Abstract
In order to develop the accuracy of cross cut test, some factors were investigated. Cellophane tape is widlely used in the cross cut test. It was found that the conditions of taping up, the peeling rate and angale must be accordance with JIS. While the temperature and humidity specifications during testing are described in JIS, a great care is required for storage, since the humindity has a strong influence on the performance of the pressure sensitive adhesives during storage as well as upon the results of a peel-off test. The fast rewinding rate from a reel of pressure sensitive adhesive tapes seem to make a rough surface. It must be noted these factors. The cellophase tape showed almost the same peel adhesion for various coated steel plates with different base and post coatings. Therefore, it was clarified that the cellophane tape is suitable for the cross cut test. The trench introduced by a cutter knife on the coated steel plate was observed by a laser microscope. In order to form the stable trench, it was found to be useful in accordance with JIS regulations except the blade angle at the trench introduction.
