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D1334-18 – Standard Test Method Technical Guide
📐 Scope and Referenced Documents
D1334-18 establishes a definitive referee test method for the determination of the wool base content and the clean wool fiber present in a lot of raw wool. The procedure involves commercial-scale scouring of the entire lot, followed by rigorous laboratory tests on samples of the scoured wool.
This standard relies on a comprehensive framework of supporting ASTM standards for terminology and complementary test methods, as detailed in the table below.
| 🟦 Standard | 📏 Title and Role in D1334-18 |
|---|---|
| D123 | Terminology Relating to Textiles |
| D584 | Test Method for Wool Content of Raw Wool—Laboratory Scale |
| D1060 | Practice for Core Sampling of Raw Wool in Packages |
| D1113 | Test Method for Vegetable Matter and Other Alkali-Insoluble Impurities in Scoured Wool |
| D2720 | Practice for Calculation of Commercial Weight and Yield of Scoured Wool, Top, and Noil |
| D4845 | Terminology Relating to Wool |
⚙️ Test Procedure Summary
The procedure begins with the entire lot of raw wool being weighed and processed through standard commercial scouring and drying equipment. Section 4.1 of the standard specifically requires special precautions against loss of wool at any stage of the operations to ensure the integrity of the final yield calculation.
Following commercial drying, the scoured wool is weighed. Representative samples are then taken for critical laboratory determinations including oven-dried weight (mass), alcohol-extractable matter, mineral matter, vegetable-matter base, and other alkali-insoluble impurities. These values form the basis for the final percentage calculations.
⚠️ Units of Measure: U.S. Customary Units are regarded as the standard because of common commercial practice. SI units provided in parentheses throughout the standard are for information only (Section 1.2).
💡 Trade Terminology: Per Note 3 of the standard, the term “weight” is used throughout this test method instead of the technically correct term “mass,” reflecting long-standing industry practice.
📊 Calculated Components and Results
The primary results of the test method are the Wool Base Content and the Clean Wool Fiber Present. These are calculated as percentages of the net weight (mass) of the lot of raw wool, derived from the commercial scales and the laboratory analyses of the scoured samples.
| 🔍 Component Analyzed | 🎯 Purpose in Calculation |
|---|---|
| Oven-Dried Weight | Provides the absolute dry fiber mass for the base calculation. |
| Alcohol-Extractable Matter | Measures residual grease, oils, and soaps not removed by commercial scouring. |
| Mineral Matter | Quantifies sand, dust, and other non-combustible residues. |
| Vegetable Matter Base | Determines burrs, seeds, and plant impurities (per Test Method D1113). |
| Other Alkali-Insoluble Impurities | Captures remaining non-wool, non-vegetable contaminants. |
Section 5.1 identifies this test method as satisfactory for use as a referee method. For conversion of the wool base into commercial weights of scoured wool, top, or noil, users are directed to Practice D2720.
❓ Frequently Asked Questions
🔍 What is the difference between Wool Base and Clean Wool Fiber Present?
The Wool Base Content is the percentage of oven-dried wool fiber free from all impurities. The Clean Wool Fiber Present is a commercially adjusted value that accounts for typical allowances for residual grease and moisture, representing the yield of scoured wool as traded in commerce.
© 2026 TNLab — This article is a technical interpretation for reference only. The original standard as published by ASTM International takes precedence.