ASTM D1668-97a(R2021) pdf free download

ASTM D1668-97a(R2021) pdf free download.Standard Specification for Glass Fabrics (Woven and Treated) for Roofing and Waterproofing
1. Scope
1.1 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 units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with 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 the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Classification of Fabric Treatments with Generally Applicable Usage
4.1 Type I, Asphalt Treated—Type I is suitable for use with all asphalts and asphalt-based compounds. 4.2 Type II, Coal-Tar Pitch Treated—Type II is suitable for use with all coal-tar pitches and coal-tar pitch-based com- pounds (Note 1). 4.3 Type III, Organic Resin Treated—The purchaser and supplier shall agree on an organic resin that is compatible with or is suitable for, or both, the plying liquid plying materials either specified or to be used. This organic resin shall not be water soluble. N OTE 1—In some instances the purchaser may specify the use of Type I or II for systems using other than coal-tar bitumens or asphalt.
5. Materials and Manufacture
5.1 The untreated (greige) scrim (open basket weave) or leno (locked weave) fabrics shall conform to the requirements as specified in Table 1. 5.2 In the process ofmanufacture, the fibers ofthe untreated glass fabric shall be thoroughly and uniformly coated using equipment which, in combination, handles the fabric and uses a machine speed in a total process that will not injure or distort the weave of the fabric. 5.3 Glass fabric is usually woven in nominal widths of0.91, 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 in 1.83 and 2.74-m [72 and 108-in.] wide fabrics to obtain incremental fabric roll widths of 0.91 m [36 in.]. These extra warp threads with a slitting space between each set (a set of two) of bunched warp threads create a duplicate or “dupe” selvedge with a “brush” edge created by the cut fill threads instead of the usually wrapped fill threads seen in a smooth selvedge. This type offabric selvedge edge is, and has been, an acceptable fabric design (pattern) in both the weaving and construction industry. 5.4 Brush edge of the “dupe” selvedge is not to be included in the measurement of the finished roll width. 5.5 The purchaser may specify widths of more than or less than 0.91 m [36 in.]. These widths can be furnished at the manufacturer’s option.
6. Physical Properties
6.1 Coated Fabric—The coated fabric shall conform to the requirements as specified in Table 2. The coated fabric shall not flake at 0 °C [32 °F] when flexed 180° over 25 mm [1 in.] outside diameter mandrel and then immediately reversed. 6.2 Finished Fabric—The finished fabric shall be capable of retaining its original shape and shall consist of a right angle weave set pattern without bunching either the warp or fill threads when unrolled during normal handling. There shall be no sticking at temperatures of 10 °C [50 °F] and above unless such stickiness is required or specified, or both, by the purchaser. 6.3 Finished Roll—The finished roll shall present a neat square edge with no loose warp threads. The fabric termina- tions shall be sealed using tape or the like and without the use of staples or heat.