Cap material is otherwise known as bottle cap regrind, and is a result of PET bottle recycling.  It is typically produced as a mixed polyolefin, with the polyolefin mixture varying dependent on region.  Typically we have tested samples ranging from 60/40 PE/PP to 85/15 PE/PP.  Other contamination again varies depending on source and processor, with PET content significant (over 30% in some cases) while paper and films make up the other contamination.

BOSS will produce 3 streams from the cap material, comprising;

PP rich.  This is free of paper, films and PET with the only contamination being HDPE.  Depending on settings this fraction can be purified to over 95% on the first pass.

PE rich:  This stream, the 2^nd float fraction, is produced with up to 98% PE purity on the first pass.  It will be free of PET, but will contain the film fractions and paper contamination.  These can be removed by putting a zig-zag into the drying process and Impact can advise and supply if necessary.

Sink fraction: This will be predominately PET, although a small % of PE is also lost into this stream.  Any PVC labels will also be found here.

This is an excellent way of up valuing a mixed cap material stream.  Good value increase is realised by removing the PET contamination to 100% while the PE and PP streams allow you to sell a high-value product instead of a lower value mixed Polyolefin.