Ventilation insert

A ventilation insert for deposition in or on a textile, the ventilation insert comprising:

• a ply, which is at least partly covered by an absorbent material having a cross-linking degree from 4.7×10−5 to 1.9×10−1 and comprising ventilation apertures,
• wherein the exposure of the ply to a liquid causes at least some of the ventilation apertures to close by swelling of the absorbent material and evaporation of the liquid causes the closed ventilation apertures to reopen;
• and
• wherein the ply is obtained by a method comprising
• a) treating the ply including the ventilation apertures with a mixture comprising (i) an absorbent material precursor comprising polymerizable monomers or oligomers and a crosslinker, (ii) a wetting agent, and (iii) an initiator, wherein the wetting agent is admixed to adjust a DIN 55660 surface tension of the mixture to a range from 10 to 72 dyn, and
• b) polymerizing the monomers or oligomers to form the absorbent material and to form a fusional bond between the absorbent material and the ply,
• wherein the fusional bond comprises at least a regional attachment of the absorbent material to the ply.