ISO 9782:2026

• Abstract:

  This document specifies a method for the determination of the apparent volatile-matter content in pre-impregnated yarns, tapes, mats (SMC) and fabrics. The method is applicable to all unidirectional and multidirectional fibre-reinforced prepregs and all thermosetting-resin matrices, unless otherwise specified in product specifications. The method does not apply to unimpregnated reinforcement fibres. NOTE For products with a polyester-resin matrix (UP), the result will be lower than the real value.

• Status: Published
• Publication Date: 06-Jul-2026
• ICS: 83.120 - Reinforced plastics
• Technical Committee: ISO/TC 61/SC 13 - Composites and reinforcement fibres
• Drafting Committee: ISO/TC 61/SC 13/WG 2 - Laminates and moulding compounds
• Current Stage: 6060 - International Standard published
• Start Date: 07-Jul-2026
• Due Date: 21-Nov-2027
• Completion Date: 07-Jul-2026

• Revises: ISO 9782:1993 - Plastics — Reinforced moulding compounds and prepregs — Determination of apparent volatile-matter content
• Effective Date: 07-Jan-2025

Overview

ISO 9782: Plastics - Reinforced moulding compounds and prepregs - Determination of apparent volatile-matter content is an internationally recognized standard published by the International Organization for Standardization (ISO). This standard specifies a method for determining the percentage of volatile matter in reinforced plastics, particularly in moulding compounds and prepregs that use thermosetting-resin matrices. The volatile matter is quantified as the percentage mass lost when a specimen is heated for a specified period in an air-ventilated oven.

This test is important for quality assurance, production monitoring, and research, as the volatile-matter content significantly impacts the processing, stability, and ultimate performance of fiber-reinforced plastic products. The standard applies to both unidirectional and multidirectional fibre-reinforced prepregs, excluding unimpregnated reinforcement fibres.

Key Topics

• Scope of Application
  • Applies to pre-impregnated yarns, tapes, mats (such as sheet moulding compound or SMC), and fabrics utilizing a thermosetting-resin matrix.
  • Not applicable to unimpregnated fibres.
  • Particularly relevant for epoxy, phenolic, polyester, silicone, and polyimide resin systems.
• Testing Principle
  • The method involves heating the specimen at a controlled temperature for a prescribed time in an air-circulating oven and measuring the mass loss.
  • The loss of mass corresponds to the apparent volatile-matter content.
  • Specific precautions for moisture correction are included when aramid fibres are used.
• Standardized Procedure
  • Precise sampling and preparation to ensure consistency.
  • Requirement for at least three test specimens taken from defined locations in the sheet or sample.
  • Specific equipment such as precision balances (accurate to 0.1 mg), sample holders, and desiccators.
  • Conditioned specimens and controlled test atmospheres as per ISO 291.
• Calculation and Reporting
  • The apparent volatile-matter content is calculated as a percentage of mass lost relative to the initial specimen mass.
  • The arithmetic mean of at least three measurements is reported.
  • Full documentation and traceability of the test process, including test conditions and any deviations, are required.

Applications

ISO 9782 is essential across industries where fiber-reinforced plastics and composite prepregs are fabricated or applied. Typical uses include:

• Quality Control: Ensuring consistency and reliability of prepreg materials before moulding or further processing.
• Manufacturing of Composites: Validating raw material properties for applications in aerospace, automotive, marine, electronics, and sports equipment.
• Research and Development: Supporting the optimization of resin formulations and processing conditions.
• Regulatory Compliance: Demonstrating conformity with international standards for safety, performance, and durability in composite materials.
• Supplier Certification: Providing a standardized basis for certifying batches of prepreg or moulding compounds during procurement or production audits.

Related Standards

When implementing ISO 9782, it is beneficial to reference other relevant standards for plastics and composites, including:

• ISO 291: Plastics - Standard atmospheres for conditioning and testing
• ISO 1172: Textile-glass - Yarns, rovings and fabrics - Determination of textile-glass and mineral content
• ISO 11357: Plastics - Differential scanning calorimetry (DSC) for thermal analysis
• ISO 1268: Fibre-reinforced plastics - Methods for producing test plates
• ISO 14125: Fibre-reinforced plastic composites - Determination of flexural properties

These standards, together with ISO 9782, help ensure consistent, high-quality results across supply chains and technical disciplines working with reinforced plastics and composite materials.

Keywords: ISO 9782, plastics standard, volatile-matter content, reinforced moulding compounds, prepregs testing, composite materials, fibre-reinforced plastics, thermosetting resin, quality control, air-ventilated oven method.

International
Standard
ISO 9782
Second edition
Plastics — Reinforced moulding
2026-07
compounds and prepregs —
Determination of apparent volatile-
matter content
Plastiques renforcés — Compositions pour moulage et
préimprégnés — Détermination de la teneur apparente en
matières volatiles
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Sampling and test specimens . 2
6.1 Sampling .2
6.2 Shape and dimensions .2
6.3 Preparation and number of test specimens.2
7 Sample conditioning and test atmosphere. 2
7.1 Sample conditioning .2
7.2 Test atmosphere .2
8 Procedure . 2
9 Calculation and expression of results . 3
10 Precision . 3
11 Test report . 3
Annex A (informative) Precision data obtained from an interlaboratory test . 4

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13, Composites
and reinforcement fibres.
This second edition cancels and replaces the first edition (ISO 9782:1993), which has been technically
revised.
The main changes are as follows:
— the requirement for the weighing accuracy of balances has been raised from ±1 mg to ±0,1 mg;
— a timer has been added in the apparatus clause;
— the symbol V for volatile-matter content in the calculation formula has been supplemented;
c
— the number of test specimens has been changed from "three" to "at least three";
— the following instruction has been added to 8.4 “The specimens should be placed so that the maximum
surface area is exposed to the circulating heat.”;
— a precision statement has been added in Annex A.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
International Standard ISO 9782:2026(en)
Plastics — Reinforced moulding compounds and prepregs —
Determination of apparent volatile-matter content
1 Scope
This document specifies a method for the determination of the apparent volatile-matter content in pre-
impregnated yarns, tapes, mats (SMC) and fabrics.
The method is applicable to all unidirectional and multidirectional fibre-reinforced prepregs and all
thermosetting-resin matrices, unless otherwise specified in product specifications.
The method does not apply to unimpregnated reinforceme
...