Recycling technology for film

Production and post-consumer scrap are valuable secondary resources to produce first-class products.

The material to be processed can be in different conditions in terms of humidity, contamination, printing, and of course form. The reuse of the material is either in the same or various other applications; goal is a content of up to 100 %.

For the film recycling industry, Starlinger recycling technology offers a spectrum of innovative machinery solutions (recoSTAR dynamic and recoSTAR universal) for the efficient recycling of all kinds of film materials. Source of waste is in-house production scrap, post-industrial waste from e.g. film conversion, as well as post-consumer waste including agricultural film. Polymers (or their blends) such as PE (LDPE, HDPE, LLDPE), PP (BOPP), PA (BOPA), PET (BOPET), PS, PLA, etc. can be processed with a choice of pre-treatment, extrusion, filtration and pelletising modules.

 

Recycling production scrap: maximising profit in-house

Production scrap has to be dealt with throughout the film production chain, no matter if the production process is for blown films or cast films. At the same time a variety of economic factors like rising resin prices, cost reduction pressures, and stronger competition have led to higher awareness concerning production costs.

Heavily printed film requires efficient degassing solutions; highest efficiency is achieved with the Starlinger C-VAC module. Optionally, the line can be equipped with CaC03 flushing for increased machine uptime.
Multi-layer film, sometimes metallised, is composed of a variety of materials. Homogenisation for high melt quality is achieved through customised screw design.
Lamination structures are composed of different polymers, e.g. PET/PE, or different materials, e.g. polymer/Al. Reuse of the material is possible to a certain extent by separation; the tool of choice is a speciality filter.
BOPP, BOPET and BOPA production scrap requires sophisticated material logistics as it is discontinuous production scrap and has low bulk density. Starlinger offers turn-key projects from edge trim cutting to final pellets storage.
In-line recycling of multiple trims from stretch film production is recommended. Full attention of the operator on the main process is ensured through high automation of the recycling line, e.g. automatic stand-by/restart mode.

Post-industrial and post-consumer recycling: tackle the task

A variety of disturbing factors can pose a challenge to the recycling process and consequently influence the quality of the regranulate. In case of post-industrial waste (production scrap not processed in-house, conversion waste from slitting and die cutting, etc.), the material might be wet from outside storage or hygroscopic behaviour, printed, or dirty from inappropriate materials handling. Additionally, the film scrap might be a mixture of unidentifiable polymers, or laminated with other materials such as paper or aluminium.

Post-consumer film waste can come from households or agricultural use. In both cases, the film has to go through a sorting and washing process before extrusion. The input material in the form of shredded flakes usually holds a high amount of humidity and foreign particles. The choice of equipment is crucial; the focus is on good drying, degassing and filtration. Upgrading can be achieved with additives.
Agricultural film may show high levels of possibly abrasive foreign particles and humidity even after the washing process. Selecting the right construction materials for the parts in contact with the polymer increases life time and reduces operating costs.
Industrial packaging film often contains high paper content from labelling. The C-VAC module removes this kind of contamination before degassing and ensures the most efficient extraction of volatiles.
Post-consumer packaging from households requires proper washing; the composition of the waste is often unknown to the recycler. SMART feeder and correct screw design ensure best homogenisation.
Polymer content of paper based beverage containers shows high contamination of aluminium and paper, as well as high moisture levels. A combination of optimum drying in the SMART feeder and continuous filtration allows to produce reusable pellets.
PO labels, a side product of PET bottle washing lines, are highly printed and often contaminated with PET flakes. With the C-VAC module, PET contaminants are removed before entering the highly efficient degassing module.

 

recoBATCH combines the traditional recycling process with compounding of additives. Properties during extrusion are improved and raw material costs for the film and tape production are reduced. Production of your own masterbatch is possible.

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