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)
Beside-The-Press Series granulator are ideal for the processor who has small injection molding machines and wants a lot of value in a small package. This quiet, energy efficient granulator conserves valuable floor space while producing quality regrind from robot-fed sprues, runner and small parts. All models feature tangential feed, case hardened cutting chambers, low-speed motor and staggered rotors with replaceable cassette knives. The staggered rotor design produces more cuts per revolution, resulting in higher throughput. Smaller bites reduce the chance of jamming or shearing. The scissor cutting action of slanted cassette rotor knives produce superior quality regrind. The staggered rotor, combined with a low-speed motor, offers cleaner, quieter cutting and uses less energy.
The Single Shaft Shredder has been designed exclusively for efficient recycling of polymer materials.
Energy saving: A Single Shaft Shredder followed by a grinder/granulator is a solution that is very energy effective. Compared to a solution with a single large grinder/granulator for the job, the Single Shaft Shredder in combination with a optimized grinder/granulator do the job much more effective.
V-CUT cutting technology: The unique V-CUT Technology, is a combination of V-knife cutting angle, cutting speed and sequential cutting. It provides a best shredding solution for plastic materials.V-CUT provides a sheer and smooth cut with low stress and therefore requires less motor power.
Hydraulic PUSHing system: The pneumatic PUSH-system is auto-regulating, efficiently absorbing vibrations and mechanical stress that occur in tough applications. The special hopper design allows material to feed directly into the rotor.
Special gear box design: The Single Shaft Shredder design contains no compromises. Its unique cutting technology together with a Special gearbox requires lower motor power for the job, minimizing energy consumption.
Easy cleaning/access: The design puts handling in focus. Cleaning the machine for new materials or colors is easy. Just remove a front side plate, and you have quick access to the machine’s interior.
Screenless operation: As the material is cut into uniform pieces, the Single Shaft Shredder operates with & without a screen, although screens can be installed as an option when smaller chip sizes are required.
Easy maintenance: The front opening makes it possible to access the rotor of the machine fast and easily. All knives, rotating and fixed are easy accessible. The rotating knives are reversible and are of cassette type, simplifying maintenance.
