Flexibility and new capabilities keep panel saws a workhorse in the plant.
|Improvements to the pushers, carriages and grippers have helped to improve the productivity and flexibility of panel saws. Photo courtesy of Delmac Machinery Group.|
Already considered a workhorse in the woodworking plant, the panel saw continues to improve in capabilities. Wood & Wood Products queried experts on the changes and benefits they see coming for these productive machines.
"Small batch sizes, 'one piece flow,' customer order by order and lean manufacturing are all factors that are influencing manufacturing techniques and process considerations in today's environment, where we are looking to maximize flexibility and reduce inventory costs," says Andrew Jowett, key account manager for SCM Group-USA. "In order to address these factors, panel sizing and panel saw manufacturers have gone to the next level by introducing high-speed saw carriages, smart pressure beams, moving clamps and optimized PLC programs, to name but a few.
These elements enable the panel saw user to maintain high levels of output, regardless of the complexity of cutting patterns and batch size."
Bill Pitt, Stiles Machinery vice president/general manager of Holzma, says he believes speed will continue to be an important factor in the development of panel saws. "Panel saws of the future will be faster, with more features built in to reduce idle times," he says. Pitt adds that "lights out" technology also is a foreseeable development for U.S. woodworking plants, as it is in Europe, where panels are cut without operators being present. "Even in the smallest front load machine, every movement will be optimized fully."
For safety and cutting quality reasons, always keep the saw blade opening in the machine table as small as possible. Also, if you have cutting quality issues, try to reduce the pressure beam pressure. Less pressure is better than too much.
The best preventative maintenance tip is to keep the saw clean. On a daily basis inspect and clean out the area under the cut line of all trims to avoid a buildup of debris and interference with the saw carriage and service cables.
One way to improve panel saw productivity is with the use of stops. One method is to utilize a quick stop gauge that consists of a metal extrusion with an embedded scale and an adjustable stop block, for making repeat cuts at any length. Another method for production shops is to use a stop bar gauge. It consists of a metal extrusion with an embedded scale and multiple flip stops, making it very easy to set up a variety of stops at different lengths while eliminating multiple measurements.
Manufacturers need to keep a set of blades they know work perfectly set aside. If they encounter a problem, typically chipping, they can best diagnose the problem by switching to the reliable blades that cut chip free and see if the problem is actually from another source.
-Patrick Neville, Holz-Her U.S.
Chipping or poor cut quality is a common complaint and often has nothing to do with the machine. The cause of the problems can come from one of four sources, what I refer to as the "three Ms and T" - man, material, machine, and tooling. Before you attack the most complicated of the four, the machine, eliminate the other three first as the source of the problem. Make sure your material is of good quality. Never buy the cheapest stuff available. If you have recently changed suppliers, and then the chipping started, try a piece from the previous supplier and see if the results change. Is the operator experienced with the machine? If he is new to you or to the machine, watch him make some cuts. Is there something he is doing that is obviously incorrect? If so, make sure you take that out of the equation with some retraining.
Andreas Schwarz, executive vice president of Schelling America, says his customers also are looking for speed and ease of use, with all functions fully automatic. "The movements of the saw carriage are optimized to the point where there is no wasted time. The pressure beam is mounted onto guideways and is made of aluminum to reduce mass, hence increasing speed and precision. All of the above has cut cycle times almost in half," says Schwarz.
In addition to Schwarz, others also noted how structural changes have helped to optimize these machines.
According to Patrick Neville, Holz-Her regional manager, "Some of the unique features include a frame that is self-supporting and torsion resistant with two longitudinal beams, one on each side of the cut line. Saw carriages, rack-and-pinion driven, are made from extremely strong cast iron to reduce vibration and large integrated ribs ensure structural rigidity. The saw carriage is supported by the beams on both sides of the cut line and are electronically controlled and continuously variable featuring saw blades with a quick-change locking device. Linear hardened prismatic guideways offer strong, quiet and accurate movement of the longitudinal and vertical movement of the saw carriage. The same lineal guideways are used on the side aligner and pusher assembly for smooth movement and accuracy," says Neville.
Rob Rogers, Mayer product manager for Delmac Machinery Group, also noted features that have improved productivity and flexibility in the panel saw. "[Having] a rack-and-pinion carriage and pusher enables acceleration and deceleration to be maximized," he says. "Optimized movements reduce cycle times and bar coding reduces errors and secondary steps, improving throughput and efficiency." Rogers adds.
The need for improving throughput also was addressed by Randy Jamison, North American Selco product manager, Biesse America. In the case of twin-pusher technology, he says, "The ability to perform more than one function at a time allows for additional cycles in a given production period. Flexibility is not sacrificed."
"The nature of current day production obligates beam manufacturers to think outside the box and reconsider everything," says Mark Craig, North American sales manager for Giben America. He cites moving gripper technology on both the X and Y axis as one such development. "This innovation answers two of the main concerns of most modern panel cutting applications: flexibility and productivity," says Craig. "The moving clamp technology offers even greater advantages when featured on an angular cutting system as the typical limitations of a standard angular plant can be overcome by allowing more complex, elaborate cutting patterns with multiple cross cutting strips processed in one pass. The gains in output can more than double, and even triple, that of a similar fixed clamp angular system."
Others also note developments in auxiliary equipment for improving productivity. "Ergonomic handles along with laser lines and digital readouts are making vertical panel saws more user friendly and efficient," says Tom Houska of Safety Speed Cut. "The ability to interchange a router with the saw in less than a minute for dado cuts also has eliminated the need for dado blades and improves the safety of operations."
