-
JIS K 6251: 2010 (JRMA/JSA)
JAPANESE INDUSTRIAL STANDARD
Translated and Published by Japanese Standards Association
Rubber, vulcanized or thermoplastics- Determination of tensile
stress-strain properties
ICS 83.060
Reference number: JIS K 6251 : 2010 (E)
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K 6251 : 2010
Date of Establishment: 1993-02-01 Date of Revision: 2010-12-20
Date of Public Notice in Official Gazette: 2010-12-20 Investigated
by: Japanese Industrial Standards Committee
JSA 2011
Standards Board Technical Committee on Chemical Products
JIS K 6251: 2010, First English edition published in 2011-08
Translated and published by: Japanese Standards Association
4-1-24, Akasaka, Minato-ku, Tokyo, 107-8440 JAPAN
In the event of any doubts arising as to the contents, the
original JIS is to be the final authority.
All rights reserved. Unless otherwise specified, no part of this
publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
Printed in Japan AT
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K 6251 : 2010
Contents
Page
Introduction
...................................................... 1
1 Scope ......................................................
1
2 Normative references
...................................................... 1
3 Terms and definitions
.............................................................................................
2
4 Principle
............................................................................................................
4
5 General ......................................................
4
6 Test piece 5 6.1 Dumb-bell-shaped test piece
...................................................... 5 6.2
Ring-shaped test piece
...................................................... 6 6.3
Selection of test pieces
............................................................................................
6
7 Testing apparatus
...................................................... 8
8 Number of test pieces
...................................................... 10
9 Sampling and preparation of test pieces
...................................................... 10 9.1
Dumb-bell-shaped test piece
...................................................... 10 9.2
Ring-shaped test piece
...................................................... 10
10 Conditioning of samples and test pieces
...................................................... 10 10.1
Period from vulcanization or moulding to testing 10 10.2 Storage of
samples and test pieces
...................................................... 10 10.3
Conditioning of samples
...................................................... 11 10.4
Conditioning of test pieces
...................................................... 11
11 Gauging of dumb-bell test pieces
...................................................... 11
12 Measurement of test pieces
..................................................................................
11 12.1 Dumb-bell-shaped test piece
...................................................... 11 12.2
Ring-shaped test piece
...................................................... 11 12.3
Median thickness
...................................................... 12
13 Procedure
................................................................................................................
12 13.1 Dumb-bell-shaped test piece
...................................................... 12 13.2
Ring-shaped test piece
...................................................... 12 13.3
Measurement for obtaining tensile strength, tensile stress at
break
and elongation at break
...................................................... 13 13.4
Measurement for obtaining tensile stress at a given elongation 13
13.5 Measurement for obtaining tensile stress at yield and
elongation at
yield
............................................................................................................
13
(i)
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K 6251 : 2010
14 Temperature of test
...............................................................................................
13
15 Calculation of results
....................................................................
................ 13 15.1 Dumb-bell-shaped test piece
................................................................................
13 15.2 Ring-shaped test piece
..........................................................................................
14
16 Expression of results
.............................................................................................
16
17 Test report
........................................................................................
16
Annex A (informative) Precision
..................................................................................
17 Annex B (informative) Analysis of ITP data and dumb-bell shape
........................ 21 Annex JA (informative) Comparison table
between JIS and corresponding
International Standard .... .......................... 26
(ii)
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K 6251 : 2010
Foreword
This translation has been made based on the original Japanese
Industrial Standard revised by the Minister of Economy, Trade and
Industry through deliberations at the Japanese Industrial Standards
Committee as the result of proposal for revision of Japanese
Industrial Standard submitted by the Japan Rubber Manufacturers
Associa-tion (JRMA)/Japanese Standards Association (JSA) with the
draft being attached, based on the provision of Article 12 Clause 1
of the Industrial Standardization Law applicable to the case of
revision by the provision of Article 14.
Consequently JIS K 6251: 2004 is replaced with this Standard.
This JIS document is protected by the Copyright Law. Attention is
drawn to the possibility that some parts of this Standard may
conflict with a patent right, application for a patent after
opening to the public, utility model right or application for
registration of utility model after opening to the public which
have technical properties. The relevant Minister and the Japanese
Industrial Standards Committee are not responsible for identifying
the patent right, application for a patent after opening to the
public, utility model right or application for registration of
utility model after opening to the public which have the said
technical properties.
(iii)
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JAPANESE INDUSTRIAL STANDARD JIS K 6251 : 2010
Rubber, vulcanized or thermoplastics-Determination of tensile
stress-strain
properties
In troduction This Japanese Industrial Standard has been
prepared based on the fourth edition
of ISO 37 published in 2005 and ISO 37 TECHNICAL CORRIGENDUM 1
published in 2008 with some modifications of the technical
contents.
The portions given sidelines or dotted underlines are the
matters in which the con-tents of the original International
Standard have been modified. A list of modifica-tions with the
explanations is given in Annex JA.
1 Scope This Standard specifies the determination method of the
tensile stress-strain prop-
erties of vulcanized rubbers and thermoplastic rubbers. The
properties to be determined shall be the tensile strength,
elongation at break,
stress at a given elongation, elongation at a given stress,
tensile stress at yield and elongation at yield. The measurement of
the tensile stress at yield and the strain at yield applies only to
vulcanized rubbers and thermoplastic rubbers having the yield.
NOTE: The International Standard corresponding to this Standard
and the sym-bol of degree of correspondence are as follows.
ISO 37: 2005 Rubber, vulcanized or thermoplastic-Determination
of tensile stress-strain properties and TECHNICAL CORRIGENDUM 1
:2008 (MOD)
In addition, symbols which denote the degree of correspondence
in the contents between the relevant International Standard and JIS
are IDT (identical), MOD (modified), and NEQ (not equivalent)
according to ISO/ lEe Guide 21-1.
Warning: Persons using this Standard should be familiar with
normallabora-tory practice. This Standard does not purport to
address all of the safety problems, if any, associated with its
use. It is the responsibil-ity of the user to establish appropriate
safety and health practices.
2 Norma ti ve references The following standards contain
provisions which, through reference in this text,
constitute provisions of this Standard. The most recent edition
of the standard (including amendments) indicated below shall be
applied.
JIS K 6200 Rubber-Vocabulary
JIS K 6250 Rubber-General procedures for preparing and
conditioning test pieces for physical test methods
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2 K 6251: 2010
NOTE: Corresponding International Standard: ISO 23529
Rubber-General procedures for preparing and conditioning test
pieces for physical test methods (MOD)
JIS K 6272 Rubber-Tensile, flexural and compression test
equipment (constant rate of traverse)-Specification
NOTE: Corresponding International Standard: ISO 5893 Rubber and
plastics test equipment-Tensile, flexural and compression types
(constant rate of traverse)-Specification (MOD)
JIS Z 8401 Guide to the rounding of numbers
---------------------------------------------------------------------------------------
3 Terms and definitions For the purposes of this Standard, the
terms and definitions given in ~~_~_~ __ ~~~_~_,
and the following terms and definitions apply. In addition, the
illustration for explanation of terms for tensile test is shown
in
figure 1.
