Post-consumer waste PCW recycling

The methods of recycling depend very much on the type of the waste stream and the degree of cleanliness. The relatively clean PCW can be processed by similar methods as those used for industrial scrap. The readily identifiable constituents of such mixed waste streams, e.g., soft drink bottles (PET) and milk containers (HDPE) can be separated and recycled as single polymer recyclates. After removing these containers, the tailings of PCW are made of 50-75 wt% of PE s, 25 wt% of PS, ABS and their blends, and 

It is good to remember two ways for generating well-performing, immiscible blends generation of phase co-continuity [Morrow et al., 

and orientation [Sullivan and Hoyt, 1996], In the latter patent, commingled blends, mainly composed of hbrous PET and PA scrap, are hrst cleaned, then agglomerated near T, stabilized, dried to 0.01 wt% H O, and extruded at 275-280°C through spinnerets with diameter 0.3 to 1.2 mm. The hlaments are drawn at 90°C to a draw ratio of DR = 2.95-3.3. 

20% fiberglass -i- 5% other materials, density = 750 kg/m, tensile strength = 8.6 MPa. 

The experience indicates that it is easier to recycle unfilled than filled polymers. In all cases re-stabilization of the resin is required. Some polymers e.g., PI, PPS, POM, and LCP) are less susceptible to degradation than others. By contrast, the condensation polymers, viz. PA, and PEST, are difficult to reprocess without loss of performance. In most cases, the engineering resins and polymer blends require upgrading. 

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