In the coating industry, the measurement of viscosity is not only a key factor in product quality control, but also a technical parameter that can not be ignored in the process of coating application. The accuracy of viscosity measurement directly affects the application performance of coatings, including leveling property, coating property and drying time. In many viscosity measurement methods, the outflow cup method is widely used because of its simplicity and economy.

The basic principle of the outflow cup method

The basic principle of the outflow cup method is to use the gravity of the liquid itself to generate flow, and determine its viscosity by measuring the time that a certain amount of liquid flows from the viscosity cup at a certain temperature. This method is suitable for low viscosity Newtonian or near Newtonian paints, such as varnishes and paints.

Different types of discharge cups

Coat -4 cups:

Coated -4 cup is China’s national standard viscosity cup, simple design, easy to operate. It consists of a cylindrical upper and a conical lower container with a capacity of 100 ml and a standard leakage nozzle of 4 mm at the bottom. Despite its wide use, it is mainly suitable for coatings with kinematic viscosity in the range of 60 to 360 mm²/s.

ISO outflow cup:

ISO drain cups are designed according to international standards and come in a variety of apertures, making them suitable for a wider range of applications. Its design feature is that the cone Angle is 120°, which helps to reduce the turbulence generated when the liquid enters the outflow hole, making the liquid flow more stable.

The viscosity of the coating was determined by efflux cup method

The importance of precision

Accurate viscosity measurement is very important for coating quality. Inaccurate viscosity measurements can lead to paint construction problems, such as run-off, thin coatings, or paint marks. In addition, different types of discharge cups require regular calibration to ensure the accuracy of the measurement.

Selection and calibration of outflow cups

Selecting the appropriate discharge cup is the key to obtaining accurate results. For example, coated -4 cups are suitable for low to medium viscosity coatings, while ISO effluent cups are suitable for a wider viscosity range. In addition, regular calibration of the discharge cup is essential to ensure the accuracy of its viscosity determination.

As an economical and practical method for viscosity measurement, the efflux cup method plays an important role in the coating industry. Understanding the different types of discharge cups and their scope of application, as well as maintaining the accuracy of viscosity cups, is crucial to ensuring the quality and performance of paint products.