This paper deals with the method to measure the scratch resistance of the plastic plates.
We studied about the relation between the amount of scratches left on the plastic plates when injured by means of the Mar resistance tester and the ratio of their gloss diminution measured by the gloss meter.
As the result, we learned that the rate of gloss diminution on the plastic plate due to the artificial scratches by Mar resistance tester, were related only to the amount of scratches on it when the ratio of the gloss diminution was more than 45%, and that the initial conditions of the plate (color, surface gloss etc.) did not affect it.
And we found that there was linear relation between the breadth of the scratch groove made on the plastic plate by the Clemens tester and the rate of the gloss diminution of the plate injured by Mar resistance tester.
Thus we learned that the scratch resistance of the plastic plate could be found by measuring the breadth of the scratch groove marked on it by the Clemens tester.
The above mentioned facts have been confirmed as the result of having tested the plate artificially scratched, but the test of the naturally scratched plate showed nearly the same result as the above mentioned one.
