Polymeric sheets

Abstract

Polymeric sheets having on one or both sides a fabric texture and, optionally, a network of elongated channels in the interior of the structural framework of the sheets. In one embodiment, the sheets comprise a plurality of interbonded continuous polymeric ribs extending in a direction parallel to the plane of the sheets. These ribs impart a fabric texture to both sides of the sheets and define between them recessed portions on each surface of the sheets. The elongated channels extend throughout the ribs. The open area between the ribs can vary from zero to 60%. In another embodiment, the sheets have an ultra-thin, pinhole-free polymeric membrane on one side and a fabric texture on the other side. The sheets are useful as burn coverings where they serve as synthetic, temporary replacements for damaged or missing skin. The sheets have physiologic properties similar to human skin, excellent drapability characteristics, recessed portions which provide a reservoir for wound debris and, in certain embodiments, a dermal surface which permits wound adherence by fibroblastic ingrowth. Sheets having a fabric texture on each surface are prepared by (1) applying a polymer to a skeleton sheet having a fabric texture to form a layer of polymer at the surfaces of the skeleton sheet, (2) curing the applied polymer, and (3) treating the composite with a solvent which dissolves the skeleton sheet but not the polymer. Laminated sheets in which only one side has a fabric texture are prepared by (1) applying one or more layers of polymer to a support surface, (2) partially embedding a sheet having a fabric texture in the layer of polymer, (3) curing the polymer to form a composite of the sheet and polymer, and (4) separating the composite from the forming surface. All or a portion of the embedded sheet optionally can be removed by treating the composite with a solvent which dissolves all or part of the embedded sheet but not the polymer. Non-laminated sheets in which only one side has a fabric texture are prepared by (1) applying a skeleton sheet having a fabric texture to a backing surface, (2) applying a polymer to the skeleton sheet, while it is against the backing surface, to form a layer of polymer at the surfaces of the skeleton sheet and a thin membrane layer of polymer between the skeleton sheet and the backing surface, (3) curing the polymer, and (4) separating the sheet of cured polymer containing the sheet of fabric texture from the backing surface. All or a portion of the sheet of fabric texture optionally can be removed by treating the sheet with a solvent which dissolves all or part of the sheet but not the polymer.