Flame-resistant cleanroom fabrics differ from traditional cleanroom fabrics in many ways. Because polyester tends to melt upon exposure to flame, cleanroom FR fabrics are made from filaments such as DuPont Nomex fiber. The Nomex filament for cleanroom applications is specifically engineered, and is not intended to shed fibers in the same manner as traditional Nomex. These fabrics must meet NFPA 70E ATPV ratings for arc flash protection while satisfying the stringent contamination-control requirements of the most demanding cleanroom environments.
Though destructive product testing demonstrates the PPE characteristics of these fabrics and garment systems, are they fit for stringent cleanroom use? One cleanroom laundry decided to find out. Extensive washing, drying, and particle and fiber testing were used to investigate whether cleanroom FR garments truly belong in a cleanroom gown room.
The initial belief at the inception of the trial was that the FR garments would shed relatively high amounts of both particles and fibers, and would shed somewhat more than the continuous-filament polyester garments. Though the FR garments did start off with elevated shedding, none of the trial garments exceeded the USL of the Class A classification of ASTM F51, or the Category 1 classifications of the Helmke Drum Tests. Additionally, repeated washing and drying demonstrated even less particle and fiber shedding – a pattern that is not atypical of polyester garments.
When compared with the polyester garments, the FR garments also performed well, showing comparable results during the trial. Though this trial fails to document the longevity and associated variables of continued processing to the perceived industry standard of 100 replicates for typical cleanroom garments, it does demonstrate that, at least at the outset, FR garments designed for cleanroom use do belong in the cleanroom.
This cleanroom tip was taken from “Employee Protection and Contamination Control … Contradiction in Terms?,” which appeared in the January 2013 issue of Controlled Environments.