Viscosity is an important factor in quality control when it comes to painting. Different viscosities will yield different results, so if you want a consistent result in the finish of a painted surface, you must know the ideal viscosity of your paint, and then do everything technically feasible to maintain that viscosity.
Viscosity itself, however, is prone to many factors, and temperature is a key element. While specific numbers will vary, higher temperatures mean lower viscosities, while lower temperatures mean higher ones. And all of this comes into play at the most critical moment of all: right when it’s time to apply the paint to the surface.
Temperature Changes All the Time
There are two basic issues at work when looking at temperature control as a means of maintaining viscosity. The first, most fundamental consideration is the viscosity level desired. This changes based on the formulation used for the paint, and the surface(s) it is being applied on. Steel that is being painted glossy black will likely require a very different viscosity for the paint than will a carbon fiber substrate being painted in beige. Your actual optimal viscosity level varies based on color and formulation choice and substrate material.
The other factor is much more complex. This is getting the temperature to the desired point by the time the paint is sprayed out of the nozzle. In most cases, it is not as simple as, for example, storing the paint at 70°F when it needs to be at 70°F for application. This is because a lot can happen in an industrial process between the time the paint is taken from storage and the time it leaves the nozzle.
Storing the paint at one temperature does not guarantee it remains at that temperature “in transit” - traveling through pipes routed at different heights and distances, can change the temperature of the paint. Putting that paint through pumps or other regulating mechanisms can also alter the temperature. By the time the paint arrives at the nozzle, it may have risen and/or dropped in temperature several times.
Technology Steps In
Modern temperature control systems take a holistic approach to temperature. Temperature is monitored—and adjusted—sometimes in more than one place—with control systems and protective features—such as insulation or jacketed pipes to control temperature variation—in combination as required to provide accurate, even control.
The best way to achieve this on an industrial scale is to “work backward.” Rather than start at the paint storage area and work toward the end, you start at the “end point” - often referred to as the "point of application" and work backwards toward the source, implementing temperature control as required to achieve and maintain the desired temperature (and thereby viscosity) you need for the application.
In this way, your first goal—achieving the viscosity required for successful application—is always the driving force behind how the control systems are conceived and executed. And this gives you a substantially higher first-pass yield from your process.
Quickly convert visocisty measurements from one unit to another with this helpful Viscosity Conversion Table.