The Warmth that Surpasses Down: Mizuno's "Techfill Breath Thermo" Is Amazing!

While down is lightweight and warm, it significantly loses loft and insulation properties when wet. When wearing cold-weather gear that uses synthetic down (chemical fiber down), the insulation remains relatively unaffected compared to down. This type of material is resilient against infiltration from rain or sweat, although its normal insulating performance is slightly inferior to that of down. Traditionally, it was understood that down and synthetic down have their respective advantages and disadvantages.
 
However, surprisingly, the synthetic down wear that "Mizuno" is set to unveil in autumn 2024 not only maintains better insulation when wet from rain or sweat but is also warmer than down in normal conditions. The arrival of outerwear that is consistently warmer than down is groundbreaking. Thus, I visited Mizuno Corporation and spoke with Hiroki Sakurai from the Global Apparel Product Division about the "Techfill Breath Thermo Insulated Coat" in detail.

Layers of Ultra-Thin Synthetic Down Resembling Waterfowl Feathers with Water Resistance to Enhance Insulation

Upon wearing it, the coat is light and warm. Could this warmth be attributed to Mizuno's renowned heat-generating material "Breath Thermo"? It seems a bit premature to notice a difference from the moment you put it on, considering the moisture-absorption heat-generating properties of the "Breath Thermo" material...
 
"The new functional material 'Techfill Breath Thermo' provides excellent synthetic down that surpasses down's warmth even without considering the heat-generating effect. Furthermore, it has the ability to convert moisture from the body into heat, enabling you to feel even warmer while wearing it.
 
"In many cases, insulated garments that use synthetic down maintain warmth by placing sheet-like down between the exterior and lining of the garment. The CLO value (thermal insulation value) is used as an indicator of warmth, with a higher CLO value indicating a warmer garment. It is generally known that down has a higher CLO value than synthetic down."
 
When wet, down loses loft and substantially lowers its CLO value, whereas synthetic down remains relatively unaffected. This has been the typical relationship between down and synthetic down. Mizuno has reportedly made significant efforts, including experiments in the "Environmental Testing Laboratory" at its Osaka research and development facility "Mizuno Engine," to incorporate down's advantages into synthetic down.
 
"By referencing down, we have successfully developed the synthetic material 'Techfill Breath Thermo' with unique improvements applied to sheet-like down to ensure its insulation performance surpasses that of down in normal conditions."