Test Background
The cupping test of paints and varnishes can evaluate the resistance to cracking or separation from the metal substrate after the coatings of paints, varnishes and related products are gradually deformed by indentation under standard conditions. It is suitable for single coating or composite coating systems. For composite coating systems, each coating can be tested separately or the entire system can be tested.
Zhongke Testing Reliability Experiment Center has the capability of reliability testing of various paints and varnishes, and provides professional cupping test services for paints and varnishes.
Scope of tests
Color paint is divided into primer and topcoat: primer is divided into primer, putty, mid-coat, sealer, anti-rust paint, etc.; topcoat is divided into enamel paint, special topcoat, etc.
The paint and film of varnish are transparent and are divided into ester varnish, shellac varnish, phenolic varnish, alkyd varnish, acrylic varnish, polyester varnish, high-performance varnish, fluorocarbon varnish, etc.
Test method
1. The product or system under test should be prepared into a coating film with uniform thickness on a test plate with a uniform surface texture.
2. After drying/curing, first place the coated test panel between two rings, that is, between the fixed ring and the telescopic die, and then use a hemispherical punch to push the test panel into the telescopic die at a stable rate so that the test panel forms a dome shape with the coating facing outward to measure the elasticity of the paint film.
3. The deformation is increased to a depth agreed upon by the parties concerned or until the coating has just begun to crack or detach from the substrate, and then evaluate the results.
Test standard:
GB/T 9753-2007 Paints and varnishes Cupping test
ISO 1520-2006 Paints and varnishes Cupping test
BS EN ISO 1520-2007 Paints and varnishes Cupping test
EN ISO 1520-2007 Paints and varnishes Cupping test
