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D1059-17 – Standard Test Method Technical Guide
📐 Specimen and Scope
This test method, designated D1059-17 (Reapproved 2022), covers the determination of yarn number for cotton, woolen, worsted, and man-made fiber yarns taken from packages or textile fabrics where the yarns are intact and can be removed in measurable lengths. It is not applicable to napped or cut pile fabrics. Because this method uses short-length specimens, typically 1 m (1.1 yd) or less, the results are considered approximations of yarn number. For a more precise determination, refer to Test Method D1907.
| 🟦 Parameter | 📏 Specification | 📐 Reference |
|---|---|---|
| Specimen Length | 1 m (1.1 yd) or less | Section 4.1 |
| Tension for Testing | 0.25 to 0.75 cN/tex (gf/tex) | Section 1.2 |
| Conditioning | Per Practice D1776 | Section 2.1 |
| Sampling | Per Practice D2258 | Section 2.1 |
⚙️ Test Procedure and Tension Settings
Specimens of prescribed length are cut from a conditioned sample under prescribed tension and weighed. This method is applicable to yarns that stretch less than 5% when tension is increased from 0.25 to 0.75 cN/tex (0.25 to 0.75 gf/tex). For yarns that stretch more than 5%, tension may be adjusted by mutual agreement—lower for elastomers or higher to remove crimp from textured yarns. This adaptability ensures the method can be applied to a variety of yarn types while maintaining accuracy.
📊 Yarn Number Calculation and Precision
The yarn number is calculated from the mass and measured length of the specimen using equations (Eq 2 and Eq 3) detailed in the standard. It is critical to note that any error in the reported length is multiplied during calculation, so precise measurement is essential. The values in SI units are regarded as standard, with parenthetical values for information. This method provides a quick approximation suitable for routine checks, but for critical applications, Test Method D1907 is recommended for greater accuracy.
💡 Tip: Ensure all samples are conditioned according to Practice D1776 in a standard atmosphere before testing to minimize variability due to moisture content.
⚠️ Warning: Because any error in length measurement is multiplied when calculating yarn number (see Eq 2 and Eq 3), use calibrated instruments and verify readings carefully to avoid significant inaccuracies.
❓ Frequently Asked Questions
🔍 What types of yarns are suitable for testing with D1059?
The method is applicable to cotton, woolen, worsted, and man-made fiber yarns from packages or fabrics, but not from napped or cut pile fabrics.
💡 Why are the results from this method considered approximate?
Due to the use of short-length specimens (typically 1 m or less), any measurement errors have an amplified effect on the yarn number calculation, making the results approximate.
⚡ What tension should be used during specimen preparation?
For yarns stretching less than 5%, use a tension of 0.25 to 0.75 cN/tex (or gf/tex). Adjustments can be made for other yarn types by mutual agreement.
📌 How is the yarn number determined from the specimen?
The yarn number is calculated from the specimen’s mass and length using equations provided in the standard (Eq 2 and Eq 3), which convert the mass per unit length to the appropriate yarn numbering system.