The air filter sector suffers from the reliance on nonrenewable materials such as minerals and petroleum oil, thus a shift toward sustainable materials must be intensively researched. Synthetic biobased polymers provide comparable properties to the petroleum derived ones, thus may be explored as alternative materials with potentially lower impact to environment through the entire life cycle. At the same time, the current availability of suitable synthetic biobased polymers is rather narrow, while their properties are not tuned for filter production. This study aimed to produce filtering materials using four types of commercially available biobased polymers through the melt blowing technique, and to characterize their properties.

The following fully or partially biobased injection-grade polymers were tested: poly (butylene succinate) (NaturePlast SAS), polyamide (EMS-Chemie AG), polylactic acid (TotalEnergies Corbion Ltd.), polyhydroxyalkanoate (NaturePlast), and a polyhydroxyalkanoates/polylactic acid blend (NaturePlast). The granules of the polymers were fed via a single screw extruder to a 0.2 mm nozzle melt blowing die, where high-speed hot air converted the molten polymers into fine fibers, which were then collected on a rotating drum to form a micro-nanofibrous nonwovens. Filtration efficiency, pressure drop, and mechanical properties.

The tested polymers were able to form nonwoven materials that possessed suitable mechanical properties, except PHA, which produced brittle fibres that did not form a suitable nonwoven matrix. The morphology of fiber matrixes is presented in Figure 1, displaying a mixture of sub-micrometer and micrometer fibres. Melt blowing conditions were varied to achieve the set efficiency (ePM1>80%)...