Investigation of Mechanical Properties of Nonwoven Recycled Cotton/PET Fiber-Reinforced Polyester Hybrid Composites

This study investigates the mechanical properties of nonwoven hybrid composites made from recycled cotton/polyethylene terephthalate (PET) with various fiber weight percentages (100/0, 0/100, 75/25, 60/40, 50/70, 60/40, and 25/75). The multilayered nonwoven carded webs are manufactured by the carding machine, while the manual lay-up technique is used to fabricate nonwoven-reinforced composites. Their tensile, flexural, and impact properties and microstructure are then examined. It is found that the tensile modulus and strength increase with the increase in cotton, while the impact strength improves with the increase in PET. The composite of 75% cotton/25% PET offers 92.13% and 67.87% higher tensile modulus and strength than the composite of 25% cotton/75% PET; however, the composite of 25% cotton/75% PET shows 83.09% and 36.22% higher flexural modulus and strength, and 187% more impact strength, respectively, than the composite of 75% cotton/25% PET. The outcome of this study indicates that nonwoven composites with higher contents of recycled cotton can potentially be applied in building and construction sectors where substantial tensile strength is necessary, while composites with comparatively higher contents of recycled PET may be used for various potential applications (e.g., helmets, surfboards, and automotive interiors) where significant flexural and impact strengths are required.