石膏入り高密度ポリエチレンのスパイラル・フロー・テスト

抄録

The spiral flow tests have been carried out on high density polyethylene (SHOLEX 4250H) and the same polymer mixed with 50wt% gypsum by use of a vertical type injection molding machine with a spiral cavity.
The results obtained are as follows:
(1) For both of the materials, the spiral flow length is expressed by a polynominal whose variables are injection pressure, resin temperature, mold temperature and injection rate.
(2) The spiral flow length measured for both of the materials is affected primarily by injection pressure and secondarily by mold temperature. For the high density polyethylene mixed with gypsum, the spiral flow length is affected by resin temperature more strongly than by injection rate.
(3) The range of the combination of injection pressure and resin temperature in which injection molding of the mixture is possible, shifts to the high pressure side as compared with that for the pure high density polyethylene at the same temperature. But the extent of the range is almost equal for both of the materials.