3.1 tensile stress S the force applied so as to extend the test
piece divided by the area of the initial cross-section of the test
piece
3.2 elongation E tensile strain produced in the test piece by
tensile stress, which is expressed by the ratio to the initial
length
NOTE: The elongation is expressed by the ratio (%) to the gauge
length.
3.3 tensile strength TS maximum tensile force recorded in
expanding the test piece to the break divided by the area of the
initial cross-section of the test piece
NOTE: See figure 1 a) to figure 1 c).
3.4 tensile strength at break TSb tensile force recorded when
the test piece is broken divided by the area of the initial
cross-section of the test piece
NOTE 1 See figure 1 a) to figure 1 c). NOTE 2 The values of TS
and TSb may be different if, after yielding at Sy, the
elongation continues along the drop in stress resulting in TSb
being lower than TS. See figure 1 c).
3.5 elongation at break Eb elongation when the test piece is
broken, expressed by the ratio (%) to the initial length
NOTE: See figure 1 a) to figure 1 c).
3.6 elongation at a given stress Es elongation when the test
piece is subjected to a given tensile stress, expressed by the
ratio (%) to the initial length
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3 K 6251: 2010
3.7 stress at a given elongation Se tensile force required to
produce a given elongation (E %) to the test piece divided by the
area of the initial cross-section of the test piece
NOTE: In the rubber industry, this definition is widely
identified with the term "modulus"; however, care should be taken
to avoid confusion with the use of "modulus" in other industries to
denote the slope of the stress-strain curve at a given
elongation.
3.8 tensile stress at yield Sy tensile stress at the first point
where some further increase in elongation occurs without any
increase in tensile force before the test piece is broken
NOTE: This corresponds to the inflection point [see figure 1 b)]
or the maximum point [see figure 1 c)].
3.9 elongation at yield Ey elongation at the first point where
some further increase in elongation occurs without any increase in
tensile force before the test piece is broken, expressed by the
ratio (%) to the initial length
NOTE: See figure 1 b) and figure 1 c).
S S
y S y I------::~--"""
Eb E Ey Eb E a) b)
S Y
Sy TS TS b E : elongation
Eb : elongation at break Ey : elongation at yield S : tensile
stress Sy : tensile stress at yield TS : tensile strength TSb :
tensile strength at break
Ey Eb E y : yield c)
Figure 1 Illustration for explanation of terms for tensile
test
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4 K 6251: 2010
3.10 test length of a dumb-bell (gauge length) reference length
used to measure the elongation within the narrow portion of a
dumb-bell-sha ped test piece
NOTE: Generally, it is indicated by gauges, and hereafter
referred to as "gauge length" (see figure 2).
4 Principle The standard test pieces of either dumb-bell-shaped
test pieces or ring-shaped test
pieces are expanded by the tensile testing machine at a constant
rate of traverse of the grip or the pulley. The tensile force or
the elongation shall be measured when the test piece is expanded at
the specified rate of traverse.
5 General The dumb-bell-shaped test pieces and the ring-shaped
test pieces do not necessar-
ily give the same values for their respective stress-strain
properties. This is mainly because the stress is not uniform over
the cross-section of the ring. Also, this is be-cause the
dumb-bell-shaped test pieces may give different measured values
depend-ing whether the narrow portion thereof is parallel or at
right angles to the grain.
The main points to be noted in selecting the dumb-bell-shaped
test pieces and the ring-shaped test pieces are as follows.
a) Tensile strength The dumb-bell-shaped test pieces are
preferable for determi-nation of tensile strength. The ring-shaped
test pieces give lower values than those of the dumb-bell-shaped
test pieces.
b) Elongation at break The elongation of ring-shaped test pieces
and that of dumb-bell-shaped test pieces give approximately the
same values, provided that the elon-gation of ring-shaped test
pieces is calculated as the ratio to the initial internal
circumference and the dumb-bell-shaped test pieces are taken at
right angles to the grain.
If it is required to study grain effects, the dumb-bell-shaped
test pieces should be used, for which ring-shaped test pieces are
not suitable.
c) Elongation at a given stress and stress at a given elongation
For the test pieces, the dumb-bell-shaped type 3 and the
dumb-bell-shaped type 5 are prefer-able.
The elongation of ring-shaped test pieces and that of
dumb-bell-shaped test pieces give approximately the same values,
provided that the elongation of ring-shaped test piece is
calculated as the ratio of initial circumference to the median and
the elongation of dumb-bell-shaped test pieces is calculated as the
average of the values when taken parallel to the grain and when
taken at right angles to the grain.
The ring-shaped test pieces are suitable for automated testing
due to the ease of handling of the test pieces, and also for the
determination of stress at a given elongation.
d) Selection of test pieces For the test pieces used for
testing, dumb-bell-shaped test pieces of seven types,
dumb-bell-shaped type 1, dumb-bell-shaped type 2, dumb-
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5 K 6251: 2010
bell-shaped type 3, dumb-bell-shaped type 5, dumb-bell-shaped
type 6, dumb-bell-shaped type 7 and dumb-bell-shaped type 8, and
ring-shaped test pieces of two types, ring-shaped type 1 and
ring-shaped type 2 shall be used.
The dumb-bell-shaped type 3 and the dumb-bell-shaped type 5
shall be the stan-dard test pieces among dumb-bell-shaped test
pieces. Dumb-bell-shaped type 1 test pieces are used for the sample
with small elongation, dumb-bell-shaped type 2 test pieces are for
the sample with small tensile strength, and dumb-bell-shaped type 6
test pieces are for the sample whose width is too narrow to prepare
the standard test piece.
For the ring-shaped test pieces, ring-shaped type 1 test pieces
shall be the stan-dard test pieces.
Miniature test pieces of the dumb-bell-shaped type 7,
dumb-bell-shaped type 8 and ring-shaped type 2 shall only be used
where insufficient material is available for the larger test
pieces. Miniature test pieces may give somewhat higher val-ues for
tensile strength at break and elongation at break than the larger
test pieces.
The results obtained for a given material are likely to vary
according to the shape of test piece used, therefore the results
obtained for different materials shall not be regarded as
comparable unless the same shape of test piece has been used.
When preparation of test pieces requires buffing or thickness
adjustment, test results may be affected.
6 Test piece
6.1 Dumb-bell-shaped test piece The shape of dumb-bell-shaped
test piece shall be as specified in figure 2.
2
1 Gauge 2 Gauge length (see table 1)
Figure 2 Shape of dumb-bell-shaped test piece
The shapes and dimensions of dumb-bell-shaped test pieces shall
be as specified in figure 3 and table 1. The initial gauge length
shall be as specified in table 1, and shall not exceed the length
of narrow portion of the test piece.
