By Kevin Yanik
Portable Plants & Equipment, portableplants.com
Brand-new horizontal grinders don't come cheap. Y es difícil justificar la inversión en uno si no se va a usar durante algunos periodos en el año.
This was Glenn Kafka’s logic as he explored purchasing a new horizontal grinder for his pine bark operation a few years ago. But because his Mosinee, Wis.-based company, Kafka Granite, only grinds pine bark about two weeks out of the year, Kafka needed a second use to pull the trigger on an equipment purchase.
"I thought how else can I pay for this thing," says Kafka, whose core business is the production of landscape and architectural aggregates. "I started looking into the shingle market and found out Wisconsin was sort of new to it."
Now, Kafka says his Peterson 6710B track-mounted horizontal grinder processes more shingles than it does pine bark. Kafka has also found land-clearing opportunities for the grinder, and those keep the Peterson 6710B and Kafka’s Diamond Z tub grinder in action most of the year.
Shingles give Kafka’s horizontal grinder some unique use throughout the year, though.
"I grind and screen right into an 8-ft. x 20-ft. Allis-[Chalmers] Ripl-Flo incline screen," says Kafka, who estimates that he recycles about 20,000 tons of shingles each year. "There's issues with the screen - getting the right amount of water flow mainly. Injecting water is very critical to keep the chamber cool. How you go about that makes a difference."
If the material gets too wet, for example, it blinds the screen. If it gets too dry, Kafka says the material can gum the rotor.
"It's all trial and error," he says. "You learn by your mistakes. Shingle grinding is a different animal. You learn every day."
Kafka quickly learned that debris, as it is with other grinding applications, is an issue related to recycling asphalt shingles.
"I've had everything from rear ends out of a car or a truck go through this thing to 2- to 3-in. plate metal," he says. "Sometimes you get lucky. Other times you don't get so lucky."
Grinders will chew up rocks if they find their way into the grinder, Kafka adds. But tramp metal? That's the biggest problem he encounters when grinding shingles.
"A rock will nick teeth and wear it, but the machine will pound the rock up and shove it through without any damage," he says. "The machine has a hard time passing through a big chunk of steel."
The 6710B's grate system has a gate that opens for operators to remove metal chunks when the machine detects such material. The system provides some relief, Kafka says, but metal can cause significant damage in a matter of seconds.
"I've had it happen at a mill, I believe," he says. "A piece got in there. It bent and busted bit holders. I had just put in grates and it wrecked every single grate in it - that was probably about $8,000 worth of grates."
The incident also sheered off and bent the anvil and ripped off cheek plates.
"It was the most damage that was ever done to that machine," Kafka says. "It was a bad day and several days [thereafter] of reconstructing."
So capturing obstructive material before it’s loaded into the hopper is a must.
"I've had people bring me satellite dishes, front doors and 40 pieces of plywood," Kafka says. "It's hard to catch them all. If you turn your back, someone tries to sneak in that stuff."
For shingles, Kafka says he doesn't accept anything except clean shingles to grind. Kafka Granite does have bins on site where metal and debris can be unloaded. But even that option and signs deterring such material from being unloaded on site aren't always enough to prevent people from dumping potentially obstructive materials.
"I had a guy sneak in here with the front door of a home," Kafka says. "I'm talking about a metal door with the jam on it and the window in it. I don't know when he snuck in here, but he dropped that baby off.
“Sometimes I don’t know what people are thinking.”
Kafka estimates his company grinds 60 percent of its shingles off site. Most of the shingles processed on site are typically brought in on the backhaul of a rock delivery.
Pinpointing large shingle loads to process isn’t an easy task, Kafka says, but opportunities to haul shingles back are available.
"A lot of guys started off landfilling shingles and getting $40 a ton," Kafka says. "They just kept piling them up and never did anything with them."
A number of landfills like that exist around the country, Kafka adds. His job is to find those landfills and bring the shingles to his site for processing.
"I've found several sites where I've moved in and basically cleaned them up," Kafka says. "I haven't been charging. So far I've just been saying, 'I'll come in and bring them out of there.'"
Once shingles are grinded and screened, Kafka Granite sells and delivers the processed material to asphalt companies. The finished product is ultimately used in new asphalt pavement mixes.
"It's got a very high oil content," Kafka says. "The state only allows them to mix about 5 percent into the mix design. I think most asphalt companies settle in at about 3.5 percent."
Other markets served
In addition to recycled asphalt shingles, Kafka Granite produces landscape and architectural aggregates.
"We crush nothing but specialty aggregate," says Glenn Kafka, owner of Kafka Granite. "When I say specialty aggregates, we go into floor tile, quartz countertops that go into two-part epoxy resin for overlays of bridge decks and streetscapes. That market took 30 years to grow."
Kafka Granite also supplies aggregates to municipalities and golf courses for pathways, as well as aggregates used on baseball fields.
“I have probably 40 different colors, and we blend aggregates and create new colors,” Kafka says.
The company recycles a number of miscellaneous products, as well, including glass and porcelain. It custom grinds to about 100 different specs, Kafka adds.
"We'll meet any spec anybody needs," he says. "I don't care if they call and say they want from a 3/4 in. all the way down to a 75 mesh - we'll make it happen, with anything in between there."