1、Designation: D6658 08 (Reapproved 2013)Standard Test Method forVolatile Matter (Moisture) of Wet Blue by Oven Drying1This standard is issued under the fixed designation D6658; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of volatilematter (moisture) in all types of wet blue and wet white.1.2
3、 This test method was originally developed for wet blue,however, this test method can be used to test wet white. For wetwhite testing, substitute the term wet white for wet blue in thestandard.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included
4、 in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to us
5、e.2. Referenced Documents2.1 ASTM Standards:2D6659 Practice for Sampling and Preparation of Wet Bluefor Physical and Chemical Tests3. Summary of Test Method3.1 The prepared wet blue or wet white specimen is heatedin a forced air oven for 8 to 24 h at 100-105 C, placed in adesiccator, cooled, and rew
6、eighed. The loss in weight repre-sents the volatile matter.4. Significance and Use4.1 The result obtained by this test is normally considered tobe the moisture content of the wet blue or wet white sample.This result is used to correct all other chemical tests to amoisture-free basis.4.2 Materials th
7、at are volatile under these conditions, otherthan water, may be present in the wet blue, although theiramount in any normal wet blue would be expected to be a verysmall percentage of the total volatile matter.4.3 Under the conditions of this test, certain materials in wetblue, such as protein fiber
8、and chromium tanning salts, mayretain moisture. Other materials, such as natural animal fats,may be oxidized. Both of these effects produce negative errorsin the moisture determination.4.4 The amount of volatile matter (moisture) released by agiven sample varies with (a) method and time of samplepre
9、paration, (b) weight of sample taken, (c) temperature andtime of the oven drying, (d) type of oven (gravity versusmechanical convection) used.4.5 Because of the above unknown errors, the result of thistest is a purely arbitrary value for the moisture content of thesample. It is, therefore, essential
10、 that the method be followedexactly in order to obtain reproducible results among labora-tories. This is particularly true if other chemical analytical testsbeing performed on the same sample are reported on themoisture-free basis.5. Apparatus5.1 Appropriately sized weighing container with cover sui
11、t-able for oven use.5.2 Oven, forced air capable of attaining a steady 100-105C, with a thermoregulator system. A thermometer accurate to1 C should be used to check and monitor the oven set point.5.3 Balance, capable of weighing up to 100 g with anaccuracy of 6 0.001 g.5.4 Desiccator, any convenient
12、 form or size, using anynormal desiccating agent such as calcium sulfate, calciumchloride, or silica gel.6. Sampling6.1 The leather shall be sampled in accordance with PracticeD6659.7. Procedure7.1 Insert the empty weighing container and cover in theoven at 100-105 C for1hormore to insure dryness.7.
13、2 Remove the container and cover from the oven andplace in a desiccator and cool to ambient temperature.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.02 on Wet Blue.Current edition approved May 1, 2013. Published May
14、2013. Originallyapproved in 2001. Last previous edition approved in 2008 as D6658 08. DOI:10.1520/D6658-08R13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the st
15、andards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17.3 Weigh the container and cover and record to the nearest6 0.001 g.7.4 Transfer 10-15 g of wet blue prepared as specified inD6659 into
16、the previously weighed container.7.5 Weigh the covered container to the nearest 6 0.001 gand record.NOTE 1It is essential that weighings be made promptly.NOTE 2The specimens for all chemical tests to be reported on amoisture-free basis should be weighed out at the same time as the moisturespecimens.
17、7.6 Oven DryingPlace the weighing container with thesample and with cover ajar on a shelf in the forced air oven at100-105 C for a minimum of 8 612 h or a maximum of 24612 h.7.7 After the determined drying time cover the bottle, placein the desiccator, and cool to ambient temperature.7.8 Weigh the c
18、overed container and record to the nearest 60.001 g.8. Calculation8.1 Calculate the percent volatile matter (moisture) as fol-lows:Volatile matter moisture!,%5 S 2 D!/S 2 B!# 3100 (1)where:S = weight, grams, of original specimen plus coveredcontainer,B = weight, grams, of empty covered container, an
19、dD = weight, grams, of oven-dried sample plus coveredcontainer.9. Report9.1 Report the percent volatile matter (moisture) for eachspecimen. If more than one specimen is tested, report theaverage of the specimens to the nearest 0.01 %.10. Precision and Bias10.1 Six different laboratories, each using
20、a single differentwet blue sample, dried different wet blue samples at 105 C for8 612 h and for 24 612 h. The average difference obtainedbetween the two drying times was: 0.03 %. A t-test of theaverage differences produced a value of t = 0.516. Thetabulated value at the 95 % confidence limit for 5 d
21、egrees offreedom is 2.571. Therefore since the calculated t is less thanthe tabulated t, there is no significant difference between thetwo drying times.10.2 This method is purely arbitrary and the bias cannot berelated to the true moisture content of the sample.11. Keywords11.1 blue stock; moisture;
22、 volatile matter; wet blue; wetwhiteASTM International takes no 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 ris
23、kof infringement of such rights, are entirely their own responsibility.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 thi
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25、your views known to the ASTM Committee on Standards, at the address 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D6658 08 (2013)2
