ASTM D2210-00

Standard Test Method for Grain Crack and Extension of Leather by the Mullen Test

SCOPE
1.1 This test method covers the determination of the resistance of leather to grain cracking and for measuring the extension of the leather. It is limited to light leathers such as shoe uppers, garment, gloves, and upholstery. This test method does not apply to wet blue.  
1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Sep-2000
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.03 - Footwear

Relations

• Replaced By: ASTM D2210-00(2004) - Standard Test Method for Grain Crack and Extension of Leather by the Mullen Test
• Effective Date: 01-Sep-2004
• Referred By: ASTM D2322-14(2023) - Standard Test Method for Resistance of Shoe Upper Leather to Artificial Perspiration
• Effective Date: 10-Sep-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 2210 – 00
Standard Test Method for
Grain Crack and Extension of Leather by the Mullen Test
This standard is issued under the fixed designation D 2210; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope and other defects will cause considerable variation in the
results by concentration of the applied force to the weak points.
1.1 This test method covers the determination of the resis-
This test method is excellent for manufacturing control, speci-
tance of leather to grain cracking and for measuring the
fication acceptance, and service evaluation in the lasting
extension of the leather. It is limited to light leathers such as
property of leather. This test method may not apply when the
shoe uppers, garment, gloves, and upholstery. This test method
conditions of the test employed differ widely from those
does not apply to wet blue.
specified in the test method.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Apparatus
responsibility of the user of this standard to establish appro-
5.1 Testing Machine, as shown in Fig. 1. The machine shall
priate safety and health practices and determine the applica-
be hand- or power-driven. The machine shall hold the speci-
bility of regulatory limitations prior to use.
men firmly, without slippage, between two annular, plane,
2. Referenced Documents unpolished (matte) surfaces that may have fine, spiral tool
marks not over 0.010 in. (0.25 mm) in depth.
2.1 ASTM Standards:
5.2 Upper Clamping Surface—The upper clamping surface
D 1610 Practice for Conditioning Leather and Leather
(clamping ring) shall have a circular opening 1.240 6 0.010 in.
Products for Testing
(31.50 6 0.25 mm) in diameter and shall be connected to the
D 1813 Test Method for Measuring Thickness of Leather
clamping mechanism through a swivel joint to ensure an even
Test Specimens
clamping pressure.
3. Terminology
5.3 Lower Clamping Surface—The lower clamping surface
(diaphragm plate) shall be 0.219 6 0.003 in. (5.56 6 0.08 mm)
3.1 Definitions:
thick and have an opening of 1.240 6 0.01 in. (31.50 6 0.52
3.1.1 extension—the amount of stretch of leather over the
mm) in diameter. The circular edges of the openings that come
diaphragm under pressure.
in contact with the specimen and the rubber diaphragm shall be
3.1.2 grain cracking—the appearance of cracks on the
rounded to a radius of not over 0.025 in. (0.64 mm) to prevent
surface of the leather as the leather is extended over a
any cutting action. During the test, the circular edges of the
diaphragm under pressure to form a sphere.
openings in the two clamping plates shall be substantially
4. Significance and Use
concentric with no overlapping of any point.
5.4 Diaphragm, of rubber, 0.034 6 0.002 in. (0.86 6 0.05
4.1 The test method is designed to measure the force
mm) thick, clamped under the lower clamping plate so that,
required to crack the grain of leather by steady hydraulic
before the diaphragm is stretched by pressure underneath it, the
pressure on a diaphragm of definite diameter applied to the
center of its upper surface is below the plane of the clamping
flesh side of the specimen to form a sphere. The cracking of the
surface.
grain is a result of failure under elongation or stretch. The
5.5 Dial Gage, as shown in Fig. 2, to measure the extension
elongation or stretch of the leather can be measured at different
of the leather specimen and mounted on the machine through
loads or at the failure of the grain to determine if the stress
screw shaft or on side of clamps on platform. This gage shall
leather will withstand under lasting conditions. Cuts, scratches,
be calibrated to read directly to the nearest 0.001 in. (0.03 mm).
It shall be equipped with a flat anvil and a presser foot.
This test method is under the jurisdiction of ASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.03 on Footwear. This test
method was developed in cooperation with the American Leather Chemists Assn. The sole source of supply of the apparatus known to the committee at this time
