Patent attributes
A bulky sheet material having three-dimensional protrusions comprises a first fiber layer and a second fiber layer provided on at least one side of the first fiber layer. The first fiber layer contains thermally shrunken heat-shrinkable fibers. The second fiber layer comprises heat non-shrinkable fibers. The first fiber layer and the second fiber layer are partly joined together at a large number of joints formed by fusion bonding. The joints are formed by melting and solidification of a heat fusible resin having a higher melting point than the shrinkage starting temperature of the heat shrinkable fiber. The second fiber layer forms a large number of protrusions between the joints by the heat shrinkage of the first fiber layer while leaving the joints as depressions.
