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In this paper, based on the thin-wall moulding under high
processingpressure. A theoretical model contains the pressure
term is developed by combining the Williams-Landel-Ferry(WLF)
semi-experiential equation and the weld-line strength model of
the molecular chains crossing the interfaceand self-diffusion.
Then applying optimal theory to find the optimal material.
According to the theoretical model, the high pressure would lead
to the high viscosity and low molecular diffusion and reduce the
degree of bounding. However, the traditional weld-line theory
can't modify this fact. Therefore,it would be more accurate for
thin part to predict the degree of bounding byapplying the
theoretical model adding the pressure term. According to the
analytic result it was better for using higher melt temperature
in the moulding process. For the thin-wall material, it is
better for selecting lower density, lower plateau modulus,
higher the ratio of mean-square end-to-end distance to average
molecular weight, lower molecular weight andlower glass
transition temperature matreial and must be permitted by
mechanicalproperties.
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