Characterisation of barrier properties of woven fabrics for surgical protective textiles

The pore morphology of textile filter structures is important for numerous technical applications. It determines the functional properties of surgical textiles, such as the effective barrier function and wearing comfort. Surgical and protective textiles must fulfil both of these contradictory functions. To date, basic research has not been successful, either theoretically or experimentally, in describing the complex correlation between the 3D pore structure of woven textiles and their barrier properties while simultaneously remaining permeable. In an attempt to clarify this issue, high density multi-filament woven textiles were categorised according to their geometry, pore morphology, permeability and retention properties by virtual modelling of their 3D pore morphology. Differentiation was made between mesostructures (pores between the yarns) and microstructures (pores within the yarn itself). In this process it was possible to identify the influence of weaving parameters on the pore morphology and determine their resulting functional properties. Various new testing methods were developed and successfully implemented to characterise and evaluate the barrier properties. The experiments show that by selecting specific yarns and weave constructions, the permeability and woven structure can be positively influenced and adapted to fulfil a wide range of requirements. A major finding is that the permeability and retention properties of the weave can be independently controlled by choosing suitable machine parameters. Specifically, by varying the shed closing time a clear shift in the pore size distribution to smaller pore diameters can be achieved without altering the air permeability. A correlation between the construction and processing parameters and the 3D pore morphology of the woven textile was ascertained. The relation between the properties of a weave and the machine and construction parameters is extremely complex due to their interaction.