TESTING METHODS FOR POWDER COATING
TESTING METHODS FOR POWDER COATING
These test methods are designed for two purposes: Performance reliability and Quality control
1/ GLOSS TEST (ASTM D523)
Test coated flat panel with Gardner 60 degree meter. Coating shall not vary 5% from data sheet requirements on each material supplied
2/ BENDING TEST (ASTM D522)
Coating on 0.36 inch thick phosphated steel panel shall withstand 180 degree bend over 1/4" mandrel. No crazing or loss of adhesion and finish at the bend be able to removed with 3M Y-9239 tape.
3/ HARDNESS TEST (ASTM D3363)
Faber Castell wood pencils are used in hardness of 1, 2, 3, 4. Coating shall show no marks from 2H pencil.
4/ CROSS HATCH ADHESION TEST (ASTM D3359)
Scribe parallel lines through coating to substrate, 1/4" apart a distance of one inch. Scribe anoth set of parallel lines 1/4" apart and perpendicular to the first set. Apply any sticky tape then remove quickly. Results should be no lifting of the cured powder between scribe lines.
5/ CHEMICAL RESISTANCE TEST (ASTM D1308)
Place approximately 10 drops of test solvent, consisting of 95% by weight toluene and 5% by weight Methal Ethly Ketone on the surface of the coating. Allow to stand for 30 seconds. Wipe off with soft, dry cloth. Coating shall show no more than a slight circular mark.
6/ IMPACT TEST (ASTM D2794)
Coating on 0.36 inch thick phosphated steel panel shall withstand impact with 1/2" Gardner impact tester ball at 26 inch pounds direct and reverse. No grazing of loss of adhesion. Finish shall not be able to removed at impact area with 3M Y-9239 tape.
7/ SALT SPRAY CORROSION TEST (ASTM B117)
Use a 5% salt solution at 92-97 degrees F in a sealed weather cabinet. Scribe X in steel Zince phosphated test panel to bare metal. Inspect every 24 hours. End test and toto hours after 1/4" creepage from scribed area. Creepage shall not exceed 1/4" in either direction from scribe line after 500 hours exposure.