Intrinsic Viscosity – RheoSense

In the simple words, the resistance capacity of a liquid or fluid material is defined by its viscosity. So, it’s nothing but a mechanical friction between molecules in motion. Higher viscosity means higher resistance to deformation of the liquid because of mutual attraction of the molecules. Viscosity is denoted by a symbol η (eta) – a ratio of the shearing stress to the velocity gradient in a fluid.

Consider an example of viscosity with water and honey, water flows relatively freely than honey; it is because honey has the higher viscosity than water. There are various industrial or commercial applications viscosity measurement devices that help you understand the flowing nature and motion of a particular material in a given temperature.

Viscosity is a subject of Rheology

The flowing behaviors of different materials or matters are studied under Rheology. It’s actually a science of deformation and flow of different matters that are put under the controlled testing conditions.

It considers the matters’ liquid, soft solid or semi-liquid state to see their flow under different circumstances. Soft matters like polymer, blood, sludge, silicates, and other biological materials are considered for viscosity measurement. There are basically two types of viscosity – Dynamic or absolute viscosity and kinematic viscosity.

In industrial sphere, Rheology is considered to understand how a fluid material is rubbed, pumped, molded, coated, mixed, sprayed, extended, extruded, chewed, swallowed, transported, stored, heated, cooled, and aged. So you can understand how comprehensive industrial applications are associated with rheology.

Measurement of viscosity and industrial applications

The readings of viscosity vary with different fluid and soft liquid matters. There are different ways to measure viscosity starting from capillary tube methods that were used in early of the 20^th century. Now there are many manufacturers of viscometers that come up with different techniques including nanotechnology and digital scanning.

Capillary viscometer uses some specially designed tubes in which a volume of liquid passes through. It shows the flowing speed and space variation under a shear stress (the force required to move matter within an area).     

Zahn Cup is a high shear viscometer that has a small hole in the bottom to measure the flowing speed of a liquid. This device is often used for quality control in the paint industry.

Falling sphere viscometer helps you to record a specified point by dropping a fluid sample through it. This device is widely used to see the quality of fuel in the engines.

Vibrational viscometer helps to measure an oscillating electromechanical resonator that is immersed in a particular fluid. On the other hand, rotational viscometer can measure the torque that can turn an object into the fluid form. It’s very much used in production labs to scale a fluid quality.

New technology used in high shear viscometer

The advanced viscometer technology is being used to measure fluid viscosity with higher accuracy, better repeatability, and automation facility even for a small sample volume. The high shear rate is easily drawn to assist industrial processes. For example, viscometer/rheometer-on-a-chip (VROC) technology has revolutionized the way viscosity is measured for industrial applications ranging from fuel, paint, plastic, toothpaste to food products and pharmaceutical industries.   

Rheology and Measurement of Intrinsic Viscosity:

The study of flow and deformation of the liquid or soft materials comes under Rheology. The flow and deformation of a material are influenced by its viscosity, and a small sample rheometer can be used to find strain rate of that fluid material. Strain rate actually indicates the distance over which a material moves amidst an external force. So this stress-strain relationship in different materials is analyzed under rheology. There are various industrial applications in which intrinsic viscosity is taken for quality control.

An appropriate rheometer for you:

Simulating process and quality checking system mostly use capillary and torque rheometers, whereas dynamic rotational viscometers are recommended for assessing a resin’s molecular structure.

Capillary rheometer is proved to be a more sophisticated version of viscometer that can measure the shear rate at multiple points on the curve. It helps to determine whether a material is fit for the further process and application or not. The manufacturers like RheoSense are there to offer the improved version embedded with advanced software and hardware accessories that expand the range of testing capabilities.

Small sample rheometer for precision reading:

Viscometer-Rheometer-on-a-Chip (VROC) is the latest and high-end device to measure viscosity. It combines microfluidic and MEMS (Micro-Electro-Mechanical Systems) technologies that can measure the accurate viscosity of a fluid material; even of a small quantity of both Newtonian and non-Newtonian fluids. In technical words, this feature can give you high shear rate viscosity measurements up to as little as 20 microliters of sample.

There are microfluidic devices in this version that can read high shear rates without encountering flow stability. The VROC viscometers can measure viscosity by maintaining complete enclosure of fluid materials, so they don’t evaporate during the measurement procedure. Such small sample rheometers are widely used in several industrial applications and protein therapeutics.

Advancement in rheometers: 

The accuracy in the viscosity reading depends on a lot how advanced your rheometer or viscometer is. It’s a precision instrument designed with a geometric configuration to measure a wide range of viscosities via strain and strain rate. Different materials respond to stress differently and strain rate varies. This variation is precisely measured with the help of advanced techniques by the automatic viscometers. After that, the flowing behavior of the materials is quantified in material properties such as viscosity, elasticity, and modulus.

MEMS and Microfluidics are the latest and highly efficient technologies to measure viscosity. They can give accurate results of a fluid’s viscosity in different environments and setups.

Preciseness Defines A Quality Viscometer

Viscometer is used to measure the viscosity of a material or fluid’s resistance to flow under an applied stress in a provided environment. Viscosity is represented by the symbol η "eta" which is the ratio of the shearing stress to the velocity gradient in a fluid.

Precisely a viscometer can measure the viscosity’s quality. The installation of new technology like rheometer-on-a-chip, innovative MEMS and microfluidics provides more precise and accurate measurement of viscosity of a substance/material. Moreover, such technologies make it very easy to operate and take a reading of viscosity.

Why to measure viscosity:

The measurement of viscosity is considered to see the behavior of a fluid material in a particular environment and design. Since viscosity of a material changes dramatically with temperature, engineers or experts use viscometer to understand what will happen to fuel fluids in different temperatures and pressures. This instrument is widely used in research labs to measure new as well as existing fluids’ viscosities for industrial applications. Now, viscometers are being used extensively in different industries for quality control.

Types of Viscometer:

There are several types of viscometers being used in laboratories and industries. The portable viscosity testers are most used in commercial applications.

U-Tube Viscometers are mostly used laboratory settings. Falling sphere viscometers, falling piston viscometers, rotational viscometers, bubble viscometers, and rheometers are some other types of viscometers that are available with technical innovations to measure plasma viscosity. Different forms of viscometers are being explored as per the requirements of small sample volume, high shear rates, different temperatures, quality monitoring and other research works.

Applications of Viscometers:

The application of viscometers in wide variety of material and chemical industries is proved. They are extensively used in quality control for food and beverages, cosmetic products, chemical items, and research and development. In different process conditions of materials, they are needed to be pumped and flow in different shapes and designs.

A material’s viscosity is important to consider in its dipping and coating performance. For example, inks, paints, toothpastes and chocolates are some products that need viscosity and texture application in different temperatures and circumstances.

Rheometers are applied to measure a material’s properties like molecular weight and density that virtually affect its flow behavior. It’s a usual instrument of technical sales department to test viscosity of a fluid material.

Viscometry is taken in mineral oils and lubricants including motor oil, fuel oil, and gas well drilling fluids. Other commercial applications of plasma viscometer include adhesive materials, beverages, chemicals, food products, paints & coatings, petroleum products.