ISO/R 816:1968

Title missing - Legacy paper document

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-1967
• Technical Committee: ISO/TMBG - Technical Management Board - groups
• Drafting Committee: ISO/TMBG - Technical Management Board - groups
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 01-Jan-1973

Standards Content (Sample)

UDC 678.41678.7 : 620.172 Ref. No. : lSO/R 816-1968(E)
IS0
I NTERN AT1 O N A L O RG A N I2 AT I ON FO R STAN DARD l ZATl O N
IS0 RECOMMENDATION
R 816
DETERMINATION OF TEAR STRENGTH
OF SMALL TEST PIECES OF VULCANIZED RUBBERS
(DELFT TEST PIECES)
1 st EDITION
September 1968
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.

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BRIEF HISTORY
The IS0 Recommendation R 816, Determination of tear strength of small test pieces of
vulcanized rubbers (Delft test pieces), was drawn up by Technical Committee ISOlTC 45, Rubber, the
Secretariat of which is held by the British Standards Institution (BSI).
Work on this question by the Technical Committee led, in 1962, to the adoption of a Draft
IS0 Recommendation.
In November 1963, this Draft IS0 Recommendation (No. 630) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature, by
the following Member Bodies :
Czechoslovakia Netherlands
Argentina
Germany New Zealand
Australia
Austria Hungary Poland
Brazil India Spain
Switzerland
Bulgaria Israel
United Kingdom
Canada Italy
U.S.S.R.
Chile Japan
Yugoslavia
Colombia Korea, Rep. of
Three Member Bodies opposed the approval of the Draft :
France
Sweden
U.S.A.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council,
which decided, in September 1968, to accept it as an IS0 RECOMMENDATION.
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ISO/R 816-1968 (E
IS0 Recommendation R 816 September 1968
DETERMINATION OF TEAR STRENGTH
OF SMALL TEST PIECES OF VULCANIZED RUBBERS
(DELFT TEST PIECES)
I. SCOPE
This IS0 Recommendation describes a method for the determination of tear strength of small test
pieces of vulcanized rubbers using the Delft test pieces.
2. PRINCIPLE OF METHOD
The test consists of measuring the force required to tear across the width of a small test piece
containing a slit in the centre. The slit and the test piece should be cut in one operation. The test does
not necessarily give results agreeing with those given by the method using the crescent test piece.*
3. APPARATUS
The test piece should be stretched in a tensile testing machine capable of a substantially constant rate
of traverse of the moving grip. This rate should be 500 t 50 mm/min.
The capacity of the test machine sliould be such that the force required to cause tearing of the test
piece will be not less than 15 nor more than 85 of that capacity.
NOTE. Inertia (pendulum) type dynamometers are apt to give results which differ because of trictional arid
inertial effects. An inertia-less (for example, electronic or optical transducer type) dynamometer gives rctults which
are free from these effects and is therefore to be preferred.
4. TEST PIECE
4.1 Dimensions of standard test piece
The test piece should be rectangular and should conform to the shape of the die shown in
Figure 1 below.
Slit to be symmetrical with rlie width
Dimensions of test piece
B Width 9.0 t O. 1
s Slit 5.0 t O. I
FIG. 1 ~ Die
*
See IS0 Recommendation U 34, Determination of tear strength of vulcanized natural and synthetic rubbers
(crescent test piece).
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ISOlR 816-1968 (E)
The test piece should be cut from a sheet by punching with the die, using a single blow of a
mallet or (preferably) a single stroke of a press. The rubber may be wetted with water or a soap
solution, and should be supported on a sheet of slightly yielding material (for example, leather,
rubber belting or cardboard) on a flat rigid surface. The construction of the die and of the
knife which cuts the slit is shown in Figure 2 and Figure 3 .
The tear strength is particularly susceptible to grain effects in vulcanized rubber. Normally, ail
test pieces are prepared with the grain at right angles to their length, but in cases where grain
effects are significant and are to be evaluated, two sets of test pieces should be cut from the
sheet, one at right angles to the grain and the other parallel to the grain.
The thickness of the test pieces should be 2.0 f 0.2 mm.
4.2 Measurement of test piece
The thickness of the test piece should be measured by means of a micrometer gauge having a
pressure foot approximately 6 rnm in diameter which exerts a pressure of 0.2 bar on the
...

Rif. No : ISO/R 816-1968 (F)
CDU 674.243
IS0
ORGAN I SAT1 ON I NT ERN AT1 O NA LE DE NOR MA LIS AT1 ON
R E CO M M A N D AT1 O N I SO
R 818
PANNEAUX DE FIBRES
D É F I N ITI ON - c LASSI F I CATI ON
ière EDITION
Septembre 1968
REPRODUCTION INTERDITE
Le droit de reproduction des Recommandations IS0 et des Normes
IS0 est la propriété des Comités Membres de I’ISO. En consé-
quence, dans chaque pays, la reproduction de ces documents ne
peut être autorisée que par l’organisation nationale de normali-
sation de ce pays, membre de I’ISO.
Seules les normes nationales sont valables dans leurs pays respectifs.
Imprimé en Suisse
Ce document est également édité en anglais et en russe. I1 peut être obtenu auprès des organisations
nationales de normalisation.

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HISTORIQUE
La Recommandation KO/R 818, Panneaux de fibres - Définition - Classification, a été
élaborée par le Comité Technique iSO/TC 89, Panneaux à base de bois ou d’autres matièresfibreuses
lignocellulosiques, dont le Secrétariat est assuré par le Deutscher Normenausschuss (DNA).
/-
à cette question furent entrepris par le Comité Technique en 1959 et
Les travaux relatifs
aboutirent. en 1964, à l’adoption d’un Projet de Recommandation ISO.
En mai 1966, ce Projet de Recommandation IS0 (No 956) fut soumis a I’enquete de tous les
Comités Membres de I’ISO. I1 fut approuvé, sous réserve de quelques modifications d’ordre rédac-
tionnel, par les Comités Membres suivants :
Afrique du Sud, France Royaume-Uni
Rep. d’ Inde Suède
Allemagne Irlande Suisse
Autriche Israël Tchécoslovaquie
Belgique Norvège U.R.S.S.
Canada Nouvelle-Zélande Yougoslavie
Chili Pays-Bas
Colombie Pologne
Corée, Rép. de Portug
...