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Estimates of Thermal Conductivity for Unconditioned and Conditioned Materials Used in Fire Fighters' Protective Clothing .


pdf icon Estimates of Thermal Conductivity for Unconditioned and Conditioned Materials Used in Fire Fighters' Protective Clothing . (188 K)
Vettori, R. L.

NISTIR 7279; 33 p. November 2005.

Keywords:

protective clothing; fire fighters; thermal conductivity; heat transfer; test methods; thermal analysis; uncertainty

Abstract:

Fire fighters' protective clothing provides a limited amount of thermal protection from environmental exposures produced by fires. This level of thermal protection varies with the design, materials, construction, and fit of the protective garments. Limits of thermal protection may be analyzed using the thermophysical properties of garment materials. However, little information is currently available for analyzing and predicting protective garment thermal performance. To address this need, a research effort was begun to measure the thermal properties of fire fighters' protective clothing materials. This report presents thermal conductivity data for ten materials used in fabricating fire fighters' protective clothing. These materials included: (a) outer shell fabrics, (b) moisture barriers, and (c) thermal liner battings. The thermal conductivity data for each material was obtained twice. Once when the material was new and once after the material had undergone a conditioning process of five washings and dryings by a contract cleaner that specializes in cleaning, decontaminating and repair of fire fighters' protective clothing. The thermal conductivity of individual protective clothing materials was measured using the test procedure specified in ASTM C 518 Standard Test Method for Steady-State Thermal Transmission Properties by Means of Heat Flow Meter Apparatus. Measurements producing estimates of thermal conductivity for a single layer of materials were carried out at mean test temperatures of 20 DGC (68 DGF), 48 DGC (118 DGF), 55 DGC (131 DGF), and 72 DGC (162 DGF). No visible physical changes were observed with any of the materials tested at these temperatures. For unconditioned materials, the thermal conductivity estimates ranged from 0.034 W/m K to 0.093 W/m K. For the conditioned materials the thermal conductivity estimates ranged from 0.033 W/m K to 0.089 W/m K. Thermal conductivity values increased for all materials as mean test temperatures were increased.