Air pollution represents a significant challenge because ultra fine particles can adversely affect the human body, particularly the respiratory and cardiovascular systems. In this context, the demand for air filtration systems using sustainable technologies based on renewable and recyclable resources has increased. Specifically, fibrous filtering media derived from biodegradable polymers, such as polylactic acid (PLA) and Lignin are promising, once they combine physical filtration mechanisms with active interactions with air contaminants.

The objective of this work is to develop new polymeric filter media through the solution blowing spinning (SBS) technique, an innovative method proposed as an alternative to electrospinning. SBS allows lower production costs, higher production rates, the ability to directly deposit fibers with improved sustainability. The processing conditions and physicochemical and morphological properties of the filter media were characterized to obtain an air filter media with higher collection efficiency and lower pressure drop. The polymeric solution was obtained by blending a 14 wt.% polymer solution in chloroform with a lignin solution prepared in N,N-dimethylformamide (DMF).

Lignin contents of 30 and 40 wt.% were evaluated to assess their influence on the process. SBS was performed at a solution flow rate of 8.5 mL·h⁻¹, applied pressure of 2 bar, a needle-to-collector distance of 23 cm, and a fixed solution volume of 20 mL. Three different support materials were employed: a stainless-steel grid, a PVC-coated fiberglass grid, and a 3D-printed polylactic acid (PLA) honeycomb.

Different supports yielded distinct filtration performances when using a formulation containing 30% lignin. The PVC-coated fiberglass grid exhibited the highest efficiency, approximately 82%, whereas the stainless-steel support showed substantially lower efficiency, decreasing to about 38%. These results