Mat material and method for manufacturing the same

Abstract

A lightweight mat material having excellent sound absorption and thermal insulation properties comprises a mixture of glass fibers and sheath-core composite fibers, wherein the melting temperature of the sheath portion is lower than the melting temperature of the core portion. The glass fibers are fused with the sheath portions of the composite fibers by melting on at least one surface of the sheet-shaped mat material.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a mat material and a method for manufacturing the same, and in certain preferred embodiments, to a lightweight mat material or the like having excellent sound absorption and / or thermal insulation properties.[0003]2. Description of the Related Art[0004]Various proposals have been made to achieve a mat material having excellent sound absorption and thermal insulation properties. For example, Japanese Patent Publication No. 2008-291393 discloses a vehicle mat material obtained by uniformly mixing an inorganic fiber having high heat resistance, a crimpable inorganic fiber or a flame-retardant organic fiber, and an organic fiber having a low melting point, and subjecting the cotton-like material to heat treatment.[0005]However, known mat materials have thus far been unable to achieve sufficient sound absorption and thermal insulation properties for certain applications and uses.SUMMARY OF THE...

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Benefits of technology

[0006]Therefore, it is an object of the present invention to provide an improved mat material, such as but not limited to a lightweight mat material having excellent sound absorption and thermal insulation properties, as well as a method for manufacturing the same.

[0008]In one aspect of the present teaching, a glass fiber may be used as the inorganic fiber. In addition or in the alternative, a fine count fiber having an outer diameter of 3 to 9 μm is preferably used. The outer diameter of the inorganic (preferably glass) fiber is more preferably between about 4 to 6 μm, most preferably about 5 μm. If the fine count fiber is used, the number of fibers increases, so that a porous material is obtained. Accordingly, sound energy is readily converted into thermal energy in such a porous material, thereby improving the sound absorption properties of the mat material. Preferred glass fibers are two glass fiber yarns available from Nitto Boseki, headquartered in Tokyo, Japan with a main branch in Fukushima, Japan, under product numbers ECD 450 and ECD 900. ECD 450 has the following specifications: filament diameter 5.3 microns, filament count 200, twist 1.0 / 25 mm, tex 11.2 (g / 1000 m) and length per kilogram 89.2 (km / kg). ECD 900 has the following specifications: filament diameter 5.3 microns, filament count 100, twist 1.0 / 25 mm, tex 5.6 (g / 1000 m) and length per kg 178.5 (km / kg). Thus, glass fiber yarns suitable for use in the present teachings may also have one or more of the following optional attributes: filament count 50-250, tex 4-13 and / or length per kilogram 80-200 (km / kg).

[0012]Mat materials according to the present teachings may have one or more of: improved flame retardant properties, decreased specific heat capacity and / or improved heat retention and thermal insulation properties due to the presence of the inorganic fibers. In particular, a fine count sheath-core composite fiber is preferably used, and the inorganic fiber is mixed with the sheath-core composite fiber, which preferably have different specific gravities from each other. In this case, a mat material is formed, in which sound energy is readily converted into thermal energy, so that good sound absorption properties are exhibited. Furthermore, if a semi-fused sheath-core composite fiber is used as the sheath-core composite fiber, a porous material is obtained, because the fibers will have a variety of diameters, thereby also improving the sound absorption properties.

[0013]As described above, in at least certain aspects of the present teachings, a lightweight mat material having excellent sound absorption and thermal insulation properties can be obtained.

Problems solved by technology

However, known mat materials have thus far been unable to achieve sufficient sound absorption and thermal insulation properties for certain applications and uses.

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