МЕТТЛЕР ТОЛЕДО рекомендует
  • кондуктометр
  • кабель
  • титратор
  • весы
  • электрод
Все категории
  • Все категории
  • Оборудование
  • Поддержка
  • Библиотека
  • Мероприятия и вебинары
  • Другое
Filter
Главная страница По применению Стандартные задачи взвешивания в лаборатории Sieve Analysis

Sieve Analysis

Digitalize and Automate Determination of Grain Size Distribution Workflows

Позвонить специалисту
Sieve Analysis - Particle Size Distribution

Sieve analysis or a gradation test is an important method for assessing the particle size distribution of granular material. Particle size influences material properties like flow and conveying behavior (for bulk materials), reactivity, abrasiveness, solubility, extraction and reaction behavior, taste, compressibility, and many more. Particle size determination is therefore essential for a wide range of industries, such as food, construction, plastics, cosmetics, and pharmaceuticals, to optimize process engineering and to ensure the quality and safety of final products.

To measure particle size distribution, different methods and procedures can be applied, depending on the sample material, expected particle sizes, and the scope of the examination. These include direct image analysis, either static (SIA) or dynamic (DIA), static light scattering (SLS), also called laser diffraction (LD), dynamic light scattering (DLS), and sieve analysis. Sieve analysis is the traditional and most used method to measure particle size distribution.

Why sieve weighing is important

The advantages of sieve analysis include it is easy to use, requires minimal investment costs, offers accurate and reproducible results in a comparatively short time, and has the ability to separate particle size fractions. The sieve analysis procedure by differential sieve weighing is a tedious and error-prone process. Using an accurate balance with convenient features and digital data management can quickly pay off.

High-Throughput Experimentation (HTE)

How to Do Sieve Analysis

Watch this video and find out why particle size analysis is so important and how to do sieve analysis step-by-step.

The impact of the particle size distribution can be huge and its analysis by sieve weighing is a tedious and error-prone process. Automate your sieve analysis workflows: make guided processes and digital data management an integral part of all your sieve weighing!

 

Jump to one of the following sections to explore and learn more:

  1. Sieve analysis, a typical workflow
  2. Common methods for analyzing particle sizes and distributions
  3. Request free support for fast and error-free sieve weighing
  4. The challenges of sieve weighing in sieve analysis
  5. Featured weighing solution for sieve analysis: Excellence level precision balance connected to LabX™ laboratory software
  6. Free eGuide: Determination of particle size distribution by sieve analysis
  7. FAQ – frequently asked questions about sieve analysis

 

Sieve Analysis Workflow

Typical Workflow for Sieve Analysis

A sieve stack consists of several sieves stacked on top of each other with increasing mesh size, with the sample placed on the top sieve. Sieving is carried out to the point where the sample mass on each sieve does not change (= constant mass). Each sieve is weighed, and the volume of each fraction is calculated in weight percent, giving a mass-based distribution.

Preparation steps
1. Method development: based on the material to be tested, choose a suitable standard method, select the appropriate sieves in the stack to ensure uniform distribution on each sieve, and determine the required sample quantity. Preliminary tests can help specify these parameters
2. Preparation of sieves or stacks, e.g., pre-recording of the sieves (identification and tare weight)
3. Sampling
4. Sample preparation, e.g., pre-drying, conditioning or sample division

Sieve weighing steps
5. Weigh sieves empty, from bottom to top or from the pan (A), the smallest mesh size (B) to the largest mesh size (E); identify every sieve, subtract tare
6. Add the sample
7. Sieving (manually or using the sieve shaker)
8. Back weigh fractions in every sieve, from top to bottom or from the largest mesh size to the smallest mesh size
9. Result analyses, evaluation, and interpretation

Equipment maintenance
Like other precision measuring instruments in the laboratory, test sieves require regular care to maintain the standard of performance, this includes:

  • Careful cleaning after each run
  • Performance checks prior to use and periodic routine checks, e.g., testing with proficiency test samples
  • Calibration: Periodic calibration and recertification of test sieves (ASTM E11 or ISO 3310-1).

 

Common Methods for Analyzing Particle Sizes and Distributions

The method of choice to determine particle sizes and distributions depends on the target substance and the expected particle sizes.

