A strip of fabric hangs with its end in liquid, and the height reached after a fixed time is recorded in each direction. Wicking depends on fiber wettability, pore size and fiber orientation, so carded webs usually wick faster in MD. Absorbent and acquisition layers need good wicking to spread liquid, while barrier layers are designed to resist it.
MD wicking is 40 millimeters but CD is only 15, so the fluid runs straight to the ends of the pad.
Also heard as
- capillary rise
- wick
Related terms
Absorbency
How much liquid a nonwoven takes up and how fast, usually reported as grams per gram and absorption time.
ADL
Acquisition distribution layer: the lofty layer under a diaper topsheet that takes in liquid and spreads it to the core.
MD
Machine direction: the direction a nonwoven travels through the line, along the length of the roll.