Nonwoven filter materials made of polylactide and polypropylene with mineral filler

The purpose of this article is to explore the possibilities of producing nonwoven materials based on polylactic acid modified with a calcium carbonate-based filler and to analyze their properties. Polymer nonwoven materials made from high-flow polypropylene and thermoplastic polylactic acid were produced using the melt-blown method on a laboratory setup designed for creating polymer nonwoven materials. The distribution of fiber sizes based on their apparent diameter was studied using image analysis software applied to images obtained through optical microscopy. The images were captured using an MBS-10 microscope with 15x magnification, and their analysis was performed with the ImageJ software equipped with the specialized DiameterJ plugin. The particle retention capability of the nonwoven material was evaluated in an air environment using a test stand equipped with a Temtop PMD331 aerosol particle counter (ISO-21501). It has been experimentally confirmed that nonwoven materials made from composite polylactic acid and polypropylene can be successfully produced using equipment designed for polypropylene processing. Structural parameters of the fibers and their particle retention capabilities were analyzed. Samples of nonwoven materials made from polylactic acid exhibited an average fiber diameter that was 13 % smaller than that of polypropylene materials when both were modified with 15 % calcium carbonate-based filler. Additionally, PLA-based nonwoven materials demonstrated improved filtration efficiency and a reduction in average fiber diameter with the addition of up to 45 % calcium carbonate filler. It has been established that fibers of polylactic acid filled with calcium carbonate exhibit a higher number of intersections and a smaller apparent diameter, which contribute to the improved filtration properties of the materials. The technological conditions for processing polylactic acid modified with calcium carbonate have been determined, enabling the regulation of the structural characteristics of nonwoven materials across a wide range.