Chrominfo: July 2018

Wednesday, July 11, 2018

Particle Size Distribution by Sieve Analysis

Sieving is an easy and generally used method of categorizing powder as per to its physical size alone, Sieve method includes a wide particle size range. The micro-mesh sieves arrange the aperture size in descending order. Different types of aperture ranges are accessible. Sieving executes by manual or machine movement, with either be dry or wet, the main variables that affect the sieving results contained very fine particle size, particle shape, time and method of agitation, initial sieve loading. Due to the limitations of the size at the bottom, sieving, there is not a suitable method to characterize the full particle size distribution of the powder, however, with other methods, it can act as a means of Pre-classification of powder. Overall, sieving is best suitable for analyzing the powder that contained a large size fraction. i.e. 50 µm.

Particle size determination by Coulter counters

The particle size and particles count in coulter counter method depend on the assessable changes in electrical impedance produced by a nonconductive particle that suspended in an electrolyte. In this method of particle size analysis, the particle is suspended in the conductive solution such as electrolyte solution.

Here is mention some advantages and disadvantages of the Coulter counter method in particle size analysis let’s check it.

Advantages of the Coulter counter method in Particle Sizing

The operation is very easy.
Short testing cycle.
Comparatively high accuracy.
Most consistent method since we obtain information of size the of each particle.

Disadvantages of the Coulter counter method in Particle Sizing

Size range is Narrower.
Apertures get Easily blocked.
Electric conductivity of medium essential.

You may also like this

Particle Size Distribution by Sieve Analysis

Particle Size Determination by Laser Diffraction Method

Particle size determination by Sedimentation method

Advantages and Disadvantages of sieving method in Particle Sizing

Particle size determination by sieving method

Advantages and Disadvantages of Optical Microscopy in Particle Sizing

Particle size determination by optical microscopy

Methods of Particle Size Analysis

Principle of Particle Size Analysis

What is Particle Size Analysis

Particle Size Determination by Laser Diffraction Method

LASER Diffraction is also known as edge diffraction. Refraction in the form of a light change angle in the journey through the particle. When the process of particle size is under process, without the need to stop the manufacturing process, the LASER can be measured by diffraction techniques. Because of its having broad range it is a broadly used technique of particle sizing for materials that range from hundreds of nanometers to several millimeters.

Here is mention some advantages and disadvantages of laser diffraction method in particle size analysis let’s check it.

Advantages of Laser Diffraction method in Particle Sizing

The Method is consistent.
Time-saving method.
Simple operation.
Wide test range.
Results are accurate and reproducible.
The dry test is available.

Disadvantages of Laser Diffraction method in Particle Sizing

Test results are dependence to distribution pattern.
Cost of the instrument is high.

You may also like this

What is Particle Size Analysis

The principle of Particle Size Analysis

Methods of Particle Size Analysis

Particle size determination by optical microscopy

Advantages and Disadvantages of Optical Microscopy in Particle Sizing

Particle size determination by sieving method

Advantages and Disadvantages of sieving method in Particle Sizing

Particle size determination by Sedimentation method

Particle size determination by Coulter counters

Particle Size Distribution by Sieve Analysis

Particle size determination by Sedimentation Method

If any particle falls in liquid, it gradually settles down, the Bigger particle is settled faster than the smaller particles, this principle is to work in particle size determination. The particles of the same density, they are settled only on the basis of size so large particles settled quickly at the bottom of the sediment than the smaller size particles.

Here is mention some advantages and disadvantages of the sedimentation method in particle size analysis let’s check it.
Advantages of the sedimentation method in Particle Sizing

It has a low cost for analysis.
Consistent as entire of a sample is screened.
Continuous operation without disturbance.
Results are accurate and reproducible.
Relatively broad test range.

Disadvantages of the sedimentation method in Particle Sizing

Test cycle of sedimentation method is long.

You may also like this

What is Particle Size Analysis
The principle of Particle Size Analysis

Methods of Particle Size Analysis

Particle size determination by optical microscopy

Advantages and Disadvantages of Optical Microscopy in Particle Sizing

Particle size determination by sieving method

Advantages and Disadvantages of sieving method in Particle Sizing

Particle size determination by sieving method

Advantages and Disadvantages of sieving method in Particle Sizing

Particle Size Determination by Laser Diffraction Method

Particle size determination by Coulter counters

Particle Size Distribution by Sieve Analysis

Advantages and Disadvantages of sieving method in Particle Sizing

Here are some advantages and disadvantages of the sieving method in particle size analysis, let's check it.
The advantages of the sieving method in Particle Sizing:

The analysis includes fast and easy handling of the instrument.
The results of particle sizing are accurate and reproducible.
It is a time-saving method.
The cost of the instrument is lower than other methods.

