MRF TECH TALK
Five steps to prepare material for intelligent sorting BOOSTING HIGH-TECH SORTING PERFORMANCE AT THE MRF BY MARK NEITZEY
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utomation. Artificial intelligence. Robots. Whatever new technology a MRF may be in the market for, there are multiple factors to consider. At Van Dyk Recycling Solutions we visit MRF operations all over the U.S. and Canada. We see first-hand the challenges these sites face, such as highly-contaminated inbound material streams and inbound stream changes due to various factors, ranging from light-weighting, the Amazon effect, reduction of ONP, increase of film and trash, to high maintenance costs and increasing end product quality demands. There are also challenges with respect to maintaining a safe working environment and manual sorting labour issues – like finding willing candidates to show up every day and dedicate themselves to sorting through trash. Whatever technology is being considered – and there are some really cool systems out there (robots, optical sorters, material monitoring cameras) material needs to be properly prepared first for it to be properly recognized,
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sorted or monitored. Any separation device – a screen, an optical sorter or a robot – likes to be fed a steady diet of consistent material, on a single layer of the conveyor. If possible, material should be consistent by size with fines removed, and similar by shape, rigidity and density. The following are five ways to help prepare material so that MRF operations can get the most out of their intelligent optical sorter or robot.
SCREEN FOR SIZE – WITHOUT GETTING WRAPPED UP
Mechanical screens remain an important piece of the puzzle at a MRF to help separate material into different fraction sizes, preparing material for further sorting or intelligent separation. Large fractions and fines can be removed and a target size can be directed to an intelligent separation device such as an optical sorter or robot. In the last few years screens have been greatly improved. Van Dyk and many other suppliers now offer non-wrapping screens that properly size material without allowing film bags to be wrapped around their shafts.
SEPARATE 2D FROM 3D – THE IMPORTANCE OF BALLISTIC OR ELLIPTICAL SEPARATORS
An elliptical or ballistic separator performs highly accurate separation of 2D and 3D materials. Paddles “walk” 2-dimensional objects (such as film bags and light sheet paper) over the screen. Items with rigidity (bottles, cans, 3D cardboard) bounce backward. Also, the paddles have true two-inch holes in them to allow the last bit of glass fines to fall through. With minimal maintenance and no star changing required, the elliptical separator has clearly become the best choice for final clean up at the MRF, whereas more traditionally a commingled or polishing screen would be used. With the ability to remove light sheet paper, film and fines, the elliptical screen is becoming a must have to properly prepare a container line for further processing (whether using optical sorters, robots or human pickers).
CONVEYOR BELTS – HOW THEY PLAY A PART
Conveyor belts and sequencing play a large role in the success of any intelligent separation device. This is because
