Developing high-performance recycled nonwoven structures for safety footwear: A focus on perforation resistance

Abstract

In this work, the polyester waste, which comes from the cutting of anti-perforation insoles, was reused to produce new anti-perforation structures to be incorporated back into the company, thus creating a closed-loop circular economy. Nonwovens were produced by incorporating polyester waste and commercially recycled polyester in an 80:20 ratio, using the needle-punching technique. To increase the perforation resistance behavior of nonwoven, one of the two high performance fabrics were incorporated: basalt or aramid fiber fabric. These structures were manufactured by layers, interleaving nonwovens with layers of basalt/aramid fiber fabric, using needle-punching. Several parameters were studied to improve the perforation resistance of the structures: number of passes in the needle-punching process; number of basalt/aramid fiber fabric layers; nonwoven thickness; layer orientation angle; needling entry angle; compression molding technique. The resulting structures are eligible for certification (>1100N) and achieved a maximum perforation resistance of 1283 N. This study embodies the principles of a closed-loop circular economy, with AMF company (a safety footwear Portuguese company) repurposing its own waste (polyester) to create a new product (insoles), which is then incorporated into their safety footwear.