The dumb-bell-shaped test pieces shall be prepared using the
appropriate punch-ing die (see table 3).
For the non-standard test pieces prepared by cutting out from
the product, the maxi-mum thickness of the narrow portion shall be
3.0 mm for _~_~!!?-_1?_~~~g~~~_~~~~ __ ~;YJ?_~ __ ~~
dumb-bell-shaped type 2, dumb-bell-shaped type 3 and
dumb-bell-shaped type 5, 2.5 mm
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6 K 6251: 2010
for dumb-bell-shaped type 6 and dumb-bell-shaped type 8, and 2.0
mm for dumb-bell-shaped type 7.
Table 1 Shapes and dimensions of dumb-bell-shaped test pieces
Unit: mm
Shape Dimensions of main part Designation in
Thickness of Width of Initial gauge corresponding International
narrow portion narrow portion length Standard (ISO 37)
Dumb-bell-shaped type 1 2.00.2 10.00.1 40.0 0.5 -
Dumb-bell-shaped type 2 2.00.2 10.00.1 20.00.5 -
Dumb-bell-shaped type 3 2.00.2 5.00.1 20.00.5 Type lA
Dumb-bell-shaped type 5 2.00.2 60+0.4 . 0.0 25.00.5 Type 1
Dumb-bell-shaped type 6 2.00.2 4.00.1 20.0 0.5 Type 2
Dumb-bell-shaped type 7 1.00.1 2.00.1 10.00.5 Type 3
Dumb-bell-shaped type 8 2.00.2 4.00.1 10.00.5 Type 4
6.2 Ring-shaped test piece The shapes and dimensions of
ring-shaped test pieces shall be as specified in fig-
ure 3 and table 2. The standard ring-shaped type 1 test piece
shall have the inside diameter of 44.6 mm
0.2 mm. The average thickness and the average width shall be 4.0
mm 0.2 mm. The standard ring-shaped type 2 test piece shall have
the inside diameter of 8.0 mm
0.1 mm. The average thickness and the average width shall be 1.0
mm0.1 mm. The width of every ring-shaped test piece shall nowhere
deviate from the median by not less than 0.1 mm.
6.3 Selection of test pieces For both dumb-bell-shaped test
pieces and ring-shaped test pieces, those contain-
ing foreign matters, containing bubbles or having flaws shall
not be used for testing.
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120 40 40
Dumb-bell-shaped type 1
100 (25) 20 40
Dumb-bell-shaped type 3 75
(12.5) 25
-;3-:& ..-'
N '(ji
Dumb-bell-shaped type 6
50 (8.5) 16 17
I r-- \" - 1-- ~ ---
--P.\ ~~ -0 'S'
Dumb-bell-shaped type 8
o
o
-.;;j"
LD N
LD oj
LD ~
0
LD ~
Ring-shaped type 1
LD N
100
7 K 6251: 2010
Unit: mm
o LD ~~ __ ~ ______ +-~N
Dumb-bell-shaped type 2
(25)
~~ y
115 33 41
Dumb-bell-shaped type 5
35 (4.5) 1 2 11.5
Dumb-bell-shaped type 7
I
--~~ I
Ring-shaped type 2
Figure 3 Shapes and dimensions of test pieces
Table 2 Shapes and dimensions of ring-shaped test pieces
Unit: mm Shape Outside Inside Width Thickness One half of
internal
diameter diameter circumference of test piece
Ring-shaped type 1 52.6 44.60.2 4.00.2 4.00.2 70.0
Ring-shaped type 2 10.0 8.0 0.1 1.00.1 1.0 0.1 12.6
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8 K 6251: 2010
7 Testing apparatus
7.1 Punching die and cutter All punching dies and cutters shall
be as specified in 8.3 of JIS K 6250. The punch-
--------------------------------
ing die for sampling the test piece shall satisfy the dimensions
specified in figure 4, figure 5, table 3 and table 4.
A o
For dumb-bell-shaped test piece For ring-shaped test piece
Figure 4 Shapes of punching die for test piece
! I ! I
! I ! L _____ I ___ ~
x~ A
o
\ N (Y)
lLJ lL. ~--------_+~--------_+-r---+
1 Fixing position to punching device 2 Ground smooth 3
Ground
Unit: mm
x
x
Figure 5 Shape of punching tool for dumb-bell-shaped test piece
(example of fixed die)
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9 K 6251: 2010
Table 3 Dimensions of punching die for dumb-bell-shaped test
piece
Unit: mm
Shape Dimension measuring position A a) B b ) C b ) D E F Rl
R2
Dumb-bell-shaped type 1 120 (15) (25) 40.0+~:g 10.00.1 25.00.5
21.0 2.0 25.0 2.0 Dumb-bell-shaped type 2 100 20.0+~:g
Dumb-bell-shaped type 3 5.00.1 11.0 1.0
Dumb-bell-shaped type 5 115 (16) (25) 33.02.0 60+0.4 . 0.0 25.0
1.0 14.0 1.0 25.0 2.0
Dumb-bell-shaped type 6 75 (12.5) (12.5) 25.0 1.0 4.00.1 12.5
1.0 8.00.5 12.5 1.0 Dumb-bell-shaped type 7 35 (7) (4.5) 12.00.5
2.00.1 6.00.5 3.00.1 3.00.1 Dumb-bell-shaped type 8 50 (8.5) (8.5)
16.0 1.0 4.00.1 8.50.5 7.50.5 10.0 0.5 Notes a) To avoid the
breaking at shoulder part (part of RJ or R2) of dumb-bell-shaped
test piece,
a greater overall length may be necessary for the length of wide
end tab (grip part). b) Band C are the numerical values for
reference, which are determined by Rl and R2.
Table 4 Dimensions of punching die for ring-shaped test
piece
Unit: mm
Shape Dimension measuring position
G H I
Dumb-bell-shaped type 1 52.6 44.60.2 4.00.2
Dumb-bell-shaped type 2 10.0 8.0 0.1 1.0 0.1
7.2 Thickness gauge The instrument for measuring the thickness
of dumb-bell-shaped test piece and the
thickness of ring-shaped test piece shall be as specified in
10.1 a) of JIS K 6250. The instrument for measuring the width of
ring-shaped test piece shall be that the
contact point and base plate shall be shaped to fit the
curvature of the ring-shaped test piece.
7.3 Cone gauge A calibrated cone gauge or other suitable
instrument shall be used to measure the
inside diameter of ring-shaped test pieces. The instrument shall
be capable of mea-suring the diameter with an error of not
exceeding 0.01 mm. The means of support-ing the ring-shaped test
piece to be measured shall be such as to avoid any significant
change in the dimension being measured.
7.4 Tensile testing machine
7.4.1 The force-measuring system and the extensometer shall be
as specified in clause 6 and clause 9 of JIS K 6272. The
force-measuring system shall have an
ac---------------------------------------------------------------------
curacy of Class 1 or superior. The testing machine shall be
capable of operating at rates of traverse of 100 mm/min, 200 mm/min
and 500 mm/min.
