The device consists of a mixer that can rotate at different speeds, with different spindle sizes depending on the consistency of the paint. It measures the viscosity by calculating the torque required to rotate a needle immersed in the fluid being analysed at a constant speed. The Brookfield Viscometer is based on the principle of rotational viscometry. The viscosity is determined with the aid of an ASTM D562 table, and it is expressed in Krebs units. Using a stopwatch, the time it takes for the blades to spin 100 times for a given weight is calculated. The Stormer viscometer consists of a standardised mixer with 2 blades that are immersed in the fluid and rotated by applying weight. They are widely used in paint, ink, and adhesive manufacturing, although not advisable for non-Newtonian fluids (whose viscosity varies with the temperature and shear stress applied to them). It is a viscosity measuring tool that is very quick to use and easy to handle. The cup number used is tabulated for a viscosity measurement. This time, measured in seconds, is proportional to the viscosity of the fluid. the time it takes for a certain volume of liquid to flow through a capillary or orifice. The measuring principle of these viscometers is based on the concept of ‘flow time’, i.e. 4, etc.) They also include a vessel for the liquid. Orifice viscometers such as the Ford, Zahn or BYK-Gardner cups are devices which, as their name suggests, are shaped like a cup and have an orifice that may vary in size (No. In the sector of paints and related products, the most used tools are: Orifice viscometers: Ford, Zahn and Gardner cup There are a number of devices that can measure viscosity. Normally, viscosity would be measured at 25 ✬. When measuring the viscosity of paint (and that of any fluid) the measuring temperature must be included (as it has been pointed out in the case of water) as it has a great influence on the result. From the point of view of equivalence: 1 cps = 1 mPa This is mainly because the viscosity of water, the reference fluid, is 1,0020 cP at 20 ☌. With respect to the Poise, the use of its multiple, the centipoise (cP), is more common. Its unit of measurement is the Poise, although in the International System (SI), it is measured in Pascal-second (Pa In this sense, the greater the fluidity, the lower the viscosity of the liquid. Viscosity could be understood as opposite to fluidity. This resistance to flowing is due to the friction between its molecules, which move at different speeds, and collide with each other making motion difficult.
Viscosity can be defined as the resistance of a liquid to spilling. In this article we will analyse these fundamental characteristics that must be taken into account during the manufacturing process of paints.
Even if they have been previously determined during formulation, it is necessary to verify that the manufacturing process is correct and whether the desired result will be obtained once the paint is applied. Viscosity, specific weight or colour are some of the characteristics specific to paint that must be controlled during the manufacturing process.
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