Viscous material dispensing system and method with feedback control

Abstract

A system for accurately dispensing controlled amounts of viscous material. The system includes a pressurized supply of the viscous material, a dispenser connected with the pressurized supply and a feedback control for ensuring that a discrete dispensed amount corresponds closely to the desired dispensed amount for a particular application. The different methods of feedback control include changing pressure of the pressurized supply after measuring a dispensed amount and comparing the dispensed amount with a stored value representing the desired amount. Another manner of feedback control includes changing an air operating pressure associated with the dispenser. A third type of feedback control includes adjusting the duration that the dispenser is maintained on to dispense the viscous material. Each of these types of feedback control are preferably used in succession, as necessary, to ensure that the desired amount of viscous material is discharged from the dispenser. Methods of controlling an amount of viscous material discharged from a dispenser further include using one or more of the feedback controls described above.