Rotary drum screener for separating differently sized plastic pieces and filtering out strands

A rotary drum screener, comprising:

• a feeder configured to receive plastic pieces to be screened and further configured to direct the plastic pieces through an opening within a rotary bearing;
• a rotary drum that is connected to the rotary bearing and configured to receive the plastic pieces from the feeder, the rotary drum including a helical blade surrounded by a perforated screen that is transmissive to plastic pieces with a diameter smaller a maximum hole diameter of the perforated screen;
• a housing for the rotary drum;
• a collar coupled between the rotary bearing and an inner surface of the housing, wherein the collar includes a notch;
• and
• at least one air nozzle mounted to the inner surface of the housing and oriented to blow air into the rotary drum through the notch in the collar, wherein the at least one air nozzle is configured to blow air directly onto the helical blade within the rotary drum to prevent or mitigate blockages in the rotary drum.