ASTM D1907/D1907M-12(2018)

5.1 Test Method D1907/D1907M is considered satisfactory for acceptance testing of commercial shipments, since it has been used extensively in the trade for that purpose.

5.2 This test method is intended primarily for the determination of the average linear density of yarns. However, the variations identified by the results may also provide useful information. If the coefficient of variation is to be calculated, each skein must be weighed separately, and a larger number of skeins will need to be tested (as compared to the number of skeins to be tested for the determination of the average yarn linear density alone).

5.3 This test method includes seven options, depending on whether the yarn is scoured before weighing, weighed in the conditioned or oven-dried state, or whether or not the results obtained are adjusted for commercial moisture regain, or a commercial allowance. Option 1 (unscoured, conditioned yarn) is generally used for yarns spun on the cotton system, while Options 6 and 7 (scoured, oven dried yarn, plus commercial moisture regain, or allowance) are generally used for filament yarns, or yarns containing wool fibers. The specific options to be used in any instance shall be agreed upon by the parties, or as prescribed in test methods or tolerances.

5.4 In Options 2, 3, 5, 6, and 7, an oven-dried sample is obtained by exposing the yarn in an oven with a supply of air at standard textile testing conditions, as described in 6.3.

1.1 This test method covers the determination of the linear density of all types of yarn in package form, subject to the limitations of size and stretch given in 1.2 and 1.3. Provision is made for expressing yarn linear density in all the traditional yarn numbering systems.

1.2 This test method is applicable to yarns that stretch less than 5 % when tension on the yarn is increased from 0.25 to 0.75 cN/tex [0.25 to 0.75 gf/tex]. By mutual agreement, and use of a lower than specified reeling tension, this method may also be adapted to measure the linear density of yarns that stretch more than 5 %, under the above force.

1.3 This method is applicable to yarns finer than 2000 tex. However, it may be also adapted to coarser yarns by the use of skeins of shorter than specified lengths, and alternate reeling conditions, agreeable to the interested parties.

1.4 Depending on the procedure used to calculate the moisture content of the yarn being tested, and its actual moisture content, or finish content, or both, one or more of the following options may be utilized.

1.5 Specimens used to determine yarn linear density may also be used to determine the skein breaking strength of the yarn. Hence, this method provides the sequence of steps to be followed, to determine both these yarn properties.

1.6 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 non-conformance with the standard.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.