Method of controlling the temperature of moulds for plastics processing

摘要

In conventional methods of temperature control, an adaptation of the temperature conditions to the process parameters at any one moment is not possible, and it is not possible to compensate for disturbances in the injection-moulding process nor the unfavourable position of cooling surfaces with respect to the mould contour in the case of complicated moulds. Taking these disadvantages as a starting point, the object was to provide a method which, while taking into account the parameters of the injection-moulding operation at any given moment, including disturbances of the process which occur, ensures adequately good adaptation of the average mould temperature to a set temperature, to be predetermined, with simultaneously self-adjusting control, and which operates without additional energy. As a solution, it is proposed that the temperature-controlling process is separated into two phases, an initial phase and a steady-state operating phase, with different temperature-controlling conditions in each case, the initial phase being ended after the predetermined set mould temperature is reached or exceeded for the first time, and the average mould temperature being measured continuously throughout the entire cycle at a precisely defined location and a surge of coolant which takes into consideration the temperature control in the previous cycles being introduced at the point in time Z2, which is fixed by a signal of the machine sequence control at a time close to the injection operation, in order ... in the time period of greatest temperature difference between injected melt and ... Original abstract incomplete. <IMAGE>