|Revised Test Method Further Defines Fabric Count
Textile purchasers and suppliers check the acceptability of woven fabric in commercial shipments with ASTM D 3775, Standard Test Method for Fabric Count of Woven Fabric.
As its name implies, D 3775 determines fabric count, but some import technicians use it for thread count, a different measurement. Therefore, members of ASTM Subcommittee D13.60 on Fabric Test Methods, who developed the standard in 1998, developed a new definition of woven-fabric count in a revised edition of D 3775 that will be available next month.
Its hard to agree on acceptability when counting fabric warp (ends) and filling yarns (picks) with different methods. ASTM D 3775 describes fabric count as the number of warp ends and filling picks in a woven fabric without consideration for the number of single yarns in a plied yarn. Thread count has been described as the amount of ends and picks multiplied by their respective number of single yarns in a plied yarn, added together, says consultant Raymond Casper, Lytle, Texas, who helped to develop ASTM D 3775.
Subcommittee members consider fabric count the best way to determine the warp-end and filling-pick count of a woven fabric, according to Casper, a retired senior technologist from Owens Corning Science and Technology Center, Granville, Ohio, who was in textiles for nearly 40 years.
The intent of the method is to count warp ends and filling picks in woven fabric, he says. It does not provide for the factoring in of the number of single yarns that make up a plied yarn when determining fabric count.
To clarify the test methods use, the subcommittee added a second sentence to the standards Section 9.1.4 to further define fabric counting.
At their October 2002 meeting in Norfolk, Va., Committee D13 members proposed additional revisions for future consideration:
w Change the title from Fabric Count of Woven Fabric to End Count and Pick Count in Woven Fabric which is the intent of the method;
Revise the definition for filling and pick to agree with the definition for end that clearly describes that a plied yarn is an individual yarn;
Add a definition for end count to complement the current definition for pick count; and
Add a definition for thread count and its calculation as the sum of the end count and pick count for one square inch of woven fabric without any consideration for the number of single yarns in a plied yarn.
To obtain further technical information, contact Raymond Casper, Lytle, Texas (phone: 830/772-5988) or Subcommittee D13.60 chairman Robert Holcombe, Safety Components, Fabric Tech, Greenville, S.C. (phone: 864/240-2624). Committee D13 meets March 16-19 in Kansas City, Mo. For meeting or membership details, contact Maxine Topping, manager, Technical Committee Operations, ASTM International (phone: 610/832-9737). //
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