As we all know, the scratch resistance of the arc surface of electroplated tinplate has always been a point of attention in the industry, but is there a unified test method? How to use a test method to compare the surface scratch resistance of electroplated tin plate?
The coating film pencil hardness method and the coating film scratch hardness method based on the pencil Hardness Tester can test and evaluate the scratch resistance of the surface.
Instrument used: pencil Hardness Tester
Test method: refer to the national standard GB6739-86.
1) Make five scratches on the surface of the sample for each test, start the test with the hardest pencil, and replace it with a lower level of pencil one after another until you find a pencil that only plows the film once among the five scratches, and then The next level of pencil represents the pencil hardness of the surface of the electroplated tin plate to be tested. If the surface of the tinplate is not plowed, the pencil of this grade represents the pencil hardness of the surface of the tinplate to be measured.
2) Since 6B is the softest level in GB6739-86, and we found in the actual test that when the thickness of the tin plating layer is relatively large, when testing with a 6B pencil, there are often more than one plow scratches, and the next level should be changed according to the standard pencil. At present, standard pencils softer than 6B cannot be obtained. Therefore, according to the actual situation we measured, we re-graded according to the original grading standards in order to compare the relative hardness.
a) The specified hardness is divided into 20 grades, from 1Hp to 20Hp in turn. Among them, 1Hp is the hardest, 20Hp is the softest, and the hardness decreases from 1Hp→20Hp.
b) When tested with a 6H pencil, if the coating is not plowed, the hardness is defined as 1Hp; when tested with a 5H pencil, if the film is not plowed, the hardness is defined as 2Hp; and so on.
c) When testing with a 6B pencil, if among the five scratches, there is a plow mark in only one pencil mark line, it is defined as 14Hp; if there are two or more scratches with a plow mark, each pencil mark One plow scar in the mark line was defined as 15Hp, the one with two plow marks in each pencil scratch line was defined as 16Hp, and so on. This is based on the number of plow scars
