Use of waste fibers as reinforcement in polymer composites

Kotliar et have explored the use of carpet face yam and textiles as 

The work emphasized shredded carpet selvage to which various amounts of cut waste fibers such as nylon 6, nylon 6,6, polyester and cotton were added. Fabric bits of waste denims and cotton-polyester fabrics were also used. The waste carpet blend was then coated with phenolic or urea formaldehyde resins that were dispersed in a water base. The composites contained various amounts of different fibers or fabrics and 7.5 to 20 wt% adhesive solids with respect to the fiber content. 

The fibers were spray coated and molded in a heated press at 150 to 200 °C and 3.4 MPa. Test results show that one can achieve high flexural moduli of 2.4-2.8 GPa with face yam, i.e. fibers that bind to the matrix such as nylon, polyester and cotton. These values, together with flexural strengths of 34--48 MPa, make the products suitable for many outdoor and transportation applications. 

Gowayed et explored the use of edge trim of polypropylene (PP) fabric waste (from the carpet backing) to reinforce a polyethylene (PE) matrix. Four layers of 0.1 mm thick PE film were laid with a single layer of washed PP fabric waste. Then they were molded at a temperature of 150 °C and a pressure of 290 kPa. It was found that the resulting PE/PP composite, with 25% PP volume fraction, exhibited a three-time increase in tensile strength and a 60% increase in flexural modulus when compared to the properties of pure PE. 

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