本标准规定了一个经验性的试验程序来评价色漆、清漆及有关产品的涂层在标准条件下经压陷逐渐变形后，其抗开裂或抗与金属底材脱离的性能。 本标准适用于单涂层或复合涂层体系，对复合涂层体系来讲，可对每一涂层分别进行试验或对整个体系进行试验。 本标准适用于船舶防污漆。
1 Scope
This standard specifies an empirical method for assessing the resistance of a coating of paint, varnish or related product to cracking and/or detachment from a metal substrate when subjected to gradual deformation by indentation under standard conditions.
This standard is applicable to single-coat or multi-coat system. For a multi-coat system, each coat may be tested separately or the complete system may be tested.
The method may be carried out as follows:
— either as a “pass/fail” test, by testing to a specified depth of indentation to assess compliance with a particular requirement;
— or by gradually increasing the depth of indentation to determine the minimum depth at which the coating cracks and/or becomes detached from the substrate.
2 Normative References
The following normative document contains provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 3186-2006 Paints, Varnishes and Raw Materials for Paints and Varnishes — Sampling (ISO 15528:2000, IDT)
GB/T 9271 Paints and Varnishes — Standard Panels for Testing (GB/T 9271-1988, eqv ISO 1514:1984)
GB/T 13452.2 Paints and Varnishes — Determination of Film Thickness (GB/T 13452.2-1992, eqv ISO 2808:1974)
GB/T 20777-2006 Paints and Varnishes — Examination and Preparation of Samples for Testing (ISO 1513:1992, IDT)
3 Principle
The product or system under test is applied at uniform thickness to flat panels of uniform surface texture.
After drying/curing, the elastic properties of the paint film are determined by first placing the coated panel between two rings, namely the retaining ring and the drawing die. The panel is then pushed by a hemispherical indenter at a steady rate into the die so as to form a dome shape with the coating on the outside.
The deformation is increased either to a depth agreed between the interested parties or until the coating cracks and/or detaches from the substrate, and the result is then assessed.
4 Apparatus
4.1 Cupping test apparatus, which conforms to the design and dimensions shown in Figure 1 and consists essentially of the following components:
4.1.1 Drawing die, made of surface-hardened steel and of which the surface in contact with the test panel is plane-polished.
4.1.2 Retaining ring, of which the surface in contact with the test panel is plane-polished and parallel to the contacting surface of the die.
Foreword II
1 Scope
2 Normative References
3 Principle
4 Apparatus
5 Sampling
6 Test Panels
7 Procedure
8 Supplementary Test Conditions
9 Expression of Results
10 Precision
11 Test Report
Bibliography
