METHOD AND APPARATUS FOR DISPENSING LIQUIDS AND SOLIDS

摘要

A system (Fig. 16) for metering and dispensing component liquids and solids has a microprocessor-based control system and progressive cavity pumps which provide accurate control of component ratios, shot sizes, flow rates and dispense durations. The system has feedback components (58, 66, 60, 68) for controlling the pressure, flow rates, fluid levels and amounts of fluids dispensed. The pressure in the flow system is used to control the pumps (34, 36) rather than a valved nozzle (49). The system may be used as a sprayer with compressed air added. Back and forth movement of the pump provides compensation for pressure changes. A mold charging system uses pressure to control the pumps which are cycled on and off to avoid overpressurizing the mold. The rate of pressure increase is used to control the rate of flow from the pumps as the mold approaches completion of the charge to avoid overpressurizing the mold.