How to Reduce Noise in Stone Processing

Noise is inevitably generated in stone processing, regardless of the equipment or processing method used. Especially when improper operation or overloading occurs, the intense and harsh noise can severely impact the surrounding environment. The harm caused by noise is significant, particularly in the following aspects:

1. Long-term exposure to high levels of noise can lead to noise-induced hearing loss.
2. Noise can affect people’s normal work, study, and daily life.

So, how is noise generated during stone processing? It mainly comes from the following sources: cutting tooth noise, blade vibrations, and material friction sounds.

Cutting Tooth Noise: This noise occurs when the saw blade rotates at high speed, and the teeth of the blade interact with the surrounding air, causing air pressure fluctuations that produce noise.

As the saw blade rotates, each cutting tooth generates monopole radiation flows and periodically expels them through the cutting gap, causing a change in air pressure and creating exhaust noise. The intensity of this exhaust noise increases dramatically as the blade’s speed increases. It is proportional to the sixth power of the airflow speed and the fifth power when the speed is lower. At high rotational speeds, when the frequency of the vortices’ separation is close to the blade’s natural frequency, resonance occurs, producing a “screeching” sound.

Vibrations of the Saw Blade: Saw blades are thin and usually have poor rigidity. Under external forces, they are prone to vibrations, which, in turn, can cause friction between the material being processed and the blade, generating noise.

So, what effective measures can be taken to reduce the generation of noise?

1. Designing the Saw Blade Structure to Achieve Noise Reduction

• Evenly Distributed Small Holes: Without compromising the balance or rigidity of the saw blade, small holes of the same size can be evenly distributed on the blade’s body. These holes can be filled with high-damping alloys or non-metallic materials to reduce the propagation of elastic vibrations, thus eliminating high-frequency noise.
• Noise-Reducing Slits: In addition to maintaining the blade’s rigidity, noise-reducing slits of various shapes (curved or straight) can be set at evenly spaced intervals along different radii on the blade body. The principle of noise reduction is that sound waves generated by friction and impact between the blade and the material are dampened as they propagate through the blade body, reducing high-frequency resonance and lowering noise intensity.
• Composite Damping Structure: The use of composite damping structures in vibration and noise reduction engineering is becoming common. A composite damping structure involves bonding several layers of elastic materials to form a high-damping structure that retains the strength of the metal materials. This structure has excellent damping properties at both normal and high temperatures (80–100°C), and it dissipates vibration energy efficiently, providing noise reduction across a wide frequency range.

2. Installation and Usage Methods for Noise Reduction

• Clamp Disc Modification: Increasing the diameter of the clamp disc, while ensuring it does not affect the cutting height, enhances the saw blade’s rigidity and reduces bending vibrations, which is highly effective in reducing noise. Research has shown that when the clamp disc diameter reaches three-quarters of the saw blade’s diameter, noise reduction is at its best.
• Additionally, to improve the blade’s elasticity and ensure uniform stress, grooves can be created on the clamp disc to insert rubber strips or soft metals.
• Installing Soundproof Covers: Using a soundproof cover to reduce the overall noise produced during cutting is an effective method. The cover can be made from steel plates with inner layers of damping and sound-absorbing materials, such as ultra-fine glass wool, and lined with fiberglass cloth. Perforated plates can be used to ensure that the system does not resonate during operation, thus preventing the creation of new noise.

3. Noise Reduction Effectiveness

• Composite Blade Structure: Can reduce noise by approximately 10 decibels.
• Vibration-Damping Flange Disc: Can reduce noise by around 3 decibels.
• Noise-Reducing Holes or Slits: Can reduce noise by about 5 decibels.
• Overall Soundproof Cover: Can reduce noise by approximately 10 decibels.

4. Other Measures

• Proper Operation: Correct operation and avoiding overloading are also essential for reducing noise. By standardizing operations, excessive vibration and unnecessary noise can be minimized.
• Maintenance: Regular maintenance of the saw blades and equipment helps prevent additional noise caused by wear and tear or damage.

These measures can significantly alleviate noise issues, improve the working environment, and protect the hearing and health of workers. Custom-designed equipment and regular maintenance services can further enhance noise control effectiveness.