Patent ID: 7291247

Claim:
An absorbent sheet formed by: (a) bleaching cellulosic fiber and producing fiber with a durable elevated curl index by way of a process comprising: (1) feeding a first cellulosic pulp including Kraft fiber to a refining gap defined between opposed surfaces, at least one of the surfaces being rotatable with respect to its opposed surface; (2) concurrently heat-treating, bleaching and convolving the cellulosic fiber pulp including Kraft fiber in the refining gap at a temperature of from about 230° F. to about 370° F. and a pressure of from about 5 to about 150 psig, the treatment taking place at high consistency in a bleaching liquor including a peroxide bleaching agent under conditions selected so as to preclude substantial fibrillation and attendant paper strength and fiber bonding development; (3) recovering said pulp wherein the length weighted curl index of the treated fiber is at least about 0.12; and (b) incorporating the Kraft fiber with the elevated curl index provided by way of steps (a)(1), (a)(2) and (a)(3) in the absorbent sheet by mixing pulp prepared by way of steps (a)(1), (a)(2) and (a)(3) with a second pulp having a lower length weighted curl index to produce a mixed pulp having a length weighted curl index intermediate the fiber with the elevated curl index and the second pulp; and forming an absorbent sheet from the mixed pulp.