TIL is equipped with the Skin Model, to determine the comfort of fabrics and clothing

Clothing represents one of the determining factors in generating the sensation of thermal and hygrometric comfort.

In particular, three distinct functions can be attributed to clothing:

– thermal insulation

– barrier to vapor transpiration

– thermoregulation mechanism.

In order to objectively determine the thermo-hygrometric comfort of clothing items, it is necessary to determine the thermal resistance (Rct) and evaporative resistance (Ret).

In order to be able to provide this important analytical service, the TIL laboratory has equipped itself with the Skin Model (Sweating Guarded Hotplate).

This equipment in fact allows you to carry out tests relating to the determination of the two fundamental parameters already described: the Ret and the Rct, both materials relating to clothing used in sports, but also for underwear and for work uniforms and military.

The evaporative resistance Ret (Resistance to Evaporative Heat Transfer) measures the breathability of a fabric, i.e. its ability to be crossed by humid air

and is expressed in Pa*m2/W. In practice, this parameter indicates the breathability value which is made up of the quantity of water vapor that manages to pass through a square meter of fabric in 24 hours.

Breathability can be related to the porosity of the material, as the greater the breathability of a material, the lower the possibility of condensation being generated on the surface of the material itself. In fact, the greater the breathability of a fabric

the greater the ease with which the humidity generated by the human body is removed from the surface of the skin, thus increasing the feeling of comfort.

The Ret values can be grouped into a scale where the lower values correspond to the better breathability performance of the textile materials.

The thermal resistance of clothing (Rct) represents the resistance to the heat flow generated by the clothing and the layer of air placed between the fabric and the skin. In the international system, thermal resistance is expressed in m 2 K/W, although it is often described with an inconsistent unit of measurement, the “clo” (1 clo = 0.155 m 2 K/W).

The average Rct value generally refers to the entire body covered by the item of clothing and obviously also takes into account the uncovered parts, such as the head and hands.

For the evaluation of comfort, a value of Icl = 0.5 clo for the summer period and Icl = 1 clo for the winter period can be assigned, by convention. The Icl value of the naked body is = 0.