Particle size analysis methods:

  1. Sieve analysis
  2. Direct image analysis, either static (SIA) or dynamic (DIA)
  3. Static light scattering (SLS), also called laser diffraction (LD)
  4. Dynamic light scattering (DLS)
Sieve Analysis Results

Sieve analysis is the traditional method for determining particle size distribution. Solid particles ranging in size from 125 mm down to 20 μm can be measured quickly and efficiently by dry or wet sieving using standard test sieves.

Sieve analysis is specified in a number of national and international standards as an obligatory test method for a variety of analytical and industrial processes. A quick search for the keyword "sieve" yields over 150 individual standard results on the ASTM website and over 130 results on the ISO website. These results provide information on what sieve sizes are required for a particular material. Each standard describes in detail how to perform the particle size test, including sample size, test duration, expected results, and acceptance method.

Examples of standards:

  • ASTM C136: Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates
  • ASTM D422: Standard Test Method for Particle-Size Analysis of Soils

Most of these standards require that the sieves used have to meet certain technical requirements described in specific sieve standards such as ISO 3310 or ASTM E11 / E 323.

Direct image analysis allows the determination of the physical properties of individual particles (size, shape, and surface morphology). The crucial difference between dynamic and static image analysis is that in static image analysis particles are located on a carrier and do not move relative to the camera during the acquisition, such as with a microscope, whereas in dynamic image analysis particles move passing a detector.

Static Image Analysis (SIA) is primarily used to measure narrow size distributions, with an emphasis on characterizing very fine particles. It provides high-resolution particle images that allow an extremely accurate description of size and shape, but it is time-consuming. SIA is mainly used in research and development.
Standard: ISO 13322-1.

Dynamic Image Analysis (DIA) is a number-based particle characterization method, applicable for samples larger than about 1 µm. If smaller particles are also to be measured, Laser Diffraction (LD) is the method of choice. DIA is a modern particle size characterization method ideally suited for routine measurements of bulk goods, powders, granules, and suspensions. In many industries, the DIA has already replaced traditional sieve analysis.
Standard: ISO 13322-2.

Static Light Scattering (SLS) or Laser Diffraction (LD) can determine volume-based distributions, pharmaceuticals (API), and PSD in liquids and slurries. Laser Diffraction is the most common method for the determination of particle size distributions other than traditional sieve analysis. It is based on the deflection of a laser beam by an ensemble of particles dispersed in either a liquid or an air stream.
Standard: ISO 13320.

Dynamic Light Scattering (DLS) is based on the Brownian motion of dispersed particles in solution. It is a non-invasive technique for measuring the size and size distribution of molecules and particles typically in the submicron range.
Standard: ISO 22412.

 

Sieve Analysis Experts

Do You Need Advice?

Would you like to know:

  • How to make your sieve analysis easier, quicker and less error-prone
  • How to increase throughput and reduce the cost per sample?

Our team of experts is always on hand to offer help and advice, please do not hesitate to contact us.

 

Sieve Analysis Challanges

The Challenges of Sieve Weighing In Sieve Analysis

The steps involved in sieve analysis are:

  1. Weigh the empty sieves
  2. Add the sample
  3. Sieve for 5-10 minutes
  4. Back weigh
  5. Clean the sieves

A standard sieve stack usually consists of 5-10 sieves, which makes the whole process quite time-consuming.

Challenges of sieve analysis are:

  • How to avoid or prevent mixing up the sieves? Has the order of the sieves always been followed correctly?
  • How to ensure that no process steps were skipped or that nothing was measured twice?
  • Has everything been recorded correctly? Were all results transcribed without error?
  • How to ensure that calculations are performed correctly?

 

Sieve Analysis - Balances and Software

Featured Weighing Solution for Sieve Analysis: XPR or XSR Precision Balance Connected to Labx™ Laboratory Software

 

Automate and digitalize your sieve weighing workflow to speed up the process and make it less error-prone. Invest in an XPR or XSR precision balance connected to LabX™ laboratory software for a fast return on investment by speeding up the process, increasing throughput and reducing cost per sample.

Guided and automated process

The process can be started from the touchscreen on the balance. The user is given secure step-by-step guidance through the entire workflow. Using automatic weight detection, sieves can be weighed consecutively without touching a key. All tare weights are stored accurately and completely.
The SmartTracTM graphical weighing aid makes it easy to weigh your sample to a specific target value and prevents you from overloading your sieves.
For back weighing, simply resume the task on the balance screen and weigh the loaded sieves in the correct order, as guided on the screen. The weight values are automatically recorded once a stable value is reached.

