Abstract: A method for manufacturing an extensible paper, is herein described. The method comprises the steps of: providing pulp fibers in form of a pulp having a first length-weighted average curl index; mechanically treating the pulp fibers using a pulp compression process to induce fiber deformations such that the resulting pulp fibers have a second length-weighted average curl index higher than the first length-weighted average curl index; forming a wet web using the mechanically treated pulp fibers; drying the wet web under restraint to form a dried web; and adding a polymer to the dried web. An extensible paper is also described that comprises: pulp fibers having a length-weighted average curl index CLW; and a polymer in an amount of from 2 to 40 wt % based on the weight of the extensible paper; wherein the extensible paper has a Gurley air resistance below 20 s/100 mL and an elongation at break of at least 7%.

Abstract: A process for producing cellulosic fiber with a high curl index is disclosed. The process can include mechanically treating and chemically crosslinking kraft pulp. The mechanical treatment of the pulp can include convolving and mechanically treating a pulp at in a plug screw and steam tube at temperatures above 100° C. and pressures above 3 bar. The mechanically treated pulp can be crosslinked with a crosslinking agent. The product fiber can exhibit a curl index of greater than 0.35, and can be at least 50% higher than the initial curl of the starting pulp material.