text: This invention relates to bandages and bandage materials. More particularly, this invention relates to self adhesive, air permeable, water impermeable bandages.
  Self-adhesive wound dressings or bandages are generally composed of a backing sheet, an absorbent material, and an adhesive material. The backing sheet serves as a protective barrier preventing mechanical and foreign particle irritation of the wound or other area of the skin adversely affected by injury, disease or the like. The backing sheet further serves as a mechanical support for the absorbent material. Finally, ideally the backing sheet does not inhibit healing by preventing air flow to and from the wound. The ingress and egress of air from the site hinders the creation of a stagnant healing atmosphere which would result in a localized unsanitary condition. This last function is often at odds with the first two functions mentioned because in order to have adequate mechanical support and protective coverage, prior art devices are constructed in a manner which inhibits air permeability. In the alternative, air flow is emphasized to the detriment of protective action and mechanical support. This is seen in the well known prior art wherein the backing material is perforated to achieve gas flow, yet only limited hydrostatic resistance is offered.
  The absorbent material in prior art bandages serves to absorb wound discharge. The fastening means is usually adhesive and it serves to retain the bandage at the application site or wound. Note that the absorbent material is not necessary for all applications of bandaging material. For example, in a situation where visual inspection of a wound is important and bodily fluids are not secreted to the extent that an absorbent gauze is necessary, a transparent membrane having the feature of gas permeability and yet offering adequate protection of the wound site is desirable.