For any panel processing operation, the edgebander has become the lynchpin of success. When it's running smoothly, work flows smoothly. But when the machine acts up, the bottleneck it creates can cut workflow to a trickle.
That's why it is so surprising that many plants often overlook basic maintenance chores that will keep their edgebanders up and running. Edgebander technicians say these shops are risking, at the very least, poor performance from their machines, and at the worst, they may face more dramatic and costly machine failures.
Technicians say that it may be the apparent complexity of edgebanders compared to simpler woodworking machines that puts people off from properly maintaining their machines. But the basic maintenance operations for most machines are quite simple and take very little time, considering what production time could be lost if the machine starts acting up.
Cleanliness is crucial to successful edgebander operation. That's one thing on which every edgebander technician we talked to agrees. "In 80 percent of our cases (of edgebander problems), it's the customer not keeping the machine clean," says Ed Moran, national sales and product manager for Advanced Technology Division, Edgebanders, at SCM Group USA. "If they just keep it clean they're 70 percent ahead of everyone else."
Tracey Bell, technical service manager for Holz-Her U.S. Inc., echoes those sentiments. "The simplest thing, but very important, is just blow the machine off. If you can, cover it up at the end of each day." He notes that edgebanders have a lot of moving and working parts that can easily be fouled by dust. Even if the dust doesn't actually stop the machine, it will affect the precision tolerance of followers on the workpieces. That could lead to ragged cuts or bad glue edges.
Steve Jones, Brandt product manager for Altendorf America, says, "A lot of it starts with basic common sense things. Keep the machine clean and blown out of debris at the end of day." He recommends allotting at least five minutes at the end of every day to clean the machine. "One of the better ideas I've seen is to take a drop cloth and cover the machine at the end of day," he says. "Overnight all the dust in the air tends to settle."
Torben Helshoj, president of Laguna Tools, agrees that dust and dirt are prime concerns, but he suggests regular cleaning alone won't do the trick. "You need exceptional dust collection," he says. One of the areas where this can become a critical issue is the trimmers. Dust there can cause problems for linear motion bearings and affect the quality of the cut.
Bell agrees with Helshoj on the dust collection issue. "The main thing with edgebander problems is a lack of dust collection, particularly inadequate intake. It's especially important to get dust off tracer wheels because they get bumped by dust."
Basic lubrication is another area that is often overlooked, technicians say. Like his colleagues, Helshoj of Laguna Tools emphasizes the importance of following the manufacturer's lubrication recommendations and maintenance schedule. He says particular points to look out for are chain drives and linear motion bearings.
Jones says lubrication is important and shouldn't be a chore because, "There really are not a lot of things that need lubrication. Twice a week, give the feed track a shot of lubricant. Some machines even have automatic lubrication."
Moran recommends regular lubrication of the track system, the gluing system, the pneumatic system, guideways and linear motion bearings.
"The most common mistake is using the wrong lubricant," says Bell. Holz-Her recommends the use of silicone lubricant for its machines, he says, but individuals should check manufacturer's recommendations for whatever machine they own. Even if there is an oiler on the air lines, don't rely on that to do all your lubrication, Bell adds.
Pneumatics bring special issues to edgebanding maintenance. "Moisture in your air lines can be an enemy to any machine with pneumatic cylinders," says Jones. "You really need to pay attention to that." He says a plant located in an area such as Florida, where there is high humidity for a high percentage of the year, may want to take special measures. "An air dryer extends the life of your cylinders," he says.
Kerry Barlow, general manager of Fletcher Machine, says, "One major problem we encounter is folks that put a tremendous amount of glue in the pot, and then leave it hot and let it cook out." To help solve that problem, he says, the Fletcher edgebanders are designed with a lower pre-melt temperature for the pot, and then glue is brought up to final temperature at the roller.
"Having air that's clean is very important," says Paul Byrd, national sales manager for Adwood. "An edgebander has a lot of electric/pneumatic valves. If there is salt, moisture and air involved, there is going to be rust. But there are inexpensive ways to clean air." He recommends using a ceramic filter or putting a dryer on the air system.
Helshoj says pneumatics generally run better with a dryer, but many systems without one encounter few or no problems. Still, he says, "Putting a drying system in could extend the life of the machine as much as three or four times."
Glue systems require special attention. Byrd says there are a number of maintenance issues that involve glue, glue pots and how glue is used by the machine. "Anytime you're dealing with hotmelt glue, it leaves a residue on the part it touches," he says. "That needs to be cleaned, but it's hard to predict how often. It depends on use; the more you use a bander, the less maintenance required because you're flushing the system."
A particularly common mistake has to do with glue selection, says Byrd. "A lot of times it goes back to buying the wrong glue product," he says. "Different glues have different viscosity and operating temperatures." He says if people use a glue designed for the wrong machine, bond problems may arise.
Byrd, who teaches a lot of industry classes, also cautions that some glue bond problems may have nothing to do with the edgebander itself. "The market doesn't understand that high-pressure laminate is not a 100 percent friendly product to hotmelt glue," he says. Sometimes the material needs to be prepared. The backer sometimes needs a primer. "It may appear to be bonded well, then it's in a hot or cold environment, and the edge pops off," he says. "It's a very common problem."
Another glue-related issue Barlow sees is customers who try to use cheap replacement glues. He says Fletcher has worked closely with the research department of Jowat to develop glue recommendations for a variety of edgebanding materials.
Moran says he's also encountered problems where edgebander owners have looked for less expensive glue and run into trouble. "It may not have the properties necessary for staying in the glue pot," he says. "It may burn faster."
