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Volume, Type of Wood and Products Key Factors in Starting Grinding Operations: Buying Decision, Grinding Options
Grinding: Suppliers of grinding equipment discuss options, strategies for setting up grinding operations for pallet and sawmill businesses; list of advertisers with contact information.
By Diane M. Calabrese
Date Posted: 5/1/2008
Match the machine to the goal. In a nugget, that is what manufacturers of grinding equipment would tell a pallet manufacturer, lumber remanufacturer or sawmill owner planning to purchase a wood grinder for the first time.
Wood fiber is valuable. Making the most of it adds to the bottom line. Scrap pallets, sawdust and slabs may have once been considered waste, but no longer.
Grinders convert slabs, ‘lily pads,’ short logs, trim ends, edgings, used pallet parts, scrap pallets and other wood material into a valuable product. Grindings are purchased by other companies to be burned for fuel and other businesses that process it into wood fuel pellets, pulp, landscape mulch, playground substrate, particleboard and more. They extend the service of wood in used pallets and building materials.
We asked representatives of manufacturers of wood grinders what a first-time buyer ought to keep in mind. From their advice, we compiled the basics. To be sure, the experts that spoke with Pallet Enterprise have lots of solid recommendations, many more than we can share here and plenty to discuss with prospective buyers. (See the accompanying list of advertisers that manufacture or sell wood grinders.)
Begin with a reality check. Having spare wood fiber is not the same as having enough wood fiber to support grinding operations.
“They have to figure out their cost, what they’re putting into the machine, what they’re going to get out of it,” said Tom Lane Jr., CEO of Lane Recycling Machinery in Ruckersville, Va.
The market for wood fiber products will always be there, although niches may change. Still, in order to pay for a grinder, a company must grind a certain volume of wood. Some companies that do not have enough scrap wood material may seek a contract to grind for a local government or other wood products businesses before they buy a grinder. That is a good approach, but Tom called it the classic chicken or egg dilemma—whether the contract or the grinder comes first.
A 5-yard dumpster of scrap wood each week may seem like a lot of waste material, but it may not be enough wood to justify the investment in a grinder. The volume must be sufficient to cover the cost and operation of the machine.
Vince Hundt, head of sales and marketing at Rotochopper in St. Martin, Minn., said volume should be at least 20 cubic yards per day (100 cubic yards per week) to support a grinder operation as an add-on business venture.
The destination of the grinding product and how much other companies will pay for it are important factors in weighing the minimum volume of wood required. A high-quality, value-added product is worth more, such as high-quality colored mulch. Do you sell your product on the wholesale level or at retail? Finally, who is going to haul the product? Transportation costs may be the most difficult to figure.
Ask for help with a cost-benefit analysis, suggested Vince. Rotochopper and other companies interviewed for this article will help provide such analyses.
If the potential economic benefit is there, space and zoning are the next factors a prospective buyer has to assess. A satellite location may be necessary for the grinder if there is insufficient space or a community will not allow grinding at an existing location.
When all the ancillary issues are resolved, a company is ready to make a choice. It’s all about knowing what you need.
“We recommend trying the product before buying,” said Jason Morey, who works in marketing for Bandit Industries in Remus, Mich. “A grinder is a major purchase and should be evaluated before making a decision.”
Even before a trial, said advertisers, talk not only to the grinder manufacturer but also to businesses with grinding operations. Visit their facilities and look at their plant layouts. “Selecting a grinder that best fits one’s needs on the applications they are doing is the most important step in minimizing labor,” said Jason.
Grinders are equipped differently to reduce wood. Some machines use knives or cutting tools to shred, cut or chip the wood. A hammermill type grinder uses hammers or teeth to pulverize the material and can tolerate the sort of debris found in pallets, construction waste and junk wood, noted Jason.
Characteristics of the wood waste to be processed by the grinder are important, too. Even pallets differ in the resistance they pose to a mill. Crating pallets may contain angle iron or large bolts, said Dave Rutherford, a sales representative for Continental Biomass Industries (CBI) in Newton, N.H.
Choosing a mill or grinding mechanism for breakdown “really depends on what end product you are trying to make and if there is contamination in the material,” said Ed Donovan, another sales representative at CBI. If the only contamination is nails, a forged rotor running at high rpm would be suitable, he indicated; for heavily contaminated material, a solid steel rotor would be his recommendation.
“Sawmill waste can be difficult because of the metal contamination that is usually found in the wood pile,” said Rutherford. Beyond that, the desired product dictates the best choice of product for sawmills.
Many machinery manufacturers recommend a four-pocket chipper for sawmill waste. It produces a small chip that can be supplied to wood fuel pellet manufacturers.
“In many applications the single-shaft shredder has replaced the older style hammermill or hog,” said Vikki Van Dam, inside sales and marketing manager at WEIMA America in Fort Mill, S.C. Instead of swinging hammers, the shredder cuts the material with indexable knives that can be rotated four turns before being replaced, an arrangement that contributes to labor and time savings.
