1、Designation: D 644 99 (Reapproved 2002)An American National StandardStandard Test Method forMoisture Content of Paper and Paperboard by Oven Drying1This standard is issued under the fixed designation D 644; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1
3、This test method covers the determination of the mois-ture in all papers, paperboards, and paperboard and fiberboardcontainers, except those containing matter other than water thatis volatile at 105C.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its
4、 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.NOTE 1This test method is technically equivalent to TAPPI T412 83.2. Referenced Documents2.1 ASTM Standards:D 585 P
5、ractice for Sampling and Accepting a Single Lot ofPaper, Paperboard, Fiberboard, or Related Products23. Significance and Use3.1 The moisture content of paper and paperboard mayaffect the purchase cost and can also have an effect upon theperformance of the paper in a given application since moisturec
6、ontent can affect properties including, but not limited totensile strength, tearing resistance, dimensional instability,permanence, printability, flexibility, and runability on varioustypes of paper processing machinery and equipment. Knowl-edge of moisture content is necessary to calculate, to a dr
7、ybasis, analytical results obtained from test specimens weighedat ambient or conditioned moisture content.4. Apparatus4.1 Weighing Container, airtight, for weighing the specimenbefore and after drying. A glass weighing bottle with a groundstopper is suitable for specimens of the order of 2 g. Thewei
8、ghing bottle may be of either high or low form; a volumeof about 100 mL is appropriate. An airtight metal container,preferably containing a light-weight large-mesh wire basket, issuitable for larger specimens, particularly those over 10 g.4.2 Thermometer, to indicate the temperature of the dryingove
9、n. This thermometer shall include the temperature rangefrom 100 to 110C, and its scale shall be divided in 1intervals.4.3 Drying Oven, constant-temperature, equipped withmeans for ensuring adequate temperature control and aircirculation, a means to separate the heating coils from thesample containme
10、nt area (generally the oven bottom plate),and preferably equipped with means for drying the air enteringthe oven.4.4 Chemical Balance, sensitive to 1 mg, for weighingspecimens of 2 g and under, and sensitive to 0.05 % of theoriginal weight of the specimen for larger specimens.4.5 Desiccator, in whic
11、h weighing containers and speci-mens are cooled after drying. It is recommended that anhy-drous alumina (indicator grade) be used as the desiccant.5. Test Specimens5.1 When moisture is determined for the purpose of calcu-lating the results of a chemical analysis of paper or board on amoisture-free b
12、asis, the test specimens shall weigh not lessthan 1 g, and preferably not less than 2 g each. At the time ofinitial weighing, these specimens shall be in moisture equilib-rium with the samples being analyzed.5.2 When moisture is determined for the purpose of calcu-lating the amount of moisture in a
13、shipment, the test specimensshall weigh not less than 50 g each, and shall be taken fromsamples obtained in accordance with Practice D 585.5.3 When moisture is determined on combined board orcontainers that are to be tested for other physical properties,test specimens shall weigh approximately 50 g,
14、 and shall betaken so as to be representative of the material being tested. Inthe case of containers, specimens shall be cut from unsealedsections, and preferably from unprinted sections, of the con-tainer, and shall be taken from each type of container beingtested.1This test method is under the jur
15、isdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Feb. 10, 1999. Published April 1999. Originallyapproved in 1955. Last previous edition approved in 1994 as D 644 94.2Annual Book of ASTM Standard
16、s, Vol 15.09.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Procedure6.1 Determine the tare weight of the oven-dried weighingcontainer as follows: Heat the open container (container,stopper or cover, and wire basket, if any) in t
17、he oven at 105 63C for 1 h. At the end of that period, quickly close thecontainer, remove it from the oven, and place it in thedesiccator to cool for 1 h. Remove the closed container fromthe desiccator, momentarily loosen the cover to equalize thepressure, and then weigh the container.6.2 Transfer t
18、he test specimen to the tared weighing con-tainer as soon as the specimen is withdrawn from the sample ofmaterial under test, and close the container immediately. Greatcare must be taken to avoid change in moisture content duringthe transfer of the specimen from the sample to the container.Handle th
