Use of modified polymer fibre materials as filter elements for treatment of multiphase media

Abstract

Fibre materials manufactured with modern, environmentally clean, solution-free, meltblown technology are convenient and economical polymer filters. The method of manufacturing fibre materials for such filters can be introduced in polymer processing plants interested in implementing progressive technology and expanding the line of polymer fibres and commercial articles manufactured from them.Filtration of multiphase media -liquids or gases -is the unavoidable companion of many modern manufacturing processes. With respect to structural organization, polymer fibre materials have long been considered optimum filtration systems, so that they are used in the most varied sectors [1][2][3]. A number of promising versions of fibre filter elements based on melt blowing technology -aerodynamic spinning of fibres from melts of large-tonnage manufactured polyolefinshas now been developed [4,5]. The developments in creating polymer fibre filters in Belarus are gradually approaching industrial introduction [6].Liquids and gases are filtered directly on porous fibre filters under the effect of many mutually interrelated factors; the fundamental ones are the flow rate of the filtered dispersion medium, the concentration of disperse particles of contaminants in it, the shape and size of pores and channels in the porous fibre filter, and the intensity of interactions in the "contaminant particle-filter membrane" system. The presence of electric or magnetic fields of determined strength in the system, whose simultaneous effect on the contaminant particles can significantly increase the filtration efficiency, is especially important. In industrial separators, the fields are usually regenerated with powerful voltage sources. However, some varieties of porous polymer fibre filter materials have electrical and/or magnetic activity, so that using them as feed for filtration systems is expedient and economically justified [1][2][3]. For this reason, the search for progressive methods of modifying polymer fibre materials becomes pressing. There are two groups of such methods -incorporating active additives in the fibres and treating the fibres in electric or magnetic fields. Many studies have shown that it is useful to combine several methods of treating the fibres [4,5,7].Electrical treatment of the spun hot melt-blown fibres in a corona discharge field of varying strength is usually used to give filter materials electrical activity, and filling the fibres with magnets (usually barium or strontium ferrites) followed by treatment in pulsed magnetic fields is used to impart magnetic activity [1]. At the same time, it has repeatedly been noted [5,7] that the electret and magnetic properties become interconnected in such fibres. For this reason, we can hypothesize that composite fibre materials can exhibit combined -adsorption, electrical and magnetic -activity with respect to filtered multiphase media in contact with them [8].We demonstrated the possibilities of some varieties of polymer fibre filter elements obtained with melt blowing techn...