Multi-layered water-decomposable fibrous sheet

A multi-layered water-decomposable fibrous sheet with a plurality of layers each having a different fibrous constitution integrated therein, the fibrous sheet having a total sheet weight between 20 and 100 g/m2, comprising:

• a top layer on a top surface and a back layer on a back surface each including fibrillated rayon and other fibers having a length of between 1 and 10 mm, the content of the fibrillated rayon being at least 3% by weight of all fibers constituting each layer, the fibrillated rayon having a degree of beating of at most 700 cc, having a degree of fineness in a range of 1 to 7 denier, and having primary fibers of a predetermined fiber length and microfibers extending from the primary fibers, the primary fiber having a length of between 1.8 mm and 10 mm at the peak of its self weighted average fiber distribution, the microfibers having a length of at most 1 mm and being present in an amount of between 0.1 and 65% of the weight of the fibrillated rayon, the microfibers being at least of entangled with and hydrogen-bonded to at least one of other microfibers and other fibers, and
• an interlayer disposed between the top layer and the back layer including fibers having a length of between 1 and 10 mm but containing no fibrillated rayon, the fibers being at least one of entangled with and hydrogen-bonded to each other, or the interlayer including fibrillated rayon in an amount smaller than that in the top and back layers, the microfibers of the fibrillated rayon being at least one of entangled with and hydrogen-bonded to at least one of the other microfibers and the other fibers.