Effect of Fiber Surface Treatment in Carpet Recycling

Abstract

Vacuum assisted resin transfer molding (VARTM) has been used to fabricate engineered composite materials from post-consumer carpet waste. The process is unique, and applicable to any type of carpet. The technique can be used to make laminated structures for load-bearing applications. The mechanical properties of the composites obtained are 200% higher than that of other carpet based composites. Failure characterization of tested material shows no fiber-matrix adhesion, so various surface treatment methods have been used to modify the surface chemistry of the fibers so as to improve the fiber-matrix bonding. Solvents such as, methanol, isopropanol, sodium hydroxide, and potassium hydroxide are used for surface treatment. Carpet pieces are soaked in these solvents for 12 hours, and then air dried at room temperature. FTIR spectrometry is used to determine the change in the chemistry of the fibers. A considerable change in the chemistry is observed. Atomic force microscopy is used to determine any change in the surface morphology of fibers after surface treatment. An increase in the surface roughness is observed. Composites fabricated after surface treatment show 38% increase in flexural strength and 50% increase in flexural modulus. A decrease of 50% in porosity is also observed. This increase in mechanical properties is attributed to the modification of fiber chemistry, and also, the change in surface morphology.