Water vapor transport through multilayer wound dressings

Abstract

Prediction on the base of analysis of the laws of moisture transfer the property of multilayer packages of wound dressing to carry out the transfer of drugs and metabolic fluids in such systems.In the course of experimental studies of penetration of moisture through the packages of wound coatings, in which in different variants of the arrangement of used samples with different raw material composition and density (nonwoven cotton fabrics and linen fabric), were determined parameters of distribution of the liquid and the dimensions of the wetted zone in the upper, lower and middle layers.It has been found that, starting with a certain thickness, most of the liquid accumulates within the package, which changes the general shape of the wetting zone. The surfaces of wetted zones for different package variants, which show a fairly pronounced maximum inside the material, are obtained. The analysis of the dynamics of the change of the wetted zone surface allowed to formulate the problem of determining the location of additional material in the multilayer wound covering. This gives the opportunity to accumulate the highest moisture content inside the material package, which improves the quality of wound dressings. A study on the effects of additional wetting in multi-layer packets of textile medical materials has revealed for the first time the effect of increasing the concentration of fluid inside such systems, which we called "paradox of internal concentration". This effect appear in the fact that at certain ratios of discrete environmental parameters, the maximum propagation of the liquid occurs not on the material surface, but at a certain depth, in the place of location of the material of high density. The appearance of the effect is determined by the parameter that binds the geometric properties of the material and the discrete parameters of the liquid passing. Practical significance. The investigated processes of wetting of multilayer dressing materials can be used to predict conditions of their real functioning, proceeding from the requirements of operational situation. This allows solving problems of durability of bandages. The criterion of longevity may be the prevention of the exhaust outlet to the surface or the restriction of the exhaust emission area on the outer surface of the wound dressing in certain volumes.