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Grinder Buying 101: Experts Suggest Considerations to Evaluate Before Choosing a Grinder
Grinders don’t come in one-size-fits-all. Here’s what you need to consider when choosing a grinder for your company.
By DeAnna Stephens
Date Posted: 2/1/2010
Buying a grinder is a significant investment for a company. Choosing the right one is not something that should be done on the spur of the moment or based on price alone. Grinders do not come in one-size-fits-all. The growing demand for wood fiber makes having the right grinder, in terms of both input and output options, even more important for any pallet company looking to expand into this new market. Before your company purchases a new grinder, make sure that all the important questions have been asked and answered.
Is Grinding for You?
Mona Tracy, owner of Trace Equipment has helped many pallet companies think through the grinder buying process. She said that because grinding is a separate business, a company should look into it both as a way to meet their needs and as another source of income.
“It’s not just something that you’re going to do and let it run itself,” Mona said. “You have to pay attention to that business.”
She recommends doing research to find out what end products could be sold locally. “Look in your area. Find out if you do have a sellable product. See if it is going to be a good deal for you to get into it financially.”
This could include turning your wood waste into animal bedding, pellets, playground fiber, engineered wood or mulch. It could be sold to local farms, hardware stores, landscapers and the forest service, or used in your own boilers to heat or run your facility.
“A lot of times people don’t know what’s out there,” Mona said. “They find out that if there is a need, not only do they have to grind, they may consider coloring, they may have just a seasonal area for it. They may build up their grinding for two or three months and then start selling in the spring for mulch.”
“So look around, see what radius you want to cover, get some good resources for a final product, make it a good sellable product and make some money on it.”
Mona also suggests looking into local restrictions that may affect grinding.
“Before you can get into grinding, find out what your restrictions are and what you can do in your area,” she said. “There may be local restrictions on grinding because of the noise factor and material buildup. Grinding can be a good addition to your current business.”
Once you know that you want to pursue buying a grinder, you have to decide what grinder is best for you. This will be determined by several factors –
• What you need to grind?
• What you want the end product to be?
• What your expected volume is and how much it costs to run?
How Much Do You Want to Grind?
Jeff Williams, president of Pallet Repair Systems, said the two biggest mistakes that he sees companies make when purchasing a grinder is buying based on price alone and buying a machine that doesn’t have enough capacity to meet their needs beyond the first year or two.
“I’ve often seen this type of short-sighted decision whereas the buyer really should consider the larger picture and as a longer term investment into their business,” Jeff said.
Both the volume you need to grind now as well as the volume you will need to grind in the future should be considered as you choose your grinder.
“You have to know the volumes that you’re going to need,” said Jack Cress, CEO of Cresswood. “If you need to do 20 tons an hour you’re going to have to go with one technology. If you need to do three tons, four tons, or five tons an hour, that’s a different technology.”
The basic rule of thumb is that higher speeds are needed for higher volumes.
“Every technology has its pluses and minuses in the sense that you have to know what the shredder needs to do,” Jack said. “If it needs to do 15,000 – 20,000 pounds an hour, then low speed technology probably isn’t the way you want to go.”
Other considerations that should be taken into account when choosing between a high-speed and low-speed grinder is where you plan to have the grinder located.
“A low-speed, single-shaft shredder like Cresswood produces runs anywhere from 70 – 300 rpms, it is a lot slower,” Jack said. “You can put a machine like that right into your work environment. It’s safer because you’re running at a much lower rpm, it’s quieter.”
What is Your End Product?
Once you’ve found a machine that can produce the needed volume, you need to make sure it can produce the end product you are looking for. If your end product is mulch you may want a grinder that colors as well. If it is animal bedding, you may want to purchase a system that includes a secondary shred to get the wood waste down to the right size.
“You need to have a uniform product no matter what shredder or type of machine you have,” Jack said. “You have to have a value added product when you get done.”
And remember, your target customers may have their own specifications; so make sure you know what those are in advance.
What Kind of Separation Do You Need?
Nails and other scrap metal need to be removed from the wood residue in order for the end product to be sellable. Knowing what percentage of separation you need will determine what kind of extraction system you need in your grinder. The amount of separation needed will most likely be determined by the specifications of the buyer.
There are several ways of removing metal debris, but no separator can produce 100% debris-free material. Jack said the most preferred method in the pallet industry is the cross-belt separator. It is self-cleaning, meaning it removes the metal from the magnet and dumps it into a collection bin. Jack also said the best way to get the most nails and get the best separation is with a magnetic pulley head. Like the cross-belt separator, it is self-cleaning. According to Jack, many customers use both separators within one system, for a higher separation rate.
How Much Does It Cost to Grind Per Unit?
Figuring out how much it costs to grind per ton or cubic yard is a good way to choose between diesel and electric powered grinders, according to Jack. This cost would include maintenance, labor and fuel or power.
Diesel machines tend to be more expensive to run than electric, according to Jack, but they do have some benefits. They are usually high-speed, self-contained and portable, making them a good choice for use out on location.
One advantage of electric-powered machines is that they usually cost less to run.
“Where low-speed technology has its benefits is the cost per unit; it is lower than high-speed technology,” Jack said. “If the company doesn’t need those huge outputs, then there are some benefits to look at that kind of technology to fit their needs.”
How Easy Is the Machine to Operate and Maintain?
Gibb Harrington, director of new development for Rotochopper, said ease of maintenance is one of the most important considerations. He suggested having someone from your company’s maintenance crew look at any grinders you are considering buying to see how easy it is to deal with the normal maintenance required such as changing the cutting teeth, cleaning and repairing.
This is also an area where the manufacturer or supplier could play a role. Rotochopper sends a service tech on site when new equipment is installed to train operators on how to work the equipment, according to Gibb. They also have online monitoring that allows them to adjust machinery remotely.
Bear in mind that labor costs may differ from one design to another. Grinders that must be fed in batches will end up costing more in labor costs than one that can simply be dumped into. You don’t want to end up paying for workers to stand and feed the machine by hand unless you can justify it by the profit you will receive from the end product.
Profiting from wood residues is a growing opportunity that many pallet companies should consider. The demand for wood residue has risen as the stream coming from the housing market and sawmills has slowed, giving pallet companies a chance to benefit from an emerging market. The most important thing for interested companies to remember is to make sure they know what they need before they purchase. This will allow them to buy a grinder that fits their needs and helps them turn a profit.