Efficient weighing

With the AutoZero function and automatic result recording, weighing is unbeatably fast and secure. The high stability provided by the unique SmartPan™ weighing pan means you get your results up to twice as fast compared to weighing on a standard weighing pan. Data and results are automatically recorded on the built-in results protocol, eliminating time-consuming and error-prone manual data input/output. Multiple interfaces (4 USB, 1 LAN) allow easy export of results to a PC or other system.

Error-free documentation

LabX™ offers comprehensive data management and full traceability; it takes care of all data and calculations automatically. After the last weighing step is done, the final result is ready. The complete solution can be tailored to individual process requirements and integrated with your company's existing ERP/LIMS system, allowing bi-directional transfer of tasks and results. All data is securely stored in a centralized database and customized reports can be generated at any time.

Durable and easy to clean construction

XPR and XSR balances have been designed to withstand harsh conditions and to be easily dismantled without the use of any tools. All parts are dishwasher proof - smooth surfaces and rounded edges make balance cleaning very easy.

 

Sieve Analysis Guide Free PDF

eGuide: Determination of Particle Size Distribution by Sieve Analysis

Download our free eGuide and learn the essentials of sieve analysis, including use cases, workflows, best practices, and efficient solutions. In an easy-to-digest way it presents use cases in various industries and explains their importance in each segment. It also compares different methods of particle size analysis, explains the workflow for sieve analysis and shares best practices, including 7 tips & tricks for proper sieve analysis.

The Lean Lab approach with Continuous Improvement Processes (CIPs) helps uncover further opportunities for sieve analysis process optimization.

This eGuide discusses the following 6 CIP objectives:

  1. Speed up
  2. Ensure reliable results
  3. Have SOPs at hand
  4. Ensure error-free back weighing
  5. Avoid transcription errors
  6. Standardize reports

Related Content

FAQ

Frequently Asked Questions on Sieve Analysis

What is the recommended sample size to be used for sieve analysis?

In sieve analysis experiments, there is often a tendency to use samples that are too large, as it is assumed that this will make the test results more accurate. However, this compromises the accuracy of the result, as each individual particle does not have the opportunity to present itself on the surface of the test sieve. Generally, a 25–100 g sample is recommended. A procedure exists to help establish the appropriate sample size, using a sample splitter to reduce the sample to different weights (25 g, 50 g, 100 g, 200 g), and testing samples in the various weight ranges. If the test with a 50 g sample shows approximately the same percentage passing the fine sieve as a 25 g sample, whereas a 100 g sample shows a much lower percentage passing, this would indicate that the 50 g sample is the appropriate sample size.

What is the difference between sieve diameters in ASTM standards vs. ISO/BS standards?

In the ASTM standards, sieve diameters are measured in inches, while millimeters are used in the ISO/BS standards. There is a slight difference between 8 inches and 200 mm or 12 inches and 300 mm diameter. In reality, 8 inches equals 203 mm and 12 inches equals 305 mm. Therefore, test sieves with a diameter of 8 inches and 200 mm cannot be nested, nor can test sieves with a diameter of 12 inches and 300 mm.

What are the differences between mesh numbers and wire spacing in ASTM standards vs. ISO/BS standards?

Mesh number represents the number of wires per inch (25.4 mm). Woven wire sieves are sold either by mesh number or by the wire spacing. The ASTM American standards use mesh numbers, whereas ISO/BS International and British standards tend to use wire spacing.

How does air humidity in the lab affect sieve analysis?

Very dry conditions can cause fine powders to adhere both to the sieve components and to each other with strong electrostatic charges. Ideally the relative humidity (% RH) should be between 45% and 60%. 

What are the advantages of sieve analysis over alternative techniques, like image analysis methods?

The advantages of sieve analysis include low investment costs, easy handling, precise and reproducible results in a relatively short time and the ability to separate the particle size fractions. Therefore, this method is commonly used instead of methods using laser light or image processing.

What are the limitations of sieve analysis?

One limitation is the number of size fractions obtainable, which limits the resolution. A standard sieve stack consists of a maximum of 8 sieves which means that the particle size distribution is based on just 8 data points. Further limitations are that this technique only works with dry particles, the minimum limit of measurement is 50 µm, and the method can be rather time-consuming.