As per ISO 1519 OR as per ASTM D 522 Paints and varnishes — Bend test (cylindrical mandrel) shall be carried out.
How to test the same in site level:
This test procedure for assessing the resistance of a coating of paint, varnish or related product to cracking and/or detachment from a metal or plastics substrate when subjected to bending round a cylindrical mandrel under standard conditions. For a multi-coat system, each coat can be tested separately or the complete system can be tested.
The method specified can be carried out either as a “pass/fail” test, by carrying out the test with a single specified size of mandrel, to assess compliance with a particular requirement; or by repeating the procedure using successively smaller mandrels to determine the diameter of the first mandrel over which the coating cracks and/or becomes detached from the substrate.
Two types of apparatus are specified,
The method specified can be carried out either as a “pass/fail” test, by carrying out the test with a single specified size of mandrel, to assess compliance with a particular requirement; or by repeating the procedure using successively smaller mandrels to determine the diameter of the first mandrel over which the coating cracks and/or becomes detached from the substrate.
Two types of apparatus are specified,
type 1 being appropriate for use on test panels of thickness up to 0,3 mm, and
type 2 for use on test panels of thickness up to 1,0 mm. Both types of apparatus have been found to give similar results with the same coating, but normally only one will be used for testing a given product.
Also known as CYLINDRICAL BEND TEST to know the crack bridging, elasticity, elongation, flexibility of coating in LAB.
Also known as CYLINDRICAL BEND TEST to know the crack bridging, elasticity, elongation, flexibility of coating in LAB.
How to test the same in site level:
The coating and paint properties mainly include physical properties (such as appearance, density, thickness, mechanical properties like bond strength, abrasion resistance, residual stress, etc.) and chemical properties (such as chemical composition, Coating and Paint testing
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ReplyDeleteCylindrical Bend Test .