Time monitored process for controlling injection molding cycle
Abstract
Abstract PROCESS CONTROL FOR INJECTION MOLDNG MACHINES IN WHICH THE VISCOSITY OF THE PLASTICIZED MATERIAL IN A SHOT BEING PREPARED IS MONITORED AS A FUNCTION OF RAM INJECTION SPEED (RATE OF MELT FLOW) AT CONSTANT HYDRAULIC PRESSURE. THE INTERVAL IS MEASURED DURING RAM ADVANCEMENT BETWEEN THE TIME AT WHICH A PRESSURE RELIEF VALVE OPENS AND THE TIME THAT THE MOLD CAVITIES ARE SUBSTANTIALLY FILLED (WHEN THE RAM IS AT END OF STROKE). IF THE TIME PERIOD EXCEEDS OR FALLS BELOW PREDETERMINED LIMITS, EITHER (1) THE HEAT INPUTE TO SUBSEQUENT SHOTS BEING PREPARED MAY BE RESPECTIVELY RAISED OR LOWERED IN INCREMENTS, (2) HIGH PRESSURE INJECTION TIME MAY BE RESPECTIVELY ADDED OR SUBSTRACTED IN INCREMENTS TO INCREASE OR DECREASE THE POINT IN TIME AT WHICH LOWER SECONDARY HYDRAULIC PRESSURE IS APPLIED, OR (3) INJECTION PRESSURE MAY BE RESPECTIVELY RAISED OR LOWERED.
Inventors
- 👤 H Hutchinson
- 👤 V Arpajian
- 👤 R Malcomson
Bibliographic Details
Claims Analysis
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