ASTM D6076-97
(Test Method)Standard Test Method for Shrinkage Temperature of Leather
Standard Test Method for Shrinkage Temperature of Leather
SCOPE
1.1 This test method covers the determination of the shrinkage temperature of all types of leather. The heating medium is water when the shrinkage temperature is at or below 98°C. The heating medium is a glycerine-water solution when the shrinkage temperature is above 98°C.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, 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
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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
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Designation: D 6076 – 97
Standard Test Method for
Shrinkage Temperature of Leather
This standard is issued under the fixed designation D 6076; 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 5. Significance and Use
1.1 This test method covers the determination of the shrink- 5.1 This test method is designed to determine the tempera-
age temperature of all types of leather. The heating medium is ture at which a thoroughly wetted leather specimen experiences
water when the shrinkage temperature is at or below 98°C. The shrinkage. In this test method, shrinkage occurs as a result of
heating medium is a glycerine-water solution when the shrink- hydrothermal denaturation of the collagen protein molecules
age temperature is above 98°C. which make up the fiber structure of the leather. The shrinkage
1.2 The values stated in SI units are to be regarded as the temperature of leather is influenced by many different factors,
standard. The values given in parentheses are for information most of which appear to affect the number and nature of
only. crosslinking interactions between adjacent polypeptide chains
1.3 This standard does not purport to address all of the of the collagen protein molecules. The value of the shrinkage
safety concerns, if any, associated with its use. It is the temperature of leather is commonly used as an indicator of the
responsibility of the user of this standard to establish appro- type of tannage or the degree of tannage, or both, of that
priate safety and health practices and determine the applica- particular leather (especially for the more hydrothermally
bility of regulatory limitations prior to use. stable tannages such as chrome tannage).
2. Referenced Documents 6. Apparatus
2.1 ASTM Standards: 6.1 Stand, for supporting the testing equipment.
D 1517 Terminology Relating to Leather 6.2 Indicating Device, either of the two devices listed as
follows:
3. Terminology
6.2.1 Theis Shrinkage Meter Dial—a dial indicator having a
3.1 Definitions—For definitions of general leather terms face divided into 360 to 380°, with one revolution of the dial
used in this test method, refer to Terminology D 1517.
hand corresponding to 12.7 mm (0.5 in.) of specimen move-
3.2 Definitions of Terms Specific to This Standard: ment, and with leeway for four revolutions of the dial hand.
3.2.1 shrink—to contract or become smaller.
6.2.2 AGD (American Gage Design) Dial Indicator—A
3.2.2 shrinkage—the temperature at which noticeable mechanical device capable of registering on a scale a reading
shrinkage occurs when a leather specimen is gradually heated
of the shrinkage or swelling movement of the specimen in a
in an aqueous medium. ratio of at least 25 units of dial movement (or greater) to 1 unit
of specimen movement, and shall accurately detect by move-
4. Summary of Test Method
ment of the dial needle the point at which shrinkage begins.
4.1 A leather specimen is thoroughly soaked in the aqueous
The indicator shall have a spindle capable of attachment to the
medium that will be used to heat the specimen for this test
specimen and to the adjustable weight assembly.
method. This specimen is then fastened between two clamps
6.3 Immersion Heater, 250 to 500 W, with a heating element
(one fixed and one movable) and immersed in the aqueous
not longer than 140 mm (5 ⁄2 in.) and a depth of immersion not
medium. The aqueous medium is gradually heated until the
in excess of 152 mm (6 in.).
specified temperature is reached without shrinkage or until
6.4 Variable Speed Stirrer, with small blades.
shrinkage is indicated by a deflection of the dial needle which
is attached to the movable clamp.
A shrinkage meter apparatus setup meeting these specific requirements was
formerly available from the Arthur H. Thomas Co., Philadelphia, PA. The minimum
number of apparatus setups required for an order makes the cost of new apparatus
This test method is under the jurisdiction of ASTM Committee D31 on Leather of this type prohibitive. Used apparatus of this type may still be available from
and is the direct responsibility of Subcommittee D31.07 on Physical Properties— tanneries or laboratories that have gone out of business or from used equipment
General. This test method was developed from Federal Test Method Standard No. dealers.
311, Method 7011.1, in cooperation with the U.S. Defense Personnel Support The sole source of supply of the apparatus known to the committee at this time
Center, Directorate of Clothing and Textiles, Philadelphia, PA and the U.S. Army is B.C. Ames Co., Lexington St., Waltham, MA 02254. If you are aware of
Natick Research, Development and Engineering Center, Natick, MA. alternative suppliers, please provide this information to ASTM Headquarters. Your
Current edition approved Feb. 10, 1997. Published March 1997. comments will receive careful consideration at a meeting of the responsible
Annual Book of ASTM Standards, Vol 15.04. technical committee, which you may attend.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6076
6.5 Spring-loaded Clamps—(alligator type), two, mounted the heating medium shall be the glycerine-water solution
vertically one above the other and sufficiently far apart for described in 7.1.
gripping the full width of the specimen at the ends. The bottom 9.3 Prepare the specimens as follows prior to mounting in
clamp shall be fastened to the end of a U-shaped rod that can the holding clamps. Place more than 15 specimens in a 1–L
be turned sideways. The upper clamp shall be movable suction flask containing approximately 300 mL of the required
sideways as well as up and down. heating medium at room temperature. Stopper the flask and
6.6 Metal Supporting Plate, with apertures for the stirrer, apply a vacuum for 15 to 60 s and then release for 15 to 60 s.
thermometer, immersion heater, and the rod fastened to the Continue an intermittent vacuum until all the specimens settle
upper specimen clamp. to the bottom of the flask. Gently shake the flask each time the
6.7 Variable Transformer, capable of controlling the rate of vacuum is released to prevent specimens that are ready to sink
heating (3 to 5°C/min) of the aqueous medium and capable of from being entangled with other specimens. One hour after the
maintaining a temperature of 98 6 0.5°C. last release of vacuum, remove the first specimen from the
6.8 Thermometer, nitrogen-filled over mercury, with a white flask and mount in the shrinkage meter.
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