The Role of Crimped Fibers in High-Loft Nonwoven Top Sheets

The Mechanical Interlocking Mechanism

When crimped fibers are formed into a nonwoven web, their wavy shapes become entangled with one another. This mechanical interlocking is the key to the high-loft structure. Unlike straight fibers, which slide past each other under pressure, crimped fibers lock together and resist displacement. This interlocking creates a porous, resilient structure that can recover its original thickness after compression.

How Crimped Fibers Enhance Top Sheet Performance

• Loft (thickness): Crimped fibers increase the bulk of the nonwoven by up to 50–80% compared to straight fibers at the same basis weight. This loft provides a cushiony feel and improves liquid handling capacity.

• Compression recovery: The spring-like nature of crimped fibers allows the top sheet to recover its thickness after being compressed. This is critical because a top sheet that stays thick maintains its pore structure, allowing consistent liquid intake.

• Liquid strike-through: The high porosity created by the interlocking fiber network reduces resistance to fluid flow, allowing liquid to pass through more quickly.

• Resistance to wet collapse: Crimped fibers retain their structure even when wet, preventing the top sheet from matting down. This maintains a gap between the skin and the wet core, reducing rewet.