1、Designation: D 6658 01 (Reapproved 2006)Standard Test Method forVolatile Matter (Moisture) of Wet Blue by Oven Drying1This standard is issued under the fixed designation D 6658; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A 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 test method covers the determination of volatilematter (moisture) in all types of wet blue.1.2 This stand
3、ard 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 use.2. Referenced Documents2.1 AS
4、TM Standards:2D 6659 Practice for Sampling and Preparation of Wet Bluefor Physical and Chemical Tests3. Summary of Test Method3.1 The prepared wet blue specimen is heated in a forced airoven for 8 to 24 h at 100-105 C, placed in a desiccator, cooled,and reweighed. The loss in weight represents the v
5、olatilematter.4. Significance and Use4.1 The result obtained by this test is normally considered tobe the moisture content of the wet blue sample. This result isused to correct all other chemical tests to a moisture-free basis.4.2 Materials that are volatile under these conditions, otherthan water,
6、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 and chromium tanning salts, mayretain moisture. Other mat
7、erials, 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 samplepreparation, (b) weight of sample taken, (c) temperature and
8、time 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 that the method be followedexactly in order to obtain re
9、producible 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 suit-able for oven use.5.2 Oven, forced air capable of attai
10、ning 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 form or size, using anynormal desiccating agent such as
11、calcium sulfate, calciumchloride, or silica gel.6. Sampling6.1 The leather shall be sampled in accordance with PracticeD 6659.7. Procedure7.1 Insert the empty weighing container and cover in theoven at 100-105 C for1hormore to insure dryness.7.2 Remove the container and cover from the oven andplace
12、in a desiccator and cool to ambient temperature.7.3 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 inD 6659 into the previously weighed container.7.5 Weigh the covered container to the nearest 6 0.001 gand record.NOTE 1It is es
13、sential that weighings be made promptly.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.02 on Blue Stock.Current edition approved Oct. 1, 2006. Published November 2006. Originallyapproved in 2001. Last previous edition
14、approved in 2001 as D 6658 - 01.2For 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 standards Document Summary page onthe ASTM website.1Copyright ASTM International
15、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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.7.6 Oven DryingPlace the weighing container with thesample and with
16、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 covered container and record to the nearest 60.001 g.8. Calculation8.
17、1 Calculate the percent volatile matter (moisture) as fol-lows:Volatile matter moisture!,%5 S D!/S B!# 3 100 (1)where:S = weight, grams, of original specimen plus coveredcontainer,B = weight, grams, of empty covered container, andD = weight, grams, of oven-dried sample plus coveredcontainer.9. Repor
18、t9.1 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 a single differentwet blue sample, dried different wet blue samples at
19、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 degrees offreedom is 2.571. Therefore since the calculated t is less tha
20、nthe 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; volatile matter; wet blueASTM International takes no position respecti
21、ng 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 responsibility.This stand
22、ard 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 to ASTM Internation
23、al 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 address shown below.T
24、his 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 6658 01 (2006)2
