English to French Law/Patents Medical: Health Care patent about dressings, bandages for skins wounds

In that context I dont understand the word "aperture" (orifices?)

.Composite sheet material comprising a sheet layer having apertures, an adhesive coating layer on said sheet layer having apertures....


Composite sheet material according to claim 1, characterised in that the sheet layer having apertures has a thickness ranging from about 0,01 mm to about 2 mm;