Blade changes aim to reduce wood machining noise levels
August 2, 2016 | 3:05 pm CDT
As woodworking factories and shops get busier, they are also getting noisier - largely a function of saw blades and cutting tools doing their duties.
The high noise emissions of circular saws is one area of particular concern, since the frequency of even and idling saw blade spinning can damage hearing - and is unpleasant both for operators and their colleagues. That noise can be so piercing, it can even bothersome to neighboring workplaces.
On circular saws, it is usually the saw blades that cause the high sound pressure level. According to safety regulators in Germany, from which so much of the U.S. industry sources its machinery, with conventional saw blades this level always falls within the auditorily damaging range of 85 decibels (dB) and higher, where experts reckon it can cause auditory damage. (A German Noise and Vibration Protection Ordinance obligates noise protection measures to be taken and users to wear hearing protectors from this value.)
Source: Leuco Tools
An additional solution is noise-reduced circular saw blades, which regulators say helps in most cases to significantly reduce the sound pressure level. Here is the reduction from 85 dB(A) with such blades:
- Up to approx. 13 dB(A) with the saw idling
- Up to approx. 6 dB(A) when sawing aluminium
- Up to approx. 11 dB(A) when sawing wood panels
- Up to approx. 11 dB(A) when sawing plastic profiles
- Up to approx. 13 dB(A) when sawing hardwood edge-banding.
A reduction of 3 dB is equivalent to a 50 percent drop in sound energy, and thus is a major reduction in the risk of damage. With a drop of 10 dB, the perceived noise is only half as loud, say regulators in Europe.
Leuco Tool, which introduced the nn-System (No Noise) saw blade at Ligna last year, cites a European Union directive on noise that requires companies across the Continent to provide hearing protection for workplaces with a noise level higher than 80 dB. From 85 dB on, employees are required to wear hearing protection.
Leuco, exhibiting in Booth 5553 at IWF 2016, says in a backgrounder on its nn-System blade, that most workplaces in the woodworking and furniture industries, as well as joineries, exceeds the noise level of 85 dB.
SCM measures the noise level of the planing performed on a Minimax Lab 300 plus testing a conventional and a Xylent blade. It will be at IWF 2016.
The noisiest production steps are sawing and planing, with noise levels between 83 and 103 dB, followed by milling with 82 to 94 dB. The noise is caused either by idle running of the tools or during operation. In the case of saw blades, there is a lot of time when the machine is idling and the saw blade is just rotating without touching the workpiece or material.
According to Leuco, noises during idling can sometimes be louder than during operation with so-called "whistling" or "whining" saw blades. Leuco says it reduced the size of the gullets on its diamond-tipped saw blades, which its says cut up to 6 dB off the sound level compared to conventional diamond-tipped saw blades. Leuco is quick to point out its saw blades aren't noiseless - just quieter.
Leitz Tooling launched its Premium line of horizontal panel saw blades last year, with "laser ornaments" in the blade body filled with a special polymer for vibration damping and accuracy. The Premium” line blades are aimed at cutting expensive or delicate materials, including laminated particleboard and MDF, as well as veneered panels. The design will deliver chip-free, no tear-out finish quality. And Leitz says because of its superior engineering, these Premium blades are much quieter than standard blades, a factor reducing overall plant noise and contributing to greater employee safety and satisfaction.
NAP Gladu launched SuperSilent saw blades in 2014, featuring patented innovations that extend blade life, reducing buildup of sawdust and chips, and reducing noise levels by 20 dBs. Patented MicroGeo saw geometry provides effortless, uninterrupted sawing in both rip and crosscut applications. The 2mm ultra-thin kerf and polycrystalline diamond tips produce smooth, scalpel-like cuts and extend blade life dramatically compared to carbide tipped blades.
Misenheimer Inc. is introducing its QuietCut Pro, a new design in surfacing cutters which it says has a true helical orientation of inserts mounted on a shear angle, allowing for a continuous cutting wing that stays in contact with the wood surface on each revolution. This achieves an extremely smooth finish, says the company, while reducing spindle vibration and noise levels up to 20dB.
Charles G. G. Schmidt & Co. carries a large selection of 10" and 12" diameter low noise laser cut saw blades for closet and cabinet production. Manufactured on laser cut plates, the company says these blades cut long and smooth while generating less noise than conventional blades. Blades for ripping, cross cutting, laminates and solid surface materials are available. Many tooth configurations are available. See our new catalog, No.1100 for a complete list of all of our tooling and accessories.
Quieter Wood Planing
Felder Group introduced its quieter planer/thicknessers at Ligna 2015 in Hannover, Germany, with its Silent-POWER spiral cutterblock designed to reduce noise emissions by more than half when planing. Felder says the continuous pulling cut ensures tear-free results when planing all types of wood, and it features all the advantages of a spiral cutterblock at considerably lower operating, investment and adjustment costs.
Quieter operation coincides other engineering improvements, that also extends blade life as much as 20 times longer than standard blades, according to Felder. There are four highly precise cutting edges on each knife, with optimized chip extraction and reduced chip volume. Joint cuts are tear free.
SCM Group will be showing results of its research and development on wood manufacturing noise, which last year yielded Xylent - its pronunciation is a play on the word "silent" - a technology it will show in its Minimax planer. Exhibiting in Booths 6052 and 6069 at IWF 2016, SCM will show Minimax with a range of spiral cutterblocks, designed to suit surfacer requirements, thicknessers and 4 in 1 combinations.
The European cutterblocks are designed specifically for the MiniMax and SCM machines, so feed rates, number of teeth, and cutter diameter are precisely in sync. And added advantage, says SCM, is the planers using Xylent give a slippery smooth finish to wood pieces delivered at the back of the machine.
SCM did careful measurement of the noise level of the planing performed on a Minimax Lab 300 plus combination machine, varying the planer we used , in order to highlight the potential of the Xylent cutterblock developed by SCM Group, which it says verifies that the cutterblock is able to reduce the noise level during the processing of 13 dB.
Measurement was made in an anechoic chamber, a dedicated structure to measure the actual noise level of a machine, used to meet Italian and European regulations and used for official tests on noise.
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