LIGHT WEIGHT PACKAGING SORTING PLANTS 22-23 Primary feeding-dosing The waste deposited in the reception area are collected with the loading shovel (unload yard) or grapple hook (pit), transferred and unloaded in the dosing feeder with variable speed and flow limiter, used to control the treatment flow rate. Bulky waste sorting Waste regularly supplied by the feeder is unloaded in a bulky waste sorting conveyor belt, where sorting operators select the materials which due to their size or shape are detrimental to subsequent treatments, such as film sheets, cardboard, EED waste, etc. The selected bulky materials (recoverable and non-recoverable) are stored in containers located under the sorting cabin for delivery to the recycler or the treatment rejects section. Bag opener Non-sorted waste is downloaded by the same sorting belt in a bag opening unit designed to extract the materials from the bags when they are ready for the remaining sorting operations. Classification in trommel The components of the bags are subjected to a sieving process using a trommel or revolving sieve, which classifies the materials into three sizes: • Fine components with a high content in organic and inert material. • Intermediate components with a high content in recyclable packages. • Large components or sieving rejects. Classification in ballistic separator The stream of intermediate size materials is subsequently subjected to ballistic classification according to size, shape and density, and again separated into three new material streams: • Stream of heavy-rolling material formed by the majority of the heavy and/or rolling material, mainly packaging for liquids, metal packaging and beverage carton. This falls down the inclined slope of the ballistic separator. • Stream of light flat materials, mainly formed by cardboard, paper and other film plastics with a flat or flattened shape that rise up the inclined plane of the separator. • Stream of fine materials made up of fine material that could not be sieved in the trommel because it was attached to or blocked by other material, which falls through the mesh of the separator. The amount of material reaching each of the three fractions will depend on the quality of the material introduced in the equipment. For examples, in facilities with 75-85% of requested material at the inlet, the classification performed by a ballistic separator is about 80% rolling material, 15% light flat material, and 5% fine material. At facilities where the sorting operations are performed manually, the ballistic separator is not used. The material arriving from the trommel is taken directly to the sorting cabin, where the operators sort the requested materials.
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