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10 K 6251: 2010
7.4.2 The testing machine shall be equipped with the device
capable of indicating the maximum tensile force, and in the case of
using a dumb-bell-shaped test piece, with automatically clamping
grips, and in the case of ring-shaped test piece, with the de-vice
capable of rotating the test piece while expanding.
7.4.3 For tests at temperatures other than the standard
laboratory temperature, a suitable thermostatically controlled
chamber shall be fitted to the tensile testing machine. The
procedures for achieving higher or lower temperatures shall be as
speci-fied in 11.2.2 of JIS K 6250.
8 Number of test pieces A minimum of three test pieces shall be
tested.
NOTE: The use of five test pieces will give a lower uncertainty
than the test with three test pieces.
9 Sampling and preparation of test pieces
9.1 Dumb-bell-shaped test piece The dumb-bell-shaped test pieces
shall be prepared as specified in clause 8 of JIS
K 6250. The dumb-bell-shaped test pieces shall be taken, as far
as possible, parallel to the grain of the material. Ifit is
required to study grain effects, the dumb-bell-shaped test pieces
shall be taken at right angles to the grain.
9.2 Ring-shaped test piece The ring-shaped test pieces shall be
prepared as specified in clause 8 of JIS K 6250
by cutting, punching or moulding.
10 Conditioning of samples and test pieces
10.1 Period from vulcanization or moulding to testing For all
test purposes, the minimum period from vulcanization or moulding to
test-
ing shall be 16 h. For non-product tests, the maximum period
from vulcanization or moulding to testing
shall be 4 weeks and, for evaluations intended to be comparison,
the tests shall be carried out after the same interval, as far as
possible.
For product tests, as far as possible, the period from
vulcanization or moulding to testing shall not exceed 3 months.
In other cases, tests shall be made within 2 months of the date
of product receipt by the customer.
10.2 Storage of samples and test pieces Samples and test pieces
shall be stored to protect from all external influences such
as light and heat likely to cause damage during the period from
vulcanization or moul-ding to completion of testing.
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10.3 Conditioning of samples
11 K 6251: 2010
All samples other than those taken from latex shall be
conditioned as specified in 6.1 of JIS K 6250 without humidity
control, for not less than 3 h prior to taking the test pieces.
Latex samples likely to be affected by humidity shall be
conditioned under the en-vironment with humidity control as
specified in 6.1 and 6.2 of JIS K 6250 for not less than 96 h prior
to taking the test pieces.
10.4 Conditioning of test pieces All test pieces shall be
conditioned as specified in clause 9 of JIS K 6250. If the
preparation of test pieces involves buffing, the interval
between buffing and testing shall be 16 h or over to and including
72 h.
For tests at the standard laboratory temperature, test pieces
that do not require further preparation may be tested immediately,
if they are taken from the conditioned test samples. Where
additional preparation is involved, the test may carried out after
the minimum conditioning of 3 h at the standard laboratory
temperature.
For tests at temperatures other than the standard laboratory
temperature, the test pieces shall be conditioned at the
temperature of test for a period sufficient to enable the test
pieces to attain substantial equilibrium as specified in 11.2.2 of
JIS K 6250 (see 7.4.3).
11 Gauging of dumb-bell test pieces The dumb-bell-shaped test
pieces shall be marked with two gauges to define the
initial gauge length specified in table 1 with a suitable
marker. The test piece shall be unstrained when it is marked, and
the gauges shall be marked
clearly and with accuracy on the narrow portion of the test
piece equidistant from the
-----------------------------------------------
centre of the test piece at right angles as shown in figure
2.
12 Measurement of test pieces
12.1 Dumb-bell-shaped test piece The thickness of the
dumb-bell-shaped test piece at the centre and at each end of
the initial gauge length in the narrow portion shall be measured
with the thickness gauge. The median of the three measurements
shall be used in calculating the area of the cross-section. The
distance between the cutting edges of the die in the narrow portion
shall be used as the width of the test piece, and this length shall
be measured as specified in clause 10 of JIS K 6250 to the nearest
0.05 mm.
12.2 Ring-shaped test piece The width and thickness of the
ring-shaped test piece shall be measured at six ap-
proximately equally spaced positions around the ring. The median
of each set of mea-surements shall be used in calculating the area
of the cross-section. The inside diameter shall be measured to the
nearest 0.1 mm. The internal circumference and the mean
circumference shall be obtained according to the following
equation.
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12 K 6251: 2010
Ci=nXH
Cm=n x (H+ W) where, Ci = internal circumference (mm)
H = inside diameter (mm) Cm = mean circumference (mm) W = width
of ring (mm)
12.3 Median thickness If two groups of test pieces (either
dumb-bells or rings) are being compared, the
median thickness of each group shall be within 7.5 % of the
median thickness of the two groups.
In anyone ring-shaped test piece, none of the thickness
measurements shall differ by not less than 2 % from the median
thickness.
13 Procedure
13.1 Dumb-bell-shaped test piece The test piece shall be
attached to the tensile testing machine ensuring that the
end tabs thereof are gripped symmetrically so that the tensile
force is distributed uni-formly over the cross-section. If
necessary, the extensometer shall be set. The test-ing machine
shall be activated and the change of gauge length and the change of
force shall be monitored throughout the test to an accuracy
according to the required prop-erties or within 1 %.
The nominal rate of traverse of the grip shall be 500 mm/min 50
mmlmin for dumb--------- ------------
~~~_l_~~_J:l:~J?~~_~~r~}~_~_~~~~?_~~_~~~~~J?~~ __ ~yJ?~_~?
dumb-bell-shaped type 3, dumb-bell-shaped type 5 and
dumb-bell-shaped type 6 test pieces, and 200 mmlmin~_?g_ mmlmin for
dumb-bell-shaped type 7 and dumb-bell-shaped type 8 test
pieces.
Any test piece that broke outside the gauges or yields outside
the narrow portion shall be discarded, and the test shall be
repeated on an additional test piece.
13.2 Ring-shaped test piece The test piece shall be attached
with a minimum of tensile force around the two
pulleys. The testing machine shall be activated and the change
of transverse distance of pulley and the change of force shall be
monitored throughout the test to an accu-racy according to the
required properties or within 1 %.
The nominal rate of traverse pulley shall be 500 mm/min _~_~Q
mm/min for ring-shaped type 1 test pieces and 100 mm/min 10 mm/min
for ring-shaped type 2 test pieces.
The diameter of a pulley, when a ring-shaped test piece is
attached, shall 25 mm for ring-shaped type 1 test pieces and 4.5 mm
for ring-shaped type 2 test pieces.
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13 K 6251: 2010
13.3 Measurement for obtaining tensile strength, tensile stress
at break and elongation at break
For the purpose of obtaining tensile strength and tensile stress
at break, the maxi-mum tensile force and the tensile force at break
until the test piece broke shall be measured as specified in 7.4.
