SIST EN ISO 7822:2000

Textile glass reinforced plastics - Determination of void content - Loss on ignition, mechanical disintegration and statistical counting methods (ISO 7822:1990)

Migrated from Progress Sheet (TC Comment) (2000-07-10): SC2 Res; 2/1998: UAP ballot shall be started ONLY after examination of ISO 7822 ++ is completed. This re-examination has not been completed and the UAP ballot has ++ not been approved by the SC2. SC2 requests the results of the voting not be con- ++ sidered (TA/990317)

Textilglasverstärkte Kunststoffe - Bestimmung der Menge vorhandener Lunker - Glühverlust, mechanische Zersetzung und statistische Auswertungsverfahren (ISO 7822:1990)

In dieser Norm sind drei Verfahren zur Bestimmung der Menge vorhandener Lunker von textilglasverstärkten Kunststoffen oder Verbundwerkstoffen festgelegt, deren Bestandteile feste Stoffe sind.

Plastiques renforcés de verre textile - Détermination de la teneur en vide - Méthodes par perte au feu, par désintégration mécanique et par comptage statistique (ISO 7822:1990)

S stekleno tkanino ojačeni polimerni materiali - Določanje praznin v materialu - Žaroizguba, mehansko drobljenje in statistična števna metoda (ISO 7822:1990)

General Information

• Status: Published
• Publication Date: 30-Apr-2000
• ICS: 13.220.40 - Ignitability and burning behaviour of materials and products
• ICS: 83.120 - Reinforced plastics
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-May-2000
• Due Date: 01-May-2000
• Completion Date: 01-May-2000
• Ref Project: EN ISO 7822:1999 - Textile glass reinforced plastics - Determination of void content - Loss on ignition, mechanical disintegration and statistical counting methods (ISO 7822:1990)

Relations

• Child: SIST EN ISO 1172:2000 - Textile-glass-reinforced plastics - Prepregs, moulding compounds and laminates - Determination of the textile-glass and mineral-filler content - Calcination methods (ISO 1172:1996)
• Effective Date: 22-Dec-2008
• Child: SIST EN ISO 11667:2000 - Fibre-reinforced plastics - Moulding compounds and prepregs - Determination of resin, reinforced-fibre and mineral-filler content - Dissolution methods (ISO 11667:1997)
• Effective Date: 22-Dec-2008

Overview

SIST EN ISO 7822:2000 is an international standard developed by CEN and ISO for the assessment of void content in textile glass reinforced plastics (TGRP). The void content, or volume of air pockets and gaps within the composite, is a critical factor influencing the mechanical and physical properties of reinforced plastics. This standard specifies reliable methods to accurately determine void content using loss on ignition, mechanical disintegration, and statistical counting techniques. It primarily applies to composites where constituents are solid materials, focusing on enhancing quality control and consistency in manufacturing textile glass reinforced plastics.

Key Topics

• Void Content Determination
  The standard covers three principal methods to evaluate void content in textile glass reinforced plastics:

  • Method A: Loss on Ignition
    Measures voids based on weight loss due to burning off resin components, effective when test effects on materials are well known.
  • Method B: Mechanical Disintegration
    Involves crushing the composite to open voids and measuring volume differences; suitable when densities are unknown or indeterminable.
  • Method C: Statistical Counting
    Uses micrographic sections analyzed under a microscope with grid overlay to statistically count void fractions, applicable for void content ≤1% by volume.

• Measurement Principles and Accuracy

  • Loss on ignition assumes known behavior of resin and fibers during ignition.
  • Mechanical disintegration is destructive and requires careful handling, especially with ductile matrix materials.
  • Statistical counting provides high accuracy with potential for manual or automated analysis.

• Apparatus and Equipment
  The methods require precision instruments such as muffle furnaces, pyknometers for volume measurement, disintegration presses, microscopes with grid oculars, polishing machines and embedding molds for micrographic sample preparation.

• Sample Preparation and Conditioning
  Proper specimen dimensions and conditioning under standard atmospheres are essential for reproducibility. Specimens must be clean, dry, and representative of the composite material.

• Calculation and Reporting
  The void content is expressed as a percentage of composite volume. Detailed formulas and procedures are provided for calculating densities, volumes, and void percentages. Test reports include method details, material descriptions, number of specimens, individual and average results, and additional observations relevant to the applied method.

