1、Designation: D646 13Standard Test Method forMass Per Unit Area of Paper and Paperboard of AramidPapers (Basis Weight)1This standard is issued under the fixed designation D646; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 This test method covers the dete
3、rmination of the massper unit area of paper and paperboard.1.2 In the SI metric units system, the mass per unit area ofpaper and paperboard is expressed in grams per square meter(g/m2).1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in this
4、standard.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. Ref
5、erenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD685 Practice for Conditioning Paper and Paper Productsfor TestingD1776 Practice for Conditioning and Testing Textiles3. Summary of Test Method3.1 The area of several sheets of the paper or paperboard isdetermined from linear
6、measurements and the mass is deter-mined by weighing. The test-result is calculated from the ratioof the mass to the area.4. Significance and Use4.1 Most paper is bought and sold in accordance with itsmass per unit area, and therefore has great significance both tothe consumer and the producer in de
7、fining price. Also, thevalues of many physical properties such as bursting strength,thickness, and bulk are interpreted and specified with regard tothe particular mass per unit area involved.5. Apparatus5.1 Weighing Device, readable and accurate to within0.25 % of the applied load. When in use, the
8、weighing deviceshall be shielded from air currents.5.2 Cutting Device, such as a “four square” cutter, or otherdevice for ensuring right angles between the edges.5.2.1 When a template is used for preparing test specimens,the paper should be cut to exact size with a sharp knife on ahard surface, such
9、 as a hardwood board.5.3 Scale, such as a finely graduated steel rule reading in0.5 mm, capable of measuring the dimensions of the testspecimen to an accuracy of 0.2 %.6. Sampling6.1 Sampling shall be consistent with documented internalpractices as agreed upon between sellers and buyers beforepurcha
10、se.6.2 From each test unit of the sample, cut a sheet with adimension of 200 6 5 200 6 5 mm.7. Calibration7.1 Checking of Weighing Device:7.1.1 Check the accuracy of the weighing device frequently(7.3) by applying accurately measured masses with bothincreasing and decreasing loads. When using a shee
11、t-weighingdevice, be sure that the device has been properly calibrated tothe required accuracy (5.1).7.1.2 Before each use, see that frictional effects are suffi-ciently minimal and that the zero reading is sufficiently correctas to ensure the required weighing accuracy.7.2 Checking of Cutting Devic
12、eFrequently (7.3) check thecutting by using the scale (5.3) to measure the lengths of the1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on Industrial Fibers andMetallic Reinforcements.Current edition approved July 1
13、, 2013. Published August 2013. Originallyapproved in 1941. Last previous edition approved in 2007 as D64696 (2007) whichwas withdrawn February 2010 and reinstated in July 2013. This test method isrelated to TAPPI T 410 om-13, which is technically identical, and is similar toInternational Standard IS
14、O 536, Paper and BoardDetermination of Grammage.DOI: 10.1520/D0646-13.2For 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
15、 website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1four sides of 20 test specimens. Accuracy is attained when thestandard deviation of all lengths is less than 0.5 % of the meanlength.7.3 Frequency of CheckingThe frequency of ch
16、ecking in7.1 and 7.2 should be based on experience. A new deviceshould be checked several times before being put into use.Then, if in continuous use, it should be checked twice dailyuntil stability is established, then weekly, monthly, or lessfrequently as indicated by its stability, unless moved or
17、 undulydisturbed. Because of wear, the cutting device may requiremore frequent checking than the weighing device.8. Conditioning8.1 Condition and test the specimens in an atmosphere inaccordance with Practice D1776 or D685, unless the “asreceived” value is required.9. Procedure9.1 Cut the specimen w
18、ith the accuracy specified in 6.2.9.2 Measure the height and width with the accuracy speci-fied in 5.3.9.3 Weigh each test specimen with an accuracy specified in5.1.10. Calculation10.1 From the measurements, calculate the mass per unitarea of each test specimen. The mass per unit area in grams persq
19、uare meter is calculated by the equation:BW 5MA5MHW(1)where:M = the mass of the specimen, g,A = the area of the specimen, m2,H = the specimen height, m,W = the specimen width, m, andBW = the mass per unit area (basis weight) in g/m2.11. Report11.1 Report the following information:11.1.1 Testing cond
20、itions.11.1.2 The actual total area tested.11.1.3 The mass per unit area in grams per square meter.12. Precision and Bias12.1 The repeatability standard deviation from a singleoperator has been determined to be 0.94 %.12.2 An interlaboratory study of this test method is beingconducted and a complete
21、 precision statement is expected to beavailable on or before 2015.13. Keywords13.1 aramid paper; basis weight; mass per unit areaASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard ar
22、e 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 standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not
23、revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which yo
24、u 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.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United
25、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D646 132
