Why We Need the Thermal Conductivity Test?

When wearing clothes in cold or hot climates, the temperature of clothing, especially close-fitting, varies with the temperature of the skin. People should choose suitable clothes to ensure comfort, or at least in adverse weather conditions to protect the human body. The thermal conductivity of fabrics can ensure the comfort of clothing, for example, the clothing with high thermal resistance from thermal conductivity has a better function of preventing cold, while the clothes with low thermal conductivity rating can give a cool feeling. Therefore, testing the thermal resistance of materials(fabrics) has an important reference significance for improving people’s clothing comfort.

Thermal Resistance Test Principle

The thermal conductivity equipment produced by our company adopts the flat plate fabric insulation method. Place the sample to be tested on an electric hot plate, transfer heat to an electric heating plate so that make it reaches constant temperature state, and test the heat needed to maintain the constant temperature of an electric heating plate. This method has been adopted by ASTM as the standard number ASTM D1518.

Testing Method for Thermal Resistance of Fabric

How to test thermal conductivity? At present, there are many methods and thermal conductivity test equipment to measure the thermal resistance of textiles, there are three kinds of commonly used heat resistance test methods.

Tubular fabric insulation method: use the thermal testing equipment, when testing, wrap the sample on the sample holder and cover it with a cover. Cooling and heat dissipation after heating the tube for a period of time. The data and process are controlled by a computer, the moisture retention rate and the thermal resistance can be obtained directly.

Flat plate fabric insulation method: use the conductivity tester, the flat plate insulation instrument consists of an experimental plate, protective plate, bottom plate, plexiglass cover, temperature sensor and an open door to form a constant temperature difference environment. During the test, place the samples on the test plate, testing the external heat needed to maintain the experimental plate in unit time. From this, the moisture retention rate, heat transfer coefficient and thermal resistance of the fabric were calculated.

Cooling rate method: also called the cooling method, use the thermal conductivity measuring instrument. During the test, cut off the power when the sample is heated to a certain temperature, let the sample cool naturally only through the cover of the fabric without heat supply, evaluate the heat transfer property of the fabric by the time taken for cooling.