In the case of dumb-bell-shaped test piece, the elonga-tion at
break shall be obtained by measuring the gauge length when it broke
by the suitable means. In the case of ring-shaped test piece, the
elongation at break shall be obtained by measuring the distance
between two grips which is equal to the traverse distance of the
centre of pulley at break.
13.4 Measurement for obtaining tensile stress at a given
elongation In the case of dumb-bell-shaped test piece, the tensile
stress at a given elongation
shall be obtained by reading the tensile force when the distance
between gauges has reached to the given distance by the suitable
means. In the case of ring-shaped test piece, the tensile stress at
a given elongation shall be obtained by reading the tensile force
when the distance between two grips has reached to the given
distance.
13.5 Measurement for obtaining tensile stress at yield and
elongation at yield The tensile stress at yield and the elongation
at yield shall be obtained by mea-
suring the tensile force and the gauge length at the first point
where tensile force does not increase but elongation increases as
specified in 7.4. For the measurement, a re-corder capable of
recording the tensile force-elongation curve or a device capable of
mea-suring the tensile force and elongation automatically shall be
required.
14 Temperature of test The test shall be carried out as
specified in 6.1 of JIS K 6250. When other tem-
peratures are required, these should be selected from 11.2.2 of
JIS K 6250. The same temperature shall be used throughout anyone
test or series of tests in-
tended for the comparison.
15 Calculation of results
15.1 Dumb-bell-shaped test piece The tensile strength TS (MPa)
shall be calculated according to the following equa-
tion (1).
TS = Fm
............................................................................
(1) Wt
The tensile strength at break TSb (MPa) shall be calculated
according to the following equation (2).
Fb TSb =-
...........................................................................
(2) Wt The elongation at break Eb (%) shall be calculated according
to the following equa-
tion (3).
Eb = Lb -Lo xiOO
.............................................................. (3)
Lo
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14 K 6251: 2010
The stress at a given elongation Se (MPa) shall be calculated
according to the fol-lowing equation (4).
S = Fe
............................................................................
(4) C Wt
The elongation at a given stress Es (%) shall be calculated
according to the follow-ing equation (5).
E = Ls - Lo x 100
............................................................... (5)
S L
o
The value of force Fe (N) corresponding to the required stress
shall be calculated according to the following equation (6).
Fe = SeWt
..........................................................................
(6)
The tensile stress at yield Sy (MPa) shall be calculated form
the force recorded at yield according to the following equation
(7).
Fy S =- ......................................................
(7) y Wt
The elongation at yield Ey (%) shall be calculated according to
the following equa-tion (8).
L -L E = y 0 x 100
.............................................................. (8)
y Lo
where, Fb : Fe :
Fm:
Fy :
La: Lb : Ls :
Ly :
Se : t :
W:
15.2 Ring-shaped test piece
force at break (N) force at given strain (N) maxim urn force (N)
force at yield (N) initial gauge length (mm) gauge length at break
(mm) gauge length at given stress (mm) gauge length at yield (mm)
stress at given elongation (MPa) thickness of narrow position (mm)
width of narrow portion of punching die (mm)
The tensile strength TS (MPa) shall be calculated according to
the following equa-tion (9).
TS = Fm
..........................................................................
(9) 2Wt
The tensile strength at break TSb (MPa) shall be calculated
according to the following equation (10).
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15 K 6251: 2010
Fb TSb =-
.........................................................................
(10) 2Wt The elongation at break Eb (%) shall be calculated
according to the following equa-
tion (11). nd+2Lb -Cj Eb = x 100
....................................................... (11)
Cj
The tensile stress at a given elongation Se (MPa) shall be
calculated according to the following equation (12).
S = Fe
...........................................................................
(12) e 2Wt
The distance between pulley centres (mm) corresponding to given
elongation Le (mm) shall be calculated according to the following
equation (13).
L = CmEs + Cj -nd
............................................................ (13) e
200 2
The elongation at a given stress Es (%) shall be calculated
according to the follow-ing equation (14).
E = 1td + 2Ls - Cj x 100
........................................................ (14) s
C
m
The value of force Fe (N) corresponding to the required stress
shall be calculated according to the following equation (15).
Fe = 2SeWt
........................................................................
(15)
The tensile stress at yield Sy (MPa) shall be calculated
according to the following equation (16).
Fy Sy = 2Wt
...........................................................................
(16)
The elongation at yield Ey (%) shall be calculated according to
the following equa-tion (17).
1td +2Ly -Cj Ey = xl 00
....................................................... (1 7)
em
where, C: initial internal circumference of ring (mm) Cm:
initial mean circumference of ring (mm)
d: diameter of pulley (mm) Es: elongation at given stress (%)
Fb: force at break (N) Fe : force at given strain (N) Fm: maximum
force (N) Fy: force at yield (N)
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16 K 6251: 2010
16 Expression of results
Lb: distance between pulley centres at break (mm) Ls: distance
between pulley centres at given stress
(mm) Ly: distance between pulley centres at yield (mm) Se:
stress at a given elongation (MPa) t: thickness of ring-shaped test
piece (mm)
W: width of ring-shaped test piece (mm)
The tests shall be carried out for tensile strength, tensile
stress at break, tensile stress at yield, tensile stress at given
elongation, elongation at break and elongation at yield on at least
3 test pieces, and the median of respective values obtained by
clause 15 shall be rounded as specified in JIS Z 8401.
----------------------
The tensile strength and the tensile stress shall be expressed
with three signifi-cant figures. The rounding range in such a case
shall be that equivalent to the small-est place of significant
figures. The elongation at break and the elongation at yield shall
be expressed with 10 of rounding range.
1 7 Test report The following items shall be included in the
test report.
a) the number of this Standard b) details of sample and test
piece
1) a full description of sample and test piece 2) compound
details and moulding condition (vulcanized conditions, etc.) 3) a
description of preparation for test pieces
the method of preparation of test pieces (buffing, etc.), shape
and dimensions of test piece
the sampling direction of dumb-bell-shaped test piece relative
to grain (if known) 4) the number of test pieces tested
c) test details 1) test conditions (temperature of test, and
humidity if necessary) 2) testing apparatus 3) any deviations from
the specified measuring method 4) items not specified in this
Standard and details of items that likely influence
results
d) test results, i.e., the median of properties determined as
specified in clause 15 e) the date of test
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A.l General
Annex A (informative) Precision
17 K 6251: 2010
The within-laboratory repeatability and the inter-laboratory
reproducibility of this method were calculated as specified in
ISO/TR 9272. Original data were treated for outliers at the 5 % and
2 % significance level on the basis of the procedures specified in
ISO/TR 9272.
A.2 Details of inter-laboratory reproducibility test
programmes
A.2.1 Two inter-laboratory test (ITP) programmes The first ITP
in 2001 was as follows: Three different compounds of NR, SBR and
EPDM were used for tensile tests. A
test result for this test method was the average or median of
five separate measure-ments of each of the properties as indicated
in A.2.2. A total of 23 laboratories in eight countries
participated in the programme.