The disadvantages of the sieving method in Particle Sizing:

It works only with dry particles.
The minimum limit of measurement is 50μm.
There is a possibility of further reduction in size, which can cause errors.

Particle size determination by sieving method

In this method Particles ranging from 50 to 1500μm are measured. It is a rough and fast way and can obtain weight distribution of particle size. Sieves of various pore sizes are used for sieve the powder.

The sample of the supposed quantity is kept on the sieve top and tapped. In doing so, large sized particles are retained by a particular sieve number. Thus the particles pass through the holes of sieves on the basis of size and move to different levels. Small size particles are settled on the finest sieve.

Advantages and Disadvantages of Optical Microscopy in Particle Sizing

Here is mention some advantages and disadvantages of optical microscopy in particle size analysis let’s check it.
Advantages of Optical microscopy in Particle Sizing:

It is the simplest method for particle size analysis.

The shape analysis is available by Optical microscopy method.

It allows viewing the particles.

Contamination and agglomeration of the particles can be detected.

Simple to count the particles.

An electron microscope or scanning electron microscope can be used to measure very small particle size.

Disadvantages Optical microscopy in Particle Sizing:

Optical microscopy takes a long test cycle.

It is not possible to test the ultrafine particles by the microscopy method.

The depths of the particle are not accessible.

Testing of ultrafine particles not possible.

This is a tedious and slow method.

You may also like this

Particle size determination by optical microscopy
What is Particle Size Analysis
The principle of Particle Size Analysis
Methods of Particle Size Analysis
Particle size determination by sieving method
Advantages and Disadvantages of sieving method in Particle Sizing
Particle size determination by Sedimentation method
Particle Size Determination by Laser Diffraction Method
Particle size determination by Coulter counters
Particle Size Distribution by Sieve Analysis
Advantages and Disadvantages of Capsules
Advantages and disadvantages of colorimetry
Advantages and disadvantages of conductometry
Advantages and Disadvantages of Flame Photometer
Advantages and disadvantages of fluorescence spectroscopy
Advantages and disadvantages of glass electrode
Advantages and Disadvantages of Nanotechnology

Particle size determination by optical microscopy

In this method a compound microscope is used, Inspect particles for their size and shape directly through a microscope. The particle can be measured using this method from 0.2 μm to 100μm in size range. The particle dimension is measured directly by seeming in the microscope or by the projection for a better view.

Methods of Particle Size Analysis

The particles are small solid materials and there is in almost every substance or matter, the size and structure of particle are measured for different purposes. Larger size particles are settling better, whereas smaller particle is less. Particle size mostly affects the proprieties of the material such as their dissolution, solubility, and stability etc.

Particle size is a common word and holds a broad variety of sizes of substance, there are several methods are used for particle size determining, only a some are fundamental, that is, do not need calibration through other methods, microscopic method is one of these, However it is used as a regular method of measurement in many areas.

There are several methods used for the particle size analyze, besides laser diffraction. Sieving is the oldest method that still generally used for relatively large particles size ie. > 1mm and for measuring small size particles is. < 0.5um, the Dynamic Light Scattering is the simple methods to use.

Here are mentions some methods for Particle size determination are as follows.

1. Optical microscopy

2. Sieving method

3. Sedimentation method

4. Coulter counter method

5. LASER Diffraction method

Principle of Particle Size Analysis

Particle size analysis is a technical procedure that determines the particle size of the material, which is a solid or liquid sample. Particle size analysis is a significant test and is used for quality control in several industries. About each manufacturing was milling or grinding is utilized. Particle size is an important factor in establishing the efficiency of manufacturing processes and performance of the final manufactured goods.

The range can be measured by optical microscopy of particle size in 0.2-100 microns. The size in this method is expressed as the projected diameter (DP) which describes the diameter of the area, similar to the asymmetric particles observed under the microscope. This method provides number distribution which can be converted into a further weight distribution.

The optical microscope is to determine the particle size of the following type of samples.

Particle size analysis in suspension.

Globule size distribution in the emulsion.

Particle size analysis in aerosols.

Particle Size Analysis by Optical Microscopy.

Particle size is estimated with the help of eyepiece micrometer.

