Air-through bonding is a thermal bonding method in which fibers are bonded together using hot air. The fiber web formed in the carding line and layered by the crosslapper is prepared with special low-melting-point bonding fibers. This fiber web is then passed through a dedicated oven where hot air flows through the fabric structure.

The hot air softens the low-melting fibers, allowing them to bond with the surrounding fibers. During the cooling stage, these fibers solidify again, creating a strong yet bulky structure. This method achieves bonding without damaging the fiber structure, resulting in high-loft, soft, and flexible nonwoven fabrics.