The second ITP in 2002 was as follows: One compound of NR was
used for tensile tests. The compound formulation was
the same as the NR compound used in the first ITP. A total of 17
laboratories in six countries participated in the programme.
The fully vulcanized rubber test pieces were sent to each
laboratory for evaluation in both ITPs. The composition of rubber
compound used in test are shown in table A.5.
A.2.2 Test properties The test properties to be measured were
the tensile strength at break (TSb ), elongation at break (Eb),
stress at 100 % elongation (SlOO) and stress at 200 % elongation
(S200)
A.2.3 Test pieces Three types of dumb-bell-shaped type 3 (Type
1A in ISO 37), dumb-bell-shaped type 5 (Type 1 in ISO 37) and
dumb-bell-shaped type 6 (Type 2 in ISO 37) were tested.
The dumb-bell-shaped type 5 was tested with two initial gauge
lengths of 20 mm and 25 mm in the first ITP, but for the second
ITP, only test pieces with the gauge length of 25 mm were
tested.
A.3 Precision results The calculation results ofNR, SBR and EPDM
of the first ITP are shown in table A.1,
table A.2 and table A.3. Also, the calculation results of NR of
the second ITP are shown in table A.4.
Symbols used in these tables are as follows. r =
within-laboratory repeatability in measurement unit (r) =
within-laboratory repeatability in percent (relative value) R =
inter-laboratory reproducibility in measurement unit (R) =
inter-laboratory reproducibility in percent (relative value)
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18 K 6251: 2010
Table A.I Precision for NR compound (first ITP) Property
Dumb-bell shape/gauge length Median Within-laboratory
Inter-laboratory
N= 23 x 2 = 46 repeatabili ty rep rod ucibili ty
r (r) R (R) TSb Dumb-bell-shaped type 3/20 mm 34.88 0.67 1.91
2.63 7.54
Dumb-bell-shaped type 5/20 mm 34.25 1.10 3.20 3.35 9.79
Dumb-bell-shaped type 5/25 mm 34.17 1.53 4.47 2.49 7.29
Dumb-bell-shaped type 6/20 mm 31.93 1.25 3.93 2.85 8.94
Eh Dumb-bell-shaped type 3/20 mm 687 29.9 4.35 57.8 8.41
Dumb-bell-shaped type 5/20 mm 671 42.1 6.28 57.2 8.52
Dumb-bell-shaped type 5/25 mm 670 66.3 9.89 63.1 9.41
Dumb-bell-shaped type 6/20 mm 651 29.9 4.60 60.5 9.29
S100 Dumb-bell-shaped type 3/20 mm 1.89 0.07 3.90 0.28 14.81
Dumb-bell-shaped type 5/20 mm 1.83 0.18 10.00 0.36 19.50
Dumb-bell-shaped type 5/25 mm 1.86 0.12 6.73 0.32 17.24
Dumb-bell-shaped type 6/20 mm 1.84 0.15 8.33 0.40 21.95
S200 Dumb-bell-shaped type 3/20 mm 4.58 0.38 8.25 0.70 15.26
Dumb-bell-shaped type 5/20 mm 4.49 0.45 10.08 0.85 18.97
Dumb-bell-shaped type 5/25 mm 4.42 0.52 11.82 0.77 17.36
Dumb-bell-shaped type 6/20 mm 4.39 0.39 8.79 0.87 19.85
Table A.2 Precision for SBR compound (first ITP) Property
Dumb-bell shape/gauge length Median Within-laboratory
Inter-laboratory
N= 23 x 2 = 46 repeatabili ty rep rod ucibili ty r (r) R (R)
TSh Dumb-bell-shaped type 3/20 mm 24.70 1.01 4.11 2.38 9.65
Dumb-bell-shaped type 5/20 mm 24.87 1.48 5.94 2.12 8.53
Dumb-bell-shaped type 5/25 mm 24.60 1.17 4.74 2.58 10.47
Dumb-bell-shaped type 6/20 mm 24.38 1.52 6.22 2.84 11.65
Eh Dumb-bell-shaped type 3/20 mm 459 13.9 3.04 41.1 8.96
Dumb-bell-shaped type 5/20 mm 457 29.3 6.40 39.0 8.53
Dumb-bell-shaped type 5/25 mm 458 31.4 6.85 31.6 6.90
Dumb-bell-shaped type 6/20 mm 462 32.9 7.12 48.2 10.43
SIOO Dumb-bell-shaped type 3/20 mm 2.65 0.10 3.87 0.43 16.15
Dumb-bell-shaped type 5/20 mm 2.64 0.20 7.46 0.51 19.47
Dumb-bell-shaped type 5/25 mm 2.61 0.20 7.52 0.41 15.75
Dumb-bell-shaped type 6/20 mm 2.66 0.24 9.11 0.57 21.30
S200 Dumb-bell-shaped type 3/20 mm 7.81 0.45 5.74 1.00 12.79
Dumb-bell-shaped type 5/20 mm 7.76 0.59 7.62 1.28 16.52
Dumb-bell-shaped type 5/25 mm 7.74 0.47 6.08 0.94 12.15
Dumb-bell-shaped type 6/20 mm 7.68 0.56 7.31 1.48 19.25
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Property
TSb
Eh
S100
S200
Property
TSh
Eb
SlOO
S200
19 K 6251: 2010
Table A.3 Precision for EPDM compound (first ITP) Dumb-bell
shape/gauge length Median Within-laboratory Inter-laboratory
N= 23 x 2 = 46 repeatabili ty reproducibility
r (r) R (R) Dumb-bell-shaped type 3/20 mm 14.77 0.65 4.39 1.87
12.65 Dumb-bell-shaped type 5/20 mm 14.51 1.13 7.78 2.01 13.83
Dumb-bell-shaped type 5/25 mm 14.59 1.57 10.76 2.22 15.20
Dumb-bell-shaped type 6/20 mm 14.50 1.20 8.26 2.14 14.74
Dumb-bell-shaped type 3/20 mm 471 20.2 4.28 39.2 8.34
Dumb-bell-shaped type 5/20 mm 470 22.2 4.71 32.4 6.90
Dumb-bell-shaped type 5/25 mm 474 33.8 7.13 44.5 9.38
Dumb-bell-shaped type 6/20 mm 475 21.9 4.60 42.4 8.93
Dumb-bell-shaped type 3/20 mm 2.40 0.09 3.87 0.29 12.04
Dumb-bell-shaped type 5/20 mm 2.33 0.21 8.99 0.36 15.32
Dumb-bell-shaped type 5/25 mm 2.30 0.18 7.61 0.32 13.94
Dumb-bell-shaped type 6/20 mm 2.39 0.17 7.21 0.32 13.52
Dumb-bell-shaped type 3/20 mm 5.20 0.22 4.22 0.46 8.84
Dumb-bell-shaped type 5/20 mm 5.11 0.35 6.87 0.65 12.80
Dumb-bell-shaped type 5/25 mm 5.05 0.25 4.88 0.62 12.35
Dumb-bell-shaped type 6/20 mm 5.08 0.27 5.24 0.71 14.04
Table A.4 Precision for NR compound (second ITP) Dumb-bell
shape/gauge length Median Within-laboratory Inter-laboratory
N= 17 x 2 = 34 repeatabili ty reproducibility