Chris Doblow, product manager for Altendorf saws, Stiles Shop Solutions, says he foresees a "continuity in increasing efficiency and production volume through work cell automation." He points to "intelligent features that contribute to the customersâ high efficiency and greater profitability," including graphics-oriented software within a user interface that integrates the mathematic formulas required for various cutting applications, such as unequal-miters, geometric shapes, etc. "This technology simply asks the operator to give the machine the variable dimensions, and then automatically computes the formula in providing all needed cutting angles and measurements. The saws take the 'thinking' out of the equation, thus increasing production time and continuous accuracy.â
Even entry-level machines are being impacted, says Dave Bull, Striebig product manager for Colonial Saw. "One of the recent developments is a movement toward automating the travel and return modes of entry-level machines in order to make smaller shops more productive and allow them to work easier without having to spend the money for full-featured, top-of-the-line automatic saws," he adds.
"One of the key movements we see in the industry, especially in these more challenging and competitive times, is toward lean manufacturing," Bull continues. "Companies are realizing that they don't want or need to buy the biggest, most sophisticated machine just because they can, in order to do what they really need. They are realizing that they are better off buying a - or sometimes several - high quality, reliable, flexible solution that they can tailor to their application, rather than a much larger, single-purpose machine that may sit idle too much of the time when business slows.â
As batch sizes continue to get smaller, the ability to do rips and crosscuts, while maintaining a high productivity level, becomes increasingly important, says Rogers.
Schwarz agrees. "Smaller batch sizes are going to be the future for most of our customers, thus a fast, flexible and precise saw is going to be more important than ever. Along with that, it will be important to have an answer for handling offal," he says.
Neville also agrees that increasing speed will continue to be an important factor in panel saw development. "The biggest thing is taking the delays out of the equation. Computer programs will intuit ways to save time, adjusting for the size of the material being cut and shortening cycles as needed. Saw carriages and pushers will be going with quicker speeds. The focus will be creating ways to take the delays out in any way one can.
"Now that saws are faster, we will have to adjust the speed of material handling as well to keep pace," Neville adds. "The future will involve dealing with material getting to the beam saw and getting the parts away from the saw, quickly and efficiently."
Also, as thin board becomes more frequently used, loading the board in an automatic cycle can be a difficult process, says Craig. "Some of the challenges include inconsistent material thickness, board waviness and high sheet counts per book, which make it very difficult to load with a conventional push feed system."
As Craig explains, a new system for sheet loading of 2mm-thick material involves the use of "STLD" wedges mounted to moving clamps and inserted into the stack of material, thus breaking the stack with the required number of sheets. "Once the first wedge is inserted," Craig says, "a second wedge is then inserted at the same point in the stack to ensure a proper, reliable count and no chance of a misfeed or different count at one end than the other of the stack. Once engaged, the second gripper/wedge then distances itself away from the first, in accordance to the material sheet size, to properly support the material during the forward loading movement."
Software Enhances Productivity
Machine operating, optimization and stack management software also have addressed the labor and productivity issues facing manufacturers today, says Jowett. "They facilitate the processing of mixed infeed stacks of material and the manual or automated stacking of mixed part sizes in on stack and by customer order."
Schwarz also notes another development in optimization software, with the aim of utilizing 100 percent of the offal. "We have developed optimization software that is connected with the saw at all times. Once a job is optimized, the saw starts cutting. Any offal that is generated gets labeled and is assigned a storage bin location. At the same time, the saw 'tells' the optimizer that this piece is now available. The next run then tries to use the offal before it will use a full sheet. This way, yield is close to 100 percent."
According to Craig, other developments in software include packages that address small quantity optimizations, repeating the process up to nine times while considering different parametric options.
"We have developed a new job-splitting function, which allows the user to split a job into multiple jobs to better match a given machine's characteristics," Craig says. "An example could be a business with one very flexible moving clamp machine and another more high-production intended compact angular system. In a given job, some patterns will run better on the angular and others will benefit from the flexibility of the moving clamp machine. This allows the job to be split into two jobs, each containing the patterns which best suit each machine."
Doblow says he also sees improved efforts in automation technology for sliding table saws, including printer integration packages which allow customers to download cutlists and print part labels from the saw. "This feature enables the saw to communicate with the production planning departments as cutting sequences can be easily read from scanning the workpieces using a barcode reader."
Doblow adds that it operates similar to a beam saw interface, allowing the software to "walk" the operator through the cutting sequence as all four axes move into position upon each performed cut. "This results in improved, error-free automation," he says.
Optimization via software takes many interesting forms, adds Pitt. "It is possible to drive up the yield if the customer can link several jobs requiring like materials, as opposed to cutting by jobs," he says. To keep track, label printing is essential, along with labeled carts on rollers. "Color coding offers a very easy way to identify parts on the fly. Up to 10 different colors can be used on a label," Pitt says.
Touchscreens and intensive graphics, which eliminate written text, also are important trends in panel saws. "Visual commands and graphics will speed up the process as well as remove the chance of error. Error diagnostics are becoming increasingly detailed and offer immediate feedback. If a machine has a hiccup, the operator can look at the screen and see whatâs wrong."
Larger displays and tutorials also will help to avoid problems of miscommunication, Pitt adds. "Graphics become more and more important as we move into a multilingual workforce of workers who may not have English as a first language."
Jamison adds that the software evolution will continue, "particularly as it pertains to both the statistical information and well as troubleshooting and maintenance."
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