Apparel – Guard or protector – Body cover
Reexamination Certificate
2000-03-03
2002-08-13
Calvert, John J. (Department: 3741)
Apparel
Guard or protector
Body cover
C002S081000, C002S087000, C002S093000, C002S022000
Reexamination Certificate
active
06430754
ABSTRACT:
BACKGROUND
The present invention relates to hazardous duty garments and, more particularly, to lightweight firefighting garments that protect a wearer from extreme ambient conditions.
Protective garments are designed to shield a wearer from a variety of environmental hazards, and firefighting garments are representative of such garments. A conventional firefighting ensemble comprises a turnout coat and pant, each of which includes an outer shell, a moisture barrier located within the outer shell, a thermal liner located within the moisture barrier and an innermost face cloth layer. The outer shell typically is constructed of an abrasion-, flame- and heat-resistant material such as a woven aramid material, typically NOMEX or KEVLAR (both are trademarks of E. I. DuPont de Nemours & Co., Inc.) or a polybenzamidazole such a PBI (a trademark of Celanese Corp.) fiber material. The moisture barrier typically includes a semipermeable membrane layer which is moisture vapor permeable but impermeable to liquid moisture, such as CROSSTECH (a trademark of W. L. Gore & Associates, Inc.). The membrane layer is bonded to a substrate of high flame- and heat-resistant material, such as an aramid or PBI material.
As defined in the N.F.P.A. Standard for Protective Ensemble for Structural Firefighting, 1997 ed., the firefighting garment will include three types of seams: Major A Seams, Major B Seams and Major Seams. Major A Seams are the outer shell layer seam assemblies where a rupture of the seam could reduce protection of the garment by exposing the inner layers of the garment (such as the moisture barrier or thermal liner), the wearer's station/work uniform, other clothing or skin. The Major A Seam must have a seam strength equal to or greater than 675 N (150 lbf). Major B Seams are moisture barrier or thermal barrier seam assemblies where a rupture of the seam could reduce protection of the garment by exposing the next inner layer of the garment, the wearer's station/work uniform, other clothing or skin. The Major B Seam must have a seam strength equal to or greater than 337.5 N (75 lbf). Major Seams are seam assemblies not classified as Major A or Major B Seams and must have a seam strength equal to or greater than 180 N (40 lbf).
The thermal liner is typically positioned within the moisture barrier in order to prevent the thermal liner from soaking up liquid moisture flowing through the outer shell from the ambient. The thermal liner typically comprises a layer of insulation material, such as a relatively thick layer of aramid fiber batting or needlepunch, which is often quilted to a lightweight aramid fabric substrate or face cloth. The batting of the thermal barrier traps air and possesses sufficient loft to provide the necessary thermal resistance, and the fabric substrate protects the batting of the thermal liner from abrasion from the wearer.
The aforementioned components typically are arranged within the garment so that the moisture barrier layer is positioned between the thermal liner and the outer shell. This is necessary to prevent the insulating material of the thermal liner from absorbing an excessive amount of liquid moisture from the ambient, which increases the overall weight of the garment and reduces breathability of the thermal liner, thereby increasing the stress imposed by the garment on the wearer, and reduces its loft and thermal resistance characteristics. However, one disadvantage with such an arrangement is that the laminated membrane of the moisture barrier is relatively delicate and can be damaged by heat, abrasion or puncture. Such damage results in increased exposure of the thermal liner to liquid moisture, which increases liquid moisture absorption.
Another disadvantage inherent in such an arrangement is that the moisture barrier layer adds to the bulk and weight of the garment and inhibits freedom of movement of the wearer, producing a “hobbling effect,” increasing the stress imposed on the wearer in situations requiring high activity, and accelerates the onset of fatigue. Furthermore, with such an ensemble some perspiration from the wearer is absorbed by the thermal liner. Moreover, the combination of a discrete moisture barrier and thermal liner limits breathability, especially if the thermal liner is positioned within the moisture barrier.
Additionally, many conventional firefighting garments are designed such that their thermal liner, while positioned within the moisture barrier, actually promotes the absorption of fluids, such as a firefighter's perspiration. While such a garment may provide the firefighter short term comfort by keeping the firefighter's skin relatively dry, in the long term, such a thermal liner will tend to lose its insulating characteristics (much like a wet pot-holder) because moisture conducts heat energy better than air.
Accordingly, there is a need for a protective garment in which the susceptibility of the thermal liner to absorption of perspiration moisture and other moisture is minimized; a protective garment which is relatively thin and lightweight, yet provides adequate thermal protection; a protective garment which is inherently able to withstand a temperature of 500° F. for at least five minutes without igniting, melting or dripping, making it suitable for use as a firefighting garment; and a protective garment which minimizes the restriction of movement and hobbling effect characteristic of conventional firefighting garments.
SUMMARY
The present invention is a protective garment, such as a firefighting garment, that is relatively thin and light weight. The garment possesses relatively high resistance to liquid water absorption, yet also possesses high THL (Total Heat Loss) characteristics as tested with the guarded sweating hotplate test under the N.F.P.A. (National Fire Protection Association) 1971 Standard on Protective Ensemble for Fire Fighting, 2000 edition (higher THL translates into high moisture vapor transport characteristics). The garment of the present invention includes an outer shell; a thermal liner positioned within the outer shell; a moisture barrier positioned within the thermal liner and a face cloth positioned within the moisture barrier. The thermal liner is batting, knit, spunlace, woven textile or other suitable construction of a high heat and flame resistant material (such as an aramid or PBI material, or combinations thereof) that is treated with a durable, water repellant finish to minimize liquid moisture absorption by the thermal liner. Despite the liquid moisture absorption resistance imparted onto the thermal liner by the finish, the thermal liner still retains excellent moisture vapor transport characteristics. Suitable durable, water repellant finishes may be provided by treating the thermal liner with a commercially available perfluorohydrocarbon finish, such as TEFLON (a trademark of E. I. DuPont de Nemours & Co., Inc.) and/or SCOTCHGUARD (a trademark of Minnesota Mining & Manufacturing Company). By positioning the treated thermal liner between the outer shell and the moisture barrier, the moisture barrier is protected from damage due to excessive heat from the ambient and from abrasion and wear caused by the outer shell. Additionally, by orienting the moisture barrier within the thermal barrier, the TPP (thermal protection property) of the garment is substantially increased. This allows for the reduction in the overall thickness and weight of the thermal liner throughout the garment as will be seen in the several exemplary embodiments of the invention described herein.
One exemplary embodiment of the present invention is a protective garment, such as a firefighting garment, that includes an outer shell of abrasion, flame and heat resistant material; a thermal liner positioned within the outer shell that includes at least one layer of insulating material treated with a durable, water repellant finish; a moisture barrier positioned within the thermal barrier and a face cloth positioned within the moisture barrier. The thermal barrier may consist of one or more layers of hi
Aldridge Donald
Taylor Frank P.
Calvert John J.
Lion Apparel, Inc.
Muromoto Jr. Robert H.
Thompwon Hine LLP
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