US Patent 10130527 Absorbent cores having material free areas

An absorbent core (28), for use in an absorbent article, comprising a core wrap (16, 16′) enclosing an absorbent material (60) comprising superabsorbent polymer particles. The core wrap comprises a top side (16) and a bottom side (16′), and the absorbent core comprises one or more area(s) (26) substantially free of absorbent material through which the top side of the core wrap is attached to the bottom side of the core wrap, so that when the absorbent material swells the core wrap forms one or more channel(s) (26′) along the area(s) (26) substantially free of absorbent material. The superabsorbent polymer particles have a time to reach an uptake of 20 g/g (T20) of less than 240 s as measured according to the K(t) test method.