r (r) R (R) Dumb-bell-shaped type 3/20 mm 33.13 1.19 3.60 2.71
8.17 Dumb-bell-shaped type 5/25 mm 32.26 1.86 5.76 2.21 6.84
Dumb-bell-shaped type 6/20 mm 34.75 1.53 4.41 4.04 11.63
Dumb-bell-shaped type 3/20 mm 665 22.94 3.45 83.52 12.56
Dumb-bell-shaped type 5/25 mm 640 27.26 4.26 54.44 8.50
Dumb-bell-shaped type 6/20 mm 683 30.80 4.51 94.49 13.83
Dumb-bell-shaped type 3/20 mm 1.78 0.13 7.06 0.22 12.19
Dumb-bell-shaped type 5/25 mm 1.74 0.13 7.29 0.32 18.17
Dumb-bell-shaped type 6/20 mm 1.83 0.20 11.08 0.30 16.18
Dumb-bell-shaped type 3/20 mm 4.35 0.21 4.78 0.87 20.11
Dumb-bell-shaped type 5/25 mm 4.27 0.32 7.42 1.10 25.81
Dumb-bell-shaped type 6/20 mm 4.31 0.44 10.31 1.03 23.91
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20 K 6251: 2010
Table A.5 Composition of rubber compound used in test Unit:
phr
Compound (1) NR Compound (2) SBR Compound (3) EPDM Natural
rubber (RSS#l) 100 SBR 1502 100 EPDM (JSR EP24) 100 HAF carbon
black (N330) 35 HAF carbon black (N330) 50 HAF carbon black (N330)
80 Zinc oxide 5 Zinc oxide 3 Zinc oxide 5
Stearic acid 2 Stearic acid 1 Stearic acid 1
Antioxidant 6PPD a) 2 Antioxidant 6PPD a) 2 Paraffin oil (PW-90)
50 Antioxidant TMDQ b) 2 Antioxidant TMDQ b) 2 Antioxidant TMDQ b)
2 Antioxidant wax 1 Antioxidant wax 1 Accelerator TMTD d) 1
Accelerator TBBS c) 0.7 Accelerator TBBS c) 1 Accelerator MBT e)
0.5
Sulfur 2.25 Sulfur 1.75 Sulfur 1.5
Total 149.95 Total 161.75 Total 241
Notes a) N-(1,3-dimethylbutyl)-N-phenyl-p-phenylendiamine b)
2,2,4-trimethyl-1,2-dihydroquinoline polymer c)
N-tert-butyl-2-benzothiazole sulfenamide d) Tetramethylthiuram
disulfide e) 2-merca ptobenzothiazole
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Annex B (informative)
21 K 6251: 2010
Analysis of ITP data and dumb-bell shape
B.t General This Annex considers the performance of different
dumb-bell shapes including the
dumb-bell-shaped type 3 test piece that was measured through the
ITP programmes. The dumb-bell-shaped type 3 test piece is a new
addition to the corresponding Inter-national Standard (ISO 37), but
it has been in use in Japan and other countries for many years.
Inter-laboratory repeatability in ITP showed that the
dumb-bell-shaped type 3 test piece has advantages over the
dumb-bell-shaped type 5 test piece and the dumb-bell-shaped type 6
test piece of better repeatability and, particularly, lower
incidence of breaks outside the test length. The finite-element
analysis demonstrated that the strain distribution in the
dumb-bell-shaped type 3 test piece is more uniform, which probably
accounts for its improved performance.
The values of tensile stress-strain properties determined with
the dumb-bell-shaped type 3 test piece are very similar to those
obtained with the dumb-bell-shaped type 5 test piece, but they
cannot be expected to be identical in all cases.
The dumb-bell-shaped type 3 test piece has similar overall
dimensions to the dumb-bell-shaped type 5 test piece and can be
considered as an alternative; however, it has not replaced the
dumb-bell-shaped type 5 test piece because of the huge bank of data
obtained.
B.2 Three variances for three-factor fully-nested experiments In
the comparison of the precision calculated as specified in ISO/TR
9272, R is an
indicator of the variance between laboratories (aL2), and the r
is an indicator of the total variance (on2 + 0ivr2 ) for a
particular laboratory, made up of the variance between the
measurement days (aD2) and the variance due to measurement errors
(0ivr2 ). In order to analyse on2 and aM2 separately, it is enough
to make an estimate of each component of the variance by the
so-called three-factor fully-nested experiments specified in ISO
5725-3.
The estimate of each component of the variance in the
measurements in the sec-ond ITP are shown in table B.1 and table
B.2.
Table B.t Estimate of each component of variance according to
average of three-factor fully-nested experiments for tensile
strength in second ITP
Dumb-bell-shaped type 3 Dumb-bell-shaped type 5 Dumb-bell-shaped
type 6
OL2 (0.80)2 (0.60)2 ( 1.80)2
OD2 (0.17)2 (0.67)2 (0.54)2
OM2 (1.04)2 (1.60)2 (1.08)2
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22 K 6251: 2010
Table B.2 Estimate of each component of variance according to
average of three-factor fully-nested experiments for elongation at
break in second ITP
Dumb-bell-shaped type 3 Dumb-bell-shaped type 5 Dumb-bell-shaped
type 6
OL2 (24.3)2 (20.4)2 (43.7)2
OD2 (28.6)2 (13.6)2 (21.9)2
OM2 (19.3)2 (28.1)2 (19.3)2
Of the three variances, the variance due to measurement errors
(0ivr2 ) is the most important for the dumb-bell-shaped test
pieces. Other variances (OL2 and OD2) are influenced by many
factors other than the shape of dumb-bell-shaped test pieces.
It is shown that OM2 is smallest for dumb-bell-shaped type 3,
which means that the measurement precision is the best with this
shape of dumb-bell-shaped test pieces.
B.3 Analysis of test pieces that broke
B.3.I Number of test pieces that broke outside gauges Figure B.1
shows the numbers of test pieces that broke outside the gauges.
