SYMPOSIA PAPER Published: 28 September 2020

Performance of Seams in Arc-Rated Protective Fabrics during Arc Exposures


In reference to apparel designed for protection against electrical arc exposure, the question has been raised as to whether a distinctive performance difference exists between seams sewn with flame-resistant (FR) thread as opposed to non-FR thread types. Seams have not been evaluated previously for strength or efficacy at the garment level for apparel designed for electrical workers. Justification for not evaluating seams has been twofold: First, poor seam integrity would have been sorted out in the marketplace; and, second, unlike garments for firefighters, garments worn for arc protection are not worn in constant high-heat environments and would be disposed of after an arc exposure, and therefore not requiring additional performance properties for use in increased stress environments. To date, this has slowed regulatory standards bodies from setting seam requirements for this specific protective apparel category. This paper seeks to evaluate seam strength on six types of seams—representative of those used in protective clothing construction—sewn into panels of three types of fabrics (including one two-layer configuration) and tested in the standard arc exposure tests described in ASTM F-1959/1959M-14, Standard Test Method for Determining the Arc Rating of Materials for Clothing. Seams were evaluated for seam strength in accordance with ASTM D1683, Standard Test Method for Failure in Sewn Seams of Woven Apparel Fabrics, before and after arc exposure to compare the change in seam strength between FR and non-FR seams. Results showed that across all fabrics and seam configurations, no seams opened in an arc exposure. Breaking strength results, however, did reflect a greater decrease in seam strength after an arc exposure for non-FR thread seams compared with FR thread seams.

Author Information

Kirby, Jill
ArcWear, Louisville, KY, US
Hoagland, Hugh
ArcWear, Louisville, KY, US
Baitinger, William
ArcWear, Louisville, KY, US
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Pages: 31–39
DOI: 10.1520/STP162420190093
ISBN-EB: 978-0-8031-7695-9
ISBN-13: 978-0-8031-7694-2