Measuring Thermal Effusivity of Fabrics with ASTM D7984

 

C-Therm’s MTPS technique was recently adopted as global standard for characterizing thermal performance of textiles.  Learn more about the standard and application of the MTPS method in characterizing the thermal effusivity of textiles and apparel.  Thermal effusivity, also described as thermal inertia, describes a materials ability to exchange heat with its surroundings or other materials with which it is in contact. Measuring the thermal effusivity of fabrics reveals the rate at which fabric absorbs heat when it comes in contact with skin.  ASTM International recently developed the new test method in Subcommittee D13.51 Conditioning, Chemical and Thermal Properties, part of ASTM Committee D13 on Textiles.  The standard is titled, ASTM D7984 Test Method for Measurement of Thermal Effusivity of Fabrics Using a Guarded Modified Transient Plane Source (MTPS) Instrument.  Shannon Yawney, a research analyst in product innovation at Mark’s, led the effort and explains that “when a textile is tested to the proposed method, a low thermal effusivity rate will indicate that a fabric is slow to absorb heat.  To relate that to apparel, a fabric with a low thermal effusivity would feel warmer to the initial touch and would be slower to transfer heat away from the body, keeping you warmer”.  Yawney will be joining C-Therm representatives as a guest speaker on  a special upcoming webinar explaining further the application of the MTPS method in characterizing textiles and the significance of effusivity in assessing apparel performance.