(Standard Method E 58 – 1965).
is B. F. Perkins, 939 Chicopee St., Chicopee, MA 01013-2797, [phone]. If
Current edition approved Sept. 10, 2000. Published October 2000. Originally you are aware of alternative suppliers, please provide this information to ASTM
published as D 2210 – 63T. Last previous edition D 2210 – 93 (1997). Headquarters. Your comments will receive careful consideration at a meeting of the
Annual Book of ASTM Standards, Vol 15.04. responsible technical committee, which you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 2210
FIG. 1 Mullen Tester, Model A
will be generated by pumping liquid at a rate of 15 6 2 mL/min
or by turning a handwheel at approximately 3 r/min.
5.8 Thickness Gage—A dead-weight type of thickness gage
as described in Test Method D 1813.
6. Test Specimen
6.1 The specimen shall be a square of leather 3 by 3 in. (76
by 76 mm) cut from the test unit of leather.
6.2 The specimen shall be free of mechanical damage and
surface defects.
7. Conditioning
7.1 All specimens shall be conditioned for 48 h in an
atmosphere maintained at 73.4 6 1.8°F (23 6 1°C) and 50 6
4 % relative humidity and tested under these conditions as
described in Practice D 1610.
8. Procedure
8.1 Determine the thickness of the specimen by taking three
FIG. 2 Mullen Tester with Dial Gage
measurements in the area to be cracked and determine the
average value.
5.6 Bourdon Tube—The apparatus shall be equipped with a
8.2 Place the flesh side of the specimen in contact with the
Bourdon tube, maximum-reading-type, pressure gage gradu-
rubber diaphragm of the testing machine.
ated in pounds-force per square inch and accurate throughout
8.3 Clamp the specimen securely in the apparatus in such a
the entire range of its scale to within a value of 1 % of its
manner that the leather will not be damaged.
maximum capacity. The capacity of the gage shall be such that
8.4 Rest the presser foot of the extension gage on the flat
the individual readings will be not less than 25 % nor more
surface of the specimen and set the gage at zero.
than 75 % of the total capacity of the gage.
8.5 Apply pressure to the specimen until the specimen
5.7 Pressure Control—The machine shall be equipped with
cracks.
means of applying controlled increasing hydraulic pressure to
8.6 At the moment the first crack appears in the specimen
the underside of the diaphragm until the specimen cracks. This
stop the machine, note the applied pressure from the gage, and
pressure shall be generated by a piston forcing a liquor (usually
record the value as the cracking strength of the specimen.
glycerin) into the pressure chamber of the apparatus. For
9. Report
machines shown in Fig. 1 where the cracking pressure is the
only measurement, the pressure will be generated by pumping 9.1 The report shall include the following:
liquid at a rate of 170 6 10 mL/min or by turning a handwheel 9.1.1 Cracking pressure to the nearest 5 psi (35 kPa) for
at approximately 30 r/min. For machines shown in Fig. 2 where each specimen or averaged and reported as the average of the
cracking pressure and extension are measured, the pressure test unit,
D 2210
9.1.2 Extension of the leather to the nearest 0.001 in. (0.03
Extension at Grain
Leathers Cracking Pressure, psi Crack, %
mm), converted to percentage (see Annex A1) and reported as
percentage stretch, and
Shoe upper 26 13
Upholstery 17 14
9.1.3 Thickness to the nearest 0.001 in. (0.03 mm) reported
A
Calfskin 16 22
for each specimen or averaged and reported as the thickness of
Glove 11 20
_____________
the sample.
A
3 6 1 oz, 0.0468 6 0.0156 in. (1.189 6 0.396 mm).
9.1.4 Speed the liquid was pumped to build pressure to the
10.1.2 Two Laboratories, Duplicate Specimens, Same
nearest 10 % (see 5.7).
Skin—Results for the same group of light leathers listed in
10.1.1 submitted by each of two laboratories on duplicate
10. Precision and Bias
adjacent specimens in a skin taken from the official sampling
position should not be considered suspect unless the two
10.1 The following criteria may be used to judge the
average results differ by more than 5 %.
acceptability of the results if at least 15 units have been tested:
10.1.1 One Operator, Duplicate Specimens, Same Skin— NOTE 1—The reproducibility reported in 10.1.2 is based on data
obtained at two laboratories, and a different operator. The results show
Results by the same operator in duplicate adjacent specimens
close correlation between laboratories.
in a skin taken from the official sampling position should not be
NOTE 2—The results given in Section 10 are based on tests on 30 sides
considered suspect unless the coefficient of variation exceeds:
of leather and do not apply to
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