BioCycle November 2004, Vol. 45, No. 11, p. 50
Wood grinding operations find consumer demand for colorized mulch is on the rise, both for its decorative value and longevity.

NAZARETH Pallet Company in Northampton, Pennsylvania leaves no wood scrap behind. About ten years ago, the pallet remanufacturer was faced with a disposal problem for its wood scraps that couldn’t be used in pallet repair. Until that point, it was allowed to burn the scraps, but that practice was banned. Landfilling was too costly, so Nazareth Pallet located a mulch wholesaler in the area who was willing to purchase ground wood chips at a price that covered the grinding costs.
When the mulch wholesaler informed Nazareth Pallet that it would no longer pay for the chips, the company decided it would turn a problem into a business opportunity. The mulch wholesaler had been colorizing the chips it was purchasing, and Nazareth Pallet decided to pursue that avenue itself. At the time, the company was generating about 800 cubic yards (cy) of mulch per week. It owned a Jones “MightyGiant” tub grinder, capable of processing up to 200 cy/hour, and an older Wood Products stationary grinder. A Becker-Underwood coloring machine was purchased, and, says George Frack, Jr., of Nazareth Pallet, “we couldn’t keep pace with demand during our first year of production.”
In 2001, when BioCycle first wrote about Nazareth Pallet (“Pallet Remanufacturer Supplies Colored Mulch Market,” May 2001), the company reported it had sold 25,000 cy of colored mulch in 2000. In 2004, “we are around the 50,000 cy mark,” says Frack. “We have upgraded our Becker Underwood machines, which are more water efficient. We still have the same grinding equipment.”
Frack notes that the best mulches are achieved with a double grind, producing a one-to-two inch particle. The mulch is generally stored and reground prior to coloring, and there is no evident decomposition during storage. “The pallets we receive are made of dried, seasoned hardwoods,” explains Frack. “Because the wood is so dry, it absorbs the colorant well. The mulch retains that color and it takes much longer to fade than natural mulches, which maybe retain their color for 30 to 45 days after application. With our colored mulches, buyers get a full season, and they can even leave it for the next season.”
Nazareth Pallet’s product, which it wholesales to landscapers and garden centers, typically sells for about 30 percent more than its uncolored competitor. “People pay more up front but it pays in the end because colored mulch lasts longer,” he adds. In general, demand for the product has gone up every year. While red is the color most people notice, Frack says there is actually more colored mulch out there than people may realize. “There is a lot of demand for black and brown, especially brown, because it most resembles double ground organic material but in fact it is dyed. We see a lot of that in industrial parks.”
CUSTOMIZING THE COLORS
W.D. Zwicky & Sons, Inc., based in Robesonia, Pennsylvania, has been in the wood recovery business for years. The evolution of this company has been followed in BioCycle (“Processing And Marketing Woody Materials,” September 1997; “Processing Your Way To Wood Markets,” January 1999; “Excavator Spawns Successful Wood Recycling Business,” March 2002.) Much of the wood processing takes place on job sites using mobile grinding and screening equipment. At its own yard, and other ones it has opened more recently, many different woody streams are received, from land clearing debris to damaged pallets. Key to Zwicky’s operation, and thus its success in supplying high value markets, is keeping these various streams separate once they arrive. Material is stockpiled based on its source and the type of product it will be made into. One reason for the separation, company owner Dave Zwicky told BioCycle many years ago, is the potential for fires. “The dry lumber is a great fuel source. And the green material is a source of heat. Put the two together and you have trouble.”
When it comes to colorizing ground wood, this sorting process helps maintain product quality and processing efficiency. “Our set up is such that we have so much control over what comes in and how we stage it when it gets here,” explains Zwicky. “We make colored mulch out of pallets, as the dyes do not adhere to green wood. We also are able to make some colored mulch out of roots.”
The company uses Morbark grinding equipment. It built its own coloring machine, which has a throughput rate of 500 cy/hour. Dyes are custom-made. “We make primarily red, brown and black mulches, and the market is very strong for the products,” says Zwicky, noting that the market doubled in 2003, and then doubled again in 2004. “We only do wholesale, and will custom color for our clients. We have even colorized bark for some customers.” The company also makes base chips that another supplier then colors. “In the next two months, we will produce 30,000 cy of base chips for a couple of clients,” forecasts Zwicky.
W.D. Zwicky & Sons sold 800,000 cy of wood and green waste-based products in 2003, and is expecting to top that number this year. While the company does some composting at its original site, it recently opened a 120-acre facility that will have about 35-acres of composting pads. “We are in the process of obtaining a general permit from the Pennsylvania Department of Environmental Protection that will enable us to receive a full range of source separated organic materials,” says Zwicky. – N.G.
CLEANING UP THE HEAVY FRACTION
JUSTIS Waste Recycling (JWR), based in Redding, California, designs and operates a range of solid waste processing facilities, including dirty MRFs (where recyclables are removed from the MSW stream), mixed C&D plants, and green and wood waste recycling operations. In Wilmington, California, JWR operates a C&D and MSW recycling/processing facility with a throughput capacity of 1,000 tons/day. Both waste streams are processed on the same line.
“We do an initial sort by excavator to remove any oversized items or ones that could damage the equipment,” says Rob Justis of JWR. “Materials are loaded onto a conveyor, pass over a screen, then are hand-picked to some degree. A magnet removes available metal.” The 3-inch minus fraction that falls through the first screen is conveyed to a new piece of equipment called the Maxx-Integral. Manufactured by Komptech and marketed in the U.S. by Norton Environmental Equipment, the unit “marries” a trommel screen with the Hurricane air separator (versus two separate pieces of equipment). “We’ve been operating it for about two months,” says Justis. “Basically, we are using it to clean up the fraction of the recovered C&D stream that is used for daily cover at the landfill on the site. It is designed to remove paper and plastic and we are left with dirt, wood chips and other heavier materials. We’ve been putting through about 200 to 300 tons/day of C&D and 50 tons/day of MSW.”