Nippon Paper Industries Co., Ltd.

Ayaka Hasegawa

Toru Nakatani

Masatoshi Oishi

Koji Ninagawa

Shisei Goto

Moe Fukuoka

Moe Fuchise

The present invention aims to provide complex fibers of a cellulose fiber with inorganic particles exhibiting better drainage and retention when they are used as materials for forming sheets. In the complexes of the present invention, (1) the weight ratio B/A between the inorganic content (B) in the residue remaining on a 60-mesh sieve (having an opening of 250 &#x3bc;m) after an aqueous suspension of a complex fiber having a solids content of 0.1% is filtered through the sieve and the inorganic content (A) in the complex fiber before treatment is 0.3 or more; or (2) the weight ratio C/A between the inorganic content (C) in fractions corresponding to an effluent volume (L) of 16.00 to 18.50 and an elution time (sec) of 10.6 to 37.3 and the inorganic content (A) in the complex fiber before treatment is 0.3 or more when an aqueous suspension of the complex fiber having a solids content of 0.3% is classified using a fiber classification analyzer under the conditions of a flow rate of 5.7 L/min, a water temperature of 25&#xb1;1&#xb0; C., and a total effluent volume of 22 L.

Complex fibers of cellulose fibers with inorganic particles and processes for preparing them

The present invention provides a method for reducing web break caused in preparing, by continuous paper making, a fiber sheet containing a high content of functional inorganic substance. The composite fiber sheet manufacturing method includes: generating composite fibers composed of cellulosic fibers and inorganic particles by synthesizing the inorganic particles in slurry containing the cellulosic fibers; and continuously generating a sheet by supplying composite-fiber-containing slurry including the composite fibers to a continuous paper machine. In the composite fiber generating step, at least one of (i) slurry containing cellulosic fibers having a length of 1.2 mm to 2.0 mm in an amount of 16% or more in terms of length-weighted fiber length distribution (%) and (ii) slurry containing cellulosic fibers having a length of 1.2 mm to 3.2 mm in an amount of 30% or more in terms of length-weighted fiber length distribution (%) is used.

Method for manufacturing inorganic particle composite fiber sheet

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Tokyo, Japan

Ayaka Hasegawa