In this work, a multifunctional polymer composite is made using melt-blowing technology from polypropylene (88 wt.%) and poly (ethylene terephthalate) (12 wt.%) with the addition of functional modifiers, that is, 3 g of a superabsorbent polymer and 5 g of a biocidal agent (Biohaloysite). The use of modifiers is aimed at obtaining adequate comfort when using the target respiratory protection equipment (RPE) in terms of microclimate in the breathing zone and protection against harmful aerosols including bioaerosols. The developed production method is innovative in that the two powdered modifiers are simultaneously applied in the stream of elementary polymeric fibers by two independent injection systems. Aerosols of the modifiers are supplied via a specially designed channel in the central segment of the die assembly, reducing the amount of materials used in the production process and saving energy. The results show that the proposed method of incorporating additives into the fiber structure did not adversely affect the protective and functional properties of the resulting filtration nonwovens. The produced nonwoven composites are characterized by SEM, FTIR, and differential scanning calorimetry (DSC). Given their high filtration efficiency at 5%, satisfactory airflow resistance (~200 Pa), very good antimicrobial activity, and excellent water absorption capacity, the obtained multifunctional nonwoven composites may be successfully used in filtering respiratory protective devices.

Filtering nonwovens loaded with activated carbon are among the most popular materials used in the construction of filtering facepiece respirators (FFRs) with anti-odour properties that can be used for respiratory protection at workplaces where the occupational exposure limits of harmful substances are not exceeded. Such FFRs, in addition to a polymer filter material of varying effectiveness, also contain a layer of activated-carbon-loaded nonwoven filter, which limits the quantity of chemical compounds entering the breathing zone. The aim of this work was to analyse the influence of challenge concentration (20–120 ppm), relative humidity (2–70%), flow rate (20–55 L/min), and flow pattern (steady-state and pulsating) on the breakthrough of polymer/carbon nonwovens. A commercial activated-carbon-loaded nonwoven filter was used in this study. Its morphology and textural parameters were determined using optical microscopy, image processing, and nitrogen adsorption/desorption measurements at 77 K. Breakthrough experiments were carried out using cyclohexane vapours to assess adsorption characteristics of polymer/carbon media. The results showed that the breakthrough times decreased with increasing challenge concentration (up to 30%), relative humidity (up to 73%), and flow rate (up to 72%). The pulsating flow pattern was found to be more favourable in terms of odour reduction efficiency (up to 30%). The results indicate that all of these factors should be considered during selection and performance assessment of respirators used for odour relief.

This study evaluated the bioactivity of polypropylene melt-blown filtering nonwovens used in respiratory protective devices (RPD) with a biocidal agent (alkylammonium microbiocides) on 2 mineral carriers. Two types of carriers were tested: a bentonite, with an aluminosilicate base, and a perlite, volcanic glass. High biostatic and biocidal effects of modified nonwovens with biocides were tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. Nonwovens modified with a biocide on a bentonite carrier showed an opposite reaction to a biocide on a perlite. The research also showed that 10% concentration of a biocidal agent on a perlite carrier was sufficient to inhibit the growth of bacteria (100% reduction) placed in the structure of a filtering material during normal use of RPD. A comparison of the biological activity of 2 filtering materials, each containing 10% of a perlite and produced in a laboratory and industrial conditions, showed no statistically significant differences.

The paper discusses the methods of modification of melt-blown polymer materials by the addition of a bactericidal agent or superabsorbent directly to the fibre-forming area during the melt-blown production process. It also presents tests of textile composites designed for use in selected types of personal protective equipment worn in the workplace. One example of the application of textile composites is the protective footwear insole. The insole composites contain specially developed variants of melt-blown nonwovens made from PP, PC, and PA fibres. Microbiological, hygienic, and mechanical tests have shown that the optimum insoles for all-rubber protective footwear are those made of bioactive composites containing a PC melt-blown nonwoven. Another example of composite application is the air-purifying half mask. Filter composites contain polymer nonwovens with the addition of different quantities of a superabsorbent. They have been tested for particle penetration, airflow resistance, and moisture sorption.

The paper presents a study of the protective and functional properties of nonwoven structures, such as penetration by solid and liquid aerosols, airflow resistance, and air moisture sorption capacity. Nonwovens were modified by the introduction of electrostatic charges in the structure of polymer fibers and by the addition of a superabsorbent polymeric (SAP) directly to the fiber-forming area in a melt-blown process. The resulting materials (outer nonwovens containing SAP of different grain sizes and filtering nonwovens with and without electrostatic charges) had varied morphological structures. The materials developed were characterised by high filtering efficiency at low airflow resistance and good moisture sorption ability. The study proved the possibility to apply nonwoven structures containing SAP in respiratory protective equipment used in harsh work environments at high temperature and relative humidity. The materials fabricated were found to improve hygienic comfort.

Toxicological research on the influence of noxious nanoparticles on human health indicates the need to develop efficient protective devices. In particular, this concerns respiratory protective equipment employing filtration nonwovens. This paper presents a methodology for the improvement of the filtration efficiency of electret nonwovens against nanoparticles by enriching amorphous polycarbonate (PC) with additives of different electrostatic potentials. We introduced perlite granules (positive charge) and amber granules (negative charge) to the polymer stream in melt-blown technology. Filtration efficiency was assessed by a standard method using paraffin oil and sodium chloride aerosol, as well as by a non-standard method using NaCl nanoparticles. The experiments showed that strengthening the effects of electrostatic forces by the introduction of modifiers is a promising approach to improving the efficiency of electret nonwovens against nanoparticles.