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

Area of Science:

• Materials Science
• Chemical Engineering
• Sustainability Studies

Background:

• The leather industry generates significant solid waste, often landfilled or incinerated.
• Existing hydrolysis methods for leather waste recycling produce challenging salt byproducts during neutralization.
• Sustainable upcycling of leather waste is crucial for circular economy principles in the fashion sector.

Purpose of the Study:

• To develop a zero-waste hydrolysis process for upcycling leather waste into a functional filler.
• To create versatile composites using leather hydrolysate for additive manufacturing applications.
• To evaluate the performance of these composites in 3D printing technologies.

Main Methods:

• A zero-waste hydrolysis process using sulfuric acid neutralized with calcium hydroxide was employed.
• Composites were fabricated with polyethylene-glycol-diacrylate and glycerol dimethacrylate matrices containing up to 20% leather hydrolysate powder.
• Material properties were assessed via tensile and rheological tests, and 3D printing accuracy was evaluated.

Main Results:

• A high yield of 91.3% was achieved for the leather hydrolysate powder.
• The addition of leather hydrolysate filler significantly enhanced composite tensile strength.
• Composites exhibited suitable viscoelastic behavior for 3D printing and demonstrated promising printing accuracy.

Conclusions:

• Leather waste can be effectively valorized into a powdered filler through a sustainable hydrolysis method.
• The resulting composites are suitable for Direct Ink Writing and vat photopolymerization 3D printing.
• This upcycling approach advances sustainability and circularity within the fashion industry by repurposing leather waste.