Classification of damping material
According to the structure of the material, the sound absorbing material can be divided into three categories: porous, resonance, and special structure. At present, porous sound absorbing materials are the most widely used, mainly including organic fibers, inorganic fibers, inorganic foams and foams.
1. Organic fiber sound absorbing material
The early organic fiber sound absorbing materials mainly refer to natural plant fibers, which have good sound absorption performance in the middle and high frequency range, but have poor performance in fireproof, anticorrosive and moisture proof. With the rapid development of the synthetic industry, researchers have conducted in-depth research on synthetic fibers.
2. Inorganic fiber sound absorbing materials
Inorganic fiber sound absorbing materials mainly refer to natural or artificial fiber materials which are based on inorganic minerals. These materials not only have good sound absorption properties but are light in weight and non-combustible, but they are inconvenient to install and pollute the environment and will affect them. People's health. Subsequently, metal fiber sound absorbing materials with flame retardant, high temperature resistance and high strength are available, and the sound absorbing performance is excellent, but the cost is high and the process is complicated.
3. Inorganic foam sound absorbing materials
At present, researchers mainly focus on the research of foam glass and foam metal. The foam glass is light, non-corrosive, non-flammable, odorless, and convenient to construct. Its porosity can reach more than 85%, but the process is not well controlled and the cost is high. Foam metal is a new type of porous material, mainly researching aluminum foam and its alloys. After foaming, a large number of bubbles are formed inside, and distributed in a continuous metal phase to form a pore structure.
4. Foam plastic sound absorbing material
Foamed plastic sound absorbing material mainly refers to a kind of lightweight, sound absorbing, heat insulating and flame retardant made of various resin materials, adding a little foaming agent, catalyst, stabilizer and other auxiliary materials. Corrosion-resistant and shock-proof materials are widely used in polyurethane foam sound absorbing materials, but their strength is low and inconvenient to use.