Method and apparatus for sorting recycled material

A disc for a material separation screen, comprising:

• a primary disc on a first shaft having a first outside perimeter shaped to maintain a substantially constant spacing with a first adjacent disc on a second shaft during rotation;
• a secondary disc on the first shaft having a second outside perimeter smaller than the first outside perimeter and shaped to maintain a substantially constant spacing with a second adjacent disc on the second shaft during rotation;
• the primary disc and the first adjacent disc having a different spacing location than the spacing location between the secondary disc and the second adjacent disc;
• and
• the primary disc and the secondary disc are formed from a unitary piece of molded rubber or plastic.

A screen for separating material, comprising:

• a frame;
• a first shaft mounted on the frame;
• a second shaft mounted to the frame in a substantially parallel relationship with the first shaft;
• a primary disc and an associated secondary disc mounted on the first shaft;
• and
• a primary disc mounted laterally on the second shaft in alignment with the secondary disc on the first shaft and an associated secondary disc mounted laterally on the second shaft in alignment with the primary disc on the first shaft;
• each primary disc having a larger outside perimeter than the associated secondary disc.

A method for separating material on a screen having multiple shafts, comprising:

• providing multiple primary discs each having an outside perimeter and multiple secondary discs each having a smaller outside perimeter than the primary discs;
• mounting the primary discs and the secondary discs on the shafts in alternating order where at least some of the primary discs are colinearly aligned with at least some of the secondary discs from adjacent shafts;
• rotating the shafts in the same direction;
• 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 separating the materials according to size.

A disc for a material separation screen, comprising:

• a primary disc having a first outside perimeter;
• and
• a secondary disc having a second outside perimeter smaller than the first outside perimeter;
• the primary disc and the secondary disc formed from a unitary piece of molded rubber or plastic;
• the primary disc located on a first shaft and maintaining a substantially constant spacing with a first adjacent disc on a second shaft during rotation and the secondary disc shaped to maintain a substantially constant spacing with a second adjacent disc on the second shaft during rotation.

A disc for a material separation screen, comprising:

• a primary disc on a first shaft having a first outside perimeter shaped to maintain a substantially constant spacing with a first adjacent disc on a second shaft during rotation;
• a secondary disc on the first shaft having a second outside perimeter smaller than the first outside perimeter and shaped to maintain a substantially constant spacing with a second adjacent disc on the second shaft during rotation;
• and
• the primary disc and secondary disc made from a unitary piece of plastic or rubber type material that grips certain materials while allowing other materials to fall off the screen.