Hydrophilic dressing material in which a wound contact layer, having a sponge structure composed of multiple open cells and pores that make a tunnel from cell to cell, is laminated with a protective film
Inventors
Park, Jong-wook • Kim, Hyun-Jung • Kim, Kab-keun • Yoon, Doo-hee
Assignees
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Publication Number
US-7777091-B2
Publication Date
2010-08-17
Expiration Date
Abstract
The present invention relates to a polyurethane foam dressing material with improved moisturizing rate. More precisely, the present invention relates to a hydrophilic dressing material in which a wound contact layer (10) having a sponge structure composed of multiple open cells (12) and pores (15) passing through the cells (12) is laminated with a protective film (20). The lamination is characteristically performed at 150˜250° C. under a pressure of preferably 0.25˜1 kgf/cm2, the moisturizing rate of the wound contact layer (10) is 300˜1200% and the pore area (membrane opening) takes 10˜35% of the total cell area.The polyurethane foam dressing material of the present invention prevents the invasion of foreign materials, releases absorbed exudation after changing it into water vapor or arresting the absorbed exudation inside the foam to maintain constant moisturizing, has excellent exudation absorption capacity, has a wound healing effect resulting from not adhering to a wound, is easy to change, and enhances the wound healing effect by maintaining optimum moisturizing conditions resulting from the improved moisturizing rate.
Core Innovation
The invention relates to a method for preparing a two layer hydrophilic polyurethane foam dressing material with improved moisturizing rate. The method includes laminating a wound contact layer having a sponge structure with multiple open cells and pores passing through the cells, together with a protective film, while controlling the lamination conditions. The laminating is performed by heat-press at a temperature of 150 to 250°C under a pressure of 0.25 to 1 kgf/cm².
The wound contact layer is defined to achieve specific hydrophilic and porous characteristics. The wound contact layer has a moisturizing rate of 510 to 1050%, and the pore area takes 10 to 20% of the total cell area. The mean diameter of the open cells is 50 to 300 μm, and the mean diameter of the pores is 5 to 85 μm.
The method further specifies the ratio of the open cells to the wound contact layer as 30 to 50%, the density of the wound contact layer as 0.15 to 0.45 g/cm³, and the water absorptiveness as 700 to 1800 weight%. In addition, the dressing employs a protective film in combination with the sponge-structured wound contact layer.
Claims Coverage
The document includes one independent claim directed to a heat-press lamination method that produces a two-layer hydrophilic polyurethane foam dressing material, with six dependent claims refining specific formulation and protective-film features. The independent claim is centered on tuning foam morphology and hydration performance under defined lamination temperature and pressure.
Heat-press lamination of sponge-structured wound contact layer with protective film
A method comprising laminating a wound contact layer having a sponge structure composed of multiple open cells and pores passing through the cells, with a protective film at 150 to 250°C under a pressure of 0.25 to 1 kgf/cm², wherein the laminating is by heat-press.
Moisturizing rate and pore area fraction tuning for wound contact layer
The wound contact layer has a moisturizing rate of 510 to 1050% and the pore area takes 10 to 20% of the total cell area.
Controlled open-cell and pore diameters for sponge structure
The mean diameter of the open cells is 50 to 300 μm and the mean diameter of the pores is 5 to 85 μm.
Open-cell ratio and density defined for wound contact layer
The ratio of the open cells to the wound contact layer is 30 to 50%, and the wound contact layer has a density of 0.15 to 0.45 g/cm³.
High water absorptiveness for wound contact layer
The wound contact layer has a water absorptiveness of 700 to 1800 weight%.
Protective layer as a waterproof breather film with thickness
The protective layer is a waterproof breather film 10 to 300 μm thick laminated on the wound contact layer having a sponge structure.
Protective layer tensile strength and elongation ranges
The protective layer has a tensile strength of 45 to 700 kg and an elongation of 200 to 1,000%.
Surfactant selection for hydrophilic polyurethane foam formulation
The surfactant is one or more selected from ethyleneoxide/propyleneoxide copolymers and silicon-based surfactants.
Adjuvant selection including cell growth factors
The cell growth factor is one or more selected from PDGF, TGF-β, EGF, FGF and VEGF.
Overall, the claim set emphasizes heat-press lamination of a sponge-structured hydrophilic polyurethane foam wound contact layer to a protective film, with moisturizing rate and pore structure parameters defined, and with dependent claims further specifying protective-film type and selected surfactant and growth-factor features.
Stated Advantages
Improved moisturizing rate.
Non-adherence.
Exudate management.
Contamination resistance.
Improved moisturizing/humidity.
Accelerated healing.
Documented Applications
A hydrophilic polyurethane foam wound dressing having a two-layer structure with a sponge-like wound contact layer and a waterproof breather protective film, used as a wound dressing with improved moisturizing and wound-healing effects, supported by comparative examples and tests.
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