In the recycling industry, machine screens are used for the comminution of material. The particles of the material are separated according to their size through a shredding or grinding process. The first step in that process is throwing the material through a funnel into the machine. Afterwards the rotor and stator knives cuts the material. When the good has reached the desired size, it will be finally led out through the machine screen. Due to the permanent contact between the screen and the grinded material, a great wear may occur. Thus the screen baskets have to be replaced regularly to guarantee a proper functionality.
For manufacturing reasons two types of machine screens can be distinguished:
Stamped perforated plates:
That kind of machine screens have a sheet thickness of less than 10mm and a tight staggered round perforation. This type can be found in the plastic recycling industry, especially in grinders of different manufacturers. First the perforated plates are cut by a laser then they´re got into shape by a press brake with the desired radius. If necessary, welding operations can be made, depending on the nature of the screen.
In particular on account of the tight perforation just a construction steel (S355J2G3) can be considered as a material, because it can be easily bent, stamped and welded.
To meet customer demands, we offer a particularly wear-resistant type of perforation plates, as an optimization possibility.
This type of machine screens are in most cases installed in shredders. As the material is not that highly comminuted in these machines, large holes are burned into the steel. Furthermore the holes are usually thicker than 10mm, which is why the technology of stamping is not applicable in that case.
In the standard version these screens are made of HARDOX, because this kind of steel guarantees a high wear resistance and it is nevertheless easily weldable and bendable. After the bending, the screens are often welded. Also in this area we already carried out optimizations and are able to provide on request more wear resistant materials to minimize costs.