Any product that makes small problems of big
problems gets a warm welcome from recyclers. Assisted by rising
interest in biomass and waste-as-fuel, manufacturers of wood
and green waste grinders are seeing good demand for their products.
Wood grinders come in two main versions, a gravity-fed tub design
or the increasingly popular horizontal grinder. Horizontal grinders
appeal partly because of safety. They are seen as less likely
to accidentally throw material out, presenting a hazard to operators,
than gravity-fed tub grinders. This is particularly important
in recycling yards and landfills where there may be more people
around than in land-clearing applications. As wood and green
waste recycling heats up, horizontal machines are getting a ready
At DuraTech Industries International, Inc. in Jamestown, North
Dakota, marketing manager Al Goehring says the company has added
horizontal grinders to its main line of tub models. DuraTech’s
smallest, the 2009, powers a 9 foot tub with a 325 horsepower
diesel engine. It can be trailer or track mounted. The 3010 is
475 or 540 horsepower with a 10 foot tub and can be configured
in track or trailer versions with a grapple loader option on
the fifth-wheel model. The 4012’s 950 horsepower engine turns
a 12 foot tub and can be configured with tracks and, on the trailer
model, a grapple loader. DuraTech’s newest 9564 horizontal grinder
employs a 950 horsepower motor and 64 inch hammer mill unit.
DuraTech’s larger grinders offer an oscillating unloading conveyer.
“That means the conveyer not only goes up and down to build the
piles, but it also goes left and right, so you don’t have to
move the unit as often or have another machine take away the
product,” Goehring says. DuraTech has also gone to completely
enclosed engine units, using technology developed for agricultural
combines. “It reduces the amount of debris and dust and stuff
that gets into the engine, which reduces maintenance,” Goehring
To traditional markets such as land cleaning and municipal landfills,
grinder makers are adding wood reduction for biomass and fuel.
“That’s probably the newest market,” Goehring says. “Everybody’s
concerned about that. We’re starting to see more and more of
the wood being recycled going into that type of activity.”
At Peterson Pacific Corp. in Eugene, Oregon, marketing manager
Dave Benton says their 4710B Track Mounted Heavy-Duty Horizontal
Grinder is the most popular for recycling. Its 630 to 765 horse-power
diesel engine options and 18 inch ground clearance suit it for
land clearing at volumes up to 350 cubic yards per hour, Benton
In addition to the mid-range 4710B, Peterson recently introduced
the 5710C, a 1,050 horsepower track-mounted machine with a spiral
stump splitter that can reduce large stumps to grindable size.
In March, Peterson will introduce the model 2710 for smaller
operations. Newer models have a revised release system to protect
against damage from contaminants such as large pieces of steel.
Track-mounted models are Peterson’s best sellers because they
require less support equipment such as trucks and loaders and
cost less to operate. “You’re moving the machine to the pile
instead of the pile to the machine,” Benton says. “Typically
the availability of the track-mount machine is at least 10 percent
higher than trailer mount, so the track-mount machines are actually
cheaper per ton produced.”
Peterson is experiencing healthy demand. “We sell a lot of equipment
to the municipal and private recycling yards collecting green
waste and various types of woods and that goes into various products
including compost and fuel,” Benton says.
Burrows Enterprises, Inc. in Greeley, Colorado, has a niche among
recyclers looking for low-cost tub grinders that operate from
power take offs on other machinery, typically farm tractors.
The company offers standard and low profile models capable of
producing 5 to 40 tons per hour, depending on material input
President Royal Burrows says, “Probably most of our sales in
recycling would be rose grower and flower growers and nurseries
where they want to recycle all their own trimmings and waste.”
Typically, these users are grinding nursery and orchard trimmings
to create compost, mulch or potting soil for use in their own
The company also sells its RotoTub grinders for composting. “Probably
the biggest one would be for composting applications where they
end up with a source of composting, like sludge from city sewage
plant residue, but they need a certain amount of carbon in there
and an air source to keep it fluffy so instead of having a mud
product you have air and something to help the bacteria break
it down,” Burrows says.
After venturing into sales to more intensive wood recyclers several
years ago, Burrows got out of that market due to maintenance
concerns when their machines were used in municipal landfills.
“Anything that’s wet or has a lot of leaf to it, we grind better
than anyone else on the market,” he says. “A lot of these guys
want machines that do it all, they want to be able to put in
big tree stumps, and we don’t do that.”
Nowadays, in addition to their nursery niches, Burrows is seeing
strong demand from cattle feeding operations where users grind
up baled corn stalks or hay and mix with chopped silage and other
feedstocks. “We can’t build them fast enough for the orders coming
in,” Burrows said.