The aim of his study is to determine the model test bulk used by the injection molding process. The mathematical model governing by the plate solidification will indicate the solidification time of the gate together with the beginning of the stabilization of the cavity bulk. In this test a styrene-acrylonitrile copolymer (SAN) will be used. In order to develop the model tests, the material had to be dried to establish some parameters like: injection pressure, injection time, temperature of the different stages as well as moulding temperature. The variable parameters were the time and the discharge pressure. As the model tests were fully develoved, bulks were determined, first for the mould cavity and branches and next for the single cavity which was separated from the branches. The variation of the cavity bulk for the different discharge pressures and the standard deviation were graphically represented due to the time deviation of the discharge. The results showed that the time the bulk cavity begins to stabilize matches the calculated time, for the non-flow temperature, as well as the glass part temperature, the discharge pressure.
Thermoplastical; solidification; injection bulk; PvT
