1、Designation: D 6409 99 (Reapproved 2004)Standard Practice forColor Tests with Sheepskin Skiver1This standard is issued under the fixed designation D 6409; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers making color tests of all types ofvegetable tanning extracts and of vegetable tanning materialsto determine the
3、color imparted to tanned skins.1.2 The values given in SI units are to be regarded as thestandard. The inch-pound units given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th
4、e user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1517 Definitions of Terms Relating to LeatherD 4901 Practice for Preparation of Solution of Liquid Veg-et
5、able Tannin ExtractsD 4905 Practice for Preparation of Solution of Solid, Pasty,and Powdered Vegetable Tannin ExtractsD 6405 Practice for Extraction of Tannins from Raw andSpent Materials2.2 ALCA Methods:A40 Color Tests with Sheepskin Skiver33. Terminology3.1 Definitions:3.1.1 For definitions of gen
6、eral leather and tanning termsused in this practice refer to Definitions D 1517.3.1.2 pickled skivera sheepskin skiver that has beenpickled in a solution of salt and sulfuric acid.3.1.3 sheepskin skiverthe grain split of a de-wooledsheepskin. A pickled skiver is used for this test.3.1.4 tanninan ast
7、ringent substance found in the variousparts of plants such as bark, wood, leaves, nuts, fruits, roots,etc.3.1.5 vegetable tanninsmixtures of substances (naturalproducts) obtained from plant tissues by water extractionwhich have the chemical and physical properties necessary toconvert animal hides an
8、d skins into leather.4. Summary of Practice4.1 A specimen of pickled skiver is tanned with a sample ofvegetable tanning liquor in order to determine the color whichwill be imparted to a clear, clean hide or skin that is tannedwith this tanning liquor.5. Significance and Use5.1 This practice provides
9、 a standard procedure for compar-ing the color of leather tanned with different tanning extracts ormixtures of extracts or for monitoring the color consistency oftannery liquors.6. Apparatus and Reagents6.1 Pickled Sheepskin Skiver, specially and consistentlyselected for the color test.6.2 Borax, co
10、mmercial grade such as may be used in atannery.6.3 Containers, 10 and 3 L capacity and made of suitablematerial to be resistant to the chemicals and materials used inthe tanning procedure employed by this practice.6.4 Acetic Acid, glacial, commercial grade.6.5 Sodium Acetate, crystal, commercial gra
11、de.6.6 Sodium Chloride, crystal, commercial grade.6.7 Shake Bottles, 0.95 L (32 oz), with rubber stoppers. Thebottles shall be approximately 21.6 cm (8.5 in.) overall heightand 8.9 cm (3.5 in.) diameter. One quart canning jars (Mason-type) with plastic screw-on lids work well.6.8 Shaking Machine, ro
12、tating type, equipped to hold 0.95 L(32 oz) bottles for end-over-end agitation of hide powder andanalytical solution. The speed of rotation shall be 606 2 rpm,and the machine shall be so constructed that the side of theshake bottle adjacent to the rotating shaft shall be not less than5.1 cm (2 in.)
13、nor more than 7.6 cm (3 in.) from the center ofthe shaft.1This practice is under the jurisdiction ofASTM Committee D31 on Leather andis the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This testmethod has been adapted from and is a replacement for Method A40 of the OfficialMeth
14、ods of the American Leather Chemists Association.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1999. Last previous edition approved in 1999 as D 6409 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servic
15、eastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Official Methods of the American Leather Chemists Association. Availablefrom the American Leather Chemists Association, University of Cincinnati, P.O.Box 210014, Cincinnat
16、i, OH 45221-0014.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.9 Flat Dish, 250 to 300 mL capacity; a photographic trayworks well.6.10 Rubber Roller, photographic print roller works well.7. Test Specimen7.1 The specimen shall con
17、sist of a liquor of four timesanalytical strength, prepared in a manner similar to the prepa-ration of solutions for analysis (Practices D 6405, D 4901,orD 4905). The volume shall be 400 mL for Method I (9.2)or250 mL for Method II (9.3).8. Preparation of Skiver8.1 The neck and flank portions of the
18、skiver shall betrimmed off, leaving a skin of uniform grain. The skiver maynow be cut into pieces approximately 10 by 15 cm (4 by 6 in.)or may be left whole. The skiver shall be placed in a solutionof 50 g of borax dissolved in 8 L of distilled water and at atemperature of 23 to 25C. It shall be sti
19、rred, or agitated,frequently and, at the end of 4 h, be transferred to a fresh boraxsolution, made up as before, be stirred several times and thenallowed to remain overnight therein at not less than 23C normore than 28C. Next morning, the skiver shall be transferredto 8 L of a 0.1 % solution of acet
20、ic acid, at 23 to 25C, bestirred, or agitated, frequently and, at the end of 3 h, be placedin a fresh solution of acetic acid of the same volume, strength,and temperature, and be stirred, or agitated, frequently. At theend of 3 h, the skiver shall be placed in 2 L of an aceticacid/sodium acetate buf
21、fer solution, at 23 to 25C, containing2.0 g glacial acetic acid and 10 g of sodium acetate crystals perlitre, and having a pH of 4.8 to 5.0. The skiver shall be stirredin this solution several times and then allowed to remaintherein overnight. Next morning, the skiver shall be transferredto a satura
22、ted solution of sodium chloride containing a largeexcess of the salt.9. Procedure for Making Color Tests9.1 Remove the salt from the skiver sample 10 by 15 cm (4by 6 in.) by shaking with four changes of distilled water, of 500mL each and at 23 to 25C, in a shake bottle for 15 min each.9.2 Tanning Me
23、thod I (Shake Method):9.2.1 Add the washed skiver to the 400 mL liquor sample(7.1) at 23 to 25C, contained in a shake bottle. Immediately,stopper the bottle and shake for 1 h in the shake machine.Allow the skiver to stand in the solution overnight at 23 to25C and then shake for one-half hour next mo
24、rning. Thentreat the skiver as described in 9.4.9.3 Tanning Method II (Layaway Method):9.3.1 Take a 50.0 mL portion from the 250 mL sample (7.1),dilute to 200 mL with distilled water at 23 to 25C, and pourinto a flat dish or tray (6.9). Completely immerse the washedskiver sample in this solution, gr
25、ain side up, and rock occa-sionally over a period of 1 h, or until the skiver is evenlycolored. Then discard the weak solution. Immediately pour theremaining 200 mL of the liquor sample into the dish andcompletely immerse the skiver. Rock it occasionally, cover it toprevent dust or dirt from falling
26、 onto the skiver, and allow tostand overnight at 23 to 25C. Then treat the skiver asdescribed in 9.4.9.4 Post-Tanning Treatment:9.4.1 Wash the skiver, tanned as described in 9.2 or 9.3,byshaking with two changes of distilled water, of 800 mL eachand at 30 to 35C, for 10 min each, and rinse with dist
27、illedwater, and squeeze out a number of times before, between, andafter the changes of water. Then spread it out on a glass surfaceand slick out lightly, using a rubber roller (6.10) with justenough pressure to remove the excess water. Then tack out theskiver, grain side down, on a board covered wit
28、h filter paper,and put into a dark place to dry.9.4.2 After drying, the skiver is ready for color comparisonand evaluation by the standard procedure used at a particulartannery.10. Keywords10.1 color test; sheepskin skiver test; tanning color test;vegetable tannin analysisASTM International takes no
29、 position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respons
30、ibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed t
31、o ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the add
32、ress shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 6409 99 (2004)2
