Ship cabin noise mainly comes from the engine, the working performance of the cabin noise will not only disturb and destroy the ship's own equipment, affect the use of a phone call and line communication, and the crew if a long time in the strong noise environment, attention and working ability will decrease, affect the physical and mental health. For closed space, reverberation has great influence on noise. Sound absorption and noise reduction are effective measures to reduce cabin reverberation.
The traditional sound absorption materials: organic fiber, inorganic fiber material, foam and polymer materials, but these materials have low strength, brittle and easily broken, short service life, easy to damp, easy cleaning dust, easy to form two pollution.
Taking into account the special environment on the ship and the health requirements of the personnel, should select light quality, sound absorption performance, fire-resistant, flame retardant, moisture-proof, non-toxic powder, health and environmental protection materials. In this form, Chalco Aluminum -------a new type of aluminum foam aluminum
plate came into being.
The sound absorption principle is: porous aluminum foam material has a large number of internal small voids, pores connect to each other, deep inside the material only through the pore surface is communicated with the outside world, when sound waves onto the material surface, a part is reflected off the surface of the material, the other part is added to the material inside the forward propagation, in the communication process cause pore air movement, friction with the solid body forming hole wall, due to the viscous and heat conduction, energy will be transformed into heat is dissipated, at the same time, the internal air holes in the aluminum foam media because of heat conduction effect makes the sound waves into heat, the sound energy decay.
Characteristics of Foamed aluminum:
Foam aluminum sheet is a kind of functional material with pore structure to obtain special properties, and has structural sensitivity. Its pore structure is different, the performance is not the same. Because of its unique hole structure, it has the following performance characteristics:
1. Light quality, small proportion. Aluminum foam density is only 0.15--0.50g/cm³ accounted for the same volume of fand, metal 1/50--3/52.
2.Excellent sound absorption performance. Good sound absorption properties of aluminum foams with capacity of up to 0.40--0.50., the average absorption coefficient for the aluminum foam fand 0.27g/cm³.
3. Foam aluminum, fire resistance, good temperature resistance. Generation of alumina in the foaming process of aluminum foam structure, excellent fire resistance, up to 800 ℃ began to soften, the real melting to 1000---1200 ℃, and aluminum foam encountered fire play no toxic or harmful gas. The working temperature of foamed asbestos is usually 50--500 ℃, and the working temperature of glass panel is not more than 538 ℃.
4. Moistureproof and wet resistant. Commonly used glass wool, foam asbestos and other sound-absorbing materials, often because of water absorption or moisture absorption and greatly reduce the sound absorption performance. The moisture absorption rate of foam aluminum is almost 0, and the damp environment has little influence on its sound absorption performance.
5. High mechanical strength. Foam aluminum is a foam made up of metal skeleton and bubble. It is rigid structure and has good processability. It can make all kinds of sound-absorbing board.
6. Good insulation. The general thermal conductivity of metals is 10-300W/ (m.k), the thermal conductivity of the jade 0.2W/ (m.K), aluminum foam (diameter 2.7mm, the porosity is 73%---83%) apparent thermal conductivity is 1.9--2.2W/ (m.K), can be used as heat insulation materials.
To sum up, foam aluminum is suitable for use in ship cabins.
1. Aluminum foam sheet has the characteristics of good fire resistance, flame retardant, moisture, dust free, to solve the traditional sound-absorbing material is easy to absorb moisture, the crew health hazards, more suitable as materials for ship cabin noise.
2. Ship simulation results show that the average can be reduced about 10dB installation of aluminum foam materials after the indoor noise morning, obvious effect.
After installing sound absorption finish, high frequency noise can be effectively controlled, and the effect of noise reduction in low and intermediate frequency "1000HZ" section is larger and lower.
Foam aluminium sound proof board
The foam aluminum plate punching processing, can be made into high sound absorption plate (with 2mm hole punching rate from 1% to 3%), has excellent sound absorption performance, the sound absorption rate is high. Made of foam aluminum sandwich panel, 20mm thickness, sound insulation 20 ~ 40dB. The sound absorption rate measured by standing wave method is in the range of 1000Hz to 2000Hz, and the sound absorption rate is from 40% to 80%.
Density: 0.25g/cm³ ----0.75g/cm³
Porosity: 75% ---- 90%;
Pore size: uniform distribution of 1 - 10mm, and the pore size of 4--8mm;
Compressive strength: 3Mpa---17Mpa;
Bending strength: 3Mpa ---15Mpa;
Ratio of strength to bear weight: quality can reach more than 60 times;
Other features: Fire resistance is not burning, not toxic gas; corrosion resistance, long service life.
Product specification: 2400mm*800mm*H or customized according to customer requirements.
Product application field
Because the aluminum foam product has many special properties, can be widely used in aerospace, aviation, high-speed trains, city rail train, ship manufacturing, high-speed rail, construction, tunnel and along the sound barrier and other fields, has the advantages of light weight, high absorption, high damping, high impact energy absorption, high electromagnetic shielding performance, excellent insulation high temperature, combustion characteristics of refractory. Have unique environmental friendliness.