Panel Sizing Goes on a 'Lean' Diet
CNC panel saw suppliers preach investments in optimization and material handling as two keys to increased productivity.
By J.D. Piland
Lean manufacturing is the buzzword for this age of woodworking.
More and more wood products companies are implementing the principles of lean and continuous improvements to rid their operations of waste. Even the suppliers of woodworking machinery consider lean principles when building their machines. In fact, they feel it is their responsibility to provide their customers with a machine that can accommodate said principles.
Since panel saws are a workhorse of many woodworking shops, their manufacturers must continue to tweak their products and educate their customers on the benefits of going lean - and how their machines will help them do that.
Andreas Schwarz, vice president of Schelling America, says many of his company's customers are going lean. "The thing that we see typically is that customers are producing more, but smaller, batch sizes. People are finding that they have a lot of work, but not 5,000 at a time anymore, just lots of smaller batch sizes," he says.
With so many changeovers and shorter lead times as a byproduct of lean manufacturing, panel saw manufacturers have had to focus on all aspects of panel sizing in order to keep pace with their customers' demands for lean manufacturing. Wood & Wood Products talked with a handful of panel saw suppliers about how software and material handling help increase productivity and make lean manufacturing a reality for some companies.
Opting for More
As mentioned, lean manufacturing results in shorter product runs, meaning more changeover.
With this in mind, panel saw manufacturers have improved connectivity and optimization software, and have made it widely accessible. Today, a woodworker would be hard-pressed to find a CNC panel saw that does not come with some sort of optimizing software - or at the very least, one that can accommodate software or upgrades.
"I believe the software is the cement that pulls together the tremendous flexibility and power these machines have available these days," says Andrew Jowett, Gabbiani product manager at SCM Group USA.
Schwarz agrees. "The biggest thing is the front-end organizational software that makes it work," he says.
The software holds so much power because it is the driving force behind the machine. It creates cutting patterns to optimize the yield from a given panel, creates cutlists and plots the production path of the panel after it is sized, Schwarz says.
Also, optimization software can take one panel sizing variable, such as throughput, and even out the remaining variables to get the most out of the panel, Jowett adds. For instance, if maximum throughput is desired, the cutting patterns are simplified and yield is increased.
Optimization has become so important to lean manufacturing that aspects like feed speed, which was once a heralded feature of panel saws, have taken a backseat.
"It's more internal optimization of the machine's functions," Schwarz adds. "Now, those things are more of an advantage than a machine that cuts two more feet per minute, I think."
Despite what optimization is meant to do, human error can negate the software's purpose of streamlining and increasing production. All too often, the remnants of a full panel that was cut to size for a run of smaller pieces is set aside and forgotten. Software for cataloging offal has been developed since lean manufacturing practices seek to eliminate all forms of manufacturing waste, not just materials.
This software assigns numbers and creates labels for the parts that are processed on the saw. Remnant panels are set aside in a filing system or rack to be retrieved later, when the program reminds the operator that some panels have not been maximized, Schwarz explains. The program goes through that process until each panel is completely gone, or as close to being maximized as possible.
All types of labeling and printing have become a large part of optimization and lean manufacturing. Renato Moresi, Selco national product manager at Biesse America, says labeling is a big turn-on for his customers. In fact, he says it is one of his big selling points for his company. There is so much information provided on the label, the piece can move quickly through production virtually without question, regardless of the batch size.
"Just by looking at a label, [users] will know what the piece is, what it is for and what the next operation will be," he says.
Scott Cruickshank, Southeast regional sales manager of Holzma U.S., a division of Stiles Machinery, adds, "Labeling of parts as they come from the saw ties the saw to the other machines" and saves time.
With so many features incorporated into optimization, "customers need to consider growth when purchasing optimization software," says David Lillard, Fravol product manager at Delmac Machinery Group. "Today, they may be using brand 'X' to generate parts and next year brand 'Y,' or they may need to import data from a spreadsheet or database. Having flexible optimization software allows production data to be imported from different sources. A good optimizer can increase productivity 15 to 20 percent."
Though the benefits of optimization could reach that level, Cruickshank says it is a frequently underused tool.
"Because many companies are using manual cutting tools, it is easy for the operator to follow a cutting list," he says. "I have spoken with many people who feel their operators can beat many of the low-cost optimizers for yield."
Cruickshank also says many users do not take advantage of advanced training offered beyond the initial training when a new saw is installed. Many users change software because they did not know they already had what they were looking for in the software that came with the saw.
Optimization could be all for naught if the plant is not connected via Internet or a network, which Schwarz says is the best alternative.
The networking of optimization software to a saw to an edgebander, and so on, is essential. Just as the labels help move the piece through production quickly, so does networking. A panel saw's computer interface, most often a Windows-based program, can search the network for cutlists, specification charts and any other file on the network. This allows for remote access to and from the saw; no longer is time lost asking for specs or having to go to the front office for more information.
"No machine is an island in today's plant," Cruickshank says. "The information flow from the office to the machines in the plant is commonplace. More and more companies are looking to tie multiple processes together, such as linking the saw directly to the edgebander to edge strips before cross cutting. This helps the end user by reducing set ups and eliminating handling."
Another of the attractions to connectivity is how it helps with diagnostics. Many interface platforms include programs that detect problems, whether potential or in-progress. Digital signals have been incorporated into some controllers and notify the operator of such problems quicker than the analog signals of the past, Moresi says.
The controller knows how long each operation is supposed to last. When the timing is off - because extra lubrication is needed or there is water in the cylinders - the operator is notified, Moresi adds. Then, the controller brings up photos, and sometimes videos, of the setback in question so the operator knows exactly where to look for a solution.
"Ninety percent is understanding what the problem is," Jowett says. "Then, you can learn how to fix it."
In cases where an operator cannot fix the problem on his own, troubleshooting can be accomplished via modem by the manufacturing company. The technical support team may be able to correct the problem off-site, saving the end user an expensive service call.
In terms of lean manufacturing, material handling is a tough panel-sizing feature to sell.
First, Lillard says, if each panel is going to be cut differently, material handling equipment can be expensive compared to the increased productivity. While reducing potential injury to the operator is of utmost importance, the cost for the equipment can be hard to justify; a scissors lift or two should be sufficient.
For companies that run larger batches with larger panels, quick changeover possibilities of material handling come into play. Schwarz says that with loading and unloading equipment, a book of panels can be cut and discharged while the next is prepared and entered into the saw; there is little downtime this way.
Cruickshank says that a company practicing lean manufacturing "can improve the output of a process up to 80 percent" with unloading equipment alone.
So, why has material handling equipment become so hard to sell to American companies while Europeans find it so essential? Simply put, the cost.
For example, Schwarz says a panel saw could cost $150,000. Sometimes material handling equipment can be twice that and the payback, which in America is based on a two-year return, does not justify the investment.
"The payback calculations are still based on how much an operator costs," he adds. "You multiply that by two, and, in most cases, that is $60,000 or less. Based on that calculation, it is tough to justify material handling equipment because you spend a lot more than [$60,000] on automated material handling."
Not that there isn't a desire from the smaller or medium-sized companies. They simply cannot justify the expense as easily as large woodworking companies. The time will come, however, when they will have to look beyond the price tag, Schwarz says.
"Once people get beyond the spending, I think more will start to invest in material handling because they will have to keep up with demands [of customers and lean manufacturing]," he says. "It will come that more and more the ergonomics and reduction of injury will force people to look past the two-year payback."
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