Automotive sound-absorbing material

Abstract

A thin and light-weight automotive sound-absorbing material with a superior sound-absorbing property, which can be used, for example, for automotive insulator to keep the interior of an automobile quiet. This automotive sound-absorbing material has a laminate structure comprising a sound-absorbing layer, an intermediate layer, and a sound-absorbing layer. The intermediate layer comprises a film made of thermoplastic resin with a thickness of 10 to 100μ, on which small pores are uniformly opened in such a manner that the aperture ratio would be 0.05 to 5%. The sound-absorbing layers comprise an aggregate of fibers such as felt, glass wool, etc. or porous synthetic resin layer, such as urethane foam, etc.

Description

BACKGROUND[0001]1. Field of the Disclosure[0002]The present disclosure relates to a light-weight and thin automotive sound-absorbing material with a superior sound-absorbing property that can be used, for example, for automotive insulator provided on the floor, etc. of an automobile for keeping the interior of the automobile quiet.[0003]2. Discussion of the Background Art[0004]Light-weight sound-absorbing materials based on felt are in the mainstream of the recent automotive sound-absorbing materials for reason of reducing the weight of the car body. While felt excels in sound-absorbing property, it has inferior sound-insulating property. Felt has therefore been crushed to reduce the air permeability in order to improve the sound-insulating property in the prior art.[0005]It was however difficult to give uniform air permeability throughout the entire surface of the felt, since the control of air permeability by crushing the felt resulted in the partial unevenness of the basis weight...

AI Technical Summary

Benefits of technology

[0010]A light-weight and thin automotive sound-absorbing material with a superior sound-absorbing property.

[0014]The automotive sound-absorbing material of the present disclosure is light-weight and thin, and since sound permeates the film and is absorbed uniformly by the entire surface of both sound-absorbing layers, a superior sound-absorbing property can be obtained. The automotive sound-absorbing material of the present disclosure is therefore capable of keeping the interior of an automobile quiet by absorbing noise.

Problems solved by technology

While felt excels in sound-absorbing property, it has inferior sound-insulating property.

It was however difficult to give uniform air permeability throughout the entire surface of the felt, since the control of air permeability by crushing the felt resulted in the partial unevenness of the basis weight of the felt.

For example, it is necessary to crush the felt to a thickness of 5 mm to control the air permeability of a felt with a basis weight of 1200 g / m2 to 10 cc / cm2 / sec, but the attempt to obtain said air permeability resulted in a notable unevenness of the air permeability in some parts of the felt, as shown in Table 1, thereby causing the risk of deteriorating both the sound-insulating property and the sound-absorbing property.

Although these sound-insulating or sound-absorbing structure disclosed in the prior art documents is capable of keeping the airtightness by the film, the sound-absorbing property could not be improved due the lack of air permeability.

And although the engine noise could be insulated by using these structures for dash panels, their sound-absorbing property was insufficient for absorbing the noise of the interior of an automobile.

Images