Prewashing and material preparation

PREWASHING step is particularly important when dealing with those products which present a very high level of contamination and possibly have inside some alien materials, little or nothing compatible with the plastics to be treated in the plant.


PREWASHING step is particularly indicated for treating hard products such as AGRICULTURAL FILM or baled BOTTLES (food, detergent or cosmetic containers), usually directly coming from the post-consumer collection.
The first one can in fact contain lots of soil, stones, pebbles, sand, which is better to eliminate before entering the actual recycling plant, above all for avoiding high wearing on the rest of the plant.
The second one can contain inside the bales heavy and dangerous wastes, especially due to a low quality sorting, and so it’s better to separate them for avoiding damages especially to the very fast following machines.

For these operations, according to the kind of product we are asked to treat, we propose the following solutions:


The most efficient way to eliminate sand, soil and peddles is to pass the material through an under-water PREWASHING TROMMEL which performs both the prewashing, and the elimination of these wastes, expelled through the holes of the rotating pierced sieve.
The holes diameter can change according to the application.


In event of very dirty products, or materials even harder to clean, a DOUBLE PREWASHING SIEVE, even with one pierced wall and one not pierced, will result even more efficient, almost like an actual washing.


Especially when materials in bales must be worked, it’s suggested to use, even combined with other pre-treatment machines, a PREFLOATATION TANK. It is the ideal machine for eliminating, by using the specific weight of the materials themselves, all those polluting elements which can, not only affect the quality of the product, but even cause damages on the following fast machines in the plant (striking example the presence of heavy metals inside the bales).
By using an ELLIPTIC COMB instead of the classical rolls of standard floatation tanks avoid jamming and blocks caused by the material, considering that it can usually be passed into the tank without any previous substantial shredding treatment.


It is obviously suggested to use a BALEBREAKER in all those cases – really frequent – in which the material arrives in bales; the material, once treated inside this special doser equipped with augers, will be ready for been treated with better results in terms of efficiency.
Using two special augers instead of the classical blade system of the shredders, grants not to ruin materials (i.e. Pet bottles), nor to charge the opening system with excessive efforts.