To make a bottle, sometimes you've got to break some glass.
No one, it seems, cracks more glass for more new bottles than Partners Quality Recycling Services Inc., a Rosedale company that trains its electric eyes on ton after ton of arrowhead-size glass nuggets, sorting the scraps that otherwise would have ended up in a landfill.
Since the dawn of the recycling era, haulers who pick up the beer and juice bottles left near curbs have been asked to handle those blue bags with care. A mixed bag of brown, green and clear slivers could not be efficiently separated by color, so it held no worth.
Partners' new machinery can sort the bits and pieces, an innovation that might save taxpayer dollars. The Partners system requires the bottles to be broken.
"They go to all these great lengths to keep from breaking the glass," said Monty Davison, general manager at Partners. "Now, with this new technology, if it isn't broken by the time we get it, we've got to break it."
On a recent morning, a truck deposited a load of green beer and wine bottles. Hearing the jangle of breaking glass, Davison said, "I love that sound now. Before we had these new machines, I hated that sound."
Similar sounds ring almost constantly at Partners, as load after load of glass chunks wend their way through a network of magnets and shakers and crushers and screens. Glass crashes as it's dumped into a hopper at the start of the line. The chunks end their trip in a rain of like-colored shards. They tinkle and chime as they land in a pile.
Inspecting a mound of green "cullet," Davison declared the nuggets ready for sale to a bottle mill.
"They will," he said, "make Rolling Rocks."
Recycling experts say at least a third of the glass collected for recycling ends up in landfills because it breaks before it can be sorted.
Until a few weeks ago, when the company flipped the switch on its new equipment, Partners handled glass bottles the same way as other "materials recovery facilities" (known as MRFs). It tried to keep the bottles from breaking so they could be sorted by color, by hand.
Four sorting machines
Now, Partners has invested $1 million in a computerized system that uses four optical scanners to sort glass chunks as small as three-eighths of an inch wide. The chunks fall off the end of a shaker in a stream. When the machine "sees" the color it's looking for, it shoots a blast of compressed air to push the nugget forward and onto a conveyor belt.
Partners uses four of the machines to sort up to 14 tons of glass an hour. Two of the units look for brown glass, one for green and one for the clear glass known as "flint."
The company is among a half-dozen to have purchased the machines, and no company has more units running.
"They are doing it on a much larger scale than anyone in the country," said Josh Bickman, marketing director for MSS Inc., the machines' manufacturer. "They have more machines and are handling more glass than anyone on the planet in this application."
Savings for taxpayers
Bickman said the innovation could save taxpayers money on recycling costs because government-contracted haulers could compact their loads, meaning more efficient curbside runs.
Recycling officials in Howard County say tax dollars might be saved in another way: Under their contract with Partners, the better the company does on the commodities market, the less the county has to pay the company.
Partners has contracts with Howard, Harford, Carroll and Cecil counties, and Baltimore and Philadelphia to process recyclable materials such as glass, aluminum and tin cans and plastic soda bottles.
Ever wonder how that grab bag of containers you place in a blue bag is separated? The "commingled" material rolls down a belt, where workers sort the material and toss it into bins.
The material recycled on this line is baled and stacked like oversized building blocks. Cubes of tin cans line Partners' main drive. More bales -- some of cardboard, some with plastic soda bottles -- are stacked nearby. A faint odor of trash hangs over the yard.
The company, with about 50 employees, operates off Pulaski Highway in Rosedale. It is on a corner of an expanse that has been nominated as a Superfund cleanup site because previous occupants operated an open dump.
One side of the site is dominated by a mountain of glass pieces, about 20 feet high and nearly the length of a football field. Davison figures there are about 4 billion pieces of glass in the huge pile.
The pile is "mixed broken" -- a tossed salad of broken glass in various hues, with bottle caps, aluminum pull tabs and other adulterants. The items are of no use unless they can be cleaned and sorted.
That's what they do at Partners. A loader drops the "mixed broken" into a hopper, which feeds a conveyor belt that passes under a magnet, removing bottle caps and other metal. Then it passes through another device that removes aluminum, before heading into a tunnellike building that houses the new machinery.
There, the glass is shaken over a screen, and pieces that are too small fall through it. These are "fines," which might be used in asphalt or concrete. The pieces that are an inch or wider are rerouted and cracked by another machine.
One machine detects and ejects ceramics -- bits of plates and coffee cups. This is the most serious contaminant, because its melting point is much higher than that of glass.
The glass then moves to the MSS machines, where it is shaken until it streams before hundreds of optical eyes. The eyes look like green dots of light, each shooting six beams a second to look for the right color glass.
As the piles of sorted cullet accumulated, Partners Vice President Tom Collins scooped a handful of the glass. By that point in the process, the edges are worn blunt, and the glass doesn't cut.
"You have to pick it up and spread it out so you can determine the color content," he said.
In a pile, it's hard to see what you have. Each color-separated pile has to be at least 90 percent pure. Partners can get up to $60 a ton for "flint," the glass that fetches the highest price.
Collins said it is crucial to sort the pieces efficiently.
"Don't try any hocus-pocus games," he said. "Dump it in over there, it comes out over here and put it on a truck."
Pub Date: 2/28/99