New coating outperforms the competition
14 Sep 2000
High performance coatings for industrial applications have historically been made with solvents but new advances in waterborne coatings by Whitford Plastics Ltd are changing that with the development of Xylan 7910.
Xylan 7910 not only equals the performance of solvent-borne coatings but also improves on it in three ways. First, it is environmentally friendly because it is based on water, not contaminating solvent. Second, it virtually eliminates coating loss due to overspray. Xylan 7910 has been engineered for use with a curtain coater, an application method pioneered by Whitford that is 100% efficient. This not only saves money but adds to the protection of the environment by eliminating overspray (and the need to dispose of it). Thirdly, it has remarkable colour consistency, even when used on substrate with radically different rates of absorption.
The new coating is already being used in the automotive industry, withstanding temperatures of up to 250C. Applied to gaskets, Xylan7910 facilitates the release of the part of the machined surfaces of an engine block during maintenance, thus avoiding residue.
Although most coatings will not withstand the demands of a curtain coater, Xylan 7910 has been designed for such equipment. This is particularly important with gaskets since 60% of the total surface area consists of drain and piston holes- the reason why conventional spray applications creates waste.
Xylan 7910 has excellent adhesion to both the fibrous surface of the gaskets and the steel fire rings surrounding the piston holes. Further, its consistency of colour ensures that gaskets sold in transparent packaging are aesthetically pleasing to customers, even when the absorbencies of gaskets vary considerably.
Whitford quality control manager, Phil Gardner explains, 'We were asked to produce a water-based curtain-coating product for gaskets to replace a spray-application silicone coating. The manufacturer was having problems with wastage due to excessive overspray and, of course, there were environmental and health concerns.
'We produced a coating only to discover that the company intended to manufacture a different gasket with a much higher rate of absorption. We were able to modify the coating so the colour was consistent across the whole range of gaskets.'
Whitford Plastics are on the web at: www.whitfordww.co.uk
