Table of Contents
- 1 Why we determine the viscosity of liquids?
- 2 How viscosity is determined?
- 3 What is the significance of determination of viscosity determination?
- 4 What is the importance of viscosity in pharmacy?
- 5 Why is viscosity important in mechanics?
- 6 Does viscosity change with RPM?
- 7 Which is the best way to measure viscosity?
- 8 How is viscosity expressed in the SI system?
Why we determine the viscosity of liquids?
Viscosity of a liquid is an important parameter as it can be used as an indicator of quality by the consumer, in some instances a thicker liquid being thought of as superior quality when compared to a thinner product. Viscosity is also a characteristic of the texture of food.
How viscosity is determined?
The viscous properties of a liquid or amorphous solid are primarily determined by inter-particle forces within the solution, including friction and attraction between molecules in the macrostructure. Dynamic viscosity; which is a measure of the shear stress per unit area required before a sample begins to deform.
Why is viscosity important in engineering?
Knowing the viscosity helps engineers know how a fluid will behave under different circumstances. Engineers also use this equation when designing devices. By knowing the viscosity of the fluid and the force being applied to it from the gas pump, engineers can calculate the velocity that the gas will move.
What property determines viscosity?
The intermolecular forces determine the physical properties of the liquid. Viscosity is a term used to describe the fluid friction (resistance to flow) within a fluid. The amount of viscosity is completely dependant on the amount and strength of the intermolecular bonds.
What is the significance of determination of viscosity determination?
As viscosity changes the flow properties of a liquid food and influences the appearance and the consistency of a product, this measuring variable is important in most production stages.
What is the importance of viscosity in pharmacy?
The viscosity of liquid and semi-solid preparations has to be maintained batch-to-batch to ensure uniform drug potency through all stages of production. Testing the viscosity is a very important practice by quality control in the pharmaceutical manufacturing industry.
What is the principle involved in determination of viscosity?
These viscometers use the principle of ‘rotational viscometry’, i.e. their measurement of product viscosity is based upon immersing a specifically selected spindle within a sample of the product followed by measurement of the torque required to rotate the spindle at a set speed whilst immersed within the product sample …
What does viscosity depend on?
The viscosity of a liquid usually depends on its temperature. Viscosity generally decreases as the temperature increases. Viscosity generally increases as the temperature decreases. The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another.
Why is viscosity important in mechanics?
Viscosity is a major factor in determining the forces that must be overcome when fluids are used in lubrication and transported in pipelines. It controls the liquid flow in such processes as spraying, injection molding, and surface coating.
Does viscosity change with RPM?
Viscosity measurements are made at two separate speeds, normally an order of magnitude apart, such as 50 rpm and 5 rpm. The viscosity value at 5 rpm is divided by the viscosity value at 50 rpm. For a pseudoplastic material, the ratio of the two viscosities is a number that is greater than 1.
Where does viscosity come from?
At a molecular level, viscosity is a result the interaction between the different molecules in a fluid. This can be also understood as friction between the molecules in the fluid. Just like in the case of friction between moving solids, viscosity will determine the energy required to make a fluid flow.
Why viscosity test of bitumen is done?
Viscosity test of the bitumen sample is one of the important tests on bitumen to be conducted before road construction. Viscosity measures the degree of fluidity of the bitumen sample. It ensures the quality of the bitumen used as a binder by giving a measure of fluidity at a particular temperature.
Which is the best way to measure viscosity?
There are two ways to measure a fluid’s viscosity as follows: 1 Dynamic Viscosity (Absolute Viscosity) 2 Kinematic Viscosity More
How is viscosity expressed in the SI system?
In the SI system, viscosity is expressed in kg m-1 s-1; however, sometimes viscosity values are shown in terms of the equivalent units of N m-2 s or Pa s, where the Pascal (Pa) is the SI unit of pressure and is equal to 1 Newton per square meter (Table A-1). The SI unit of viscosity is equal to 10 Poise or 1000 centipoise.
Why is the viscosity of a product important?
The product’s viscosity must be measured and monitored during production to ensure that each batch is consistent and will go through the production process efficiently. To choose the right viscosity for an adhesive, consider how the adhesive must flow, or not flow, on a part after the adhesive is applied.
What is the formula for the viscosity of a fluid?
According to Newton, the viscosity formula is, F = μ A u y Where μ i is the viscosity factor for a fluid, and the unit is: P a.