A study on the performances of filters used in dry air filtration

ABSTRACTM.Sc. ThesisA STUDY ON THE PERFORMANCES OF FILTERSUSED IN DRY AIR FILTRATIONGamze DOĞANAfyon Kocatepe UniversityGraduate School of Natural and Applied SciencesDepartment of Textile EngineeringSupervisor: Ph. D. Mevlüt TERCANFiltration is a common process in industrial applications. More attention is paid to textilebased filters because of their structures. Nonwovens frequently preferred in dry airfiltration applications. Structures of nonwovens allow depth filtration besides surfacefiltration and this gives adventage to nonwovens in air filtration applications. Theresearch work presented in this thesis focuses upon the needle-punched nonwovensproduced with and without reinforcerd material, with different needeling intensities.Besides woven reinforcing materials, needle-punched nonwoven with knittedreinforcing material was designed. Removing the disabilities of strength of filters in theusage was aimed. First, knowledge about filtration process, nonwoven filters andresearches in literature were presented. Moreover, details about the production of filtersused in this research were given. In this study, recycled polyester fiber was choosen asraw materials. Acrylic fiber was choosen as reinforcing materials. To evaluate theinfluences of needling intensity on the characteristics of nonwoven fabrics, fabricswere passed through the needling machine several times. Structural and physicalproperties determine the performances of filters, such as thickness, basis weight,breaking, tear and bursting strength and air permeability are measured. Furthermore,these physical properties are related to the dust holding efficiency, dust holdingcapacity and pressure drop. Finally, the variation of physical properties of producedfilters are examined comparatively with respect to reinforcing materials and needlingintensity.2006, 73 pagesKeywords: Filtration, filter media, needle punched nonwovens, dry air filtration,knitted reinforcing materialii