How to use the paint-4 cup Viscometer? How to use 4 cups

Viscosity is a measure of the ability of the interaction between liquid molecules to hinder the relative movement between molecules, that is, the resistance of liquid flow. This resistance, also known as internal friction, is usually calculated as the force per unit area - shear stress.

In paint production plants, viscosity is an important indicator to control product quality; for users, knowing the viscosity of paint can facilitate the control of paint film thickness during construction. The main factors affecting the viscosity are the molecular weight of the polymer, the additives added, the solvent, the type and amount of the filler, the temperature and the storage time of the coating, etc. The user's requirement for the viscosity of the coating depends on the construction method, the surface of the object to be coated, etc.

Viscometers used in coatings can be classified as follows according to their measurement principles:

(1) Outflow type viscometer. Includes capillary viscometer, Tu-1 cup, Tu-4 cup. Among them, Tu 1 cup is mainly used to measure paint varieties with high viscosity, while Tu 4 cups is usually used to measure paint varieties with viscosity below 150 seconds.

(2) Falling ball viscometer. Including falling ball viscometer, Heberer viscometer, etc.

(3) Rotational viscometer. There are rotary paddle viscometers, coaxial cylinder rotary viscometers, conical plate viscometers, etc.

Currently, outflow viscometers are widely used to measure viscosity. Tu-4 viscometer (also known as Tu-4 cup) is the most widely used, it is made of metal or plastic, simple in structure and easy to use. During the test, block the spout with your finger, fill the viscometer with the sample, then remove your finger and start the stopwatch at the same time. When the sample flow line is interrupted for the first time, turn off the stopwatch, and the total time (in seconds) for the sample to flow out of the viscometer is the viscosity of the coating (conditional viscosity), expressed in seconds.

If you don't paint -4 cups, you can use a simple method to check empirically: open the paint bucket, stir it evenly, dip it into the paint with an adjusting stick or a paint brush and lift it up, the paint on the stick or brush and the paint in the bucket are very short Time will continue to connect. Generally, the connection distance is 30-50 cm, which is the viscosity suitable for brushing; if the distance is less than 30 cm, the viscosity is too small, that is, the paint is too thin; if the distance is 50 cm, the viscosity is too high, that is, the paint is too thick. This kind of viscosity, which is subject to the construction requirements and has been applied many times without using a viscometer, is also called working viscosity.