Method for shredding and recycling used big-bags and facility for implementing the method

A method for shredding and recycling used big-bags having a continuous inner polyethylene bag and an external woven polypropylene outer, the method comprising, taken in order:

• compacting at least one big-bag to a thickness of less than 20 cm;
• conveying the at least one compacted big-bag to a shredding unit, and
• shredding the at least one compacted big-bag at the shredding unit, wherein a feed rate at which the compacted big-bag is conveyed to the shredding unit and a cutting frequency of the shredding unit perform cuts in a range of 100 to 1000 cuts/m on the at least one compacted big-bag so as to obtain strips of polyethylene from the internal bag, the strips having a width in a range of from 1 to 10 mm and a length of up to 1000 mm, and fragments of the external polypropylene outer in a form of partially unwoven pieces and filaments having a width in a range of from 1 to 2 mm and a length of up to 500 mm;
• separating the polyethylene strips from the polypropylene fragments and obtaining a first fraction of polypropylene fragments and a second fraction of polyethylene strips, and processing the second fraction of polyethylene strips by performing a second shredding of the polyethylene strips;
• cleaning the first and second fractions by performing, on each of the fractions:
• at least one air separation;
• dust removal;
• washing with water;
• and
• feeding a first extruder with the cleaned first fraction of polypropylene fragments in order to obtain polypropylene granules and a second extruder with the cleaned second fraction of shredded polyethylene strips in order to obtain polyethylene granules.