Appeal No. 1999-2601
Application 08/862,682
DISCUSSION
The appellants’ specification indicates that the process set
forth in the appealed claims is designed to produce fiber-
reinforced composite materials made of thermoplastics having high
molecular weight, which thermoplastics characteristically have
high melt viscosity. According to the appellants, “[h]igh
molecular weight improves recycling behavior because repeated
melting results in a melt which, despite its oxidative and
thermal degradation, is still in the high-molecular-weight
region” (specification, page 2). In discussing the background
art (see pages 1 through 4 in the specification), the appellants
note that the use of highly viscous thermoplastics in the subject
environment is problematic for reasons such as inadequate wetting
of the fibers and low impregnation speeds. Regarding the
asserted capacity of their invention to overcome these problems,
the appellants explain that
[i]t is surprising that such a good wetting of the
fiber material, which was not believed to be possible,
can be achieved at all using melts of high viscosity.
It is particularly surprising that this effect is
achieved at impregnation speeds which are substantially
higher than those of EP 056703 for material of low
viscosity.
The principle underlying the invention is still
unclear. Perhaps, as a result of the increased
tension, the drag flow accompanying the filaments leads
to the formation, in the vicinity of the curvatures of
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