What is cap?
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 dependent on source and processor, with PET content significant (over 30% in some cases) while paper and films makes up the other contamination.
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.
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 2nd 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.