Significance and Use 5.1 If the ink or coating is to fulfill its function, it must adhere to the substrate. Substrates and their surface preparation have a significant effect on the adhesion of inks or coatings. Therefore, a method of evaluating adhesion of inks or coatings to different substrates or surface treatments, or of different inks or coatings to the same substrate and surface treatment, is useful to the industry. 5.2 The limitations of all adhesion methods and the specific limitation of this test method to lower levels of adhesion should be recognized before using it. The intra– and inter–laboratory precision of this test method is under evaluation. 5.3 Printing area to be tested should be a solid area large enough to include the entire cross hatch pattern.Scope 1.1 This test method is based on existing Test Method D3359, with modifications to make it suitable for flexible substrates, printed electronic devices and membrane switches. 1.2 Despite the problems associated with a tape test on plastic substrates, it is our belief that this is still one of the best ways to test ink and coating for adhesion for membrane switch or printed electronic device applications. In writing this test method we are addressing several of the objections to the test method that could affect its precision and repeatability on plastic substrates. 1.3 These test methods cover whether the adhesion of coating or ink to a substrate is at an acceptable level. They do not distinguish between higher levels of adhesion, for which more sophisticated methods of measurement may be required. Note 1: It should be recognized that differences in adherability of the ink or coating surface can affect the results obtained with inks or coatings having the same inherent adhesion. 1.4 In multi–coat systems adhesion failure may occur between coats, so that the adhesion of the coating system to the substrate is not determined. 1.5 This test method is specifically designed for measuring adhesion of inks and coatings (films) that have a thickness of 5 mil (125 microns) or less, on plastics such as polyester and polycarbonate. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
