in the preferred embodiment , wound dressing 1 of the present invention comprises a transparent polymeric covering layer 10 having an adhesive layer or surface 15 on one side thereof ( fig1 ). the adhesive surface is normally protected by a release liner , comprising a pair of release liner main bodies 30 each hingedly joined to a release liner edge strip 20 by means of a flexible hinge tape 50 ( fig1 ). polymeric film 10 can be any of the various polymeric films used in breathable wound coverings . polyurethene film is one commonly used material . copolyester film is used . such films typically have thicknesses of from about 0 . 0005 inches to about 0 . 0015 inches for purposes of use in wound coverings . the adhesive material 15 applied to polymeric film 10 is a conventional wound covering adhesive . many different materials are available to those skilled in the art , most having proprietary formulas . acrylic adhesives are operable . such adhesives are usually applied to a thickness of from about 0 . 001 to about 0 . 0025 inches . it is desirable that adhesive layer 19 be sufficiently thin that the wound can breathe through the adhesive material and through polymeric film 10 . release liner edge strip 20 and release liner main body 30 can be a conventional smooth surface paper material of the type typically used for release liners . such liners typically comprise a heavyweight white paper coated on both sides with polyethylene for dimensional stability . one side of the liner is overcoated with a silicone release coating to permit ready separation of the adhesive coated film 10 from the liners 20 , 30 . release liner 20 , 30 is sufficiently thick to give some body to wound dressing 1 and make it easier to handle . release liners typically have thickness of from about 0 . 004 to about 0 . 0075 inches . each release liner edge strip is located adjacent an edge of covering layer 10 and extends inwardly therefrom a short distance , as for example from about one - quarter to about three - quarters of an inch . one - half inch is probably applicable in dressings of most sizes . release liner edge strips 20 are located opposite one another at opposite edges of covering layer 10 . each release liner main body 30 overlaps its adjacent release liner edge strip 20 by a short distance at its outside end 31 ( fig1 ). the length of overlap is from about one - sixteenth to about one - eighth of an inch . this overlap insures that flexible hinge tape 50 will not directly engage release liner edge strip 20 at its inside edge 21 . this in turn minimizes the chances that one will continue to peel release liner edge strips 20 back after main bodies 30 have been peeled back . release liner main bodies 30 overlap one another at the center of wound dressing 1 in a plow fold arrangement . one of the release liners 30 is folded back on itself to define a flap 32 . a portion 33 of the other release liner half 30 then overlaps flap 32 . this makes it easy for one to grasp the inside edges of release liner main bodies 30 to begin peeling them away from covering layer 10 . hinge strips 50 are relatively narrow , i . e ., from about three - eighths to five - eighths of an inch wide . each is aligned so that it adheres both to a portion of release liner edge strip 20 and release liner main body 30 ( fig1 and 2 ). hinge strips 50 are commercially available plastic film tapes commonly referred to as splicing tapes . it is presently preferred that the tapes be a 1 mil thickness polyester film with a silicone rubber adhesive applied to one side . the tape has a total thickness with adhesive of 2 . 5 mils , a tensile strength of 25 pounds per inch , an adhesion to steel of 35 ounces per inch and a tack level of 5 . 4 . one such tape is available from the kendall company , polyken division , boston , mass ., under the designation plastic film tapes , tape no . 781 . such splicing tapes are designed for splicing silicone coated materials and hence adhere readily to the nonsilicone coated sides of liners 20 , 30 . to use wound dressing 1 , the user first grasps release liner main bodies 30 at their inside edge portions 32 and 33 respectively ( fig3 ). as the user peels back release liner main bodies 30 , they are eventually peeled completely away from the adhesive surface 15 of wound covering layer 10 . at this point , flexible hinges 50 simply fold back as illustrated in fig3 . as a result , no continuing peeling force is being applied to the inside edges 21 of release liner edge strips 20 . there is thus much less tendency for release liner edge strips 20 to peel away from covering layer 10 . this enables one to readily manipulate wound covering layer 10 by pulling slightly on release liner main body portions 30 . the user does not need to worry about release liner edge strips peeling away from wound covering layer 10 . wound covering layer 10 can be manipulated into position over the wound , as for example on an arm 2 as shown in fig3 and 4 . once wound covering layer 10 has been patted gently in place so it adheres to the substrate to which it is to be applied , one can effect separation of release liner edge strips 20 from wound covering layer 10 in the manner shown in fig4 . basically , one folds release liner edge strip 20 over onto covering layer 10 , while at the same time continuing to pull on release liner main body 30 ( fig4 ). as release liner edge strip 20 is forced over in the direction of wound covering layer 10 , a peeling force is eventually applied along the inside edge 21 of edge strip 20 so that it is peeled away from covering layer 10 . of course , it is understood that the foregoing is a preferred embodiment of the invention and that various changes and alterations can be made without departing from the spirit and broader aspects thereof as set forth in the appended claims .
the specification discloses a wound dressing in which the release liner halves are each divided into a release liner main body and a release liner edge strip . the release liner main body overlaps a portion of the edge strip and the two are hingedly secured together by a flexible hinge .