| Summary: | 碩士 === 國立雲林科技大學 === 機械工程技術研究所 === 83 === A methodology is set forth for the numerical prediction of
the flow length and through-thickness residual stress develop-
ment in the injection molding processes for both thermoplastic
and thermoset polymers. A simplified one-dimensional mold fill-
ing model is proposed to simulate the outcome of the spiral flow
mobility tests. Modified Cross model and WLF model were used to
evaluate the temperature, curing and shear rate dependent
viscosities for thermoplastic and thermoset polymers, respe
Fl=-109.592593+0.684074P+1.053704Q+0.295741To+0.06537Tw
However , the above results are not all valid for thermoset
injection molding. One major concern is that the viscosities of
thermoset polymers grow very quickly when increasing mold
temperatures. This complex curing phenomena may cause the flow
length to get shorter at higher mold temperatures. Moreover, the
transient residual stress developments during the injection mold-
ing processes are determined as well. At the filling stage, tensile
stresses occur near the surface layer and almost zero.
The simulation work presented here can provide useful polymer
mobility data without consumptive and expensive experiments or
computation. It can also help the designers to determine the
appropriate processing conditions for different materials.
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