Notes on paint testing and analysis!

March 3, 2022 Longchang Chemical

Notes on paint testing and analysis!

Q: What are the categories of paints?

A: According to the form, it can be divided into solid paint and liquid paint; according to the use, it is divided into industrial paint and civil paint, and industrial paint is divided into color board paint, automotive paint, architectural paint, wood paint, aircraft skin paint, etc.; according to the effect, it is divided into anti-corrosion paint, anti-rust paint, waterproof paint, moisturizing paint, elastic paint, insulating paint, anti-fouling paint.

Q: What is the purpose of paint analysis and testing?

A: The performance of paint determines the quality of paint and the use of paint, which is multifaceted. In order to evaluate the performance of coatings from different perspectives, many test methods have been developed, mainly including the testing of the performance of the coating itself and the testing of the coating film performance in two aspects.

Q: What is the significance of coating performance testing?

A: Analysis and testing of coatings is an important and indispensable part of the process in the production and use of coatings, and is the main basis for the development of technical indicators of coating products, and is a specific method used to evaluate the performance and quality of coatings.

1、The test can provide data for the formula design and process conditions of selected products.

2、By analyzing and testing the paint, it can correctly reflect the quality of the paint product and control the product quality.

3、Through the data obtained from the testing test, the research of basic theory can be carried out to find out the relationship between components and performance, so as to discover the problems of the original product and the direction of improvement, and provide the basis for the development of new products.

Q: What are the common technical indicators for coating analysis and testing?

A: The indicators of physical state of coating include density, viscosity, etc. The indicators of optical properties of coating film include gloss, color, etc. The indicators of mechanical properties include hardness, flexibility, etc. In addition, the weather resistance and chemical reagent resistance of coating are also very important technical indicators when measuring the performance of coating.

Q: What is the hardness of coating film?

A: The hardness of the coating film refers to the solidity of the coating film after drying, which is used to determine the degree of damage when it is subject to external friction and collision. There are many methods to determine the hardness of the coating film, currently commonly used is the pencil hardness method. The pencil hardness method is a method of measuring the hardness of a coating film by scratching the film with a pencil of known hardness mark and using the hardness mark of the pencil to indicate the hardness of the film.

Q: What are the film adhesion test methods?

A: Film adhesion refers to its ability to firmly bond with the surface of the object being coated. Bad adhesion of the product, easy and the surface peel and lose its protection and decorative effect. Adhesion determination methods are scribing method, scribing method, torsion method, scratch method, tape adhesion method and peeling test method.

The scribing method is a test method to evaluate the resistance of the coating to detachment from the substrate when the coating is cut to penetrate the substrate with a right-angle grid pattern. The adhesion force measured by the pull-off strength method is the force required to determine the damage of adhesion between coatings or between coatings and substrates by applying a vertical uniform pull on the adhesive surface of the specimen at a specified speed.

Q: What are the methods for determining the thickness of the coating film?

A: The thickness of the coating film will affect the performance of the coating film, especially the physical and mechanical properties of the coating film are most obviously affected by the thickness, so the determination of the coating film performance must be tested within the specified thickness range. There are many methods to determine the thickness of coating film, such as the thickness of coating film on glass plate can be measured by micrometer, the thickness of coating film on steel plate can be measured by non-magnetic thickness gauge, and the thickness of plastic coating can be measured by ultrasonic method.

Q: What are the common coating test standards?

A: Different countries have different testing standards and requirements, the common ones are ISO, ATSM, GB, JIS and other standards. For example.

Common standards for hardness testing are: ASTM D3363, ISO 15184 , GB/T 6739, JIS K5600-5-4.

Thickness test common standards are: ASTM D7091, ASTM D1186, ISO 2808, ISO 2360.

Common standards for impact resistance test are: ASTM D2794, ISO 6272, GB/T 20624, JIS K5600.

Contact US