In accordance with recent trends of considering automobiles as necessities, demands for an improved interior, safety, and driving comfort are growing. To meet such demands, various kinds of interior materials or sheets are applied to a head liner, a door trim, a rear shelf, a trunk mat, a car mat, a floor material, a bonnet, a ceiling material, a construction interior material, and a soundproof material.
Recently, the interior materials have been used sheet made of a substance selected from the group consisting of papers, vinyl, knits, non-woven fabrics, felts, and a combination thereof. At this time, the interior materials function to decorate an inside of an automobile such that users are comfortable in the automobile, to keep a warmth in the automobile or to shield the inside of the automobile from heat, to insulate and absorb an exterior sound to prevent exterior sound from penetrating into the automobile, and to reduce an impact force.
Hence, the interior materials must have excellent heat insulating properties, soundproof and absorbing properties, and shock-absorbing properties as well as excellent appearance. Additionally, the interior materials must be light in weight so as to reduce a weight of the automobile, and must have excellent processability so as to be applied to a complicated internal structure of the automobile and so as to cope with the structure change in conformity to the change of a kind of the automobile.
One example of a conventional automobile interior material includes two different layers. In detail, two different layers consist of a layer in which a vinyl paper and a release paper are attached to both sides of a felt, and the other layer in which a sponge and a knit are attached to one side of a pasteboard.
In this regard, the felt absorbs and insulates the exterior sound, the release paper shields a side of the felt, which comes into contact with a ceiling, and the vinyl paper prevents a surface defect of a bottom side of the felt or the contamination of the bottom side of the felt. Additionally, the pasteboard provides resistance against the bending of the felt, and the knit attached to the sponge acting as a surface cushion is used as a finishing material giving an excellent appearance.
However, the conventional automobile interior material is disadvantageous in that one plank is produced using various materials, such as the release paper, felt, vinyl paper, pasteboard, sponge, and knit, thus a production process is long and production cost is undesirably increased. Another disadvantage of the conventional automobile interior material is that most of the materials constituting the automobile interior material cannot be recycled, thus resulting in environmental pollution.
Meanwhile, a sheet (carpet) is suggested so as to improve a soundproofing and insulating effect, in which the functional yarns are inserted into a hard non-woven fabric and then a soft non-woven fabric is laminated on the resulting structure. However, this sheet has very poor processability and thus shouldn't be used as an interior material of the automobile. As well, an improved sheet is developed, in which a polyethylene resin is coated on any one side of the sheet, but this is disadvantageous in that a surface of the sheet is contaminated or the functional yarns are agglomerated because the polyethylene resin leaks slowly from the sheet due to the heating and compression of the polyethylene resin during the processing.
Accordingly, there remains a need to develop a light automobile interior material, which can be recycled, and has improved processability, sound insulating property, soundproofing property, heat insulating property, and shock absorbing property.
Moreover, consumers want the light automobile interior material, which can absorb vibration or an impact, is not harmful to health, and has excellent appearance.