Whether it is fine art, or painting the walls of your house, most people will know that paint viscosity is an important factor in achieving success or creating an almighty mess. Here we discuss paint viscosity and how to measure it.
Paint Viscosity – Why is it important?
If you are anything like me – which I sincerely doubt – then you will have made an unholy mess whilst painting the walls of your house. Not the difficult outside sort of paint. I mean the easy stuff – ‘brilliant white’ on existing white walls, and still, somehow, it gets everywhere.
Anyone with real experience of paint will know just how important paint viscosity can be. If it just right, the job can be relatively easy. But once it thickens up and bit, or has been thinned down too much, it can be become problematic. Paint manufacturers know this, and they go to great lengths to ensure that their products leave their factories in perfect condition. Of course, once in a domestic setting, the manufacturers cannot control storage conditions, where drying out if incorrectly sealed, or temperature, can affect the viscosity.
Depending on the type of paint – and its delivery method – manufacturers will seek to produce paints with a particular viscosity. Spray paints will differ from the sort that goes on the walls. Getting the viscosity right means that it will ensure the correct level of coverage, and will determine how many coats of paint are required.
Paint Viscosity – how is it measured?
Paint viscosity can be measured using several different types of viscometer. Of all the different types of viscometer that can be used, one stands out because it was developed by a paint manufacturer, specifically to measure the viscosity of paint. Back in the day, one of the most famous paint manufacturers was Imperial Chemical Industries, more usually known as ICI. These days, it goes by the name Akzo Nobel, and sells paints under the brand name, Dulux.
ICI’s Paints Division, known simply as ICI Paints, developed what became known universally as the ICI viscometer. It used a cone and plate arrangement to measure the viscosity of paint samples. A small amount was mounted on a plate and a shallow cone was lowered onto the sample and revolved. The paint would create a drag on the rotation that could be measured. In simple terms, the more viscous the paint, the greater the drag. The original ICI viscometer employed an analogue read out, and as long as the paint fell within accepted limits, then it was fit for purpose.
Evolution of the ICI Cone & Plate Viscometer – the original (left), the original showing its inner workings (middle), and the REL Analogue (right)
The ICI Viscometer & how it evolved
In time, ICI was broken up into different divisions and some of these changed hands. The viscometer was taken up by Research Equipment London Ltd, usually just known as REL. For many years, the cone and plate viscometer was the standard way to measure paint viscosity, and was variously known as an ICI or a REL. Both of these became by-words for the cone and plate, and most manufacturers will refer to their cone and plate viscometer as an ‘ICI’ or ‘ICI-type’. Indeed, many operators still affectionately refer to it as a REL.
Of course, it wasn’t just limited to measuring the viscosity of paint. All sorts of substances could have their viscosity measured, including resins, inks, varnish, cosmetics, oils, adhesives – and even heavy-duty substances like bitumen.
In time, a digital version was developed by REL and launched onto the market. As time passed, and company acquisitions came and went, the ICI viscometer came under the ownership of ATAC. Once again, it was developed and improved, until it became the market-leading product that it now is.
Into the digital age – The REL Digital (left), The first NuLine (middle), and the current upgraded NuLine (right)
Contact Us – The original cone and plate viscometer
For more information on the latest version of the ICI viscometer – to measure paint viscosity, or anything else for that matter, email us at sales@atacgroup.com or by phoning +44 (0)1380 818411. Alternatively, click the button below to learn more about the product. And while you are there, you can even purchase one using our new e-commerce option.
Feature Image courtesy of Alessia C, Main image courtesy of David Zieglgänsberger
