Adhesion Determination of Waterborne Epoxy Heavy Anticorrosive Coating film

The sample should also be prepared before the sample adhesion test, which can be measured by the following sample for testing the pencil hardness. The measurement method is as follows: 

(1) Take out the coated metal sheet and place it flat on a piece of paper; 

(2) Use a scribe to draw a small square of 2 mm × 2 mm horizontally and vertically on the metal sheet, and gently brush off the floating powder on the surface with a brush; 

(3) Use a specific adhesive tape to stick the small squares drawn above, and record the percentage of the fallen squares to the total number of squares; 

(4) Compare with the test grading table to get the adhesion level.

Note: When using a grid tool to draw a square on the aluminum sheet coated with the prepared paint, use great force to avoid drawing incomplete squares, and the comparison of unfilled squares is invalid. Adhesion level standard is divided according to GB/T1720-79. See Table 2-4 for details of the grading standards.