Separator screen in discs or stars for waste, axle usable in such screen as well as method for modifying a separator screen in discs or stars for waste

An axle useable in a disc or star separator screen (1) for waste, comprising:

• a rotation shaft (11) defining a longitudinal axis (X);
• a plurality of discs or stars (21, 21′) integrally coupled with said rotation shaft (11);
• and
• a plurality of anti-clogging sleeves (100) coupled coaxially with said rotation shaft (11), each of said anti-clogging sleeves (100) being interposed between a respective pair of consecutive discs or stars (21, 21′);
• wherein each of said plurality of anti-clogging sleeves (100) has at least one first rotating element (130) and at least one second rotating element (110′) arranged adjacent to each other, at least one of said at least one first rotating element (130) and at least one second rotating element (110′) being a tubular body, said at least one first rotating element and said at least one second rotating element (130, 110′) being mounted idle on said rotation shaft (11) so that said at least one first rotating element and said at least one second rotating element (130, 110′) rotate independently one with respect to the other, so that one of said at least one first rotating element and said at least one second rotating element (130, 110′) continues to rotate should another one of said at least one first rotating element and said at least one second rotating element (130, 110′) block due to dirt or foreign bodies.