ISO/DIS 9782:2026(en)

ISO TC 61/SC 13/WG 2

Secretariat: JISC

Date: 2025-12-04

Plastics — Reinforced moulding compounds and prepregs — Determination of apparent volatile-matter content

Plastiques renforcés — Compositions pour moulage et préimprégnés — Détermination de la teneur apparente en matières volatiles

© ISO 2026

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester.

ISO Copyright Office

CP 401 • CH-1214 Vernier, Geneva

Phone: + 41 22 749 01 11

Email: copyright@iso.org

Website: www.iso.org

Published in Switzerland.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 13, Composites and reinforcement fibres.

The main changes are as follows:

— the requirement for the weighing accuracy of balances has been raised from ±1 mg to ±0,1 mg;

— timer is added in the apparatus;

— the symbol V_c for volatile-matter content in the calculation formula has been supplemented;

— the number of test specimens has been changed from "three" to "at least three".

— the sentence of “The specimens should be placed so that the maximum surface area is exposed to the circulating heat. ” is added in the procedure.

— a precision statement is 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.

Plastics — Reinforced moulding compounds and prepregs — Determination of apparent volatile-matter content

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.

If aramid fibres are used as the reinforcement, water absorbed by the fibres is eliminated with volatile matter at the test temperature. It is therefore necessary to correct the volatile-matter content by subtracting the water content.

The method does not apply to unimpregnated reinforcement fibres.

NOTE 1 For products with a polyester-resin matrix (UP), the result will be lower than the real value.

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 291, Plastics — Standard atmospheres for conditioning and testing

The apparent volatile-matter content is the percentage of matter lost on heating, relative to the initial mass . It is obtained by measuring the change in mass of a test specimen when heated in an air - ventilated oven at a specified temperature for a specified length of time .

4.1 Cutting device , for preparation of test specimens.

4.2 Balance , accurate to 0,1 mg.

4.3 Air-ventilated oven, capable of being maintained at the chosen temperature to within ±5 °C.

4.4 Desiccator

4.5 Suitable specimen holders, such as boats, hooks or aluminium sheets.

4.6 Timer, capable of reading 60 ± 1 min.

5.1 Sampling shall be carried out in accordance with the appropriate material specification.

5.2 Shape and dimensions

The surface area of each test specimen shall be at least 100 cm² or the mass of the test specimen shall be at least 1 g. The test specimen may be circular or square, or may have any other shape suitable for testing.

5.3 Preparation and number of test specimens

At least three test specimens shall be taken from each sample. These specimens shall be taken from locations distributed uniformly across the full width of the laboratory sample. if the sheet width is less than 30 cm, the specimens shall be taken from locations staggered along the length of the sheet. The test specimens shall be taken at least 5 cm from the edges.

6.1 Sample conditioning

A sufficient quantity of the sample to give the required number of specimens for testing (see 5.3) shall be conditioned for a time sufficient to establish temperature equilibrium in the standard atmosphere chosen for testing (see 6.2) without removing the protective sheet(s), and in a waterproof bag if necessary.

6.2 Test atmosphere

The test shall be carried out in one of the standard atmospheres specified in ISO 291.

7.1 Cut out the test specimens using a suitable cutting device (4.1) or take a suitable quantity of pre-impregnated yarn.

7.2 Weigh each specimen, with any protective sheets it may have, as quickly as possible after cutting it out, and record the mass m₁ in grams.

7.3 Remove the protective sheets, if present, and weigh them. Record their mass m₂ in grams.

7.4 Place each test specimen on a pre-weighed aluminium sheet or in a pre-weighed boat, or hang it from a pre-weighed hook (see 4.5), and insert specimen plus support into an oven (4.3) which has been pre-heated to the temperature specified in the specification for the material concerned. The specimens should be placed so that the maximum surface area is exposed to the circulating heat. Recommended temperatures and heating times for use in cases when no temperature or time is specified are given in table 1.

Table 1 — Recommended oven temperatures

7.5 After heating for the required length of time, remove the specimens from the oven. Avoid resin loss due to dripping while in the oven. Let the specimens cool in a desiccator (4.4).

7.6 Determine the specimen mass m₃ immediately after removal from the desiccator, either by direct weighing if the specimen can be removed from the holder without loss of material, or by subtracting the mass of the holder from the combined mass of holder and specimen.

Calculate the apparent volatile-matter content, expressed as a percentage by mass, of each test specimen, using the following formula:

where

V_c is the apparent volatile-matter content of prepregs, in %;

m₁ is the mass, in grams, of the test specimen together with its protective sheets(see 7.2);

m₂ is the mass, in grams, of the protective sheets if the test specimen has any (see 7.3);

m₃ is the mass, in grams, of the test specimen after heating in the oven (see 7.6).

Report as the result the arithmetic mean of the three determinations.

The details of an interlaboratory test carried out to validate the test method and the precision data obtained from this test are given in Annex A.

a) a reference to this International Standard;

b) all information necessary for complete identification of the material tested;

c) the mean value of the apparent volatile-matter content and, if required, the result of each individual determination;

d) the test conditions used;

e) the date of the test;

f) any deviation from the procedure specified.

1. 
   (informative)
   
   Precision data obtained from an interlaboratory test

A.1 General

An interlaboratory test was carried out to obtain the precision data for the method for measurement of apparent volatile-matter content with prepregs.

The study invloved 4 test sites, using two different types of prepregs, and comparing two methods of placing specimens.

A.2 Materials and methods of placing specimens

The materials chosen were:

Material 1: E-glass/epoxy prepreg

Material 2: E-glass/phenolic prepreg

The methods of placing specimens were:

Method 1: Suspension method

Method 2: Laying flat method

A.3 Results

Table A.1— Repeatability, reproducibility and mean volatile-matter content for the two specimens using suspension method

Table A.2 — Repeatability, reproducibility and mean volatile-matter content for the two specimens using laying flat method