Appeal No. 2001-0344
Application 08/900,254
DISCUSSION
A. Specification
As an initial matter, we note that the specification of the instant application on
appeal contains a dearth of information regarding the process details for obtaining a
pleatable (or pleated) filter material. At page 2, lines 18 through 21, we are told that
“[t]o avoid essentially flat bonding, the fibrous web is bonded in a tension-free manner
between profiled calender rolls without inhomogeneities over the cross section of the
fabric.” At page 3, lines 3 through 6 we are informed that “[t]he fibrous web of the
present invention is directly calendered with a three dimensional structure, without a
detour using a flat calendering step, and during calendering is bonded.”
The resulting three-dimensional structure is said to have “spacers [which] are
produced without changing the homogeneity of the non-woven fabric, and that even
under the influence of mechanical and/or thermal stresses during the filtration operation,
they do not change their shape and remain stable during the entire service life.”
This is accomplished, according to the Appellants, by using calender rolls having
a sinusoidal surface feature operating at a line pressure of 20 to 60 bar for a calender
width of 1.2 meters, and may be operated hot or cold (depending on whether the web is
preheated) (Page 3, line 25 – page 4, line 3). The fibrous web is first formed from
drawn and undrawn fibers, and calendered between the profiled rolls. We are again
told that “[t]o avoid essentially flat bonding, the fibrous web is bonded in a tension-free
manner between the profiled calender rolls 1 without inhomogeneities over the cross-
section of the non-woven fabric.” (Page 4, line 36 to page 5, line 3).
4
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007