Adhesion Test Procedure (One)
Definition of Adhesion Test ProcedureThis test is a test of adhesion. The mutual attraction of the contact parts of two different substances. A manifestation of molecular force. It only appears when the molecules of two substances are very close. Generally, the of two solids cannot be in close contact, and the adhesion between them cannot act; Liquid and solid can be in close contact, and the adhesion between them can play a role. For example, there is adhesion between the coating and the coated object.
It refers to the firmness of the combination between the paint film and the surface of the coating. This binding force is formed by the interaction between the polar group of the polymer in the paint film and the polar group on the surface of the coating. There is contamination or moisture on the coated surface; The paint film itself has large shrinkage stress; The number of polar groups is reduced due to the cross-linking of polymers in the curing process. These are the factors leading to the decrease of film adhesion. The adhesion of paint film can only be measured by indirect means. At present, the special methods for measuring the adhesion of paint film are divided into reference types, namely, the comprehensive measurement method represented by cross cutting method and circle drawing method, the peeling test method represented by pulling method and the test water test method combined with solvent and softener.
Adhesion Test KnifeGenerally speaking, the Adhesion Test Procedure is a tool to test the adhesion of the test object after coating. According to the Japanese industrial standard (JIS), it is divided into 1 ~ 5 levels. The higher the level, the stricter the requirements. When the customer specification requires level 5, it means that there can be no falling off at all.
The width of the edge of the 100 grid knife is about 10mm ~ 12mm, with an interval of 1mm ~ 1.2mm. There are 10 grids in total. When the straight line is drawn, 10 straight line knife marks with the same interval will appear. When the straight line knife mark is drawn at the vertical position, it will become a 10 * 10 100 grid square. When the 100 grid knife is drawn, it should be cut to see the substrate, not only on the coating, otherwise the test will not be established. After the adhesion test knife is finished, the tape must also be used to test whether it will fall off. First, stick the tape on the adhesion test position, press it down with your fingers, and then tear it up with instant strength to see whether the paint on the material falls off. In addition, not any kind of tape can be used. In terms of JIS standard, the brand and model must be specified. For example, 3M transparent tape 600 has a width of 3 / 4inch and a length of 1296inch and 2592inch.