Applications

• Quality Control in Composite Manufacturing
  Manufacturers of textile glass reinforced plastics use EN ISO 7822 to monitor and control void content, which impacts mechanical strength, durability, and performance of finished products.

• Material Characterization
  This standard aids researchers and engineers in assessing the internal structural integrity of composites, enabling improved design and formulation of reinforced plastics.

• Failure Analysis and Compliance
  Helps in diagnosing defects related to voids, which can lead to premature failure, and ensures compliance with industry specifications demanding maximum void limits.

• Research and Development
  Supports R&D efforts in composite materials by providing standardized, reproducible methods for quantifying internal porosity in textile glass reinforced plastics.

Related Standards

EN ISO 7822 references and aligns with several key standards for broad compatibility and accuracy:

• ISO 291:1977 – Plastics: Standard atmospheres for conditioning and testing
• ISO 1172:1975 – Textile glass reinforced plastics: Determination of loss on ignition
• Technical committee references related to plastics and reinforced materials processing.

These related standards ensure controlled testing environments, sample conditioning, and consistency in measurement techniques for the composite materials testing industry.

---

For industries involved with reinforced plastics, strictly following EN ISO 7822 enhances product reliability and supports international quality benchmarks by providing methods to accurately detect and quantify void content in textile glass composites. This comprehensive approach to void evaluation is essential for optimizing composite performance and durability.

Standards Content (Sample)

