Appeal No. 1996-2979
Application No. 08/175,376
Claim 7 is representative of the subject matter on appeal
and reads as follows:
7. A process for the production of fiberboards from
coarse wood particles and isocyanate as binder
comprising:
i) introducing the coarse wood particles and water
vapor under pressure into a pressurized digester
where the particles are softened,
ii) introducing the softened particles into a
pressurized refiner where the particles are
reduced to fine fibers,
iii) introducing the fibers into a blowing pipe,
iv) spraying the isocyanate onto said fibers after
they exit from said blowing pipe and before they
are dried, and
v) passing the so-sprayed fibers to a drier.
According to page 3 of the specification, it is critical
to spray the isocyanate onto the fibers after they leave the
blowing pipe, but before they are dried in a dryer, to avoid
lump formation in the fiber material, precuring of the
isocyanate and size specks formation on the finished
fiberboard.
The prior art references relied upon by the examiner are:
Betzner et al. (Betzner) 4,407,771 Oct.
4, 1983
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