Automobile environmental protection, sound insulation, heat insulation and damping pad
1. Sound wave propagation
To study automobile sound insulation materials, we must first understand the relevant principles of sound wave propagation.
The greater the amplitude of the sound wave, the greater the corresponding sound pressure, and the louder the sound perceived by the human ear. Audio - audio is determined by the frequency of sound waves. The higher the frequency is, the higher the audio is, which is called "sharp sound". Tone - the tone is determined by the waveform of the sound wave. The same tone, the piano and the violin play different sounds. Speed of sound: the speed of sound propagation is greatly affected by temperature. At 0 ℃, the sound velocity is 331.5m/s. The speed increases 0.61m/s for every 1 ℃. In addition, sound is also related to the medium of communication. The speed of sound propagation in water is 1500m / s, and if it is propagated in metal, the speed will increase to 5000m / s.
Choose the sound-proof and absorption materials matched with the sound-proof environment, especially for the vehicle body and chassis. In addition to the recognized gradient sound-absorbing cotton in the industry, there are also sound-proof felt, sound-absorbing board, sound-proof felt and so on, which are relatively easy to install.

2. Sound insulation material
2.1 sound insulation and damping rubber

Sound insulation and damping rubber is the foundation of automobile sound insulation engineering. Butyl rubber as the main component plays a role in damping and damping of automobile sheet metal. It can be used as the basic material of the whole automobile sheet metal sound insulation and damping. The green environmental protection sound insulation and damping gasket produced by putsman is such a material.

2.2 silencing and heat insulation cotton
Silencing and heat insulation cotton is a kind of cotton with multi fiber structure, sound-absorbing and environmental protection raw material, which meets the requirements of national compulsory standards for automobile interior decoration. It is flame-retardant, waterproof, applicable to all parts of automobile parts, widely used in automobile sound-absorbing and heat insulation services, and has high cost performance.

2.3 engine hood insulation pad
The special automobile sound insulation material for the engine hood is composed of multi fiber structure cotton + perforated aluminum foil, which can cope with the high temperature of the engine cabin. This kind of sound insulation material can provide a layer of protection for the paint surface of the engine hood. The special perforated aluminum foil design can prevent the reflection of engine heat, protect various wires in the engine cabin from high temperature baking, avoid aging in advance, and even affect the service life and driving safety All.
2.4 automobile sealing strip
Automobile sealing strip is an environmental protection rubber material imported from Malaysia, which has good resilience and anti-oxidation performance. It is applied at the side of four doors to seal the car body, sensitive to high-speed wind noise, convenient for construction, and the best choice of automobile sealing material with high cost performance.