The plant can cope with highly contaminated and thin-walled film via a prewashing unit and hydro-cyclone separation washing line.
The washed and recycled film flakes are then treated with plastics recycling technology from Erema called TVEplus (throughput: 1,100–1,200 kg/h) with laser filter LF2/350 (fineness of filtration: 110 µm and the die-face granulating system HG 244.
Nikolay Tomov, production manager, Poligroup, said the washing line transforms agricultural films and films from supermarkets into recycled material that will then be used for the production of bin liners, protective sheets and construction foils.
The three products are made up of 100% recycled plastic material from the Herbold film washing line.
“Film from household waste is a different case. It is a mix of several plastics. The real challenge here is the separation of unwanted plastics,” he said.
“Using the Herbold hydro-cyclone separation step, plastics that are heavier than water will be separated from plastics that are lighter than water.
“This process ensures heavier plastic components can be separated from the polyolefin, which is the good material of a film washing plant.”
Deposits of organic substances, a frequent feature of film from household waste, are removed by washing. In contrast, films from supermarkets often have a high percentage of paper due to affixed labels.
“It is a real challenge to separate paper from the film since these LLDPE films from supermarkets are ideal as a feeding material for recyclate used for the production of new film,” he added.
The power demand of the film recycling plant at Poligroup is 0.8 to 1.0 MW per tonne produced end product which corresponds to 0.8 to 1.0 kW per kilo end product.
In the whole system, there is a high amount of circulation water that is continuously reused. As little as 1 to 2 m³ of fresh water per tonne input material is needed for the regeneration of the circulation water.
“The extrusion system with the patented TVEplus technology has been optimized for the treatment of materials that are difficult to process such as washed mixed post-consumer film waste with a high percentage of residual humidity between 8 and 12% and a high degree of contamination,” said Tomov.
“Poligroup can recycle the PE washed film flakes (from LLDPE stretch agricultural film and LDPE industrial waste) into high-quality granulates.”
Erema is holding an in-house Discovery Day with the theme "Don't waste your waste" at its headquarters in Ansfelden, Austria, on October 29.
Company heads will demonstrate how to use in-house recycling to return up to 100% of plastic "waste" to the production process and still keep the high quality of end products as well as trials on Intarema K and TVEplus.
There will also be guest speakers from companies such as Borealis, SML, OCS and Polifilm Extrusion.