Appeal No. 1998-0299
Application No. 08/301,523
BACKGROUND
The invention is directed to a multi-layered, biaxially stretched tubular film
comprising an inner layer which comprises an aliphatic polyamide, a water vapor
barrier outer layer and an oxygen barrier core layer. The water vapor layer
comprises an olefinic polymer and the oxygen barrier layer comprises an ethylene-
vinyl alcohol copolymer or a partially aromatic polyamide. The tubular biaxially
stretched film is said to be useful for filling with food products such as sausage
fillings. (Brief, p. 2). Claim 15, which is representative of the claimed invention, is
reproduced below:
15. A multilayered, biaxially stretched tubular film for covering goods in
the liquid or pasty state, which undergo a heat treatment after the
filling, the tubular film consisting of at least the three following strata:
- an outer stratum comprising at least one water vapor barrier layer of
an olefinic polymer,
- a core stratum comprising at least one oxygen barrier layer of an
ethylene/vinyl alcohol copolymer or a partially aromatic polyamide,
and
- an inner stratum which comprises at least one layer containing an
aliphatic polyamide.
As evidence of unpatentability, the Examiner relies on the following
reference:
Oberle 4,855,183 Aug. 8, 1989
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