Sound absorption principle
Porous sound-absorbing materials, such as glass wool, rock wool, mineral wool, and plant fiber sprays, work by allowing sound waves to penetrate through a large number of tiny, interconnected pores within the material. As the sound waves travel through these pores, they rub against the material’s structure, converting their energy into heat. This is how these materials absorb sound. The sound absorption coefficient of porous materials generally increases with frequency, meaning that they are more effective at absorbing high-frequency sounds than low-frequency ones. For porous materials to be effective, they must have a large number of open, connected pores that extend deep into the material. One common misconception is that any rough surface has sound-absorbing properties. However, this is not true. For example, brushed cement or stone surfaces do not absorb sound effectively. Another misunderstanding is that materials with many internal holes, like polyethylene or closed-cell polyurethane, are good sound absorbers. In reality, these materials lack connectivity between their pores, so sound cannot pass through them easily. Instead, the internal vibrations cause minimal friction, resulting in poor sound absorption. Â
Another method of sound absorption involves perforated plates installed with an air layer behind them, such as on walls or ceilings. Even if the material itself is not highly absorbent, the combination of the plate and the air cavity can create effective sound absorption. Examples include perforated gypsum boards, wood panels, metal sheets, and even slit bricks. This technique is known as Helmholtz resonance absorption. It works similarly to the resonance effect in a thermos bottle. When sound waves hit the structure, they enter through small openings (like the neck of a bottle) and resonate with the air inside the cavity, dissipating sound energy. Helmholtz resonance is most effective at specific frequencies, where the absorption coefficient is significantly higher. Â
Thin sheets or membranes placed over a cavity, such as wooden boards or metal panels on ceilings or walls, can also absorb sound. This method is called thin plate resonance absorption. At certain frequencies, the sheet vibrates intensely, which helps to absorb a significant amount of sound energy. This type of absorption is particularly effective for low-frequency sounds.
In general, the principle of sound absorption involves creating a path for sound to enter the material. This path may consist of countless tiny holes or gaps formed by intertwined fibers. Once the sound enters, it travels through this complex network, bouncing around and colliding with the material's structure. During this process, the sound energy is gradually lost due to friction and resistance, leading to effective sound absorption.
Understanding these principles helps in selecting the right materials and structures for noise control in various environments, from homes to industrial spaces.
EDAWELD COMPANY LIMITED is a Chinese manufacturer main produce welding torches. Like mig/mag/co2 welding torches and their spare parts.
MIG/MAG/CO2 Welding torch has its own characteristic. a flexible, easy to use, simple process, welding safety, fast, reliable welding, simple maintenance, and the advantages of small investment in equipment.Manual welding guns are widely used in industrial manufacturing.
We now have a wide range of welding gun models and types. Such as selling in Europe,BZL type air gas cooled 15AK,25AK,24KD,25AK,36KD, Trafimet Type,TWC type etc, water cooled welding torch we have 501D, AW4000 and 500A type. Asian model, we have PAN,OTC, American type we have 300E, 400E, 500E etc.
We also welcome customers make their own brand welding torches, we always provide logo label and logo color boxes.
Our company always provide good quality and cheaper prices mig welding torches, welcome contact with us.
CO2 Welding Torch, MIG Welding Torch, MAG Welding Torch, Water Cooling Welding Torch
EDAWELD COMPANY LIMITED , https://www.jsedaweld.com