Shedding from Spun/Staple Yarn

Volume 8 No. 8 Shedding from Spun/Staple Yarn

Shedding is a normal characteristic of carpet manufactured from staple fibers. Staple yarns, which are used almost exclusively in cut-pile carpets, are made by chopping continuous filament yarn into typically 3-inch to 8-inch lengths of fiber that are spun or twisted into yarn, forming spun/staple yarns that are heat set to provide yarn twist retention. With the exception of silk, all natural fiber is staple yarn, and any synthetic fiber can be made into staple yarn. Staple yarns tend to be less lustrous than continuous filament yarns. These features, combined with the hand and appearance of staple yarns, allows these carpets to look and feel like much more expensive carpets made from wool.

Shedding occurs when individual spun/staple fibers work loose from tufts by the influence of traffic and vacuuming, and when sheared yarns that were not removed by manufacturing are removed later by vacuuming. Shedding should not be confused with bearding or fuzzing, which is the result of fiber slippage from a yarn bundle due to slack yarn twist, or improper latex bundle wrap and penetration. For this reason, analysis for latex bundle wrap and penetration to determine whether or not excessive shedding has occurred may not provide meaningful data. If a carpet made from spun/staple yarn is suspected of excessive shedding, testing using the Hexapod Drum test method may provide a better insight as to the amount of shedding that is occurring.

Shedding associated with a newly installed carpet made from spun/staple yarn often appears large in amount. This is because shed fibers captured by vacuuming are fluffed and agitated, and is also random in their orientation. As a result, newly installed carpets made of spun/staple yarn often initially release what can appear to be seemingly large amounts of fiber when vacuumed. Carpets having a lower yarn twist won’t hold loose yarns as securely, and are therefore more likely to shed. In addition to this, the shorter the staple fiber used in a carpet’s construction and the longer the tuft, the more loose fiber it will shed. And the heavier and denser a staple yarn carpet construction is, the more time will be required for shedding to dissipate noticeably.

The length of time noticeable shedding occurs with a newly installed carpet made from spun/staple yarn will depend on traffic level, the type vacuum used, and frequency and effectiveness of vacuuming. Vacuum models equipped with an adjustable pile height setting, beater bar and brush are generally more effective in removing loose fibers from staple yarns than suction only vacuum models. In most cases, shedding diminishes significantly within the first 3-6 months after installation when the carpet is trafficked and vacuumed regularly. However, carpet made from spun/staple yarn will continue to shed, although in miniscule amounts, throughout their lifecycle. Carpets made from spun/staple yarn may also form yarn “pills” on the carpet’s face if the carpet is not vacuumed regularly.

Despite what may appear to be significant fiber loss, shedding from carpets made from spun/staple yarns is a normal occurrence, and the shedding that occurs represent an infinitesimally small amount of the carpet’s total fiber content. Because of this, and because shedding does not negatively affect the wear characteristics or longevity of a carpet, it is not considered to be a manufacturing defect.

Written by: Mark Johnston

Technical Services Phone: 800-944-2840 Email; [email protected]

Shedding from Staple Yarns August 2008 Page 1 of 1 Revised April 2014