ISO 4907-4:2025

Plastics - Ion exchange resin - Part 4: Determination of particle size by laser diffraction method

This document specifies the test method for determination of particle size of ion exchange resin by laser diffraction, ranging from 0,1 μm to 2,0 mm.

Plastiques — Résine échangeuse d'ions — Partie 4: Détermination de la taille des particules par la méthode de diffraction laser

General Information

• Status: Published
• Publication Date: 25-Mar-2025
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Current Stage: 6060 - International Standard published
• Start Date: 26-Mar-2025
• Due Date: 12-Apr-2026
• Completion Date: 26-Mar-2025

Overview

ISO 4907-4:2025 is a pivotal international standard published by ISO that defines the test method for determining the particle size of ion exchange resins using the laser diffraction technique. This standard specifically covers particle sizes ranging from 0.1 μm to 2.0 mm, offering a reliable and precise approach for particle size analysis critical in plastics and resin industries. The document complements the ISO 4907 series focusing on ion exchange resins and provides a comprehensive methodology for accurate size distribution measurements.

Key Topics

• Scope and Application
  The standard applies to ion exchange resins, specifying the procedures for laser diffraction measurement to assess particle size distribution effectively.

• Principle of Laser Diffraction
  A sample dispersed in water is exposed to a monochromatic laser beam. Detectors measure the scattered light patterns, which are mathematically transformed to calculate the volume-based particle size distribution (PSD).

• Test Method Essentials

  • Use of water with analytical purity as the dispersion medium (ISO 3696, Grade 3 or better).
  • Sample preparation following ISO 4907-1:2023 to ensure representative sample selection.
  • Instrument calibration and alignment according to ISO 13320 standards.
  • Testing parameters including dispersion medium, refractive index range (1.53 to 1.65), and ultrasonic treatment before measurement.

• Data Analysis and Calculations
  Detailed formulas and definitions for:

  • Percent below or above specified particle sizes.
  • Percent between size ranges.
  • Effective size (D10), median size (D50), uniformity coefficient, area-weighted and volume-weighted mean particle sizes.

• Repeatability and Accuracy
  The standard presents repeatability limits with relative standard deviations across various particle size ranges to ensure testing reliability and consistency.

• Reporting Requirements
  The test report must include sample identification, reference to ISO 4907-4:2025, sampling procedures, and detailed particle size test results.

Applications

ISO 4907-4:2025 is vital for manufacturers, researchers, and quality assurance laboratories involved in:

• Ion Exchange Resin Production
  Ensuring consistency in resin bead sizes which impacts ion exchange efficiency, mechanical stability, and performance in applications like water treatment, pharmaceuticals, and chemical processing.

• Quality Control
  Monitoring particle size distribution to maintain product uniformity, optimize filtration processes, and guarantee compliance with industry specifications.

• Material Research and Development
  Investigating resin bead characteristics to innovate and improve ion exchange materials tailored for specific industrial or environmental applications.

• Environmental and Analytical Testing
  Providing accurate particle size data essential for regulatory compliance and scientific studies involving resin-based systems.

Related Standards

• ISO 4907-1:2023 – Determination of exchange capacity of acrylic anion exchange resins.
• ISO 13320 – Particle size analysis using laser diffraction methods; fundamental for instrumentation and measurement models.
• ISO 3696 – Specifications for water used in analytical laboratory processes ensuring purity requirements for precise testing.
• ISO 9276-2 – Guidelines for representing particle size analysis results, including calculation of various mean diameters and distribution moments.

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By adhering to ISO 4907-4:2025, stakeholders in plastics and ion exchange resin sectors can achieve highly accurate, repeatable particle size measurements using laser diffraction-boosting product quality and ensuring compliance with international best practices. This standard is indispensable for enhancing manufacturing efficiency, research precision, and operational reliability in industries relying on ion exchange resins.

Standards Content (Sample)

International
Standard
ISO 4907-4
First edition
Plastics — Ion exchange resin —
2025-03
Part 4:
Determination of particle size by
laser diffraction method
Plastiques — Résine échangeuse d'ions —
Partie 4: Détermination de la taille des particules par la méthode
de diffraction laser
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions .1
3.2 Symbols .2
4 Principle . 2
5 Reagents . 2
6 Apparatus . 2
7 Pretreatment . 2
8 Procedure . 3
8.1 Instrument preparation .3
8.2 Testing parameter setting .3
8.3 Testing the sample .3
9 Calculation . 4
9.1 Percent below specified lower size .4
9.2 Percent above specified upper size .4
9.3 Percent between specified range size .4
9.4 Effective size.4
9.5 Median size .5
9.6 Uniformity coefficient .5
9.7 Area-weighted mean size .5
9.8 Volume-weighted mean size .5
10 Repeatability . 5
10.1 Repeatability of effective size .5
10.2 Repeatability of median size .5
10.3 Repeatability of uniformity coefficient .5
10.4 Repeatability of area-weighted mean size .6
10.5 Repeatability of volume-weighted mean size .6
11 Test report . 6

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 61, Plastic, Subcommittee SC 5, Physical-
chemical properties.
A list of all parts in the ISO 4907 series can be found on the ISO website.
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