Direct recycling and compounding

The EBB112 twin-screw extruder line, recently developed by Binova, can be used for the immediate compounding, without densifying stage, of film grinding scrap with a particular blend of "reclaim pellets" and/or various reground materials. It is also possible to add calcium carbonate- or talc-based mineral fillers, in proportions of up to 50%. Thanks to the co-rotating twin screw extruder, the series has an output rate of up to 2,000-2,500 kg/hour and it is equipped with a gravimetric feeding system that, by means of a new patented control device, establishes the exact proportion of ground sheet with which to feed the extruder.
Co-rotating twin screw extruders for reclaiming and compounding are the company's main field of activity; constituting the heart of every extruder line, they can be built, with or without a forced feeding system, for the granulation of foam or of materials with a very low apparent density, or they can be equipped with 2-4 vents for the reclaiming of very moist materials and/or materials with heavily inked or silk-screen-printed surfaces. Indeed, a special forced degassing system guarantees maximum output even in the presence of very moist materials.
The Binova range also includes special reclaiming lines that, exploiting the combination, in a cascade configuration, of single- and twin-screw or twin- and single-screw extruders, are used to treat highly polluting and/or poorly processable waste. Plants of this kind are designed to precise specifications in order to achieve energy savings that, for some materials, are as great as 50%, while at the same time guaranteeing high quality, both of the plant itself and of the end product. Accordingly, with a last-generation EBB71 co-rotating twin-screw extruder, used for pelletising and compounding (without additives and/or mineral fillers)  mixed PP scrap coming from washing plants, it has, for example, proved possible to achieve an output of over 1,200 kg/hour. In this case, an energy consumption level of less than 0.22 kW/kg was recorded for the entire plant, including the process water cooling system.
Co-rotating twin screw extruders are considered the avenue to follow in the future as regards the reclaiming and compounding of scrap materials. This is because of the need to treat second-rate products or post-consumer waste without, as far as possible, altering their technical characteristics and/or indeed striving to enhance them with the addition of mineral or other fillers. The final product quality guaranteed by technologically advanced systems is such that it allows reclaimers and compounders to approach sectors that, until now, have been outside their field of activity.