Coating viscosity determination of the national standard [Flow Cup method]

OutFlow Cups are the most readily available paint viscosity measuring instruments in laboratories, production workshops and construction sites.

Due to the large volume of the Flow Cup and the short outflow hole, it is convenient to operate and clean, and can be used for opaque paints. The viscosity measured by the Flow Cup viscometer is kinematic viscosity, that is, a certain amount of sample. The time to flow out of a hole of a specified diameter at a certain temperature is expressed in seconds. This is a commonly used method for measuring the viscosity of coatings. Because it can be easily used in many occasions, it is widely used all over the world.

Among the national standards, the method standards for measuring the viscosity of coatings by outFlow Cup include GB/T 1723-1993 Coating viscosity measurement method and GB/T 6753.4_l988 paint and varnish with outFlow Cup to measure outflow time. In GB/T 1723-1993, use 1 cup and 4 cups of coating. Apply 1 cup for measuring paint products with outflow time not less than 20 s. Apply 1 4 cups for measuring coatings with outflow time below 150 s. Compare the difference between the two measured values not more than 3% of the average value, and take the average value of the two measured values as the measurement result.

In GB/T 6753.4-l988, four kinds of outFlow Cups with similar sizes and outflow apertures of 3 mm, 4 mm, 5 mm, and 6 mm are used to determine accurately the outflow from the outflow hole of the outFlow Cup. Experimental material with flow breakpoint. For experimental materials with outflow time exceeding 100 s, due to the delay effect, the breakpoint is difficult to determine and the repeatability is poor.