Work

Upcycling Leather Waste Through Zero-Waste Hydrolysis for Versatile 3D Printable Composites

Year: 2025

Type: article

Abstract: Leather industry produces a substantial amount of solid waste, which is frequently disposed via incineration or landfilling. While hydrolysis offers a valuable and sustainable method to upcycle leather waste, both acidic and alkaline processes present challenges due to salts produced during neutralization. This study aims to upcycle leather scraps via zero-waste acidic hydrolysis, producing a powdered filler for composites suitable for LCD vat photopolymerization and Direct Ink Writing 3D printing techniques. A zero-waste hydrolysis process was implemented using sulfuric acid neutralized with calcium hydroxide, achieving a yield of 91.3% of the initial leather mass. The composite formulations featured a green matrix composed of polyethylene-glycol-diacrylate and glycerol dimethacrylate, with embedded leather hydrolysate powder at concentrations up to 20% w/wMATRIX. Tensile tests conducted on neat resin and composites demonstrated improved elastic modulus, stress and elongation at break for materials filled with leather hydrolysate. Additionally, rheological tests displayed a suitable behavior for the selected 3D printing techniques. As a proof of concept, composites were successfully 3D-printed using both Direct Ink Writing and vat photopolymerization techniques. This work highlights the potential of leather waste, processed through a zero-waste hydrolysis method, to be valorized in composite materials suitable for additive manufacturing techniques.

Source: Polymers

DOI: 10.3390/polym17172366

Authors: Giovanni Venturelli, Luca Guida, Marinella Levi

Institution: Politecnico di Milano

Language: English

Topic: Additive Manufacturing and 3D Printing Technologies

Subfield: Automotive Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $3,258