DEVELOPMENT OF MULTILAYER TEXTILE STRUCTURES FOR FILTERING APPLICATIONS – A NEW SURGICAL MASK APPROACH

Universal mask use has emerged as one of the main strategies for reducing community transmission of the SARS-COV-2 virus. Due to the scarcity of material to produce disposable surgical masks, the governmental strategy was oriented to the community masks, even though performance levels were still not the same. This study intended to develop a new generation of surgical masks with different warp knit structures, evaluating the potential of multilayer gradient performance. The assembling methodology was also considered by modifying flat-bed calendering process parameters and manipulating final structures into a new origami design concept, and the overall mask filtration performance was reviewed. The overlapping of monolayers increased the substrate resistance to air and water vapour permeability, also influencing the water molecule's adhesion. The introduction of the web allowed a better layer assembling during the flat-bad process. Moreover, the breathability and water vapour diffusion are compromised since the adhesive web with temperature tends to merge and occupy the empty spaces between the layers. Moving forward, calendared structures without a web proved to be the best approach, meeting the certification criteria for surgical masks level I and II.