ASTM_D_1668_-_D_1668M_-_97a_2021.pdf

Designation:D1668/D1668M97a(Reapproved 2021)Standard Specification forGlass Fabrics(Woven and Treated)for Roofing andWaterproofing1This standard is issued under the fixed designation D1668/D1668M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.This specification replaces Federal Specification HH-C-466.1.Scope1.1 This specification covers finished treated(coated)woven-glass fabrics coated with either asphalt,coal-tar pitch,or an organic resin compatible with the roofing,waterproofing,or other usage as specified by the purchaser.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in nonconformancewith the standard.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD146/D146M Test Methods for Sampling and TestingBitumen-Saturated Felts and Woven Fabrics for Roofingand WaterproofingD579/D579M Specification for Greige Woven Glass FabricsD1079 Terminology Relating to Roofing and WaterproofingD3775 Test Method for End(Warp)and Pick(Filling)Countof Woven FabricsD3776/D3776M Test Methods for Mass Per Unit Area(Weight)of Fabric3.Terminology3.1 DefinitionsFor definitions of terms used in thisspecification,refer to Terminology D123 or D1079.4.Classification of Fabric Treatments with GenerallyApplicable Usage4.1 Type I,Asphalt TreatedType I is suitable for use withall asphalts and asphalt-based compounds.4.2 Type II,Coal-Tar Pitch TreatedType II is suitable foruse with all coal-tar pitches and coal-tar pitch-based com-pounds(Note 1).4.3 Type III,Organic Resin TreatedThe purchaser andsupplier shall agree on an organic resin that is compatible withor is suitable for,or both,the plying liquid plying materialseither specified or to be used.This organic resin shall not bewater soluble.NOTE1In some instances the purchaser may specify the use of TypeI or II for systems using other than coal-tar bitumens or asphalt.5.Materials and Manufacture5.1 The untreated(greige)scrim(open basket weave)orleno(locked weave)fabrics shall conform to the requirementsas specified in Table 1.5.2 In the process of manufacture,the fibers of the untreatedglass fabric shall be thoroughly and uniformly coated usingequipment which,in combination,handles the fabric and usesa machine speed in a total process that will not injure or distortthe weave of the fabric.5.3 Glass fabric is usually woven in nominal widths of 0.91,1.83,and 2.74 m 36,72,and 108 in.by the weaving mills.Extra warp(the length of the fabric)threads are included in1.83 and 2.74-m 72 and 108-in.wide fabrics to obtainincremental fabric roll widths of 0.91 m 36 in.These extrawarp threads with a slitting space between each set(a set oftwo)of bunched warp threads create a duplicate or“dupe”selvedge with a“brush”edge created by the cut fill threadsinstead of the usually wrapped fill threads seen in a smooth1This specification is under the jurisdiction of ASTM Committee D08 onRoofing and Waterproofing and is the direct responsibility of Subcommittee D08.04on Felts,Fabrics and Bituminous Sheet Materials.Current edition approved July 1,2021.Published July 2021.Originally approvedin 1959.Last previous edition approved in 2014 as D1668/D1668M 97a(2014)1.DOI:10.1520/D1668_D1668M-97AR21.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1selvedge.This type of fabric selvedge edge is,and has been,anacceptable fabric design(pattern)in both the weaving andconstruction industry.5.4 Brush edge of the“dupe”selvedge is not to be includedin the measurement of the finished roll width.5.5 The purchaser may specify widths of more than