ASTM D6076-08(2013)
(Test Method)Standard Test Method for Shrinkage Temperature of Leather
Standard Test Method for Shrinkage Temperature of Leather
SIGNIFICANCE AND USE
5.1 This test method is designed to determine the temperature at which a thoroughly wetted leather specimen experiences shrinkage. In this test method, shrinkage occurs as a result of hydrothermal denaturation of the collagen protein molecules which make up the fiber structure of the leather. The shrinkage temperature of leather is influenced by many different factors, most of which appear to affect the number and nature of crosslinking interactions between adjacent polypeptide chains of the collagen protein molecules. The value of the shrinkage temperature of leather is commonly used as an indicator of the type of tannage or the degree of tannage, or both, of that particular leather (especially for the more hydrothermally stable tannages such as chrome tannage).
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D6076 − 08 (Reapproved 2013)
Standard Test Method for
Shrinkage Temperature of Leather
This standard is issued under the fixed designation D6076; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 4. Summary of Test Method
4.1 Aleather specimen is thoroughly soaked in the aqueous
1.1 This test method covers the determination of the shrink-
medium that will be used to heat the specimen for this test
age temperature of all types of leather. The heating medium is
method. This specimen is then fastened between two clamps
water when the shrinkage temperature is at or below 98°C.The
(one fixed and one movable) and immersed in the aqueous
heating medium is a glycerine-water solution when the shrink-
medium. The aqueous medium is gradually heated until the
age temperature is above 98°C.
specified temperature is reached without shrinkage or until
1.2 The values stated in SI units are to be regarded as the
shrinkage is indicated by a deflection of the dial needle which
standard. The values given in parentheses are for information
is attached to the movable clamp.
only.
5. Significance and Use
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 This test method is designed to determine the tempera-
responsibility of the user of this standard to establish appro- tureatwhichathoroughlywettedleatherspecimenexperiences
priate safety and health practices and determine the applica-
shrinkage. In this test method, shrinkage occurs as a result of
bility of regulatory limitations prior to use. hydrothermal denaturation of the collagen protein molecules
which make up the fiber structure of the leather. The shrinkage
2. Referenced Documents temperature of leather is influenced by many different factors,
most of which appear to affect the number and nature of
2.1 ASTM Standards:
crosslinking interactions between adjacent polypeptide chains
D1517 Terminology Relating to Leather
of the collagen protein molecules. The value of the shrinkage
temperature of leather is commonly used as an indicator of the
3. Terminology
type of tannage or the degree of tannage, or both, of that
3.1 Definitions—For definitions of general leather terms particular leather (especially for the more hydrothermally
used in this test method, refer to Terminology D1517. stable tannages such as chrome tannage).
3.2 Definitions of Terms Specific to This Standard:
6. Apparatus
3.2.1 shrink—to contract or become smaller.
6.1 Stand, for supporting the testing equipment.
3.2.2 shrinkage—the temperature at which noticeable
6.2 Indicating Device, either of the two devices listed as
shrinkage occurs when a leather specimen is gradually heated
follows:
in an aqueous medium.
6.2.1 Theis Shrinkage Meter Dial—a dial indicator having a
face divided into 360 to 380°, with one revolution of the dial
hand corresponding to 12.7 mm (0.5 in.) of specimen
This test method is under the jurisdiction ofASTM Committee D31 on Leather
movement, and with leeway for four revolutions of the dial
andisthedirectresponsibilityofSubcommitteeD31.07onPhysicalProperties.This 3
hand.
test method was developed from Federal Test Method Standard No. 311, Method
6.2.2 AGD (American Gage Design) Dial Indicator—A
7011.1, in cooperation with the U.S. Defense Personnel Support Center, Directorate
of Clothing and Textiles, Philadelphia, PA and the U.S. Army Natick Research,
mechanical device capable of registering on a scale a reading
Development and Engineering Center, Natick, MA.
CurrenteditionapprovedMay1,2013.PublishedJuly2013.Originallyapproved
in 1997. Last previous edition approved in 2008 as D6076-08. DOI: 10.1520/ A shrinkage meter apparatus setup meeting these specific requirements was
D6076-08R13. formerly available from theArthur H.Thomas Co., Philadelphia, PA.The minimum
For referenced ASTM standards, visit the ASTM website, www.astm.org, or number of apparatus setups required for an order makes the cost of new apparatus
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM of this type prohibitive. Used apparatus of this type may still be available from
Standards volume information, refer to the standard’s Document Summary page on tanneries or laboratories that have gone out of business or from used equipment
the ASTM website. dealers.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6076 − 08 (2013)
of the shrinkage or swelling movement of the specimen in a 7. Reagents
ratio of at least 25 units of dial movement (or greater) to 1 unit
7.1 Glycerine-water Solution—When glycerine-water me-
of specimen movement, and shall accurately detect by move-
dium is specified for use (that is, when the shrinkage tempera-
ment of the dial needle the point at which shrinkage begins.
ture is specified or expected to be greater than 98°C) the
The indicator shall have a spindle capable of attachment to the
solution shall consist of 75 parts glycerine to 25 parts water.
specimen and to the adjustable weight assembly.
The specific gravity of the solution shall be adjusted to 1.19 at
23°C. The glycerine-water solution shall not be heated over
6.3 Immersion Heater, 250 to 500W, with a heating element
112°C.
not longer than 140 mm (5 ⁄2 in.) and a depth of immersion not
in excess of 152 mm (6 in.).
8. Test Specimen
6.4 Variable Speed Stirrer, with small blades.
8.1 The test specimen for the test shall be a rectangle of
6.5 Spring-loaded Clamps—(alligator type), two, mounted
leather 76.0 6 0.5 mm (3.0 in.) in length by 12.5 6 0.5 mm
vertically one above the other and sufficiently far apart for
(0.5 in.) in width, die cut from the sample unit of leather with
gripping the full width of the specimen at the ends.The bottom
the long dimension perpendicular to the backbone line.
clamp shall be fastened to the end of a U-shaped rod that can
8.2 Unless otherwise specified in the material specification,
be turned sideways. The upper clamp shall be movable
one test specimen shall be tested from each sample unit.
sideways as well as up and down.
6.6 Metal Supporting Plate, with apertures for the stirrer, 9. Procedure
thermometer, immersion heater, and the rod fastened to the
9.1 When shrinkage temperatures at or below 98°C are
upper specimen clamp.
specified, the heating medium shall be water.
6.7 Variable Transformer, capable of controlling the rate of
9.2 When shrinkage temperatures over 98°C are specified,
heating (3 to 5°C/min) of the aqueous medium and capable of
the heating medium shall be the glycerine-water solution
maintaining a temp
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