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Textile glass reinforced plastics - Determination of void content - Loss on ignition,
mechanical disintegration and statistical counting methods (ISO 7822:1990)
Textilglasverstärkte Kunststoffe - Bestimmung der Menge vorhandener Lunker -
Glühverlust, mechanische Zersetzung und statistische Auswertungsverfahren (ISO
7822:1990)
Plastiques renforcés de verre textile - Détermination de la teneur en vide - Méthodes par
perte au feu, par désintégration mécanique et par comptage statistique (ISO 7822:1990)
Ta slovenski standard je istoveten z: EN ISO 7822:1999
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
83.120 2MDþDQLSROLPHUL Reinforced plastics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ISO
INTERNATIONAL
STANDARD 7822
First edition
1990-09-01
Textile glass reinforced plastics -
Determination of void content - Loss on
ignition, mechanical disintegration and
statistical counting methods
Determination de Ia teneur en vide -
Plastiques renforces de verre textile -
Mthodes par perte au feu, par d&int&gration mkanique et par camptage
statistique
Reference number
ISO 7822 : 1990 (El
ISO 7822 : 1990 (E)
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. Esch 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, govern-
mental and non-governmental, in Iiaison with ISO, also take patt in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for voting. Publication as an International Standard requires
approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 7822 was prepared by Technical Committee ISO/TC 61,
Plastics.
Annex A of this International Standard is for information only.
0 ISO 1990
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronie or mechanical, including photocopying and microfilm, without Permission in
writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
INTERNATIONAL STANDARD ISO 7822 : 1990 (E)
Textile glass reinforced plastics - Determination of void
- Loss on ignition, mechanical disintegration and
content
statistical counting methods
1 Scope 2 Normative references
The following Standards contain provisions which, through
This International Standard specifies three methods for the
reference in this text, constitute provisions of this International
determination of the void content of textile glass reinforced
Standard. At the time of publication, the editions indicated
plastics or composites, of which the constituents are of a solid
were valid. All Standards are subject to revision, and Parties to
nature.
agreements based on this International Standard are encouraged
to investigate the possibility of applying the most recent editions
1.1 Method A - Loss on ignition
of the Standards indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
This method is applicable to composites for which the effects
of the loss on ignition test on the materials are known. Most ISO 291: 1977, Plastics - Standard atmospheres for condition-
ing and testing.
matrix resins and textile glass fibre reinforcements fall into this
class.
ISO 1172: 1975, Textile glass reinforced plastics - Determi-
nation of Ioss on ignition.
The method is not applicable to composites for which the ef-
fects of the loss on ignition test on the resin, the reinforcement,
and any fillers are unknown. This may include Silicone resins,
3 Principle
which do not burn off completely, and fillers consisting of ox-
ides, carbonates, etc., which may gain or lose weight. Note
that separate weight loss tests on individual materials will
3.1 Method A - Loss on ignition
usually, but not necessarily, give the same result as when all
Determination of the densities of the resin, the reinforcement,
the materials are combined.
filier(s) (if present) and the composite. Determination of the
resin content and calculation of a theoretical composite den-
The accuracy of the method is +2,5 % by volume.
sity. Comparison with the measured composite density. The
differente in densities indicates the void content.
1.2 Method B - Mechanical disintegration
NOTE - The density of the resin, in this method, is assumed to be the
This method is applicable if the composite tan be disintegrated same in the composite as it is in a moulded mass. Although there is no
realistic way of avoiding having to make this assumption, it is never-
in such a way, for example by crushing in a press, that all the
theless not strictly correct. Differentes in curing, heating, pressure and
enclosed voids are connected with the outside of the com-
molecular forces arising from the reinforcement sutface all make the
posite material. The method is destructive and has limited ap-
density of the resin in the composite different from the bulk resin density.
plication if the matrix material Shows ductile behaviour under
compression, unless it tan be made more brittle in an artificial
Composites containing inorganic fillers require special care. An
way (for example by cooling).
accurate determination of the filler content and density is re-
quired if the accuracy of this method is to be maintained.
The method is especially suitable when the densities of the con-
stituent materials are not known or not determinable.
3.2 Method B - Mechanical disintegration
The method neglects the influence of any volatile constituents
Determination of the mass and volume, before and after
that could evaporate during and after disintegration. In this
disintegration, of a fibre reinforced plastic Sample to obtain the
connection, the conditioning shall be Chosen with care. The
void content by density differente.
method also does not take into account any tut or exposed
voids at the surface of the Sample.
3.3 Method C - Statistical counting
The accuracy of the method is * 1 % by volume.
Superimposition of a Square grid of 20 to 200 Points on a
micrographic section of the material to be tested. Statistically,
the proportion of Points of the grid which are superimposed on
1.3 Method C - Statistical counting
voids corresponds to the void content of the material. The
counting method may be manual, or semi-automatic or auto-
This method is applicable to composites having a void content
less than or equal to 1 % by volume. matic using suitable apparatus.
ISO 7822 : 1990 (El
the preparation of micrographic
4.3.2 Equipment for
4 Apparatus
sections, comprising
4.1 Method A
a) a cutting machine;
b) a polishing machine;
4.1 .l Micrometer, having an accuracy of $11 Fm.
Cl a mould for encasing the section in transparent resin;
4.1.2 Balance, having an accuracy of +O,l mg.
d) an ultrasonic cleaning bath.
Muffle furnace, capable of being maintained at
4.1.3
625 *C k 5 OC. 5 Preparation and number of test specimens
5.1 Methods A and B
4.2 Method B
5.1 .l The test specimens shall be representative of the
4.2.1 Disintegrator (in its simplest form a press), in which
’
composite to be examined. The quantity and form will depend
the test material is delaminated and crushed until all the voids
on the pyknometer and the disintegration procedure used.
are connected with the outside of the composite material. lt is
When an air pyknometer is used, quantities of about 25 g or
advisable, however, to use a closed-die unit made of hardened
12 000 mm3, preferably in the form of Strips about 38 mm long,
steel as shown in figure 1.
about 10 mm wide and of the thickness of the composite, are
needed for each determination.
5.1.2 From the composite to be examined, tut a series of at
least five Strips of appropriate size and mass. The pieces shall
be clean and dry.
5.2 Method C
5.2.1 The specimens shall have the shape of a parallepiped
40 mm long and 10 mm wide, the thickness depending on the
thickness of the structure from which the specimens have been
tut, with a maximum value of 15 mm. The number of specimens
to be taken will depend on the number of sections needed and
on the nature of the structure to be tested; each specimen tan
give several sections.
Sample
5.2.2 Prepare a total of at least five sections from among the
specimens. The polishing Operation and the encasing of the
sections in cold-curing resin shall be carried out in accordance
Figure 1 - Disintegration die
with the procedures used in micrography. (See annex A.)
4.2.2 Air or gas pyknometer, suitable for measuring the
6 Atmospher
...