Fibrous structures containing a mixture of three or more different fibrous elements (filaments and/or fibers) are provided.

An alumina fiber aggregate that is formed of alumina short fibers and has been subjected to needling treatment, wherein the alumina short fibers have an average fiber diameter of 6.0 μm or more and 10.0 μm or less and a specific surface area of 0.2 m.sup.2/g or more and 1.0 m.sup.2/g or less, and a residual percentage (%) of high-temperature-cycle opened gap pressure of the alumina fiber aggregate is 45% or more. A value obtained by subtracting twice the standard error of a length-weighted geometric mean diameter of fiber diameters of the alumina short fibers from the length-weighted geometric mean diameter is 6.0 μm or more. A proportion of alumina short fibers having a fiber diameter of more than 10.0 μm is preferably 5.0% or less on a number basis.

Disclosed is a vehicular engine room manufacturing method wherein the engine room has excellent heat resistance and sound-absorbing characteristics, and scraps generated during the manufacturing process can be recycled. The vehicular engine room manufacturing method comprises the steps of: carding a thermoplastic fiber and a carbon fiber having a length of 10 to 150 mm and needle-punching the same, thereby forming a felt layer; applying heat and pressure to the felt layer, thereby forming a felt board; and applying heat to the felt board and shaping the same is formed in a desired shape.

Disclosed is a vehicular engine room manufacturing method wherein the engine room has excellent heat resistance and sound-absorbing characteristics, and scraps generated during the manufacturing process can be recycled. The vehicular engine room manufacturing method comprises the steps of: carding a thermoplastic fiber and a carbon fiber having a length of 10 to 150 mm and needle-punching the same, thereby forming a felt layer; applying heat and pressure to the felt layer, thereby forming a felt board; and applying heat to the felt board and shaping the same is formed in a desired shape.

The present invention provides a mat comprising a layer having a mixture of long and short fibers wherein said short fibers have a length of not more than about 13 mm and wherein said long fibers have a length of at least about 20 mm and wherein the amount of said short fibers is at least about 3% by weight based on the total weight of said mixture of long and short fibers.

The present invention provides a mat comprising a layer having a mixture of long and short fibers wherein said short fibers have a length of not more than about 13 mm and wherein said long fibers have a length of at least about 20 mm and wherein the amount of said short fibers is at least about 3% by weight based on the total weight of said mixture of long and short fibers.

Nonwoven fabrics are provided that include a mechanically entangled blend of fibers comprising (a) post-consumer recycled polymer staple fibers (PCR-staple fibers) and (b) one or more additional fibers, in which the one or more additional fibers are different than the PCR-staple fibers. The PCR-staple fibers are mechanically entangled with the one or more additional fibers to define the nonwoven fabric.

A process for producing a deformed nonwoven is described. The process includes the steps of: adjusting a water content of a nonwoven such that the nonwoven has at least one area having a water content of at least about 12% by weight of the nonwoven in the area, and subjecting the nonwoven to a mechanical deformation process. The deformation process is a mechanical deformation of the nonwoven and dewatering of the nonwoven to obtain a deformed nonwoven.

A process for producing a deformed nonwoven is described. The process includes the steps of: adjusting a water content of a nonwoven such that the nonwoven has at least one area having a water content of at least about 12% by weight of the nonwoven in the area, and subjecting the nonwoven to a mechanical deformation process. The deformation process is a mechanical deformation of the nonwoven and dewatering of the nonwoven to obtain a deformed nonwoven.

Disclosed is an artificial leather base material including: a non-woven fabric that is an entangle body of fibers (A) and fibers (B); and an elastic polymer applied inside the non-woven fabric, wherein the fibers (A) are crimped fibers that are formed from two types of resins with intrinsic viscosities different from each other, and that are filaments of 0.6 dtex or more, and the fibers (B) are ultrafine fibers of less than 0.6 dtex.