A year or so ago, sorting recyclable cans and bottles at Northwest Missouri State University was a decidedly low-tech job.
According to Chris Redden, the university's cowboy-hat-wearing hardscape/trash & recycling supervisor, the process consisted of dumping a 55-gallon trash bag full of used containers onto a 4-by-8 foot sheet of plywood and sorting by hand — cans in one pile, soft-drink bottles in another pile, milk jugs and other high-density plastics in a third.
Sorting through a pickup truck load of 55-gallon bags could take as long as an hour.
That just didn't seem right to Redden, a national-class Extreme Cowboy rodeo rider, and the sort of jack-of-all-trades country boy who believes anything done by hand can be done better by machine — especially a machine you build yourself.
Which, along with Michael Adwell, David Stith and Kurt Davis, the other members of Northwest's multi-tasking streets-and-sidewalks crew, is exactly what he did.
After the university received an $11,000 grant last July from the Northwest Missouri Regional Solid Waste Management District, Redden and his team constructed an automated recyclables sorting line literally out of junk iron and spare parts.
First, they refurbished an old conveyor that had been sitting unused "forever" at the university's pellet plant, where cardboard, paper and other materials are converted into boiler fuel. Then they placed the conveyor so that it empties into a modified grain hopper salvaged from a nearby farm.
The hopper is mounted on steel posts once used as mounts for the emergency telephones formerly scattered around campus in the days before cell phones became ubiquitous.
Connecting the hopper to a commercially manufactured recyclables baler, purchased with grant funds, is a chute crafted from an old metal sign.
Now, instead of rooting through a pile of cans and bottles dumped onto a plywood sheet, Redden's crew, often augmented by student workers, sorts material as it moves by on the conveyor.
Milk jugs and aluminum cans are dropped into the appropriate bins, and polyethylene terephthalate, or PET, soda pop bottles tumble into the hopper, down the ramp and into the baler.
With experienced sorters, Redden said, that same pick-up truck load of overflowing 55-gallon trash bags can now be processed in about 15 minutes.
The "new" conveyor system has dramatically increased the efficiency of Northwest's recycling operation, according to John Viau, the university's sustainability coordinator. Not only that, but assembling the machine in-house allowed Northwest to count the labor as its required match for the grant funds.
Viau said the system is a big reason why the university was able to reduce its waste stream — the amount of refuse trucked each year to Maryville's solid waste transfer station — from 705 tons in 2011 to 594 tons in 2012.
Each day during the school year Northwest employees and student workers process an average of 400 pounds of PET bottles. Using their single baler, the recycling team also processes about 400 pounds of aluminum cans each week and 400 pounds of milk jugs and other high-density plastic containers every two weeks.
Page 2 of 2 - The bales are purchased by various commercial processors who further refine the material so it can be sold to manufacturers.
Viau said Northwest's recycling operation is not breaking even yet, but that it's getting close. Since automating the system last July, recyclable sales have returned just over $16,000, and Redden expects that figure to reach $20,000 by the time the fiscal year ends June 30.
"We're not necessarily in the black," Viau said, "but we're going to come close this year to paying our costs at the transfer station."
Bringing the baler online has added efficiency by increasing the weight of sorted PET plastic per 18-wheeler truckload from three tons to 18 tons. During the coming year, Redden is hoping to boost tonnage even more by building a perforator to remove air and any remaining liquid from the bottles.
Adding a perforation unit, he said, could nearly double the weight, but not the size, of existing 370-pound PET bales.
"I've already got it designed in my head," he said.