This paper introduces a method for measuring the adhesion between layers of chlorinated rubber anticorrosive paint and similar products. Although this method can only make qualitative judgment, it is of great significance in the consideration of coating material selection and supporting system because it is consistent with practical application. The tools and materials are described in detail, as well as the procedures for testing the adhesion between the primer and the middle coat, and between the top coat and the middle coat. This approach in the industry standard HG/T 2798 in chlorinated rubber coatings have been mentioned.

1. Introduction

In the coating industry, the evaluation of coating adhesion is one of the key factors to ensure the performance and service life of coatings. This paper introduces a method for measuring the adhesion between layers of chlorinated rubber anticorrosive paint and similar products.

Adhesion between the layers testing method and its application

2. Tools and materials

In order to test, the adhesion between the layers you need the following tools and materials:

Artist sculpting knife: for cutting coating sample.

The size of the ruler: used for measuring the coating sample.

Scotch tape: Used in the test step to evaluate the coating adhesion performance.

Filter paper: Used to cover the scotch tape over the coating before testing.

3. The method

3.1 primer and middle layer adhesion between the paint

3.1.1 sample preparation on one side of a plate with a etch primer, two primer for 48 hours after coating (24 hours). After 7 days, xenon lamp accelerated aging test was performed for 180 hours. Take out the sample, place it for 24 hours, then apply two intermediate coats (24 hours apart), let it stand horizontally and dry for 7 days, and prepare three qualified samples.

3.1.2 Steps of adhesion test

Hanging from a hook will test sample for 24 hours in the hot and humid test chamber, temperature of 50 + 1 ° C, relative humidity is more than 95%.

Immediately after removing the sample, gently cover the filter paper over the painted surface to absorb excess moisture.

Use art sculpting knife blade, in the middle of the test sample location in parallel to the short side, the direction of the interval of 15 mm cutting two treaties line 40 mm in length, cut through the film to the floor.

In the central part where the cutting lines cross, attach the vertical direction of the cutting lines with scotch tape. One end of the tape needs to be turned back 20mm for tearing and pulling.

Press the tape firmly back and forth with your thumb to ensure that it adheres firmly to the coating, then quickly pull one end of the tape at a right Angle to remove the tape.

Check the lacquer film after tearing. If two or more than two pieces of test samples of the primer paint film with an intermediary between paint film does not occur, or strip width under 3 mm, is judged to be “without exception”.

3.2 surface adhesion between the paint and the middle layer

3.2.1 Sample Preparation Apply a phosphating primer to one side of a steel plate for 4 hours, then apply an intermediate primer for 24 hours, then apply a topcoat for 7 days, and conduct an accelerated xenon lamp aging test for 180 hours. Take out the sample, after 24 hours, and a middle tier paint besmear again paint, make its horizontal and drying, 7 days preparation of three pieces of qualified samples.

3.2.2 Adhesion Test Procedure The operation procedure is the same as that in 3.1.2.

Adhesion between the layers testing method and its application

4.4 Conclusion

Through the above method of testing, if two or more test samples in the adhesion test, primer and middle layer paint or top paint and middle layer paint do not peel, or peel width is less than 3mm, it is judged as “no abnormality”.

5. Reference standards

Method described in this article refer to the industry standard HG/T 2798, chlorinated rubber coatings.

Conclusion

Is to ensure that the coating adhesion between the layers of one of the important indexes of stable performance and durability. Although this method can only make a qualitative judgment, it is close to the actual use, and has great significance for coating selection and supporting system design. In the paint industry, accurate assessment of the adhesion will help to ensure that the quality of the coating and performance, thus ensuring the long-term application of coating.