1. Scope
1.1 This standard describes a procedure for evaluating and quantifying, with an optical imaging and analysis system, the separation and detachment of a painted or coated surface resulting from adhesion by tape testing (as performed according to test method ASTM D 3359).
1.2 Presented herein are the system hardware and software requirements of a suitable image capture and analysis system, as well as the general procedural requirements for conducting the image capture of tested specimens, digital processing of the images to highlight and enhance damage sites, software analysis guidelines and rating of the surface defect severity of specimens.
1.3 This test method is used to establish whether the adhesion of a coating to a substrate is at a
generally adequate level. This level is ultimately determined by the contracting parties with respect to coating durability and end-use performance requirements; and will vary depending on the type of coating system under evaluation.
1.4 This test method allows characterization of adhesion failure sites with a higher level of precision than is afforded by unaided visual means since software digital analysis of a captured specimen image allows precise geometric determination of the area bounded by each instance of coating detachment. This is performed at a pixel level within the image. While variation exists, operator-to-operator, in the application of the adhesion testing tape and its removal that can result in variable test results, this test method provides a means for performing the evaluation of subsequent test damage to specimens without the bias of variable operator influence; and that by precise measurement conducted automatically by computer software upon a digital image of the specimen. Although the operator performs the evaluation procedure with the digital imaging/analysis system, his perceptions and judgments (susceptible to deleterious influence by improper lighting, human fatigue, eyestrain and variable technique) are excluded from the damage measurement and quantification process. This represents a new and beneficial improvement in the state of the art of coatings damage-evaluation methodology.
1.5 In multicoat systems, adhesion failure may occur between coatings so that the adhesion of the
coating to the substrate is not determined.
1.6 Where multicoat systems are under evaluation, and these coating systems are comprised of
layers with even slightly varying chromatic shades, this test method (hardware permitting) allows determination of which coating layer has detached (separation layer). In such cases a relative and general comparison in adhesion performance among the various coating layers may be determined.
1.7 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 to determine the applicability of regulatory limitations prior to use.
Keywords
The title and scope are in draft form and are under development within this ASTM Committee.
Citing ASTM Standards
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