First stop shredding: primary shredding systems catch on with U.S. C&D recyclers, landfill operators.

They've enjoyed years of popularity in European markets, and now, low-speed, high-torque shredders are starting to catch on in the United States, as well.

"The European market drove these slow-speed shredders," says Patrick Andres, regional sales manager at Morbark, a Winn, Mich.-based manufacturer. "And it drove us into building them. Now, we're producing them and reaping the benefits."

Primary shredder popularity is growing particularly on the East Coast where tipping fees are higher, and landfill operators can benefit from increased volume reduction, says Marc Labry, vice president of Norton Environmental Equipment, Independence, Ohio. Among the benefits of these shredders, also known as primary reducers, are lower wear costs. The machines have fewer replacement parts to begin with, and the slower speed reduces friction and wear, says Tim Griffing, systems engineer for Continental Biomass Industries Inc. (CBI), Newton, N.H.

Griffing points out that there's a big difference between the construction and demolition debris in Europe and the United States and that adapting primary shredders to handle the more demanding U.S. material stream has been a challenge for manufacturers. "A lot of the shredders come from the European market," he says. "And some more light-duty machines have a problem standing up to the U.S. market. There's a big difference in the C&D flows between the U.S. and European market."

But the domestic interest in the machines is growing rapidly and could soon rival the popularity of secondary processing units like tub and horizontal grinders, proving useful to C&D recyclers, landfill operators and demolition contractors alike, says Andres.

TESTING THEIR METAL

The mixed C&D arena is the key area of market growth in the United States for primary shredding plants, which reduce material down to a smaller size by impaction, says Terri Ward of SSI Shredding Systems Inc., Wilsonville, Ore.

"By using a primary reducer, incoming material doesn't require extensive pre-sorting, pre-crushing or other preparation," she says. "Material flow becomes more consistent, preventing jamming and bridging throughout the material handling system, reducing downtime and maintenance costs.

Primary reducers offer a particular advantage to C&D recyclers because of their ability to handle contamination, a factor C&D processors deal with constantly in light of the diverse nature of the material. "They're very tolerable of steel," says Gert Semler, of Hammel North America, Chesterton, Ind.

Primary reducers offer some added safety to the operations of demo contractors who process mixed C&D, Andres adds. "You put metal in a high-speed grinder, and it's going to cause damage," he says. "With slow speed, it's not as dangerous. If there's something it can't break through, it just slows up and stops. You can pick it right out."

Using primary reducers can also improve manual sorting lines, says Ward. "Sort lines become safer and more efficient as pickers aren't stopping the line to struggle with oversized material," she says.

C&D recyclers often use their primary shredders in tandem with a secondary processing unit, like a tub grinder, says Griffing, which will reduce the material down further into a marketable product. "A slow speed is ideal just to break the material down for easier handling, where the high speed is designed more toward making an end product, like boiler fuel or cover," he says.

Using a primary reducer can make the whole recycling process easier, Griffing says. "It just allows you to get to the material easier," he says. "It's becoming a better tool to help C&D recyclers increase their tonnage.

In addition, Andres says using a tandem system can add to the lifespan of a high-speed grinder by making its job easier. "A slow speed will break up the metal that causes the high speeds a lot of trouble," he says. "It will keep your maintenance costs down."

INCREDIBLE SHREDDABLES

And while the equipment might not prove as beneficial in a strictly land clearing application, where the material stream is made up almost entirely of clean wood debris, the ability to handle contamination makes primary reducers particularly beneficial to any operation that might encounter metal contaminants in the material stream. "If you've got a chance for contamination, it's worth it," Andres says. "It can handle any metal you come across."

In fact, there's not much a primary shredder can't handle, says Andres, from appliances like washing machines and dryers to engine blocks.

"When it comes to primary reducers, unshreddables come down to what can actually fit into them," Andres says, noting that things like cars are better left to auto shredders. "It comes down to size."

Griffing adds that carpet and rugs can also be added to the list of unshreddables. A primary reducer can handle the material, but it's not particularly effiecient, he says, since the whole idea of the primary reducer is to make material denser, and carpet is dense enough just as it is. "[Carpets] do shred, but the gain from shredding a carpet is negligible--it almost works against you," he says. "When you put it through a shredder, it takes a square foot of carpet and makes it a big fluff ball. It actually makes carpet less dense, it pulls twines out, and things get tangled and cause other problems. It makes the operation a lot more maintenance intensive."

SAVING SPACE

Advocates say adding a primary reducer to an equipment line offers a number of advantages to recyclers and demo contractors by increasing tonnage and productivity. But landfill operators also find primary shredding useful in helping them maximize their space.

Michael Chapman, executive director of the Salem County Utilities Authority, a county-run solid waste facility in Alloway, N.J., has recently purchased an SSI PRI-MAX 4000 and has been using other primary reducers at his facility since June 2004.

He says he started looking into primary shredding systems last year following a topography study of his facility that found he was running out of room. "We needed to find a way to use up less space," he says.

And while Chapman doesn't do any traditional recycling of the material that comes into his landfill--45 percent to 50 percent of which is comprised of mixed C&D--he says the primary reducers have helped him "recycle the landfill" itself by filling spaces created by settlement of buried material with ground C&D debris.

Depending on where in the country they're located and what kind of fees they're subject to, landfill operators might be more likely to migrate into recycling once they have the use of a primary shredder, says Andres.

"In the Midwest where the restrictions aren't as high, [landfillers] will be mostly likely to just maximize their space," he says. "But in California, New York or anywhere on the coast, there are such strong regulations watching what they're burying, they're more likely to recycle."

Ward agrees and says that another of her customers, who recently bought a primary reducer for volume reduction at his landfill, is planning to build a fixed recovery facility. "He recognizes that nearly 40 percent of the material going into his landfill is wood with intrinsic value literally going to waste," she says.

However, just because someone buys a primary shredder is no guarantee that he will expand his operations into recycling. Simple volume reduction is the key issue for many landfill operators. "The bottom line is that recycling must be based on sound business practices," says Ward. "But recycling does give landfills a unique opportunity to 'double dip' in that every ton diverted makes room for another ton to bury."

In today's business climate with soaring fuel costs, primary shredding can save recyclers and demo contractors in transportation costs as well, advocates say.

"Some demo contractors will haul stuff 100 miles," says Andres. "And when diesel fuel is up to $2 or $3 per gallon, if they can get their reduction ratios down, they can save money on trucking."

Recyclers and operators can also save with primary shredding on wear parts costs, partly because these machines don't have as many wear parts as their high-speed counterparts. "Being a slow speed, you don't get a lot of wear," Griffing says.

"The cost is nearly half of what the high speeds have," says Labry. "The teeth can last anywhere from 500 to 800 hours depending on the material."

However, eventual wear on the few replacement parts that primary shredders do have--like teeth and anvil plates--is inevitable, says Andres. Manufacturers recommend hard facing wear parts to get the maximum life out of them.

"Hard surface them once a month," says Andres. "If you do have to replace them, it's not a piece of cake, it's more like a two-day job."

Professionals find primary reduction an attractive and cost-saving option whether they recycle or not. And with tipping fees and transportation costs on the rise, primary shredding plant manufacturers anticipate their popularity to continue its upward growth.

The author is assistant editor of Construction & Demolition Recycling and can be reached at [e-mail].