Note: Descriptions are shown in the official language in which they were submitted.
2134920 -
PATENT
Case No. 341900
High Speed Meat Packing Apparatus
BACKGROUND OF THE INVENTION
5 1. Field of the Invention
The present invention relates to a method of, and apparatus for, packag-
ing an article in a receptacle to obtain a substAnti~lly oxygen free pack. In
particular, the present invention relates to a method of and apparatus for
producing a package including a meat product in a substantially oxygen free
l0 heat shrinkable thermoplastic receptacle u~ ing an inert atmosphere and a
hot air shrinking means.
2. Description of the Related Art
It has been known to package an article in plastic envelopes, such as a
plastic bag, by loading the article in the envelope and then inserting the loaded
15 envelope into a vacuum chamber for the atmosphere around the envelope to
be reduced in pressure so that the air or other gas within the envelope is ex-
tracted and finally the envelope can be sealed under low pressure conditions.
The resulting package is termed a "vacuum packagen.
It is also known for the operation of the process to be such that during
20 the reduction in pressure of the atmosphere around the envelope, the wall of
the envelope balloons away from the enclosed article, so that the extraction of
air from within the envelope can be more effectively carried out. Such systems
using, for example, a nozzle to extract air from within the envelope while the
pressure of the atmosphere around the envelope ha~s been reduced to effect the
25 nece~$~ry ballooning action are known. Ballooning action is also known in
which the vacuum chamber in which the envelope is closed has two portions
of which a first portion encloses the envelope mouth and the second portion
encloses the article-enclosing rem~in~er of the envelope so that the pressure
around the exterior of the envelope can initially be reduced more rapidly than
30 the pressure within the envelope (in order to promote the desired ballooning
effect). Increased effectiveness of ballooning using several cycles of reducing
- - -
' ' 21~g2~ "
PATENT
Case No. 341900
the pressure around the envelope and within the envelope to help insure
removal of any trapped pockets of oxygen cont~ining gas is also known.
In all of these methods there is a necessity of using a vacuum chamber
to remove the oxygen cont~ininF atmosphere and a hot water heat shrink ap-
5 paratus to effectuate the shrinking of the heat shrinkable film envelope. Theuse of a vacuum chamber requires expensive, energy intensive equipment that
also limits the speed of p~rk~ing the desired articles. The use of a hot water
shrinking means is also energy intensive, and exposes the packaged article to
heat for a relatively extended period which then requires extended cooling be-
l0 fore the packaged product is ready for further distribution.
SUMMARY OF THE INVENTION
One form of the present invention relates to a process for p~rk~ing a
15 product comprising the steps of: flushing a product with a flll~hing gas;
covering the product with a heat shrinkable thermoplastic film formed in
tubular shape around the product; sealing a longitudinal seam flap of the
tubular shaped heat shrinkable thermoplastic film; sealing the product and a
quantity of the flushing gas within the heat shrinkable thermoplastic film by
20 sealing and separating the product cont~ininF portion of the tubular shaped
heat shrinkable thermoplastic film; removing the heat shrinkable
thermoplastic film sealed product from the gas flushing means; providing a
flushing gas exit hole in the heat shrinkable thermoplastic film; heat shrinkingthe heat shrinkable thermoplastic film against the product contained therein;
25 and removing the shrink wrapped product from the heat shrinking means and
sealing the flushing gas exit hole.
Another form of the present invention relates to a process for p~rkAgin~
a product comprising the steps of: loading a product onto a tray or slab;
flushing the loaded product with a flushing gas; covering the product with a
30 heat shrinkable thermoplastic film formed in tubular shape around the
product; sealing a longitudinal seam flap of the tubular shaped heat shrinkable
thermoplastic fflm; sealing the product and a quantity of the flllchin~ gas
within the heat shrinkable thermoplastic film by sealing and separating the
product cont~ining portion of the tubular shaped heat shrinkable
35 thermoplastic film; removing the heat shrinkable thermoplastic film sealed
, . .
213~2~ ~
-
PATENT
Case No. 341900
product from the gas flushing me~n~; providing a flushing gas exit hole in the
heat shrinkable thermoplastic film; heat shrinking the heat shrinkable
thermoplastic film against the product contained therein; and removing the
shrink wrapped product from the heat shrinking means and sealing the
flushing gas exit hole.
A further form of the invention relates to a package comprising a
product; a heat shrinkable thermoplastic fflm; a substantially oxygen free
flushing gas; a flushing gas exit hole; and a flushing gas exit hole sealing patch
over the flushing gas exit hole.
Yet another form of the invention relates to a package comprising a
product; a product cont~ining tray or slab; a heat .shrink~hle thermoplastic
film; a substantially oxygen free flushing gas; a flushing gas exit hole; and a
flushing gas exit hole sealing patch over the flushing gas exit hole.
Preferred forms of the invention, as well as other embodiments, objects,
features and advantages of this invention, will be apparent from the following
detailed description which is to be read in connection with the accompanying
drawings.
BRIEF DESCRIPIION OF THE DRAWINGS
In the drawings which are appended hereto and make a part of this dis-
closure.
FIG. 1 shows a schematic view of the apparatus of the present invention.
FIG. 2 shows the film being formed in a tube shape and flap ready to be
sealed by flap se~ling mP~n.~.
FIG. 3 show a schematic view of another embodiment of the present in-
vention.
DESCRIPIION OF THE pREF~RR~n EMBODIMENTS OF THE INVENTION
The present invention will be better understood from the specification
taken in conjunction with the accompanying drawings in which like reference
numerals refer to like parts.
