Poly bag and polywrap detection system
View Patent ↗A system for detecting Poly-Bag and Poly Wrap on mail pieces, intended to be a sub-assembly on a mail unit open system that automatically opens wrapped bundles of either letter or flat mail. The system generally includes two orthogonally-opposed but otherwise identical Poly Bag Detectors both controlled by a programmable controller and deploying a swinging pendulum test, plus a Poly Wrap detector employing a rolling friction wheel test.
1. A method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material comprising the steps of:
impacting said mail piece with an impact arm bearing an accelerometer;
wherein impacting comprises contacting said mail piece with impact arm;
measuring deceleration of said impact arm at said accelerometer during said mail piece impacting to determine an impact profile; and
analyzing said determined impact profile and distinguishing an impact against a poly-plastic material from an impact against paper.
2. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 1 , wherein said impact profile comprises deceleration over time.
3. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 1 , wherein said analyzing step comprises analyzing absorption of kinetic energy of said mail piece upon impact.
4. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 2 , wherein said sensing step comprises sampling deceleration over time.
5. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 4 , wherein said analyzing step comprises comparing said impact profile to a threshold.
6. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 4 , wherein said analyzing step comprises comparing said impact profile to a predetermined impact profile for poly-plastic material.
7. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 4 , wherein said analyzing step comprises comparing said impact profile to a predetermined impact profile for paper.
8. The method for analyzing a mail piece and for determining if said mail piece is wrapped in poly-plastic material according to claim 1 , further comprising the steps of,
contacting said mail piece with at least one friction wheel,
sensing the at least one friction wheel as it rolls along said mail piece to determine rolling friction,
analyzing said rolling friction to distinguish a poly-plastic material from paper.