PECooX® Biodegradable Cooling Innerwear

Japanese summers combine extreme heat with high humidity, creating a “muggy” sensation where sweat cannot evaporate efficiently. This causes discomfort, skin irritation, and bacterial growth. Traditional cotton absorbs moisture but stays wet, while polyester wicks moisture but traps heat. The innerwear market needed a material that actively cools the skin while managing moisture in humid conditions.

High-Density Polyethylene possesses unique thermal properties: thermal conductivity 3-4x higher than cotton or polyester, creating instant cool-to-touch sensation. The material’s low specific heat capacity means it doesn’t retain body heat, while its hydrophobic nature prevents moisture absorption that causes fabric to feel clammy. Unlike conventional synthetics, HDPE is 100% biodegradable under industrial composting conditions, decomposing into water and CO2 without microplastic residue.

The 75D/48F specification was carefully selected for innerwear applications. The 48-filament count creates a soft, silky hand-feel essential for garments worn directly against skin, while 75 denier provides optimal balance between lightweight breathability and durability for daily wear. The fine filaments create microscopic air channels that enhance ventilation, allowing body heat to escape rapidly while the HDPE core continuously draws heat away from the skin surface.

Pure HDPE yarn was blended with functional fibers to create the ideal innerwear fabric: 60% PECooX HDPE for maximum cooling effect, 30% moisture-wicking polyester for sweat management, 10% elastane for stretch and body-hugging fit. This hybrid construction delivers instant cooling sensation upon skin contact, rapid moisture evaporation in humid conditions, comfortable 4-way stretch for active movement, and shape retention after repeated washing.