EN ISO 7231:1997

SLOVENSKI STANDARD
01-maj-1999
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Polymeric materials, cellular flexible - Method of assessment of air flow value at constant
pressure-drop (ISO 7231:1984)
Weichelastische Schaumstoffe - Verfahren zur Bestimmung der Luftdurchlässigkeit bei
konstantem Staudruck (ISO 7231:1984)
Matériaux polymeres alvéolaires souples - Détermination de l'indice d'écoulement d'air -
Méthode a chute de pression constante (ISO 7231:1984)
Ta slovenski standard je istoveten z: EN ISO 7231:1997
ICS:
83.100 Penjeni polimeri Cellular materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATlON~MElK~YHAPO~HAfl OPTAHM3AUMR IlO CTAHflAPTM3A~MM@ORGANlSATlON INTERNATIONALE DE NORMALISATION
Polymeric materials, cellular flexible - Method of
assessment of air flow value at constant pressure-drop
Matkriaux polymkres alvbolaires soup/es - Determination de l’indice d’koulement d’air - Mbthode 2 chute de pression
constante
First edition - 1984-12-15
Ref. No. IS0 7231-1984 (E)
s UDC 678-4Q5.8 : 532.5
cellular materials, flexible cellular materials, tests, determination, air flow, testing conditions, test specimens.
Descriptors:
Price based on 4 pages
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 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, govern-
mental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
International Standard IS0 7231 was prepared by Technical Committee ISO/TC 45,
Rubber and rubber products.
International Organization for Standardization, 1984
Printed in Switzerland
IS0 7231-1984 (E)
INTERNATIONAL STANDARD
Polymeric materials, cellular flexible - Method of
assessment of air flow value at constant pressure-drop
1 Scope and field of application Traps to prevent manometer liquid being drawn into the
chamber by accidental excess pressure changes shall be pro-
This International Standard specifies a method for determining
vided. A plunger in the fluid reservoir is used to set the zero
the air flow value of cellular polymeric flexible materials. Air point after levelling the manometer.
flow values may be used to give an indication of the effects of
formulation and production variables on the cellular structure.
NOTE - The use of an inclined manometer with 2 Pa graduation is
recommended. A level mounted on the manometer should be used to
ensure that the proper degree of inclination from the horizontal is
maintained.
2 Definition
4.3 Blowers
air flow value: The volume flow rate required to maintain a
constant pressure differential across a flexible foam test piece.
The air supply may be such that positive or negative pressure
differences from atmospheric pressure are obtained across the
For the purposes of this International Standard the units of air
test piece, using compressed air, exhaust blower or vacuum
flow value are cubic decimetres per second.
pumps etc.
NOTE - A particular apparatus may be constructed to use only
positive or negative pressure.
3 Principle
4.4 Test piece mounting
A specified constant air pressure differential is created across a
standard flexible foam specimen. The rate of flow of air
A chamber of nominal dimensions 140 mm diameter x 150 mm
required to maintain this pressure differential is the air flow
depth (see figure 1) or 75 mm diameter x 1000 mm length (see
value.
figure 2) incorporating a test piece mounting and fittings for
the manometer and exhaust shall be provided. The test piece
cavity shall be 50 If: 0,05 mm x 50 + 0,05 mm x 25 + 0,05 mm.
4 Apparatus
The test piece shall be supported by suitable means, for
example by the use of vanes, wires or a perforated support.
Diagrams
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