About 500 particles were calculated to estimate the true mean

Normal cumulative frequency, such as the size frequency distribution curve has been plotted

What is Particle Size Analysis

Particle size analysis is a technical process that determines the size of the particles in the sample. Either this is a powder sample or liquid sample; it shows the particle size of the particles in which ratio in the sample particle group to be calculated or used to characterize the particle size distribution in a given sample.

Particle size analysis can be applied to solid, emulsions, suspension, and aerosol. There are several methods employed to measure the particle size, some particle size method can be used for a broad range of the samples, but several can be used for specific applications. Choosing the most suitable method for different samples is very important because different methods can produce different results for the same material.

Friday, July 6, 2018

Procedure for Angle of Repose

Following is the procedure to perform the angle of repose granules.

1. Select a glass funnel, in which there is a spherical stem of 15 to 30 mm in diameter with a flat edge, Fix funnel with a clamp.

2. Place a glass plate and position it under the glass funnel, Place a graph paper on the glass plate.

3. Take 50 grams of granules.

4. While blocking the funnel hole by the thumb, add the granule to the funnel.

5. Remove the thumb. Granule flow on paper and forms a cone-shaped pile.

6. Adjust the funnel clamp so that the gap amongst the stem of a funnel and the peak of the powder is as 3mm.

7. Until a suitable gap is achieved repeat the steps 5-6.

8. Lastly, pour granules back in a funnel and allowed it to flow

9. Unlike each other on a circular basis on graph paper, mark 4 digits. Record all readings in the table there is d is diameter and r is Radius.

10. Using two rulers measure the pile height. Keep a ruler vertically and another is horizontal to touch the pile peak. Then record the value of the vertical scale and record it in the table, this value stands for height h.

11. Repeat the process for two more trials for average readings.

Variations in Angle of Repose Methods

The following variations have been utilized in Angle of Repose Methods

• The Drained angle of repose is decided by allowing an extra amount of material located above a certain diameter base for the "drain". The shape of a cone of powder on a certain diameter basis allows determining of the drained angle of repose.

• Dynamic angle of repose is by filling the cylinder and revolving at a particular speed. The dynamic angle of repose is determined by the flowing powder the dynamic angle of repose is formed. The plane which separates the particles that slide down the top layer of powder and separates those particles rotating with the drum is called as the interior angle of kinetic friction.

The angle of repose of the powder does not have an intrinsic property, that, it is very much dependent on the method used to make powder cone.

Method of Determining Angle of Repose

The most regular methods to determine the static angle of the repose can be classified on the base of the below two significant experimental variables.

1. The height may vary as a form of pile or powder passes through the height of the funnel, can be determined relative to the base.

2. The basis on which the structure of the pile forms can be fixed diameter or the powder diameter cone may be permitted to be converted into pile forms.

Since the size of the granules decreases, the flow of granules is less freely. Particle size distribution affects granulation separation and internal flow. With comparatively small size particles, particle flow throughout the orifice is restricted, because the united forces among the particles are of a magnitude equal to the gravitational force. As gravitational force is the work of diameter raised in the third power, it is important that the particle size increases, the flow is made easy. Through the flow by the hopper, the granules display the internal flow and demixing. Due to the frictional force, the flow of the granules is interrupted. Therefore, the digression of the angle of repose is articulated as the coefficient of friction μ.

Definition of Angle of Repose

The angle of the repose has been utilized in many branches of science to show the solids flow properties. The angle of the repose is a characteristic that is related to inter particulate resistance or friction to the movement among the particles. The angle of repose test results is very dependent on the method used. As a result of the segregation of material and consolidation, experimental difficulties arise or Powder's aeration formed as a cone.

The formula for Angle of Repose.

The angle of repose is specified by θ.

It is expressed as, Tan θ = µ = h/r.

Where,

h is the height,

r= radius of the pile

and µ is the coefficient of friction.

Flow Properties of Granules

In order to maintain the uniformity of the product, the powder flow properties should be studied in terms of the quality control of the raw material, but to avoid the rigid conditions in which the process can be broken, in relation to the conditions applied. As a result, the properties of the powder flow must be deliberate and adapted as part of each development program.

The characteristics of the powder flow are typically tested in conditions of gravity loading. By measurements like the angle of repose and added handling angles, Standardized flow rate, tap density, apparent and derived index; such measurements have confirmed the reliability of the powder flow on the size and shape distribution of the particle. In a loose powder, the frictional force can be measured by the angle of repose. This highest angle is possible among the powder pile surface and horizontal plane.

Pages

Wednesday, July 11, 2018

Friday, July 6, 2018