FUNCTION / Thermal Insulation
Thermal Insulation Fabrics

Thermal insulation fabrics can keep body warm in the cold day. There are two kinds of thermal insulation fabrics.  One is fleece that is brushed treatment and it reduce air convection between fibers. Reducing air convection will cut off the cold air to take heat away from human body and keep warm. The other one is fabric with nanoparticles.  The nanoparticles can absorb light eneygy from solar and transform it to heat and store them. Then release the heat slowly to human body to make warm.


AIR LAYER designed fabrics reduce air convection between fibers. Reducing air convection will cut off the cold air to take heat away from human body and keep warm. ASIA FIT new knit technology engineered to keep warm and reduce microfiber shedding. By encapsulating lofted fibers within a multilayer, continuous yarn fabric construction, this new technology offers an air layer to advance thermal insulation efficiency and help to reduce the ocean microfiber plastic pollution.

The Rct value defines the thermal resistance of a material. Thermal resistance is to prevent heat loss, simulating the thermal resistance of the human body under stable conditions, covering the heat transfer performance of radiation, convection and conduction, thus effectively measuring the thermal resistance of the textile. It is measured with the sweating guarded hotplate. The higher the Rct value, the better the thermal insulation properties and the less heat is lost.
The unit of Rct is m²‧K / W, and the Rct value can be converted to the Clo value as follow:
1 Clo = Rct/0.155
The definition of Clo: At temperature as 21°C, relative humidity as 50%, airflow as 10 cm / s, when a person wearing his clothing feels comfortable when sitting still in a refreshing and comfortable state and keeps his body surface temperature at 33°C, then the Clo value of this clothing is 1. The Clo value is used to indicate the thermal insulation properties of the fabric, that is, the thermal impedance unit from the surface of the skin to the out layer of the garment. Fundamentally, it is possible to sum up the clo values of various layers to a total clo value of the clothing system.
Below numbers are estimated clo values to be considered for the specific end use:
Graphene Textiles

Graphene is a two-dimensional material with one carbon atom thickness and a hexagonal planar film composed of carbon atoms. At present, it is the thinnest and hardest nanomaterial in the world. It is almost completely transparent and absorbs only 2.3% of light. The thermal conductivity is as high as 5300 W / m · K, which is higher than nano carbon tubes and diamond. Graphene polyester fiber combines uniform heat conduction, low-temperature far-infrared, and anti-static functions.
Due to the excellent thermal conductivity of graphene, the body surface temperature covered by clothing quickly reaches a balanced uniform temperature state. In addition, under the condition of 25 ° C, the average emissivity rate of far-infrared light with a wavelength of 6-14 microns is high, reach to 90%. Thus, the surface temperature of the skin is increased, the capillaries are dilated, and blood microcirculation is enhanced.
Graphene can quickly absorb the moisture and sweat from the human skin, and quickly introduce it into the air to distribute it, giving the body a dry and care. At the same time, the graphene fiber material can reduce the surface resistivity of the human body and achieve the effect of antistatic.

Thermal Effusivity of Fabrics

ASTM D7984 test method measures the rate of thermal transport between a heating element and a fabric specimen. Some of the comfort properties of a garment relate to initial thermal sensations (that is, cold or warm feeling upon initial contact), where lower thermal effusivity values indicate sensations of warmth and higher values indicate sensations of coolness.
However, since this test method is mainly based on the analysis of the thermal properties of the fabric material. For fabrics that achieve thermal insulation through structural design, the test results have some deviations, making it difficult to evaluate the overall thermal insulation characteristics of the finished fabric. For example, a fabric with an air layer, such as a fleece finishing polyester fabric, its test result will occasionally be no significant difference with the plain woven of the same material.


Generating heat textiles by moisture absorption is the material of clothing that absorbs the water vapor that escapes from the surface of the human skin, and the sweat that turns into a liquid is absorbed in the clothing fibers. The process from moisture to liquid water is a dynamic conversion of kinetic energy, thus releasing heat, So that the skin can feel the heat.
ASIA FIT generating heat fiber (polyacrylate), which has higher moisture absorption than wool, Rayon, and cotton, can quickly absorb sweat and convert it into heat energy, has the effect of adjusting temperature and humidity. It can keep warm and dehumidify quickly, keep warm and breathable without being stuffy, provide a considerate and comfortable feeling for skin.