What is Particle Size Analysis and Sieving

Particle size analysis is the process of measuring and interpreting the distribution of particle sizes in a sample. It can be used to understand aspects of a material's physical properties such as flowability, dispersibility, sintering behavior and surface characteristics.

Image Analysis

IImage Analysis is one technique for particle size analysis which uses digital cameras or microscopes to determine the size and shape of particles within a sample.are taken and analyzed using specialized software to generate particle size distributions. This method can be used for particles ranging from around 5 µm up to several millimeters in diameter.

Laser Diffraction

Laser Diffraction is another common technique used for particle size determination. $Laser Diffracrion$ It works by scattering light through a sample containing particles in suspension and calculates the size distribution of the sample based on the angles and intensity of light scattered by individual particles. This method is most effective for particles between 10 µm and 2 mm in diameter.

Sedimentation

Sedimentation is a technique used to measure particle size distributions when dealing with particulates suspended in a liquid medium. Particles settle at different rates depending on their density and size, allowing for measurements of the various sizes present within a sample. This method works best for particles measuring from 1 µm up to several millimeters in diameter.

Sieving

Sieving is an offline method that uses test sieves to separate granules into particle size classes prior to further analysis.Sieving is a mechanical technique used to separate particles of different sizes. It relies on sieves of various mesh sizes which act as filters to trap particles within a certain size range. Sieving is primarily used for particle sizes ranging from 1 mm down to around 25 microns.

Sieving has many advantages compared to other particle size analysis techniques. It is relatively inexpensive, fast and easy to use, and requires minimal skill or experience to do correctly. Additionally, sieves can be used with a wide range of materials such as powders, granules, fibers, and pastes. As a result, sieving is the most commonly used technique for particle size analysis and is often employed as the starting point in a complete particle size determination process.

Equipment Needed to Conduct Sieve Tests

Sieves are the basic component of the sieve testing process. Sieve Shakers are the mechanical component that facilitate the separation by size. The parameters are defined by standards organizations such as ASTM and ISO.

Sieves

Sieves consist of a frame, usually round, that holds media consisting openings of a specified size. woven_wire_vs_electroformed_side_by_side This media can be woven wire mesh, perforated plate or electroformed. The wire mesh, the most used, are made in reference to standardize tolerance levels.

Sieve Shakers

Sieve shakers are the instrument that causes the particles to move through the sieve openings that are larger than the particles. The process leave the particles larger than the mesh openings on the mesh. Sieve shakers

can be categorized as follows:

General purpose
Heavy Duty for large samples or samples that require extra agitation
Shakers for small particles that produce special action to get small particle to pass through the mesh

Sieve Standards, Certification and Calibration

Quality control in the process of sieve testing depends on the reproducibility of results from one sieve to another. Several standards and practices have been developed to deal with this issue by organization such as ASTM and ISO.

Sieve Certification

Sieve certification is derived from standards such as AASTM E11 which defines the process of sieving, sieve construction and mesh tolerances. A sieve certification states that the individual sieve conforms to the construction standards and established tolerances.

The basic standard is the certification of a Compliance Sieve. The next two levels are Inspection and Calibration certifications.

There is also a special category known as a Mid-point Sieve. A sieve is selected as a mid-point if measurements fall in the middle of the ASTM standard. Mid -point sieves are used in master stacks and in sieving processes where reproducibility from one sieve to another is critical.

Sieve Calibration

Sieve Certification defines levels of sieve measurements and acceptable tolerances in sieve openings. Certification references these measurements but does not directly relate to the actual performance of a sieve. Calibration is a dynamic process that predicts the performance of a sieve and relates that to consequences of orverall variances in sieve openings.

Calibration is done by loading calibrated micro spheres on a sieve and applying a shaking process. The result is an evaluation of the actual performance of the sieve.

Sieving Accessories

Three are number of accessories that are helpful in conducting sieving operations.

Ultrasonic Sieve Cleaners
Using ultra sonic techniques used to clean sieves and remove stuck particles,
Sieve Cleaning Brushes
Special bruises that do not damage fine mesh but help remove blinded apertures.
Sample Dividers
Essential when testing requires a small portion of very large samples.

Particle Size Analysis

What is Particle Size Analysis and Sieving

Image Analysis

Laser Diffraction

Sedimentation

Sieving

Equipment Needed to Conduct Sieve Tests

Sieves

Sieve Shakers

Sieve Standards, Certification and Calibration

Sieve Certification

Sieve Calibration

Sieving Accessories

Ultrasonic Sieve Cleaners

Sieve Cleaning Brushes

Sample Dividers

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A discussion of mesh sizes

How to Load a Sieve Stack

Quiet Sieve Shakers are Feasible

Prediction of Sieve Performance-Calibration

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