ASTM D6441-2016 Powder Coating Hiding Power Test
Meaning and purpose
5.1 the contrast under specified film thickness is useful covering power parameters of production control and purchase specification.
5.2 the covering power, the greater the per unit area the less they get sufficient to cover the required coating. Therefore, understanding the hiding power is important for coating cost and comparing coating value.
Scope of
1.1 These test methods determine and report the hiding power of powder coatings based on two parameters:
1.1.1 Test Method A – Contrast at a given film thickness
1.1.2 Test Method B — Film thickness with 0.98 (98%) contrast.
Note 1: measuring the parameters follow the powder coatings industry practice, measurement of hiding power and the relationship between film thickness, rather than test method D344 and D2805 as well as other hiding power test methods used in “spreading rate” function.
ASTM D6441-2016 Powder Coating Hiding Power Test
Note 2: covering power by spectrophotometry is defined as 0.98 under the contrast of diffusion rate. Please refer to terms D16, D2805 and the Paints and Coatings Testing Manual for definitions of spreading rate and hiding power.
Note 3: A contrast ratio of 0.98 is generally accepted in the paint industry as representing “complete” concealing of a reflective hiding power measurement. But visually and photologically, it is slightly incomplete.
1.2 this test method covers the through the determination of electrostatic spraying of powder coatings covering power.
1.3 these test methods through reflection and thickness gauge measurement to determine the hiding power. They are restricted to coatings with a minimum CIE-Y reflectivity of 15%.
1.4 to SI units shall be deemed to be standard. The values given in parentheses are for reference only.
1.5 This standard is not intended to address all safety issues, if any, associated with its use. The user of this international standard has the responsibility to establish appropriate safety and health practices, and determine regulations limit the applicability of before use premise.