Method and apparatus for sorting recycled material

A material separation screen, comprising:

• a first shaft and a second shaft;
• and
• a first group of compound discs mounted on the first shaft and a second group of compound discs mounted on the second shaft, the compound discs having a primary disc and a secondary disc positioned against a lateral side of the primary disc;
• wherein at least some of the first and second groups of compound discs are spaced apart from adjacent compound discs on their respective shafts and at least some of the first group of compound discs on the first shaft are positioned with respect to at least some of the second group of compound discs on the second shaft such that at least some of the first and second group of compound discs at least partially overlap to form a stair-shaped gap between them.

A screen for separating material, comprising:

• a first shaft mounted on the frame;
• a second shaft mounted on the frame adjacent to the first shaft;
• a first set of compound discs mounted on the first shaft having a primary disc with a smaller secondary disc located on a side of the primary disc, wherein the first set of compound discs are spaced apart from each other;
• a second set of compound discs mounted on the second shaft having a primary disc and a smaller secondary disc located on a side of the primary disc, wherein the second set of compound discs are spaced apart from each other;
• and
• the first set of compound discs on the first shaft aligned with the second set of compound discs on the second shaft such that the first set of compound discs at least partially overlaps with the second set of compound discs forming a non-uniform gap.

A method for separating material, comprising:

• aligning or forming multiple primary discs and multiple secondary discs against each other;
• mounting the primary discs and the secondary discs on the shafts in alternating order where at least some of either the primary discs or secondary discs are aligned with discs from adjacent shafts such that non-linear gaps are formed between the discs of one shaft and the discs of another shaft, and wherein adjacent non-attached discs form separating spaces between each other;
• rotating the shafts;
• and
• dropping materials on the screen so that shaft rotation causes the material to be pushed by the discs along the screen while at the same time causing materials of particular sizes to fall between the separating spaces formed between the discs.