Adhesive dispensing method

摘要

There is a need to accurately dispense the correct volume of adhesive to fill the gap 46 in a joint between two bodies 42, 44, so as to ensure the integrity of the joint without wastage. It has been found that, for a given ramp (flow) rate of dispensed material, the time interval for the back pressure generated at a dispensing head 22 to change between two values is representative of the gap volume. By measuring this interval and, by means of a table or algorithm, determining the gap volume, then comparing this with the actual amount dispensed, the dispensing operation can be terminated when the gap is filled. For gaps of variable shape (Figs 4-6), a refinement includes further measurement of the back pressure and comparing with values for gaps of constant shape but different sizes and recalculating the volume correspondingly.