... shone on the bamboo charcoal yarn for 10 minutes, the yarn emits far infrared rays for 87% ~ 92%, and warm up the ... s with 5 oC.The bamboo charcoal powder is equally diffused in to the fiber structure and not a coating on the ... Bamboo fiber yarns are widely used in mattresses, pillows, mattress covers, sheets and underwear, shirts, warm clothing, health care apparel, socks, towels, etc. Bamboo yarn ...