ISO 7822:1990 テキスタイルガラス繊維強化プラスチック—ボイド含有量の測定—着火損失、機械的崩壊、統計的カウント方法 | ページ 2

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.

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.

1 Scope

This International Standard specifies three methods for the determination of the void content of textile glass reinforced plastics or composites, of which the constituents are of a solid nature.

1.1 Method A - Loss on ignition

This method is applicable to composites for which the effects of the loss on ignition test on the materials are known. Most matrix resins and textile glass fibre reinforcements fall into this class.

The method is not applicable to composites for which the effects of the loss on ignition test on the resin, the reinforcement, and any fillers are unknown. This may include silicone resins, which do not burn off completely, and fillers consisting of oxides, carbonates, etc., which may gain or lose weight. Note that separate weight loss tests on individual materials will usually, but not necessarily, give the same result as when all the materials are combined.

The accuracy of the method is ±2,5 % by volume.

1.2 Method B - Mechanical disintegration

This method is applicable if the composite can be disintegrated in such a way, for example by crushing in a press, that all the enclosed voids are connected with the outside of the composite material. The method is destructive and has limited application if the matrix material shows ductile behaviour under compression, unless it can be made more brittle in an artificial way (for example by cooling).

The method is especially suitable when the densities of the constituent materials are not known or not determinable.

The method neglects the influence of any volatile constituents that could evaporate during and after disintegration. In this connection, the conditioning shall be chosen with care. The method also does not take into account any cut or exposed voids at the surface of the sample.

The accuracy of the method is ± 1 % by volume.

1.3 Method C - Statistical counting

This method is applicable to composites having a void content less than or equal to 1 % by volume.

2 Normative references

The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.