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Using the knife blade of the hundred grid knife itself, cross cutting plastic, metal coating, coating surface, and then using standard tape to cover the cutting surface tear off, to judge the coating surface spalling.
It mainly evaluates the bonding ability of coatings and coatings on various substrates relative to substrates by checking the adhesion of coated products and combining with the use of various test tapes.
Matters needing attention
All cuts should be penetrated through the coating, but the cut must not be too deep.
If the coating is too thick and hard to penetrate the substrate, the test is invalid, but it should be stated in the test report.
In special circumstances or with special requirements, the adhesive tape method should be used. Adhesive tape is generally 25mm wide translucent tape, back material is polyester film or acetate fiber. The tape is pasted on the whole scratch, and then torn off at the minimum angle. The result can be calculated according to the proportion of the surface area of the film to be glued.
The test should be carried out at temperatures of 23 + 2 degrees C and relative humidity 50 + 5%.
Adhesion test standards:
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ISOGrade
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ASTMGrade
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Test result
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0
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5B
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The edge of the incision is completely smooth, and there is no spalling on the edge of the lattice.
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1
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4B
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There is a small piece of spalling at the intersection of the incision, and the actual damage in the delimitation area is not more than 5%.
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2
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3B
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The edges and / or intersections of the incisions are spalling, and their area is greater than 5%, but less than 15%.
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3
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2B
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Part of the edge along the edge of the incision is spalling or the whole piece is peeling off, and / or part of the lattice is spalling off the whole piece.
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The area being stripped is more than 15%, but less than 35%.
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4
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1B
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The large margin of the margin of the incision or some part of the grid is spalling partially or wholly. The area is larger than that of the drawing35% of the grid area, but not more than 65%.
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5
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0B
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Exceed
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