3D-Printed Recyclable Polyolefin Aerogel Filter for Air Filtration

Innovative Thermoplastic Aerogel Filter Media for Air Filtration

In a groundbreaking endeavor, mechanically recyclable thermoplastic materials were harnessed to craft lightweight and highly efficient aerogel filter media for air filtration. Leveraging the fused filament fabrication (FFF) 3D printing technique, this project focuses on creating an all-polyolefin composite filter media.

The filter media comprises isotactic polypropylene (iPP) gyroid structure frameworks and high-density polyethylene (HDPE) aerogel infill. The utilization of 3D printing filaments, extruded from HDPE and PP blends, ensures printability and recyclability within the polyolefin waste circulation.

Aerogel Micromorphology and Structure

To enhance critical gelation concentration determination, various solid content ratios of HDPE aerogel were prepared. Aerogel micromorphology was scrutinized through porosity determination and Brunauerˆ’Emmettˆ’Teller (BET) nitrogen adsorption analysis, revealing lamellar platelets in the crystalline region of HDPE aerogel.

Investigating the infill density of 3D-printed iPP gyroid frameworks, the study delves into its impact on media strength and filtration properties. Compression tests demonstrate a remarkable improvement in compressive modulus, enhancing the overall efficiency of the filter media.

Filtration Efficiency and Standard Compliance

The developed all-polyolefin composite filter media exhibits superior filtration efficiency compared to commercial surgical masks, reaching the standard for high-efficiency particulate absorption (HEPA) filters. The smaller pore size and intricate air path contribute to this heightened efficiency.

The incorporation of up to 30% HDPE in PP blends without compatibilizers affirms proper 3D printability and minimal warpage, showcasing a sustainable approach to recycling waste polyolefin materials. This study unveils a plausible method for transforming discarded materials into value-added products through both melt and wet processing.

To learn more on this topic, attend ANTEC 2024 in St. Louis. Leyao Wu, Ph.D. Candidate, University of Akron will be presenting, “3D Printing Aided Fabrication of Recyclable Polyolefin Aerogel Composite Filter for Airborne Particle Filtration“, on Tuesday, March 5.