Low-noise circular saw blades for wood and wood-based material cutting

• Applicant: Dr.-Ing. Thomas Stehle
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Acoustics
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269161372

The proposed research project is aiming in reducing the sound pressure level of rotating circular saws. A rotating circular saw blade is producing air turbulences mainly in the chip spaces which cause air pressure fluctuations. These fluctuations are being perceived by people in the form of noise. According to the HVBG noise is still one of the biggest health hazards in the industry. The emitted noise of circular saws is almost always above the permissible noise limit of 85 dB (A). To efficiently reduce the size of the chip space in the saw blade it is important to observe the chip loosening factor -and the size distribution of the chips. These factors are dependent on the material, wear state of the tool, cutting parameters (cutting speed, supernatant, tooth feed, feed rate, etc). In contrast to the metalworking no research-based evidence regarding the chip loosening factor and the chip size distribution for circular saws are known for woodworking. To minimize the noise, systematic and fundamental investigations about the necessary volume of chip space size are necessary. Therefore to minimize the noise level of the saw blade it is necessary to reduce the chip space. In order to know how much the space can be reduced research conclusions are necessary regarding the volume of the chip space size required. After the necessary minimum volume was determined for chip removal, the ideal geometry of the saw blade with minimal air turbulence and sufficient removal of the chips must be designed. The different variations in the cutting, chip space, circular saw blade body geometry for low-noise design have to be generated. These different approaches have to be varied and combined with each other to construct a low-noise circular saw blade. With the help of aero-acoustic simulations, the problem areas will be identified on the newly developed circular saw blades and then optimized. After at least three solutions were developed and produced, they must be checked for suitability in machining and noise radiation.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr.-Ing. Uwe Heisel