Mixed Waste Recycling

Mixed Waste Recycling

All film converting operations result in trim and other waste. This is quite voluminous and difficult to dispose off.
If the waste is of a single type, e.g., LDPE or BOPP or simple mixtures such as LDPE + HDPE it can be easily reprocessed.

However, when it is a laminate waste such as PET/PE (Polyester film laminated with LDPE) recycling is not possible. In such cases incineration is the usual
method but it leads to heavy smoke generation resulting in atmospheric pollution.

PPMPL have developed a process to recycle such waste. The process is ideally suited to Indian conditions and no imports of any type are involved.

Products/Applications
Currently the following extruded products are considered feasible: flooring, sheets for architectural uses, e.g., office partitions, roofing – corrugated and  therwise, slats for benches and chairs and generally any extruded sections needing mechanical load bearing capacity similar to aforesaid applications.
The resulting product has mechanical properties intermediate between General Purpose Polystyrene and HIPS.

Process
Basically, the process involves
(1-stage) Compaction of the waste  by agglomeration / grinding / shredding followed by extrusion.
(2-stage) Dry the granules, mix with the bonding/compatibiliser and other additives.
(3-stage) Extrusion into final usable shapes.
(4-stage) Lamination for decorative finish.
Depending upon the application and type of waste a filler or other additives may be added in stage (2-stage) along with bonding/compatibiliser.
Use of a compatibilizer and the control of process parameters is the key to the successful operation of the technology. The compatibilizer has also been developed indigenously and this has kept the cost of the whole process low.

Due to the presence of all kinds of inks in the PET/PE film laminate waste available from conversion industry, the final colour of the product from this reprocessed material islikely to be dark (e.g., dark green/grey/black). Some further colour variation may be brought about by the presence of metallised film in the waste.
Major pieces of machinery are listed below:
Shredder / Agglomerator / Grinder Machine
Dryer
Mixer/Blender
Extruder (profile/sheet)