Measurement of Opacity and Coverage in Thin-Film Powder Coatings

Abstract

Until recently, the field of powder coating has occupied a special area in the general field of plastics technology, somewhat apart and removed from conventional paint technology. This is mainly because coatings applied from powder are normally 10 mils thick or greater and used in applications where their outstanding corrosion protection, insulating characteristics or other functional properties are important. However, in the last several years, with the improvements made in both powder coating formulations and application equipment, coatings can readily be applied in the range of 1–3 mils. This brings the powder coating field directly in the realm of paint technology. While many of the tests used for conventional paints can also be used to measure films applied from powder, there are a number of other characteristics of a powder applied system which cannot be evaluated using conventional techniques.