ASTM D6612-00(2016)
Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester

Standard No.

ASTM D6612-00(2016)

Release Date

2000

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D6612-00(2022)

Latest

ASTM D6612-00(2022)

Scope

5.1 Test Method D6612 for yarn number and yarn number variability is satisfactory for acceptance of commercial shipments and is used in the trade.

5.1.1 If there are differences of practical significance between the reported test results for two or more laboratories, comparative tests should be performed by those laboratories to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, samples used for each comparative tests should be as homogeneous as possible, drawn from the same lot of material as the samples that results in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. Other fabrics with established tests values are used for this purpose. The test results from the laboratories involved should be compared appropriate statistical analysis and a probability level chosen by the two parties before testing begins, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results adjusted in consideration of the known bias.

5.1.2 The average results from the two laboratories should be compared using appropriate statistical analysis and a probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.

5.2 Test Method D6612 also is used for the quality control of filament yarns.

5.3 Indices of Variability: 

5.3.1 Coefficient of Variation—%CV is a standard statistical calculation and is the most common index of yarn unevenness. For most textile applications in the 80–330 dtex (70–300 denier) range, a 1.0–1.3 %CV is adequate. %CV of yarns coarser than 666 dtex (600 denier) is not routine and usually not meaningful. %CV is less discriminating that %DS.

5.3.2 Bad/Good Test—%BGT, which will normally be up to 208201;% greater than %DS value, emphasizes the greatest spread in the entire length tested, (%DS is an average). If the value is greater than 508201;% of the %DS, it suggests that there is a process that needs to be investigated.

5.3.3 Density Spread—%DS is equivalent to the Uster % unevenness (Test Method D1425) and is an indication of short-term variability. Yarns with extreme values are more likely to cause trouble in subsequent yarn processes, which makes this perhaps the most useful index. The minimum achievable and maximum tolerance spread for a yarn product will depend on the yarn manufacturing process and end use. A spread of 3–48201;% generally is, for most textile applications, in the range of 160–550 dtex (150 to 500 deniers). More critical applications, such as those using finer yarns, may require lower values.......

ASTM D6612-00(2016) Referenced Document

• ASTM D123 Standard Terminology Relating to Textiles
• ASTM D1425 Standard Test Method for Unevenness of Textile Strands Using Capacitance Testing Equipment (Withdrawn 2005)
• ASTM D1776 Standard Practice for Conditioning and Testing Textiles
• ASTM D1907 Standard Test Method for Linear Density of Yarn (Yarn Number) by the Skein Method
• ASTM D2258 Standard Practice for Sampling Yarn for Testing
• ASTM D4849 Standard Terminology Related to Yarns and Fibers

ASTM D6612-00(2016) history

• 2022 ASTM D6612-00(2022) Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
• 2000 ASTM D6612-00(2016) Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
• 2000 ASTM D6612-00(2011) Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
• 2000 ASTM D6612-00(2006)e1 Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester
• 2000 ASTM D6612-00 Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester