。017

C。-P。    Chen    et    al。  /    Expert    Systems  with    Applications    36    (2013)      10752–10759 10753

This paper discusses the application of CAE technology for the injection molding of a thin-shell plastic component (based on poly- amide PA9T) using Mold-Flow Plastics Insight Package。 In this study, a Taguchi’s L18(21 × 37) orthogonal table was applied to plan the simulation and the experiments。 Four controlling factors of melt temperature, mold temperature, injection speed, and packing pressure with three levels for each factor were selected。 The dimensions of warpage deformation of the both the x-direction and the y-direction are selected quality objective。 By implementing the DOE method is utilized to obtain an optimal parameter setting from a regression equation that relates the desired outputs with

the significant factors identified by the analysis of variance (ANO- VA)。 In this study, the melt temperature and the packing pressure was found to be the most significant factors in injection molding process for thin-shell plastic  parts。

2。 Design of experiments  approach

Depending on objectives, this study is to identify an optimal setting that targets to minimize the  warpage  of  edge in  the both of the x-direction and the y-direction。 To resolve this type of parameter design problems, an objective function, F(x), is defined as follows (Myers & Montgomery,  2002),

          1

   2 !P2      w

Table 1

Basic physical property of plastic composites PA9T。

Properties Parameter

Density (g/cm3) 1。62

Glass fiber (%) 33

Tensile strength (Room temperature)  (MPa) 190

Tensile flexural strength (Room   temperature) (MPa) 225

Elongation (%) 3。2

Heat  distortion  temperature (°C) 285

Mold  shrinkage (%) 0。1

(Kuraray Co。 Ltd。, 1998)。 ‘‘PA9T” has a superior balance of proper- ties, including low water absorption,  high  chemical  resistance, and excellent resistance to abrasion, in addition to heat-resistance, and is praised as ‘‘a new material with high functions”, compared with other existing high-temperature engineering plastics like heat-resistant polyamide (PA6T),  polyphenylene  sulfide (PPS), and liquid crystal polyesters (LCP)。 Therefore, adaptive applied to the electronic parts which require heat-resistance and dimensional stability, such as connectors, switches, relays, parts for three- dimensional circuits, bobbins, etc。 for personal computers and por- table communication devices。 Table 1 lists the basic physical prop- erties of the polyamide PA9T。

3。2。 Schematic of a specimen

DF ¼    Y dwi

i¼1

FðxÞ¼ —DF

j¼1

ð1Þ

Fig。 1 shows the dimensions of a desired final product。 It is one of cover components used in the power supply。 Fig。 1 also shows