Differential density cellulosic structure and process for making same

摘要

A differential density single lamina web of cellulosic fibers comprises at least two pluralities of micro-regions disposed in a non-random and repeating pattern: a first plurality of high density regions and a second plurality of low density regions. The high density regions comprise cellulosic fibers comprising fluid latent indigenous polymers (FLIP), such as hemicelluloses and lignin. The fibers of the high-density regions are FLIP-bonded, i.e., bonded together by a process of softening, flowing and immobilization of the FLIP between the cellulosic fibers of the high density regions. The process for making the web comprises the steps of providing a plurality of papermaking fibers comprising FLIP; providing a macroscopically monoplanar papermaking belt having a web-facing surface and deflection conduits; depositing the plurality of the cellulosic fibers on the papermaking belt to form a web; heating the web to a temperature sufficient to cause the FLIP contained in a first portion associated with the web-facing surface of the belt to soften; impressing the web-side surface of the belt into the web; immobilizing the flowable FLIP and creating FLIP-bonds between the fibers comprising the first portion of the web.