12 / Sep / 2023
Here's how Anker Stuy controls the quality and density of its paint
The density of every batch that Anker Stuy produces is measured and compared with the calculated value. We do this as an additional check to see whether the paint has been produced according to specifications. The density also indicates whether air has been mixed into the paint. Many air bubbles in the paint result in a lower density.
What is the density of paint?
The density of a material is represented by its weight per unit volume. More specifically for paint: what does a liter weigh?
Water has a density of approximately 1 kg/L, which means that a liter of paint weighs 1 kg. It is important to know the density of a paint when you have to convert wet layer thickness into grams.
Example: 150 µm wet layer thickness is specified. For a paint with a density of 1.1 kg/L, this means that you need to apply 150*1.1= 165 g/m2.
Why does the density differ per product?
Paint is a mixture of raw materials with different densities. Water has a density of 1 kg/L. Binders also have a similar density. But titanium dioxide, the pigment in white paint, has a density around 4 kg/L. That is why white paint has a higher density than a clear coat. Solvent such as turpentine has a lower density of 0.79 kg/L.
Fillers such as chalk and talc have a density between 2.6 and 2.8 kg/L. Fillers are used in primers for faster drying, better filling and sandability. That is why a primer has a higher density than a topcoat. The density is always stated on the technical data sheets that Anker Stuy issues for each product. Often in the form of a range because white and dark colors do not have exactly the same density.
How does Anker Stuy measure the density of each product?
There are several ways to measure the density of a paint. The quality control lab usually uses the sphere measurement.
The density is then measured by placing a can filled with paint on a scale and setting it to zero. Then a sphere with a volume of 100 ml is dipped into the paint. The change in weight represents density.
