Viscosity Control and Measurement Applications

Measuring viscosity is an effective way of determining the state (properties of matter) or fluidity of a liquid or gas.

It plays an important role in the quality control and various research and development stages in lab, process and research environments as well as a wide range of industries and applications including Food, Chemical, Pharmaceutical, Petrochemical, Cosmetics, Paint, Ink, Coatings, Oil and Automotives.

A viscosity control system measures the thickness of the ink used in a printing press. This is very important for the quality of a print. The printing press needs a perfect density of the ink, otherwise the process is in danger of becoming worthless.

Flexo printing, gravure and offset including label and corrugated production, require ancillary equipment and components designed to make the print process consistent and repeatable, regularly monitoring viscosity using a viscometer. Viscosity control instrumentation is supplied for solvent-based applications but the major growth now is in water-based inks. Flexographic printing, a major segment of the printing industry, is a primary application market for viscosity control.

The viscosity of coatings is one of the main factors that determines the success of the coating process. Because the repeatability and reproducibility of the coating process is often closely linked to the coating’s viscosity, it is a key control parameter.

The viscosity of a conformal coating is often temperature sensitive. To accurately measure the viscosity of conformal coating materials, , the measurements must be made on samples at a consistent temperature.

Measuring the viscosity of fluids is based on one of three phenomena: a moving surface in contact with a fluid, an object moving through a fluid, and fluid flowing through a resistive component. In lab and process environments, these phenomena utilize three major viscometers, i.e., a rotating viscometer, a Falling Ball Sensor and capillary.

Viscosity is one of the most important properties of a fluid and plays a very prominent role in the petroleum industry. The viscosity of a crude oil affects our ability to pump it out of the ground; the viscosity and volatility of a fuel affect how easy it is to atomize in the fuel injector; the viscosity of a lubricant affects its ability to protect an engine. It is an important measurement characteristic in the food, paint, polymer coating, and other industries where flow is a critical product or use characteristic.

Viscosity measurement allows the most sensitive or convenient way of detecting changes in colour, density, stability, solids content, and molecular weight.(in the chemical industry, e.g. in reactors for polymerisation).

Viscosity measurements of cosmetics are often performed for shelf-life testing to determine stability. Viscosity measurements are an important tool for a sensitive measure of material changes. Many of the formulations are complex emulsions with structures that vary over time and may be reflected in viscosity changes. Over long storage times, the viscosity may significantly increase or decrease, as product degradation occurs.

Viscosity  testing of food is used to find best composition ratios when producing items such a chewing gum, butter, margarine, bread, candy, chocolate, and other food items.

Chocolates, for example, have a wide range of flow properties which relate to enrobing and making blocks. In the viscosity measurement of chocolate products, it is common to describe the flow properties using the Casson flow curve.