Coating viscosity is one of the physical and chemical properties of liquid and colloidal system, which is used to describe the resistance of liquid molecules to mutual motion under external force. In the process of coating production and application, viscosity is a key parameter, which has an important influence on the performance and application effect of coating. This paper will introduce the definition, relevant standards, testing methods of coating viscosity, and its importance in coating production and application.

What is paint viscosity
The viscosity of the coating refers to the ability of the coating to hinder the movement of molecules caused by the interaction between molecules under the action of a certain external force. It is expressed by the ratio of shear stress to shear rate, generally measured by the speed of the liquid passing through the unit area in a unit time. The viscosity of the coating is related to the molecular weight of the polymer, and the size of the viscosity can reflect the fluidity and viscosity of the coating.

Analysis of the importance of viscosity measurement in coating production and application

Standards for viscosity of coatings

Viscosity measurement of coatings involves several criteria. Including GB/T1723-93 coating viscosity determination method, GB/T6753.4-1998 color paint and varnish with outflow cup determination of outflow time, GB/T2794-1995 adhesive viscosity determination, GB/T 9269-88 Determination of viscosity of architectural coatings – Stormer viscometer method, and determination of viscosity of GB/ T9701-88 coatings at high shear rates, etc.

The main points of coating viscosity test method are introduced

Coating 1 viscometer method: This method is suitable for paint products with a discharge time of not less than 20 seconds. Under the specified temperature and conditions, a certain amount of sample is discharged from the specified hole, and its outflow time is measured.

Coating -4 viscometer method: Suitable for paint products with a discharge time of less than 150 seconds. Under certain conditions, the sample is discharged from the paint container, and the discharge time is measured.

Analysis of the importance of viscosity measurement in coating production and application

Importance and influencing factors of coating viscosity
The viscosity of coatings has an important influence on the production and application of coatings. In the process of coating production, too high or too low viscosity can lead to coating performance and application problems. Too high viscosity will make the paint construction difficult, and too low viscosity may cause poor wettability of the paint, flow hanging phenomenon. In addition, the viscosity of the coating will also affect the gloss, durability, adhesion and other physical and mechanical properties of the film.

In the process of coating application, the appropriate properties of viscosity can make the construction more smooth, reduce the problems of coating flow and uneven film thickness.

conclusion
As an important characteristic of coatings, the viscosity of coatings has an important impact on the production and application of coatings. By using the standard measurement method, the viscosity information of the coating can be accurately obtained, so that it can be controlled and adjusted during the production process. Appropriate viscosity of the coating can ensure the performance and application effect of the coating, improve the quality of the coating and construction efficiency. Therefore, paint manufacturers and construction personnel should pay attention to the measurement and control of paint viscosity to ensure the high-quality application of paint.