Full Description

This method determines the rate of heat flow (heat flux) from a warm, dry. constant-temperature flat plate (denoted here as the hot plate) through the dry specimens of textile fabrics, battings, and other textile materials due to the combined action of heat conduction and radiation. Two test procedures may be used to perform the measurement of heat flux, either:

Procedure 1: through both the test specimen and the standard still-air layer; the specimen is in contact with the hot plate and the air layer which is situated between the specimen and the cold plate, see Figure 1.

or

Procedure 2: through the test specimen alone, when it is placed in contact with both metal plates, see Figure 2.

To test textile fabrics with thicknesses less than 3 mm, one must use Procedure 1. Thicker fabrics, battings, quilts or layered fabric assemblies may be tested either with Procedure 1 or with Procedure 2. The main difference between these two procedures is the presence of the air layer on the cold side of the fabric. This air layer, in addition to providing a standard resistance needed to increase the precision of a thin fabric test, permits the examination of the radiative heat exchange across the air layer and the influence of the surface emittance of the fabric.

This method is limited to determination of the heat flux through specimens of fabrics, layered fabric assemblies, and battings having thermal resistance and thicknesses as follows:

a. for Procedure 1: thermal resistance 0.05 to 1.5 m²*K/W, thickness not in excess of 50 mm; and
b. for Procedure 2: thermal resistance 0.10 to 1.5 m^2*K/W, thickness in the range of 3 to 50 mm.

If the measured heat flux will be used for determination of the thermal resistance (or its inverse: thermal conductance), the specimens must meet the following conditions:

The specimen should be homogeneous and the portion of the specimen over the test area should be typical of the whole specimen in every aspect.

Non-homogeneous samples such as quilted fabrics may be tested if several tests are made with the quilt lines in different positions to average out the effect of non-uniform insulation (Note 1). The testing and evaluation of a product against this method may require the use of materials and/or equipment that could be hazardous. This document does not purport to address all the safety aspects associated with its use. Anyone using this method has the responsibility to consult the appropriate authorities and to establish appropriate health and safety practices in conjunction with any existing applicable regulatory requirements prior to its use.