Fibre Recovery
Discarded floor coverings collected after domestic or commercial use supply the raw material known as post-consumer carpet for secondary processing. Bales arrive at reclamation facilities containing heterogeneous polymer streams, primarily nylon six, nylon six six, polypropylene, and polyethylene terephthalate face yarns bonded to primary and secondary backings with latex adhesives. Sorting lines separate face fibres from backing matrices because contaminants degrade extrusion melt quality during pelletization.
Operators shred the incoming rolls before passing fragments through density separation tanks where sink float stages segregate heavy calcium carbonate fillers from floating polyolefins. Cleaned polymer fractions feed directly into compounding extruders to produce recycled engineering resins for injection molding and extrusion applications.
Polymer Separation
Chemical depolymerization recovers pure caprolactam monomer from polyamide fractions by applying superheated steam under pressure to break polymer chains. Glycolysis breaks down polyester components into constituent monomers through ester interchange reactions using specific glycols at elevated temperatures. These recovered monomers undergo purification cycles to remove residual dyes and plasticizers before repolymerization into virgin grade polymers.
Mechanical recycling preserves original polymer chains by melting and pelletizing sorted material without altering chemical structures, though thermal history causes slight melt flow index variations between batches. Contamination tolerance limits remain strict because residual polypropylene in nylon melts causes phase separation and structural weakness during subsequent spinning operations.
Backing Reclamation
Thermoset latex binders anchoring face yarns present significant challenges during mechanical size reduction and thermal processing stages. Granulation equipment shatters brittle backings while leaving ductile face fibres intact through careful rotor speed adjustment and screen sizing. Separation tables utilize electrostatic charges to isolate mineral fillers from organic polymer fragments after hammer mill pulverization.
Reclaimed backing powders frequently serve as asphalt modifiers or cement kiln fuel substitutes rather than high value structural inputs due to residual adhesive chemistry.
Processing Yields
Sorting efficiency dictates final flake purity and determines whether output meets automotive or carpet tile manufacturing specifications. Moisture content in washed flakes must remain below specific thresholds prior to extrusion to prevent hydrolytic degradation of polymer chains. Reclaimed resin pricing fluctuates according to virgin petrochemical feedstock costs and regional collection infrastructure density.
Supply chain transparency requires verifiable chain of custody documentation to substantiate recycled content claims on finished goods labels.
