Appeal 2007-1168
Application 10/211,407
This argument is not persuasive. First, although the barrier function
of Lutzow's laminates might, as Tilton suggests, be decreased by "through
needling" (to coin a phrase), Tilton has not directed our attention to any
evidence that it would be destroyed. Indeed, Sorrick teaches that due to
differences in tension between the needle felt layers and the meltblown
layer, the needle holes will not be precisely aligned. This teaching appears
to apply to the Lutzow structure, as it is similar. Coupled with Lutzow's
teaching that the meltblown fibers wick liquid throughout the middle layer
(Lutzow at 2:33–38), the preponderance of the evidence indicates that needle
holes would not destroy the liquid-holding function of Lutzow's middle
layer.
Tilton also argues that the ultrasonic welding taught by Lutzow
would prevent the Sorrick filters from performing their function, in view of
the problems Sorrick associates with heat-fusing, and Sorrick's observation
that needling creates holes that increase the life of the filter. (Br. at 16.)
This argument is something of a red herring, in that we do not understand
the Examiner to have suggested that it would have been obvious to modify
Sorrick's laminates according to teachings of Lutzow. Moreover, Tilton has
not directed our attention to any credible evidence in support of his
argument. As long as the spot welding occurs "at a number of discrete
points across the length and width of the laminated sheet" as taught by
Lutzow (Lutzow at 2:57–59; and Lutzow, claim 1 at 8:10–20, which does
not specify the type of bonding), we are not persuaded that such bonding
would destroy the filtering efficiency or function of Sorrick's laminates.
Finally, Tilton takes issue with the Examiner's argument that the
variation of the meltblown polypropylene layer thickness would have been
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