Anyone who writes about the woodworking competence that comes out of southern Germany cannot ignore the town of Balingen in Swabia. It has been for several months now that people with somewhat dusty hands and a disbelieving expression on their faces are leaving the premises of AKE Knebel's headquarters there. In May, managing director Alexander Knebel presented the new Supersilent saw blades at the Ligna Trade Fair. They promise to be a revolution in the woodworking craft. The noise levels will decline by 75% and the product life will surpass that of carbide saws more than tenfold, he says. In addition, the blade is flexible enough to buck end-grain beech as well as cut spruce along the grain, or saw plywood or coated MDF. This sounds like the complete fulfillment of a wish list that carpenters, timber merchants and commercial furniture manufacturers might have about their ideal saw blade.
Every Timber-online reader is familiar with the unpleasant noise that circular saws make when operated: high-frequency squeals caused by teeth and flutes. Up to one hundred times the tools rotate per second. The air is displaced from the teeth and swirls into the gullet area – only to be cut again by the next tooth. This creates the unpleasant noise which can easily go up to 95 dB in a carpentry. Quite on the contrary, the Supersilent blades produce an accoustic pressure of only 75 dB. Due to the logarithmic nature of the sound scale this represents a 99%-reduction in noise emission – and makes the process 75% "less noisy" to the human ear.
How does it work? The development team of AKE Knebel has simply eliminated the sources of noise. Primarily, it is the gullet area of the sawblade. Rather than pushing the chips in front of the teeth in the meshing, they flock to the outer edge of the blade. "We are talking about a chip surface here, no longer about a chip pocket or gullet area for that matter", says young product manager Matthias Seemann. Then he moves on to the saw teeth themselves. 43 times over, polycrystalline diamonds sparkle from the saw blade edge. The teeth appear tiny – measuring only 2 by 2 mm. But that is enough for a solid soldering with the 1.8 mm thick body of the blade. The peculiarity lies in the shape of the teeth. "Their cross-sections have the shape of small T-shirts", says Seemann. This design forces the chips to go new ways: If the diamond dives into the wood, the chip is first forced down on the tooth face where it is split. Each half of it flows to the left and right underneath the "sleeves" of the T-shirt on to the chip surface where it stays until the blade emerges from the wood again.
Every Timber-online reader is familiar with the unpleasant noise that circular saws make when operated: high-frequency squeals caused by teeth and flutes. Up to one hundred times the tools rotate per second. The air is displaced from the teeth and swirls into the gullet area – only to be cut again by the next tooth. This creates the unpleasant noise which can easily go up to 95 dB in a carpentry. Quite on the contrary, the Supersilent blades produce an accoustic pressure of only 75 dB. Due to the logarithmic nature of the sound scale this represents a 99%-reduction in noise emission – and makes the process 75% "less noisy" to the human ear.
How does it work? The development team of AKE Knebel has simply eliminated the sources of noise. Primarily, it is the gullet area of the sawblade. Rather than pushing the chips in front of the teeth in the meshing, they flock to the outer edge of the blade. "We are talking about a chip surface here, no longer about a chip pocket or gullet area for that matter", says young product manager Matthias Seemann. Then he moves on to the saw teeth themselves. 43 times over, polycrystalline diamonds sparkle from the saw blade edge. The teeth appear tiny – measuring only 2 by 2 mm. But that is enough for a solid soldering with the 1.8 mm thick body of the blade. The peculiarity lies in the shape of the teeth. "Their cross-sections have the shape of small T-shirts", says Seemann. This design forces the chips to go new ways: If the diamond dives into the wood, the chip is first forced down on the tooth face where it is split. Each half of it flows to the left and right underneath the "sleeves" of the T-shirt on to the chip surface where it stays until the blade emerges from the wood again.
Ticking off the carpenter's wish list
T-shirt tooth and chip surface: The new saw blade combines several patented innovations © Johannes Plackner
Flexibility: Normally, laminated chipboards should be cut with a different saw blade than is used for solid wood. But changing tools back and forth is annoying and time-consuming. Supersilent renders the changing process redundant. The diamond tipped saw blades will cut plywood at a thickness of six inches just as clean as a chipboard with melamine paper layer. It will leave behind an even cut surface on an end-grain beech just as it will on spruce cut alongside the fiber. One reason for that being that friction is minimized by multiple chipping. For extremely high demands, AKE also offers a scoring saw for the trailing edge.
Silence: The person operating the Supersilent can talk with their colleague next to the saw – at a normal voice volume, without having to yell at the top of their voice. Not only the workers on the circular saw, but also the payroll accountant in the office next door will be pleased by that. It will also prevent conflict with the neighbors. And not to forget: It saves energy. 99% less noise emission also means less engine load.
Security: Less noise automatically contributes to accident avoidance. The operators hear better what is happening around them. Also, recoil is reduced. Narrow strips of ripped wood simply remain lying still next to the saw blade instead of being thrown to the rear by wide teeth. In addition, the blade can be touched without much danger of injury. To demonstrate that the AKE-CEO takes a Supersilent blade, throws it into the air and catches it with his bare hands (see picture below).
Economy: Several factors reduce the costs per cut. This is first and foremost the high product life which in turn reduces tool changing and setup costs. The high flexibility makes one blade sufficient to machine a scope of materials. Investment in expensive complete tool ranges are unnecessary.
New splitting wedges are provided
Alexander Knebel throws the blade into the air and catches it without injuries © Johannes Plackner
50 years of experience, one year of development
Those who know the workshops of AKE Knebel might be surprised at the revolutionary approach that the company has been taking at this point. Knebel cherishes traditional crafts. Still the blades are straightened by hand. It takes a hammer, a straight edge and the craftsman's skills to do maintainance work on the tools that are used in the most efficient sawmills worldwide as well as in the carpentry next door. However, craft and innovation are not mutually exclusive, but mutually supportive. After all, Swabia - where AKE is also headquartered – bases its prosperity on innovative SMEs.
Supersilent product manager Matthias Seemann proudly displays the result of the developments at AKE Knebel © Johannes Plackner
It took the experts in Balingen only ten months to develop the blade. No university, no external research institute was involved in the process. This was possible only by ingenuity and customer focus. Saw blades are available with a diameter of 303 mm. Work on other formats is ongoing. The average sawing capacity should be up to 5 km per blade. Then, once sharpened, another 4 km should be possible. Since mid-July AKE Knebel has been delivering the saw blades. A first conclusion? "Our customers are thrilled", says Seemann. "Anyone who is interested should best give us a call. We then refer him to the nearest dealer", he adds. And whoever has not been convinced by these lines should pay a visit to Balingen. And be prepared to walk away from there with some dusty hands and a disbelieving expression on the face.
