For some jobs it is sufficient to dispense an adhesive or sealant product directly from the bottle or tube onto the surfaces to be joined. In other cases, however, more precise and automated dispensing may be required. The author’s company has developed equipment especially designed to make application of its adhesive products economical, fast, precise and clean. With this equipment, customers can apply beads, drops or continuous rings of adhesives, and spray, spin and screen-print chemical sealants. Use of this equipment ensures that there is no wasted adhesive, with just the required amount of product being dispensed every time.
For most applications, a standard unit will provide all the automation a customer needs. However, there are exceptions, and in addition to the standard equipment available, manufacturers must be able to design and build equipment to meet the requirements of unique applications.
Case in point is the Norfolk based company, PSS, which makes components for use in heavy vehicles such as buses, coaches, vans, trucks, cranes and tractors. PSS needed to solve the problem of a leak in a certain inherited power steering pump application. It was discovered that a pre-formed gasket was being used to provide the seal, and irregularities in the component surface meant the gasket could not fill all the gaps – hence the leak.
The remedy called for a consistent bead of flange sealant to be applied to the surfaces of the pump to supplement the seal. When the parts are brought together, the sealant spreads between the surfaces, filling gaps, voids, scratches and surface irregularities. Once the assembly is complete, the gasket cures and forms a durable seal.
But then the question of how to apply the adhesive at a speed that was consistent with the company’s production requirements needed to be addressed. It was decided to use an XY cartesian robot, tailored to meet the customer’s needs. The author’s company provided a three-axis benchtop robot, interfaced to a syringe of sufficient size to dispense 300ml cartridges of sealant. The machine configuration enabled the processing of two assemblies simultaneously, with the cycle being started by the push of a single button. Not only does the robot apply the sealant in exactly the right position, it also controls the flow so that the right amount is deposited.
Steve Ginger is equipment manager at Henkel, maker of the Loctite brand of products