ASTM D6409-99(2014)

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Designation: D6409 − 99 (Reapproved 2009) D6409 − 99 (Reapproved 2014)
Standard Practice for
Color Tests with Sheepskin Skiver
This standard is issued under the fixed designation D6409; 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.
1. Scope
1.1 This practice covers making color tests of all types of vegetable tanning extracts and of vegetable tanning materials to
determine the color imparted to tanned skins.
1.2 The values given in SI units are to be regarded as the standard. The inch-pound units 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.
2. Referenced Documents
2.1 ASTM Standards:
D1517 Terminology Relating to Leather
D4901 Practice for Preparation of Solution of Liquid Vegetable Tannin Extracts
D4905 Practice for Preparation of Solution of Solid, Pasty and Powdered Vegetable Tannin Extracts
D6405 Practice for Extraction of Tannins from Raw and Spent Materials
2.2 ALCA Methods:
A40 Color Tests with Sheepskin Skiver
3. Terminology
3.1 Definitions:
3.1.1 For definitions of general leather and tanning terms used in this practice refer to Terminology D1517.
3.1.2 pickled skiver—a sheepskin skiver that has been pickled in a solution of salt and sulfuric acid.
3.1.3 sheepskin skiver—the grain split of a de-wooled sheepskin. A pickled skiver is used for this test.
3.1.4 tannin—an astringent substance found in the various parts of plants such as bark, wood, leaves, nuts, fruits, roots, etc.
3.1.5 vegetable tannins—mixtures of substances (natural products) obtained from plant tissues by water extraction which have
the chemical and physical properties necessary to convert animal hides and skins into leather.
4. Summary of Practice
4.1 A specimen of pickled skiver is tanned with a sample of vegetable tanning liquor in order to determine the color which will
be imparted to a clear, clean hide or skin that is tanned with this tanning liquor.
5. Significance and Use
5.1 This practice provides a standard procedure for comparing the color of leather tanned with different tanning extracts or
mixtures of extracts or for monitoring the color consistency of tannery liquors.
This practice is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This test
method has been adapted from and is a replacement for Method A40 of the Official Methods of the American Leather Chemists Association.
Current edition approved April 1, 2009Nov. 1, 2014. Published July 2009December 2014. Originally approved in 1999. Last previous edition approved in 20042009 as
D6409 – 99 (2004).(2009). DOI: 10.1520/D6409-99R09.10.1520/D6409-99R14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Official Methods of the American Leather Chemists Association. Available from the American Leather Chemists Association, University of Cincinnati, P.O. Box 210014,
Cincinnati, OH 45221-0014.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6409 − 99 (2014)
6. Apparatus and Reagents
6.1 Pickled Sheepskin Skiver, specially and consistently selected for the color test.
6.2 Borax, commercial grade such as may be used in a tannery.
6.3 Containers, 10 and 3 L capacity and made of suitable material to be resistant to the chemicals and materials used in the
tanning procedure employed by this practice.
6.4 Acetic Acid, glacial, commercial grade.
6.5 Sodium Acetate, crystal, commercial grade.
6.6 Sodium Chloride, crystal, commercial grade.
6.7 Shake Bottles, 0.95 L (32 oz), with rubber stoppers. The bottles shall be approximately 21.6 cm (8.5 in.) overall height and
8.9 cm (3.5 in.) diameter. One quart canning jars (Mason-type) with plastic screw-on lids work well.
6.8 Shaking Machine, rotating type, equipped to hold 0.95 L (32 oz) bottles for end-over-end agitation of hide powder and
analytical solution. The speed of rotation shall be 606 2 rpm, and the machine shall be so constructed that the side of the shake
bottle adjacent to the rotating shaft shall be not less than 5.1 cm (2 in.) nor more than 7.6 cm (3 in.) from the center of the shaft.
6.9 Flat Dish, 250 to 300 mL capacity; a photographic tray wor
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