For
each dumb-bell-shaped test piece, 230 test pieces were tested,
as 23 laboratories each tested five test pieces on two test
days.
y 160
140
120
100
80
60
40
20
0 A B
NR C ABC
SBR Y number of test pieces that broke outside gauges A
dumb-bell-shaped type 3 test piece B dumb-bell-shaped type 5 test
piece C dumb-bell-shaped type 6 test piece
ABC EPDM
Figure B.I Number of test pieces that broke outside gauges
(First ITP -total of 230 of each shape of test piece)
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23 K 6251: 2010
In the case of the dumb-bell-shaped type 5 test pieces made of
NR compound with a 20 mm gauge length, 159 test pieces broke
outside the gauges which corresponds to about 70 %. Also in the
case of the dumb-bell-shaped type 5 test pieces with a 25 mm gauge
length, about 60 % of the test pieces broke outside the gauges. In
the case of the dumb-bell-shaped type 6, it was about 47%. However,
in the case of the dumb-bell-shaped type 3, only 13 % of the test
pieces broke outside the gauges.
With SBR and EPDM, the probability of breaking outside the
gauges for the dumb-bell-shaped type 3 is also considerably smaller
than for the other dumb-bell-shaped test pIeces.
B.3.2 Relationship between proportion of test pieces that broke
outside gauges and tensile energy
The relationship between the proportion of test pieces that
broke outside the gauges and the tensile energy (product of tensile
strength at break and elongation at break) was also investigated.
NR test pieces differing in the volume of carbon black they
contained were prepared, and their TSb and Eb were measured. The
proportion of test pieces that broke outside the gauges was
observed. Figure B.2 shows the results of this experiment.
y
100
80
60
40
20
o
2
1 0 000 to 1 3 000 to 13000 16000
X TSh X Eh (MPa %)
16 000 to lq 000 to 22 000 to lq 000 22 000 25 000
Y percentage of test pieces that broke outside gauges 1
dumb-bell-shaped type 3 test piece 2 dumb-bell-shaped type 5 test
piece 3 dumb-bell-shaped type 6 test piece
x
Figure B.2 Relation between percentage of test pieces that broke
outside gauges and tensile energy (TS b x E b )
As the value of the tensile energy increased, the proportion of
test pieces that broke outside the gauges increased. At values of
the tensile energy of not exceeding 20 000 MPa %, most of the
dumb-bell-shaped type 3 test pieces broke inside the test
length.
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24 K 6251: 2010
B.4 Finite-element analysis A finite-element analysis (FEA) was
conducted on part of the test pieces. Figure B.3
shows the strain distribution. The analysis of the strain
distribution shows that the highest strain area appears
near the edge of the dumb-bell-shaped type 5 test piece and the
dumb-bell-shaped type 6 test piece. This observation coincides with
the results of the tensile testing described in clause B.3.
On the other hand, for the dumb-bell-shaped type 3 test piece,
the strain near the edge is at the same level as in the central
area, which means the dumb-bell-shaped type 3 test piece has a
relatively uniform strain distribution.
Small
Strain
a) Dumb-bell-shaped type 3 test piece
Large
b) Dumb-bell-shaped type 5 test piece
c) Dumb-bell-shaped type 6 test piece
Figure B.3 Example of strain distribution obtained by
finite-element method
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Bibliography
25 K 6251: 2010
ISO 5725-3 Accuracy (trueness and precision) of measurement
methods and re-sults-Part 3: Intermediate measures of the precision
of a standard measurement method
ISO/TR 9272 Rubber and rubber products-Determination of
precision for test method standards
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Annex JA (informative) Comparison table between JIS and
corresponding International Standard
JIS K 6251 :2010 Rubber, vulcanized or
thermoplastics-Determination of tensile ISO 37 : 2005 Rubber,
vulcanized or thermoplastic-Determination stress-strain properties
of tensile stress-strain properties
(I) Requirements in JIS (II) Inter- (III) Requirements in (IV)
Classification and details of (V) Justification for the national
International Standard technical deviation between JIS and
technical deviation and Standard the International Standard by
clause future measures number
No. and title Content Clause Content Classifi- Detail of
technical of clause No. cation by deviation
clause
5 General Addition The dumb-bell-shaped The dumb-bell-shaped
type 1 and the dumb-bell- type 1 and the dumb-bell-shaped type 2
used in the shaped type 2 are left rubber industry of Japan because
they are referred are added. in other JISs; however, the
6 Test piece 6.1 Dumb-bell-shaped test Addition Requirements on
dumb- deletion of dumb-bell-sha ped type 1 and the piece
bell-shaped type 1 and dumb-bell-shaped type 2 dumb-bell-shaped
type 2 will be considered.
are added. 6.3 Selection of test pieces Addition Notes on
testing are
added.
7 Testing 7.1 Punching die and 6 Addition The dumb-bell-shaped
The dumb-bell-shaped apparatus cutter type 1 and the dumb-bell-
type 1 and the dumb-bell-
shaped type 2 are added. shaped type 2 are left because they are
referred in other JISs, however, the deletion of dumb-bell-sha ped
type 1 and the dumb-bell-shaped type 2 will be considered.
7.4 Tensile testing Addition An explanation on grips is Added
for helping under-machine added as 7.4.2. standing. There is no
technical deviation.
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(I) Requirements in JIS (II) Inter- (III) Requirements in (IV)
Classification and details of (V) Justification for the national
International Standard technical deviation between JIS and
technical deviation and Standard the International Standard by
clause future measures number
No. and title Content Clause Content Classifi- Detail of
technical of clause No. cation by deviation
clause
13 Procedure 13.1 Dumb-bell-shaped Addition Requirements on
dumb- The dumb-bell-shaped test piece bell-shaped type 1 and type 1
and the dumb-bell-
dumb-bell-shaped type 2 shaped type 2 are left are added.
because they are referred
in other JISs; however, the deletion of dumb-bell-shaped type 1
and the dumb-bell-shaped type 2 will be considered.
13.2 Ring-shaped test Addition Requirements on pulley Will be
proposed to ISO. piece diameter are added. 13.3 Measurement for
Addition Added as requirements of Will be proposed to ISO.
obtaining tensile strength, JIS. tensile stress at break and
elongation at break 13.4 Measurement for Addition Added as
requirements of Will be proposed to ISO. obtaining tensile stress
at JIS. a given elongation 13.5 Measurement for Addition Added as
requirements of Will be proposed to ISO. obtaining tensile stress
at JIS. yield and elongation at yield
Overall degree of correspondence between JIS and International
Standard (ISO 37: 2005): MOD NOTE 1 Symbols in sub-columns of
classification by clause in the above table indicate as
follows:
- Addition: Adds the specification item(s) or content(s) which
are not included in International Standard. NOTE 2 Symbol in column
of overall degree of correspondence between JIS and International
Standard in the above table indicates as follows:
- MOD: Modifies International Standard.
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Errata for JIS (English edition) are printed in Standardization
and Quality Control, published monthly by the Japanese Standards
Association, and also provided to subscribers of JIS (English
edition) in Monthly Information. Errata will be provided upon
request, please contact: Standards Publishing Department, Japanese
Standards Association 4-1-24, Akasaka, Minato-ku, Tokyo, 107-8440
JAPAN TEL. 03-3583-8002 FAX. 03-3583-0462
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