射出成形におけるスキン層の生成とその影響

抄録

The purpose of this study is to establish a quantitative deformation analysis of the out-of-plane deflections occurring in a product when released from the mould.
At first, it was investigated how the thickness of the skin layer is influenced by the mould temperature, by using thermal conduction analysis and experiment. Secondly, fibre orientation in the skin layer was made clear by soft X-ray photograph and visualization. Finally, a deformation analysis was attempted with consideration for the fibre orientation in the skin layer.
The following conclusions were obtained.
(1) It became clear that skin layer formation has two patterns; one is to rotate the fibre in a 180-degree arc and another is not to rotate. The fibre in the core layer is taken into the skin layer after reaching at the flow front.
(2) As the fibre orientation is different in the skin layer from that in the core layer for injection moulding of FRTP, it is desirable to consider the influence of the fibre orientation in skin layer on the material constants.
(3) By comparing the analytical results with the experimental results, it appears that this flow analysis considering thermal conduction gives satisfactory prediction for the thickness of the skin layer.
(4) By comparing the analytical results with the experimental results of deformation, it appears that this deformation analysis considering the skin layer gives satisfactory quantitative prediction.