19、e specimen with tweezers or clean, dry rubber gloves.If a delay of over a second or two in transferring the specimento the container is unavoidable, keep the specimen covered onboth sides with several adjacent layers of the paper or boardfrom which it is withdrawn, until it can be placed in theconta
20、iner. Then discard the protecting layers of paper or board.Unless the specimen is later to be spread out in the oven, avoidfilling the container tightly. Weigh the closed container holdingthe test specimen, to allow calculation of the original weight ofthe specimen. The weighing container should not
21、 be touchedwith the fingers during these manipulations.6.3 Remove large specimens from the container. If thecontainer has a removable basket, leave the specimen in thebasket, and place the basket and open container in the oven. Ifthe container does not have a removable basket, spread thespecimen in
22、a basket or tray that will permit free circulation ofair around the specimen, and place the basket or tray and theopen container in the oven. Heat for2hat1056 3C. Replacethe specimen in its container and close the container, doingthis, if possible, without removing the specimen from the oven.Place t
23、he closed container in the desiccator, and allow it to coolfor 1 h. Loosen the top of the container momentarily toequalize the pressure, and then weigh the container to allowcalculation of the oven-dry weight of the specimen.6.4 Place small specimens in the drying oven withoutremoving them from the
24、weighing bottle, remove the stopperof the bottle, heat for1hat1056 3C, close the bottle in theoven, cool to room temperature in the desiccator, and weigh.Remove the stopper momentarily just before weighing toequalize the pressure.6.5 Repeat the required drying and weighing operationsuntil the differ
25、ence in weight between two successive weigh-ings is not more than 0.1 % of the weight of the specimen.6.6 Make all weighings to the nearest 1 mg for specimens ofthe order of 2 g, and weigh to within 0.05 % of the weight ofthe original specimen for specimens over 2 g.7. Calculation7.1 When the percen
26、tage of the moisture based on theoriginal weight is required, calculate it as follows:Moisture, % 5 W12 W2!/W1# 3 100 (1)where:W1= original weight of the specimen, andW2= weight of the specimen after oven drying.7.2 When the percentage of moisture based on the oven-dryweight is required, calculate i
27、t as follows:Moisture, % 5 W12 W2!/W2# 3 100 (2)where:W1= original weight of the specimen, andW2= weight of the specimen after oven drying.8. Report8.1 Report the moisture as the percent loss in weight of thespecimen to the nearest 0.1 %, on the basis of the originalweight (7.1) or on the oven-dry b
28、asis (7.2).9. Precision and Bias9.1 Precision:9.1.1 Repeatability The repeatability standard deviationof the procedure in this test method is approximately 0.12 %,and the 95 % repeatability limits are 0.35 %.9.1.1.1 The above repeatability values are based on TAPPICollaborative Reference Program Rep
29、orts 61 through 70. Thenumber of laboratories reporting the data contained in thesereports ranges from 10 to 16.9.1.2 Reproducibility Based upon the data cited in9.1.1.1, reproducibility standard deviations may range from0.12 % to 0.55 % with a corresponding range of 95 % repro-ducibility limits fro
30、m 0.4 % to 1.5 %.9.1.2.1 Reproducibility of results between laboratories isdependent upon the care taken to follow Section 6 exactly, andparticularly the care taken with regard to 6.2.9.1.3 Variations in ambient humidity may affect the humid-ity in the oven and therefore results of this test method.
31、 Forvery critical work, precision may be improved by placing theoven in a controlled humidity environment.9.1.4 The user of this precision data is advised that it isbased on actual mill testing, laboratory testing, or both. Thereis no knowledge of the exact degree to which personnel skillsor equipme
32、nt were optimized during its generation. Theprecision quoted provides an estimate of variation in testresults which may be encountered when the method is rou-tinely used by two or more parties.9.2 BiasThe procedure in this test method has no biasbecause the value of moisture content is defined in te
33、rms of thetesting conditions specified, and there is no determining bias.Determination of moisture content under conditions other thanthose specified in this test method may give different results.10. Keywords10.1 moisture; oven drying; paper; paperboard; waterD 644 99 (2002)2ASTM International take
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35、ponsibility.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 address
36、ed to 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
37、 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).D 644 99 (2002)3
