Thermal conductivity is a measure of how well a material conducts heat. It is typically expressed in watts per meter per kelvin (W/(m·K)). Different textile fibers have different thermal conductivities due to their unique physical and chemical properties. Here is a list of textile fibers and their approximate thermal conductivities:
- Wool: 0.04 W/(m·K)
- Cotton: 0.041 W/(m·K)
- Silk: 0.049 W/(m·K)
- Polyester: 0.2 W/(m·K)
- Nylon: 0.25 W/(m·K)
- Acrylic: 0.2 W/(m·K)
- Modacrylic: 0.2 W/(m·K)
- Aramid: 0.16 W/(m·K)
- Carbon: 150 W/(m·K)
- E-Glass: 1.3 W/(m·K)
Please note that these values are approximate and may vary slightly depending on the specific type of fiber, the processing method, and other factors. Thermal conductivity can also be affected by the presence of moisture, as water is a good conductor of heat.
For purpose of comparison, thermal conductivity of metals are listed below:
- Copper: 385 W/(m·K)
- Aluminum: 237 W/(m·K)
- Gold: 317 W/(m·K)
- Silver: 429 W/(m·K)
- Iron: 80 W/(m·K)
- Steel: 50 W/(m·K)
So then how do we use this information while designing products. Well, for an application which needs insulation or an insulating layer between two environments, you would use a fiber with poor thermal conductivity. So that would be wool.
It needs to be noted from our previous article on influence of fabric thickness on convective heat resistance of the flame retardant fabric (Read Here). That the overall fabric performance depends on other factors like, thickness, density and specific heat capacity of the fibers.
In the next article, we will look into the specific heat capacity of textile fibers.