1、Designation:D640399(Reapproved 2014)Standard Test Method forDetermining Moisture in Raw and Spent Materials1This standard is issued under the fixed designation D6403;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last re
2、vision.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 is intended for use in determining themoisture content in raw and spent materials that are extractedfor tannin an
3、alysis.The moisture content of the sample isoperationally defined to be equal to the weight loss experiencedas a result of the evaporation which occurs in the drying oven.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 Th
4、is 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 use.2.Referenced Documents2.
5、1 ASTM Standards:2D6405 Practice for Extraction of Tannins from Raw andSpent Materials2.2 ALCA MethodsA6 Moisture in Raw and Spent Materials33.Terminology3.1 Definitions:3.1.1 raw materialany of the various parts of plants thatare used as a source of vegetable tannins.3.1.2 spent materialplant tissu
6、e by-products from indus-trial processes which may contain significant quantities ofvegetable tannins.3.1.3 tanninan astringent substance found in the variousparts of plants such as bark,wood,leaves,nuts,fruits,roots,etc.3.1.4 vegetable tanninsmixtures of substances(naturalproducts)obtained from pla
7、nt tissues by water extractionwhich have the chemical and physical properties necessary toconvert animal hides and skins into leather.4.Summary of Test Method4.1 A specimen of the material sample prepared for use inPractice D6405 is dried overnight in a forced-air oven.The lossin weight represents t
8、he moisture in the specimen.5.Significance and Use5.1 This test method is used to determine the moisturecontent of materials(raw or spent)that are to be extracted fortannin analysis.The value obtained for moisture content by thistest method is used to calculate the results of the other analyseson th
9、is material to a moisture-free basis.5.2 The specimens are obtained from the material preparedfor extraction in Practice D6405.5.3 Tanning materials contain moisture in varying amounts,depending both on the nature of the material and on theclimatic conditions,therefore sampling must be carried out a
10、squickly as is consistent with thoroughness in order to avoidchanges in moisture content.5.4 Negative errors may occur in the moisture determinationbecause under the conditions of this method there may beretention of moisture by certain components(for example,hydrated salts or water bound to organic
11、 structures)of the rawor spent material or because of oxidation of other components(for example,tannins)of the raw or spent material.5.5 Positive errors may occur in the moisture determinationbecause under the conditions of this test method there may bevolatilization of certain components of the raw
12、 or spentmaterial other than water.5.6 It is known that other factors can also affect the quantityof volatile matter(moisture)released by the specimen.Thesefactors include but are not limited to:particle size of the testspecimen,quantity of test specimen,oven temperature,expo-sure time in the oven,s
13、hape of the specimen container,andtype of oven(for example,gravity or mechanical convection)used.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.01 on Vegetable Leather.Thistest method has been adapted from and is a rep
14、lacement for Method A6 of theOfficial Methods of the American Leather Chemists Association.Current edition approved Nov.1,2014.Published December 2014.Originallyapproved in 1999.Last previous edition approved in 2009 as D6403 99(2009).DOI:10.1520/D6403-99R14.2For referenced ASTM standards,visit the
15、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.3Official Methods of the American Leather Chemists Association.Availablefrom the American Leather Chemists
16、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 States1 5.7 Because of the possibility of unknown errors in this testmethod it is essential that the method be followed exactly inorder to obtain reproducible results both among specimenswithin a laboratory and for analyses between laboratories.6.Apparatus6.1 Balance,analytical balance which will weigh up to 100g with a
