Appeal No. 1998-2217
Application No. 08/644,555
Appellants are said to have discovered that
(Specification, p. 2):
[T]he reduction in bulk associated with wet-pressing
can be substantially reduced by incorporating into
the web certain fibers which have been found to
greatly diminish web densification when subjected to
the high pressures necessary for dewatering with
high intensity extended nip presses. As a
consequence, high intensity extended nip presses can
be used to dewater tissue webs without the
heretofore adverse consequence of imparting a high
degree of densification to the web.
The "certain fibers" referred to above are "modified wet-
resilient" fibers. Examples include chemically cross-linked
cellulosic fibers, heat-cured cellulosic fibers, mercerized
fibers and sulfonated pulp fibers. See Specification, p. 3.
The method of claim 1 uses papermaking fibers comprising
"at least about 10 dry weight percent modified wet-resilient
fibers selected from the group consisting of chemically cross-
linked cellulose fibers, heat-cured cellulosic fibers,
mercerized fibers and sulfonated pulp fibers." The method
comprises the steps of (1) depositing an aqueous suspension of
papermaking fibers onto a forming fabric to form a wet tissue
web, (2) partially dewatering the wet web to a consistency of
about 15 percent or greater, (3) compressing the partially
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