Corner Coating of Powder Coatings ASTM D 2967-2017
Meaning and use
4.1 This test method measures the extent to which different coating powder materials cover sharp corners. Corner coverage is affected by surface thickness, thixotropy, melt viscosity, surface tension, curing rate, and application and curing temperature.
1.1 The test method consists of determining the ratio of angular thickness (see 3.1.3) to surface thickness (see 3.1.4) of the powder coating applied to a particular surface thickness by dipping a preheated square rod into an aerated powder and curing the coating using predetermined conditions.
Note 1: The corner cover property is also called “edge cover”, but the latter is not recommended. There are widespread misconceptions and expectations about the term “edge coverage”. The test was performed on steel bars with square corners, and the results do not necessarily correlate with sharper edges, i.e., burrs. Coatings with measurable corner coverage may still not protect sharper edges from corrosion or provide the electrical insulation required for some applications.
1.2 Values expressed in SI units shall be regarded as standard. The values given in parentheses are for reference only.
1.3 This standard is not intended to address all, if any, safety concerns associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use.
1.4 This international standard is based on the internationally recognized standardization principles established in the Decision on Principles for the Development of International Standards, Guidelines and Recommendations issued by the WTO Committee on Technical Barriers to Trade.