The glue reservoir and glue temperature are also areas of critical importance, Moran says. "Every three months, you should check with a pyrometer to measure glue temperature," he recommends. The pyrometer reading should be compared to the thermostat setting. He says that sometimes heat rods can go out on a machine, and the operator just raises the temperature of the machine. Moran says that's a lot like the automobile driver who hears excess valve noise and just turns up his radio.
Moran recommends not filling glue reservoirs to the top. "You should run minimal amounts, continually feeding glue so the glue is used up," he says. "Otherwise glue begins to insulate itself from the bottom up. Quick-melt systems make sure you are constantly using fresh glue."
Helshoj says it's important to make sure the glue does not burn. "If the glue burns, it creates a scab, which prohibits new glue from going on the roller," he says.
Holz-Her's Bell notes, "We use a glue nozzle, not a glue pot." He says the glue area takes only about 10 minutes to clean, but it is one area that frequently is ignored.
Jones at Altendorf recommends giving glue tanks a thorough cleaning from once a quarter to semi-annually. "Purge the glue out of the system and replenish with fresh glue," he says. "It takes about 90 minutes. It's kind of like changing the oil in your car on a regular basis.
Still other issues may affect edgebander performance. Adwood's Byrd says that having clean voltage without a lot of fluctuation is important to efficient operation. Voltage fluctuations shouldn't vary more than 10 percent above or below recommended voltage, Byrd says. "All the equipment is self-protected, but it may cause some inconvenience," he says. "The machine may shut itself down. It's frustrating for a short period of time."
Tooling is another area of concern. "You've got to keep sharp tooling on the machine," says Bell.
Jones at Altendorf says, "People tend to use tooling longer than they should. The edgebander is a machine with multiple tooling at multiple stations. They have to pay attention to the end product coming off the machine. If the trim is getting ragged or sharp, either index tooling to a different position or change it."
"The biggest problem I see in edgebanding," says Barlow from Fletcher Machine, "is running the machine too slow." He says his company's machines should run at 50 feet per minute or higher. Otherwise the glue has too much time to cool and may not form a good bond.
Follow a strict maintenance schedule. That's the first line of defense recommended by all the manufacturers and their technicians. "The biggest problem is pure neglect," says Bell. "A lot of people have got a lot of money invested in an edgebander and don't do anything until it breaks."
Holz-Her supplies a check-off maintenance schedule with every edgebander, says Bell. That list has daily, weekly and monthly maintenance chores necessary to keep the machine running at peak performance levels.
Barlow of Fletcher Machine emphasizes that it is important for those people doing edgebander maintenance to be fully qualified. Fletcher combines initial on-site training with follow-up sessions as necessary.
Moran says SCM gives customers a maintenance procedure list based on eight hours of use a day. Where some customers get into trouble, he says, is when they add shifts and dramatically increase the use of the machine.
"When customers take it up to 16 hours a day, that doesn't necessarily mean do the maintenance twice," he says. "Actually, you're better doing it three times."
When a customer buys a machine from Adwood, says Byrd, "Every three months, on average, we send a maintenance reminder. Here are the steps needed." It also lists possible spare parts needed. Typical items covered include cleaning the glue system, checking heating elements, checking wear components like bushings and washers or any moving part and seals, then replacing them as needed. "Three months is a very conservative figure," he says. "Most can go twice that long, but I would rather sell a customer a $10 part than a $1,000 part."
For Byrd, the key is making customers aware of the importance of regular maintenance. "We're big on education," he says. "Anybody will conform to the basic maintenance requirements if they know it will save them money."
Setting edgebander tolerances
Ed Moran of SCM Group USA says an issue that comes up constantly when talk turns to edgebander maintenance is the issue of tolerances. "Tolerances have a direct impact on the consistency of the finished product," says Moran.
Each unit has some form of copying device, and maintenance schedules often do not include an inspection of the copy and pre-tensioning points on edgebanders, he says. "When copy and pre-tensions are out of calibration, the end result is poor consistency," he says.
He recommends that you check manufacturer specifications for your machine's settings. In most cases, he says, settings range from 1.0 to 3.0mm. After you have adjusted the copy settings to the specifications, it's important to check that the tension settings are also correct, he advises. "Spring tensions that are too tight can dent or scratch your materials," he warns. "Spring tensions that are too loose can cause vibration, and even worse, produce chatter marks on your finished edge."
Checklist ensures regular maintenance
Tracey Bell of Holz-Her U.S. Inc. says the company has found that the simple device of a checklist is one of the best ways to ensure that regular edgebander maintenance gets done. That's why Holz-Her supplies a plastic laminated, wipe-off checklist with each machine. The list covers daily, weekly, monthly and semi-annual chores and has check-off boxes for maintenance personnel to mark off work that has been done. Here's a sampling of some of the areas covered in the four-page list.
* Blow off and clean machine.
* Inspect water separator.
* Verify air pressure.
* Clean glue nozzle.
* Start each station separately and look for problems.
* Run a glue test.
* Run a test panel.
* Complete daily checklist.
* Clean and lubricate cylinder shafts.
* Remove glue residue.
* Check copy wheels and feeler plates.
* Inspect tooling.
* Check dust collection.
* Clean and lubricate guillotine assembly.
* Lubricate adjustment screws.
* Blow out fans on motors.
* Inspect and lubricate main track.
* Complete daily and weekly checklists.
* Check tension and lubricate drive chains.
* Clean and inspect replaceable brushes in DC drive motors.
* Inspect drive belts for wear.
* Service glue system.
* Inspect entire machine for loose parts or signs of abnormal wear.
* Blow out and clean out entire machine.
* Vacuum dust from electrical control panels.
* Inspect entire machine.
* Check oil level in main drive gearbox.
* Replace covers, make all necessary adjustments and run tests at full operating capacity.
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