Comparative Performance of Recycled PET and Commercial Fibres Under Thermal and Mechanical Stress

This study This study investigates the mechanical strength and thermal resistance of fibre produced from recycled polyethylene terephthalate (PET) bottles in comparison to commercial fibre. The objective is to assess the potential of recycled PET fibre as a sustainable material under thermal and mechanical stress. Recycled PET fibres were fabricated using a modified cotton candy machine. Beeswax treatment was applied at 60°C, 40°C, and room temperature to evaluate its influence on tensile strength. Observations on stretchability, brittleness, and wax adsorption were recorded to compare the mechanical performance of both fibre types. Thermal resistance testing involved immersing the fibres in silicone oil and subjecting them to progressive heating at 30°C, 60°C, and 80°C. Results showed that commercial fibres retained superior flexibility across all beeswax treatments, while recycled PET fibres became brittle and showed limited stretchability. However, recycled PET exhibited greater thermal stability, withstanding higher temperatures before showing signs of burning, whereas commercial fibre melted at 80°C. These findings suggest that although recycled PET fibre has lower mechanical resilience, it performs better under high temperatures. This makes it a promising candidate for applications requiring heat resistance, such as thermal insulation or packaging. However, mechanical limitations remain and may necessitate further treatment or reinforcement. The study contributes to the advancement of recycled PET in sustainable material development and offers baseline data for future enhancement of recycled fibre products.