Considered a workhorse in the woodworking plant, widebelt sanders are essential for their ability to machine a consistent, high-quality finish.
“Across all the woodworking industries, companies value a consistency of finish quality from their sander above all other capabilities. They want to be able to repeat a surface on the workpiece regardless of the species, the batch size, or the operator running the machine,” said Tim Middleton, product manager at Stiles Machinery. “The more subjectivity can be removed from the surface finish of the wood by the machine, the more desirable the sander will be.”
In addition to consistency, also critical is the ability to maintain tight tolerances. “On the top of the list of customer needs are tight tolerances, not only from side to side, but also having no ‘dubbed’ (rolled) edges,” said Harold Kapaun of the Apex Machine Group, a division of SlipCon. “With veneers getting thinner and thinner, customers demand a sander with very tight tolerances so they are not burning through their panels.”
Dressing the conveyor belt can help improve the machine’s tolerance, Kapaun said. He added that this process will also restore the grip of the conveyor belt feeding product into the sander.
Customers’ increased requirements for tight tolerances was also noted by Mike Johnson, brand manager at Biesse America. “We are seeing an increase in demand from the North American market for veneer sanding machine configurations with a working width capacity of 5 feet,” he said.
“In the past, the 5-foot width capacity demand came mainly from larger manufacturers of residential and office furniture, but today the demand is coming from a much broader range of medium-sized companies producing a wide variety of products. This has pushed us to produce machines in a much more affordable price range that have the ability to run this width of material,” Johnson added.
The need for versatility in the machine was also remarked on by Tim Sermonet, product manager at SCM Group USA. “Today’s market demands are for versatile machines that can handle many applications, such as sanding wood, veneer and sealer. As more shops are taking on a wider range of jobs companies do not want to have to purchase multiple machines.”
Keith Paxton, product manager at Holz-Her U.S., a division of Weinig, also noted the need for versatility due to the range of thicknesses, widths and media required to be sanded today. “The common item all manufacturers look for in a machine is a high quality, consistent sanded surface that is easy to reproduce, irregardless of the operator,” Paxton said.
“Everyone involved with veneer is looking for electronically controlled sanding heads, programmable edge control and program memory, capable of handling the ever thinning veneers without defects,” added Eric Johnston, sales manager for Costa Sanders/Costa & Grissom Machinery. “New effects on hardwoods and veneer panels such as saw-marks, scraping, grain highlighting and distressing top the list” of requirements, he added.
Yet despite the increased emphasis on sanding veneers today, one of the most common uses for widebelt sanders continues to be for solid wood applications, said Warren Weber, manager at SuperMax Tools. The capabilities he said he sees as still being most requested by customers include abrasive planing, “particularly for glued panels, making the joints flush, removing glue and having the panel flat,” and for uniform thicknessing of solid stock.
Gary Besonen, national woodworking sales manager at Timesavers, concurred. “The most basic capability request is to dimension/calibrate and finish sand cabinet components, doors, furniture components or any variety of products used to produce an end product made of wood,” he said. Besonen added, “Depending on the product, subsequent sanding might require an orbital sander to remove cross-scratch, brush machines to remove fuzz and break edges, or sealer sanders for other common, downstream requirements.”
Summing it up, customers want a sander that will provide a quality finish, while reducing the time needed for the process. “Customers that are reaching out to us are looking for simple, effective solutions for their panel sanding applications,” said Shawn Larkin, sales manager at Safety Speed Mfg.
“They need quick, easy precision sanding done with a soft learning curve. They are demanding consistency and low maintenance from their equipment while expecting flexibility and simplicity,” he added.
Energy Efficiency Also in Demand
Sustainable manufacturing is at the forefront in all phases of the woodworking operation, and sanding is no exception. Today’s machines are more efficient than ever, helping wood products companies to reduce their energy consumption and ultimately, their carbon footprint.
“Taking our lead from the European market in an effort to save on energy cost, the North American market is in a transition to ‘smart’ or ‘green’ machines,” said Biesse’s Johnson. “The market is asking for machines with both reduced energy demands, and machines that have the ability to monitor themselves and power down automatically when not in service.
“Software and control innovations have allowed us to provide this technology in more cost effective features than ever before,” he added.
Middleton from Stiles Machinery agreed. “Energy management systems are becoming more standard throughout the sander manufacturing community. Components such as high efficiency motors, variable frequency drives, water cooled drive motors, abrasive belt management systems, and dust collection feedback loops have greatly reduced the sanding machine carbon footprint. When using the components listed above in addition to an integrated energy management system, the sander is able to automatically go into a hibernation mode when not actively sanding parts thus reducing dust collection, air consumption and electrical power. Once a part is inserted into the machine again, the machine automatically ‘wakes up’ and all components go back to the required operational speed and power.”
Added Holz-Her’s Paxton, “Power can be reduced by 50 percent in this idle mode. The machine is timed to shut off automatically after a pre-set idle period. Drives are more efficient, so less horsepower is required for sanding. And motors become more efficient, so smaller motors can be used in items such as vacuum conveyors and feed belts,” he said.
Both SuperMax’s Weber and Safety Speed’s Larkin also cited the use of low voltage controls and energy efficient motors that meet new efficiency guidelines. According to Larkin, the trend is also being driven by the Energy Independence and Security Act of 2007, which mandates the use of high-efficiency motors for these types of applications. “Customers can also configure the power supply, if available in your electrical service, to the unit to operate under higher voltages which then reduces amperage draw, allowing for lighter gauge service wires and making more efficient use of the electrical service,” he said.
“High efficient motors, Star-Delta starters and soft start electrics are used so motors operate more efficiently or to reduce current inrush when motors are started,” added Besonen from Timesavers. “Automated start-up of the sanding head motors also prevents operators from starting more than one head at a time,” he added.
Other features that can help save energy include return systems for the dust extraction air “which eliminates cold outside air from being drawn into the plant,” said Costa’s Johnston. “For very large machines we also offer control systems that reduce the dust extraction and air required to a minimum while guaranteeing effective cleaning of the workpieces and dust removal,” he added.
“Widebelt sanders have become more energy efficient as a result of better preparation of raw material prior to assembly and sanding,” added Kapaun from Apex Machine/SlipCon.
A Look Back: Machine’s Evolution
According to Kapaun, prior to the 1980s, widebelt sanders/planers were primarily used for rough dimensioning.
“The tolerance/accuracy of the lumber being machined was not a major concern,” he said, and grain tearout and knot damage were considered the norm.
“The introduction of rough lumber abrasive planers led to better tolerances, less knot damage, grain tearout and thus the purchasing of thinner boards,” Kapaun added. While the early widebelt sanders reduced waste from the stock, they also required the use of multi-head processes in order to achieve the necessary fine finish.
“Most sanders were equipped with 50-, 40- and 30-horsepower motors and the motors themselves were becoming more energy efficient,” he said.
Developments in tooling technology, including the use of helical cutterheads with replaceable inserts, also impacted the sanding process. “In the early 2000s, spiral four-sided insert cutterheads were introduced to knife planers. The surface finish was greatly improved, reducing the amount of sanding to approximately 1/32 of an inch, or 0.030. This reduced the number of sanding heads required, lowered the horsepower needed and lowered the amount of dust and chips created. It also allowed the use of finer grit abrasive belts.”
According to Kapaun, the common grit sequence became 120, 150 or 180, followed by 220 grit. Other developments included the reduction in horsepower to 30, 25 and 20, and the use of digital thickness readouts in the sanders.
“Accuracy and finish became greatly improved,” he added.