1、Designation:D 4250 92(Reapproved 2003)An American National StandardStandard Test Method forWater-Holding Capacity of Bibulous Fibrous Products1This standard is issued under the fixed designation D 4250;the number immediately following the designation indicates the year oforiginal adoption or,in the
2、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 is designed for determining the water-holding capacity,Cwh,of bibulous paper
3、s such as facial tissues,towels,wipes,nonwovens,etc.,using predetermined times ofsoaking and excess water extraction under a predetermined lowsuction head resulting from a controlled capillary drainingaction.1.2 This standard does not purport to address all of thesafety concerns,if any,associated wi
4、th 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:2D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paper
5、board,Fiberboard,and Related ProductD 685 Practice for Conditioning Paper and Paper Productsfor TestingE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Summary of Test Method3.1 Following an initial weighing of the specimen,it is laidupon water for a
6、 period of 1 min.The wetted specimen isplaced on an excess water extractor for 15 s,during which timethe specimen experiences a 5-mm water-extracting suctioncaused by the difference between the top of the excess waterextractor and the water level in the tray.After this,thespecimen is again weighed.T
7、he observed gain in weight isused to calculate the water-holding capacity of the sample.Thisis expressed both as grams per square metre(g H2O/m2)and asthe water/fiber ratio:grams of water per 1 g of conditionedproduct(g H2O/g conditioned fiber).4.Significance and Use4.1 This test method provides a m
8、easure of the ability of atowel,or like material,to soak up water in the drying ofsurfaces,absorption of spills,etc.4.2 Water-holding capacity,as measured by this method,discriminates well among different absorbing products.5.Apparatus5.1 Flat-Bottomed Tray,with approximate inside dimen-sions of 200
9、 by 300 by 50 mm(8 by 12 by 2 in.).NOTE1Some common 2-qt borosilicate glass baking dishes areadequate.Two brass washers may be glued to the bottom of the tray withsilicone marine sealant to prevent displacement of the excess waterextractor;the two washers may accommodate any two of the three brasssc
10、rews that support the excess water extractor.5.1.1 Small Circular Spirit Level.5.1.2 Pin and Bar Elevation Indicator,set for 5 mm,seeFig.1.The tip should be dipped in hot wax from time to time.5.2 Excess Water Extractor,see Fig.2.5.3 Specimen Catcher,comprised of a piece of sheet alu-minum,about 0.1
11、2 mm thick,100 mm wide,and 125 mm long(0.0046 by 4 by 5 in.).NOTE2This item can be cut from the bottom of a lightweightaluminum cake pan.Plastic sheeting should not be used in place of metal.5.4 Specimen Holder,see Fig.3.5.4.1 Polystyrene Foam Piece,measuring about 13 mmthick,50 mm wide,and 100 mm l
12、ong(12by 2 by 4 in.),toserve as backup in the use of the specimen holder.NOTE3This can be cut from12-in.thick insulation board.5.5 Distilled Water A supply of room temperature 2361C(73 6 2F)distilled water about 50 cm above the tray.5.5.1 Siphon and Flexible Tube,terminating with a shortlength of ca
13、pillary tubing.5.5.2 Pinch Cock(screw type),to regulate the stream ofwater into the tray at a rate between two and three drops persecond,more when a heavy material is under test.The flow rateshould be such that the amount of water flowing in 1 min isseveral times the weight of water absorbed by a sp
14、ecimen.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 Sept.15,1992.Published December 1992.Originallypublished as D 4250 83.Last previous edition D 4250 83(19
15、88).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,100 Barr Harbor Drive,PO Box C70
16、0,West Conshohocken,PA 19428-2959,United States.5.6 Vertically Mounted Glass Eye Dropper,tapered enddown and with its tip immediately above the water surface inthe tray.The inside diameter of the tapered end should bebetween 2.0 and 2.3 mm.5.6.1 AspiratorThe eye dropper is connected to an aspi-rator,to remove excess water from the tray and to control thewater level through vertical adjustment of the eye dropper.5.6.2 Holder,for the eye dropper,see Fig.4.5.6.3 Float Valve Alternatively,a float va