For sawmills that want to grind slabs, an in-line system is an option. Such systems can reduce labor, said Vince, especially if the company is bundling slabs. With an in-line configuration, no one handles or touches the slabs. Also, grindings from virgin wood are coveted for products with stringent environmental regulations, such as playground substrate.
Labor can be controlled or reduced in multiple ways. “An efficient layout of an infeed conveyor is the best way to minimize labor in a pallet operation,” said Kent A. West with Tryco-Untha International in Decatur, Ill. “It eliminates the forklift operator making frequent trips to and from the grinder operation…”
Built-on loaders are another time saver. Mid-size and large grinders may be purchased with a grapple loader, said Al Goehring, marketing director of DuraTech Industries in Jamestown, N.D. “This allows the operator to load the machine as well (as operate it), making sure the machine is operating at full capacity.”
Remote control capability is another time saver, said Al. So, too, are oscillating stacking conveyors because they “allow the operator to build a wider pile of product without stopping to move the pile or the machine or have someone else move the pile,” he explained.
Screen strategy also can speed up the grinding process. For quick reduction, large screens can be used, said Goehring. A regrind can be done later on the subset of material that will be processed into mulch. “If time is not an issue, smaller screens can be used initially and the final product can be made,” he added.
Manufacturers offer a range of engine sizes on the same grinder so customers get the horsepower they need and no more. Stationary grinders can be wired to a plant’s electrical system. “If it’s going to be a permanent installation, electric is cleaner and quieter than diesel,” observed Vince.
The permutations of basic grinder design continue to grow. It’s about much more than a hammermill or knives, tub or horizontal arrangement, and overall size.
(Do not overlook size when selecting the opening of the hopper or infeed. For example, a business that expects to grind a lot of odd-size pallets may want a bigger opening so most pallets can be fed ‘whole’ into the machine.)
Manufacturers offer solutions tailored to the goals of a customer. Some specialize in custom-build. Among the many time and labor saving considerations are in-line mulch coloring technology to a second hammermill to produce sawdust quality output in one pass.
With sawmill production down because of the slumping housing industry, the volume of residual materials — like sawdust or wood grindings — available from mills also is down. There are still markets for the wood fiber, but the available supply has been reduced, so competition is keener.
For example, some farmers buy sawdust for animal bedding. Since sawdust has been in short supply, some farmers have turned to purchasing small grinders to produce their own bedding material, said Tom of Lane Equipment.
The marketplace continues to bring opportunities. Markets may change, but they continue to exist. Being able to modify a grinder or trade it in for a different machine to keep pace with changing markets is another important consideration.
Noise reduction is another factor that grinder manufacturers can address. Many wood grinder manufacturers offer machines with torque control that enable slower, quieter breakdown of heavy input like pallets.
Carbide teeth or tips get high marks from everyone. Strong and efficient, they reduce the hardest wood. “A solid carbide tooth lasts a very, very long time,” said Vince. Where there is “zero-expectation” of metal in the wood mix, such a tooth may be the best choice. Otherwise, tips that can be easily replaced are a good choice.
The hotter that metal components run, the more wear they experience. Buying a grinder means adding another piece of equipment that requires considerable maintenance. The cost of maintaining the machine should be factored into the buying decision.
Different manufacturers have various perspectives on the way the grinding mechanism affects maintenance. “When grinding, there is a lot of heat generated – friction – (and) this heat contributes to excessive wear on components,” said David Wilson, a sales and marketing representative for Concept Products in Paoli, Penn.
A mechanism that generates less heat prolongs the life of mill components. A prospective buyer can get information about the heat generated by a grinder from the manufacturer.
Besides weighing the affect of heat on the hammers or cutting tools, consider the accessibility for maintenance. Manufacturers offer a variety of easy access methods for engine and mill or knife maintenance.
Carefully consider the placement of wood reduction equipment — as you would any other kind of materials handling system. “Allow for surge capacity and eliminate multiple transition points, which can be a source of plug-up,” said Mark Lyman, president of West Salem Machinery in Salem, Ore. “Other considerations include by-pass and re-entry points to handle clean-up waste as well as capacity for future growth.”
Growth and the future may seem well beyond the scope of interest for first-time buyers of wood grinders. However, they should be part of the initial buying decision, according to grinder manufacturers.
The addition of a grinder is such a big investment that it should be tied to a business plan. The business plan forces a buyer to confront not only the cost of the machine but also the cost of operating the machine and the return from markets for the wood grinding product. The analysis of markets has to be applicable to the area a company plans to serve.
“Potential markets for wood waste residuals are extremely dependent on geographic location, and market values can vary greatly,” said Mark. Research is a must.
To summarize, know the volume of wood (per day, per week), type(s) of wood available and type(s) of product envisioned. When you know what you want to accomplish, you can go to manufacturers and ask them how they can help.
Manufacturers of Wood Grinding Equipment
Continental Biomass Industries
Cresswood Recycling Systems
Lane Recycling Machinery
West Salem Machinery