W&WP March 2004
Woodworkers, even those who operate small shops, are trading in their handheld sanders for feed-through widebelt sanders to help decrease time and labor, and increase output.
By J.D. Piland
There are several factors that influence a consumer's choice of wood furniture and cabinets. Price and quality of construction spring to mind. But to a large degree it is the visual aesthetics that can attract a customer and his or her money.
Eric Johnston of Stiles Machinery sums up the importance of a good finish this way: "The last thing you do is the first thing the customer sees." Indeed, the quality of the finish and its appearance is what will draw customers.
One key to getting a quality, consistent finish is the final sanding operation. While a skilled craftsman might be able to use a handheld sander to achieve a quality finish, the consistency is sometimes lacking. Stains might hold well in one spot and not the other. This is where the widebelt sander comes in. Widebelt sanders are becoming more common even in smaller woodworking shops because of their consistency and speed, which are vital to finishing the workpiece and getting it to the customer.
The quality of a product's finish has prompted Wood & Wood Products to talk with several manufacturers and distributors of widebelt sanders to see how important the machine can be to helping improve quality, increasing productivity and growing a business.
Tim Mueller, senior product manager at Timesavers Inc., says, "If you don't have a widebelt sander, just buying one increases your productivity."
"If you add up the hours spent hand sanding, you are paying for the [widebelt] sander already," says Steve Jones, Butfering product manager at Altendorf America. "Small shops often don't realize that any labor saved has more impact on the shop than it does on larger shops. If a smaller shop can save 12 hours a week, that could be 15 percent of their work, while it could only be 5 percent at a larger shop."
Johnston, product manager of Stiles' Heesemann Sanding Division, agrees. "If you have one man with four or five workers with orbital sanders, they will grind and grind all day long. One man (operating a widebelt sander) might do all that work in an hour." With a widebelt sander in smaller shops, there could be only one person, or at most two people - one feeding, one tailing the machine, he adds.
Keith Paxton, product manager of Kundig Sanders at Holz-Her U.S. Inc., says one feature that reduces downtime is a programmable logic controller. The PLC allows the operator to quickly select from a menu of pre-programmed setups based on the characteristics and dimensions of the workpiece.
Ed Moran, national product manager of edgebanders and sanders at Biesse America, adds that more manufacturers of widebelt sanders are going digital. One such feature is a digital measuring system that automatically measures the thickness of the piece and adjusts accordingly.
"You can't always just use the tape measure to determine the thickness. Sometimes you want to be at one-tenth of a millimeter," Moran says.
While the digital and electronic features are a little more complicated, and thus take longer to initially set up, shops are ultimately able to cut down on operator labor, or at least redirect it to other projects.
Mueller says that with these features, the required skill level for sanding drops slightly. "We've simplified the controls; you are able to have a less-skilled operator and have your more-skilled employees working on something else," he says.
Also helping save time is a fixed conveyor belt, Paxton says. With a fixed conveyor belt, the widebelt has more stability, the rollers are on the same plane as the belt and, if bumped, the belt will not move out of position, Paxton adds.
Bottom head machines are becoming more common as well. In effect, a bottom and top head sander can cut the time in half since the piece only requires one pass, rather than flipping it to sand each side separately. Jason Reddy, product manager of the Widebelt Sander Division at SCM Group USA, said bottom heads used to be so costly it was rare to see them. But now they are creeping up more, and they help eliminate making more than one pass. In the past two months, Reddy said he has quoted 10 bottom-head machines, which is a huge boost over the last three years.
As far as the exact amount of time saved, Paxton explains that an old rule of thumb is 10 raised panel doors through a widebelt sander to one hand-sanded, but that is a "very conservative" guess. Moran says an operator could do up to 25 doors in a widebelt sander while someone else does one by hand. Adding heads or a bottom sanding unit will increase output even more.
Mueller adds that upgrading to a four-head sander from a two-head sander, for example, will double your productivity.
Paxton says productivity depends most on the substrate, the conveyor speed (dwell speed) and the number of heads in the sander.
Spending tens of thousands of dollars on a machine can be a daunting task. But, as Jones says - and Mueller agrees - widebelt sanders can last 20 to 30 years. Mueller adds that he knows of machines out there that have been running strong for 35 years.
The fear of spending that money with no immediate return is relevant but sometimes unfounded. Paxton says if the product is lacquer sanded, then the payback is quick. He adds that there have been companies that come back to him and say they paid for the sander in less than a year, and there are some that take two to three years; this occurs in applications across the board, not just the larger shops, he adds.
