Liquid transmission characteristics of padding bandages under pressure

This study investigates the in-plane fluid transport characteristics of needle-punched nonwoven padding bandages. It first reviewed the existing studies related to the problems, and discussed their limits and possible improvements in dealing with complex fluid transport issues in textile porous media. The measurement of fluid transport under different pressure levels was then done using a newly designed apparatus capable of simultaneously tracing the liquid in-plane spreading along different directions, and obtaining several transport characteristics of a testing sample, e.g. the liquid flow anisotropy, the rate of movement, the area of wet surface with time, etc. Also the effects of several important factors, such as the levels of pressure applied, the specimen bulk density, and needling density of the padding products, have been experimentally investigated. In addition, based on an extended Lucas–Washburn theory, we calculated the liquid flow distance, both instantaneous speed and a more useful time-averaged speed vav at any given direction, and also defined a flow anisotropy index IA as a convenient parameter to represent the material flow anisotropy. The applications of vav and IA to actual samples have demonstrated the usefulness of these parameters in characterizing the flow nature and behavior of the materials.
Source: Journal of Biomaterials Applications - Category: Materials Science Authors: Tags: Soft Tissues and Materials Source Type: research