Staple Wool
Fiber Definitions — textile fibers, yarn fibers and fiber properties from Apparel Search
Staple is a term referring to naturally formed clusters or locks of wool fibers throughout a fleece that are held together by cross fibers. The staple strength of wool is one of the major determining factors when spinning yarn as well as the sale price of greasy wool, and virtually all fleece and better grade wool skirtings sold at auction in Australia are objectively measured prior to sale.
Staple is a term referring to naturally formed clusters or locks of wool fibers throughout a fleece that are held together by cross fibers. The staple strength of wool is one of the major determining factors when spinning yarn as well as the sale price of greasy wool.
Virtually all fleece and better grade wool skirtings sold at auction in Australia are objectively measured prior to the sale with the average results printed in a catalogue.
Staple strength is calculated as the force required to break per unit staple thickness, expressed as newtons per kilotex or N/tex. Position of Break (POB) is measured in conjunction with staple strength and is a measure of the position in the staple (base, mid or tip) where it will break given enough force. Forty or more staples must be measured to in order to conform to the Australian Standard. Wools under 30 newtons per kilotex are considered tender. Currently wools over 40 newtons per kilotex are preferred and attract a premium. Seasonal conditions or the health of the sheep may influence the soundness (strength) of the wool.
The Australian Standard requires that sale lot has a minimum of 55 staples measured with the average calculated and produced. The variability of this measure is reported as the coefficient of variation (CV%). Staple length generally determines the end use of wool, that is, whether it will be used in weaving or knitting. The longer wools are processed in the worsted system (weaving), which are called combing types, and are generally around 51 millimeters (mm) and longer. Short stapled wools are more profitably used in the woolen section where high grade material may be produced from superfine wool. Staple length (mm) is highly correlated with mean fiber length in the top (hauteur).
Although traditionally, staple length only referred to animal fibers, it is now used when referring to animal and manufactured fibers as well.
The opposite term is filament fiber, which is fiber that comes in continuous to near continuous lengths for use. Silk, taken from the cocoon of a silkworm, is called a silk filament.
References
Cottle, D.J. (1991). Australian Sheep and Wool Handbook. Melbourne, Australia: Inkata Press, 20-23. ISBN 0-909605-60-2.
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| The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/staple_(wool) . Modified by Apparel Search 8/30/08 |
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Objective Measurement at Auction
Australian practice made staple a measured science rather than a buyer's guess. Forty or more staples must be measured in order to conform to the Australian Standard, and the Standard requires that a sale lot has a minimum of 55 staples measured with the average calculated and produced; the variability of the measure is reported as the coefficient of variation, CV percent. Seasonal conditions or the health of the sheep may influence the soundness — the strength — of the wool: a drought or illness check in the sheep's year shows up as a weak point along the staple, which is exactly what the Position of Break records. A mid-staple break from a hard season tells the spinner where yarn trouble will come from, and tender wool under 30 newtons per kilotex is discounted accordingly, while sound wool over 40 newtons per kilotex earns its premium.
Length, Hauteur and Spinning Systems
Staple length (mm) is highly correlated with mean fiber length in the top, known as hauteur, which is why a single clip measurement predicts processing behaviour so well. Combing types around 51 millimetres and longer feed the worsted system, where parallel, smooth yarns are spun for weaving fine suiting and knitwear; short stapled wools go to the woolen section, where high grade material may be produced from superfine wool in lofty, fuzzy yarns for knitwear and blankets. The staple concept travelled: cotton, flax and cut manufactured fibers are all traded by staple length today, and spinners still sort every fiber delivery first by the length of its staple, because length governs how strongly fibers grip each other in yarn — the same cross-fiber grip that holds a lock of fleece together on the sheep. Reference: Cottle, D.J. (1991), Australian Sheep and Wool Handbook, Inkata Press, pages 20-23.
Common Questions
How is staple strength measured?
Staple strength is calculated as the force required to break per unit staple thickness, expressed as newtons per kilotex or N/tex. Wools under 30 newtons per kilotex are considered tender, while wools over 40 newtons per kilotex are currently preferred and attract a premium. Position of Break (POB) is measured alongside it — where in the staple, base, mid or tip, the break occurs.
How does staple length decide end use?
Staple length generally determines the end use of wool, whether it will be used in weaving or knitting. The longer wools are processed in the worsted system and are called combing types, generally around 51 millimetres and longer, while short stapled wools are more profitably used in the woolen section.
What is the opposite of a staple fiber?
The opposite term is filament fiber, which is fiber that comes in continuous to near continuous lengths. Silk, taken from the cocoon of a silkworm, is called a silk filament. Although staple traditionally referred only to animal fibers, it is now used for animal and manufactured fibers as well.