A 'Pad' on the Back
"That's when you are going to be spending a lot of money," says Johnston, referring to the loss if veneer is sanded through. Not only is the piece rejected, all of the work that went into producing the panel is for naught, he adds.
Segmented pads are particularly beneficial if veneered or lacquered pieces are run through the widebelt sander. The pads are controlled by either pneumatic or electronic means and conform to the workpiece's contours. As the piece moves through the machine, sensor rollers move across the surface of the piece controlling and moving the corresponding pad, which only touches the surface slightly, in the same motion. The pads are located on the last head of the machine and are available in amounts that depend on the width of the machine.
Reddy says the more narrow the pad, the better the finish because narrower pads can more precisely conform to the surface area. He adds pads are a great improvement over an air-filled bladder, which would conform to a workpiece's contours when lowered onto the piece.
Moran says segmented pads are used in about half the machines on the market because not all woodworkers work with veneered or lacquered pieces; some just deal with solid woods. In addition, segmented pads bump up the cost.
Perhaps the most interesting development with segmented pads, according to Jones, is their expanded use with less expensive sanders. "Smaller shops used to have a pre-conceived idea that they couldn't get segmented pads and tried to sand everything by hand," he says.
Because hand sanding can be "terribly time-consuming and inconsistent," some smaller, entry-level sanders now have segmented pad technology. And with the number of smaller shops relative to larger shops being so large, the entry-level sanders are the largest market for widebelt sanders with segmented pad technology, Jones says.
Paxton says there is some validity to the 60-30-10 rule, but that applies more to the high-end cabinetmakers. The 60-30-10 rule refers to the amount of stock removed on each head or pass when the piece goes into the machine. When using a multi-head sander, the first head would remove 60 percent stock, the second 30 percent and the last 10 percent; a single head sander would remove those same amounts on respective passes.
He adds that it has become a rule of thumb for some woodworkers to skip a grit if it is under 150. However, he urges that rule is not wise if the grit is more than 150.
The correct grit sequence for the job also determines how many sanding heads are needed. To determine the number of heads, figure the grit you want to start and end with, then count back in order of the number of different grits. For instance, if you want to start with 100 grit and end with 150 grit, with a 120-grit belt in between, then you would need a three-head widebelt sander.
Mueller adds the belt's life will decrease if a grit is skipped because it is forced to do the work of the "missing" grit.
"Most companies are going to more heads and not skipping a grit because they find it not only optimizes productivity, but also the belt life," he says. "A ton of money is put into abrasives." He estimates that woodworkers will spend more on abrasives than on the machine during the equipment's lifetime.
Moran said it is important to apply the correct tension on the sanding belts. A loose belt can have premature wear and start to feather or fray. Plus, a loose belt can create increased surface contact with the piece. More tension on the belt will also increase its life, he says.
Mueller adds that properly maintaining belts gives you "more than productivity, it decreases your cost per part." Mishandling the belts potentially decreases the life of the belt.
"When you get into fine sanding, [sanding belts] are usually made of paper rather than cloth like lower grits; they are more fragile and you could snag it and tear it easily," he says.
In the Market?
The biggest market for widebelt sanders now is the small to medium shops. As mentioned, even the smaller shops are purchasing widebelt sanders to help increase productivity and improve quality.
Jones explains that a typical first-time buyer usually goes with a single-head machine and looks at the price. Meanwhile, a second-time buyer usually goes with a double- or triple-head sander because their output increases and they need the larger capacity machine; they are focused more on the features or construction (roller, frame, bearings) of the machine.
Johnston agrees and adds that a larger shop could be running veneer all day on the same machine, and will look for size and weight rather than something that could do it all in one pass. "He could run veneer sanding in one cell, and sealer sanding in another cell. The larger shop is looking for a specific application rather than a more general one."
Paxton adds to that saying customers should consider the machine's adaptability - whether they will be able to expand their machine or buy a new one if business increases that much.
When asked what should be the No. 1 consideration when in the market for a widebelt sander, the overwhelming answer from the experts is knowing what your needs are.
"We've come to realize that a lot of people that are looking to get a sander really don't understand what they want to do. They say, 'I want to do this,' but don't know what they need," Johnston says.
Reddy agrees. He says a company needs to know what their finish grit is going to be and prepare to buy the machine that can handle it. But, he is adamant that the company should also look to the future and get something that may help better if production does increase.
As far as the payback goes, Reddy says he knows of some small to medium West Coast shops that are sanding for other companies because their sander just sits there half of the day. "This way they are able to pay off the machine quicker."
The bottom line? A widebelt sander will help boost shop productivity and take the business to the next level.
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