ASTM_D_824_-_94_2002.pdf

Designation:D 824 94(Reapproved 2002)An American National StandardStandard Test Method forRate of Absorption of Water by Bibulous Papers1This standard is issued under the fixed designation D 824;the number immediately following the designation indicates the year oforiginal adoption or,in 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.1.Scope1.1 This test method covers the determination of the rate atwhich an unsized and absorbent paper will absorb water bymeasuring the time required for the paper to absorb completelya specified quantity of water(1-4).21.2 This test method is not intended for sized papers orthose having an absorption time of over 120 s.Such papersshould be tested in accordance with Test Method D 779 or ISO535.1.3 For ink absorption of blotting paper,see Test MethodD 2177.1.4 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 use.2.Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Product3D 685 Practice for Conditioning Paper and Paper Productsfor Testing3D 779 Test Method for Water Resistance of Paper,Paper-board,and Other Sheet Materials by the Dry-IndicatorMethod3D 1193 Specification for Reagent Water4D 2177 Test Method for Ink Absorption of Blotting Paper3E 122 Practice for Calculating Sample Size to Estimate,with a Specified Tolerable Error,the Average for a Char-acteristic of a Lot or Process52.2Other Standard:ISO 535 Paper and BoardWater Absorption(Cobb Test)63.Summary of Test Method3.1 Ameasured drop of water is placed on the paper and thetime to disappearance of the shine from the wet area isdetermined.4.Significance and Use4.1 The rate of water absorption is an extremely importantproperty of most sanitary products such as paper toweling andtissues.5.Apparatus5.1 Drop-Measuring Device,for Delivery of 1-mL and0.1-mL drops,with 1-mL capacity or more,for example,measuring pipet(5),buret,or hypodermic syringe graduated indivisions of 0.01 mL.5.2 Drop-Measuring Device,for Delivery of 0.01-mLdrops,for example,microburet(6),or syringe-style pipet,graduatedin divisions of 0.001 mL.5.3 Specimen SupportA nonabsorbent horizontal squaresurface,approximately 100 mm on a side and having at itscenter a hole approximately 40 mm in diameter.NOTE1For a multi-ply specimen it may be necessary to modify thesupporting surface by bending up two opposite edges to form a cylindricaltrench.The curvature of the cylinder should be such that,when thespecimen is held in place in the trench(for example,with weights near theends),water applied to the top ply will cause it to expand downward andpush against the underlying plies,wetting them as in normal use of thematerial.5.4 TimerStopwatch or electric timer readable to 0.2 s orbetter.5.5 Light Source,to reflect from the surface of unabsorbedwater on the specimen,and situated far enough away so that itsheat will not influence the absorption time;for example,a1.5-V flashlight bulb,shaded from the eyes,placed about 200mm above the end and to the rear of the support,and operatedby a D-cell battery or bell transformer.6.Test Liquid6.1 Reagent Water,of Type II or better as defined inSpecification D 1193.1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Oct.15,1994.Published December 1994.Originallypublished as D 824 45 T.Discontinued 1984 and reinstated 1986.Last previousedition D 824 86(1990).This test method is related to TAPPI T 432 om-82,with which it is technicallyidentical.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3Annual Book of ASTM Standards,Vol 15.09.4Annual Book of ASTM Standards,Vol 11.01.5Annual Book of ASTM Standards,Vol 14.02.6Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.7.Sampling7.1 Sample the paper in accordance with Practice D 585.7.2 Where sampling is for other than acceptance testing,Practice E 122 may be used as an alternative.8.Test Specimens8.1 From each test unit of the sample select,so as to berepresentative of the unit,10 test specimens,each approxi-mately 100 by 100 mm.When the material to be tested is to beused as a multi-ply unit(as,for example,a triple-ply embossednapkin),cut and test multi-ply specimens;otherwise,cutsingle-ply specimens.9.Conditioning9.1 Condition and test the specimens in the atmosphericconditions in accordance with