FIG. 1 shows a s~hem~tic view of the apparatus 1 of the present inven-
tion wherein product indexing means 2 transports product 3 to gas flushing
means 4. Product 3 (e.g., a sub-primal of fresh red meat) is covered with heat
2134920 -
PATENT
Case No. 3-41900
shrinkable thermoplastic film 6 introduced from film supply 5 such that film 6
forms a tube shape around product 3 in area 7. Bottom longitudinal flap
sealing means 8 then seals the product 3 and the gas introduced by gas
flushing means 4 within film 6, having been sealed by bottom longitudinal
flap sealing means 8 and transverse sealing and cutting means 9. The now
sealed and flush gas filled film 6 cont~ining product 3 has a flushing gas exit
hole 11 punched in it using hot needle means 10. The film 6 is next heat
shrunk around product 3 using a hot air shrinking means 12. The presence of
the flush gas causes the film to balloon away from the product 3 and prevents
the film, during the heat shrinking process, from sticking to the product and
thereby forming gas pockets. Additionally, because the flushing gas is
substantially oxygen free any gas trapped between the product and the film
will not-have a detrimental effect upon the product. Upon exiting the hot air
shrinking means 12 a film patch 13 is sealed over exit hole 11 producing a
product 3 sealed in a sealed heat shrunk barrier film 6 which is removed from
indexing means 2 for shipment or further processing.
Yet another form of the present invention relates to a process for pack-
aging a tray or slab loaded product, in a substantially oxygen free container ofheat shrinkable, thermoplastic film.
Still another form of the present invention relates to a process for
p~ k~ng a product and an oxygen scaven~in~ agent in a substantially oxygen
free cont~in~r of heat shrinkable, thermoplastic film.
Fig 2 shows a cross-section of Fig 1 at line A-A where the film 6 has
been formed into a tubular shape and the flap 20 is ready to be sealed by flap
sealing means 8. Optionally, an adhesive 21 may be used to seal, or help seal
the flap 20.
In Fig. 3 is shown another embodiment of the present invention where
the product 3 is loaded into an oxygen barrier tray 30 before introduction to
the product index~ng means 2. Indexing means Z then transports product 3 to
gas flushing me~n.c 4. Product 3 is covered with heat shrink~hle thermoplastic
film 6 introduced from film supply 5 such that film 6 forms a tube shape
around product 3 in area 7. Bottom longitudinal flap sealing means 8 then
seals the product 3 and the gas introduced by gas flushing means 4 within film
6, having been sealed by bottom longitudinal flap sealing means 8 and
transverse sealing means 9 and cutting means 31. The now sealed and flush
- - -
213~1~20
r~
PATENT
Case No. 341900
gas filled film 6 contAining product 3 has a flushing gas exit hole 11 punched
in it using hot needle means 10. The film 6 is next heat shrunk around
product 3 using a hot air shrinking means 12. Because the fl lching gas is
substantially oxygen free any gas trapped between the product and the film
will not have a detrimental effect upon the product. Upon exiting the hot air
shrinking means 12 a sealing means 32 seals the film 6 to the edges of an
oxygen barrier tray 30 producing a product 3 sealed in an oxygen barrier
sealed tray 30/heat shrunk barrier film 6 which is removed from in~l~xing
means 2 for shipment or further processing.
The film tube forming apparatus is well known in the art and may be,
for example, an apparatus such as K-PAK m~l~hines supplied by Kartridge Pak
Inc. Likewise, the longitudinal flap sealing means and the transverse sealing
and cutting means are well known in the art and need no further discussion
here.
Hole plln~hing means and the particularly preferred hot needle means
for punching holes in film are well known in the art and need no further dis-
cussion here. Likewise, hot air shrinking of heat shrinkable film and apparatus
to do this are well known by those skilled in the art and thus no further
discussion is required here.
The indexing means is preferably a conveyer system or series of con-
veyer systems, but any suitable indexing system, whether manual or automatic
may be employed in the present invention. Further, while the complete index-
ing system apparatus and control systems are not shown, they are well under-
stood by those skilled in the art and further description is not necessary to util-
ize the present invention.
Suitable heat shrink~hle thermoplastic materials for use in the present
invention, include oriented films, and oriented film l~minates where at least
one film of the l~minate is a heat shrinkable thermoplastic film. As used
herein "film" is defined as a single layer or coextruded multiple layers. Also,
as used herein, "l~min~tes" is defined as a multi-film material having at least
one oriented film. Presently preferred are oriented films, particularly bi~xi~lly
oriented films. These films may be of a single layer or of multiple layer
construction. Multilayer films may contain more than one layer of the same
film composition or may contain different film compositions in one or more
2~3~920
._
PATENT
Case No. 341900
layers of the multiple layer film. In addition, these materials may be
coextruded or l~rnin~ted.
Film compositions suitable for use in the present invention include, for
example, an outer layer (food side) layer of ELVAX 3128 ethylene vinyl acetate
S copolymer (EVA), a first inner layer of a blend comprising 80% by weight
Dowlex 2045 linear low density polyethylene from Dow Chemical, plus 20% by
weight of EZ705-009 ethylene n-butyl acrylate copolymer from Quantum
Chemic~l~, a second inner layer of saran (e.g, vinylidene chloride/vinyl
chloride copolymer, or vinylidene chloride/methyl acrylate copoly~ner), and a
10 second outer layer of ELVAX 3128 EVA copolymer. Another preferred film
formulation comprises an outer layer (food side) comprising a blend of 90% by
weight of NA 295-000 EVA copolymer from Quantum Chemicals and 10% by
weight Dowlex 2045 or comprising 85% by weight of Dowlex 2045 and 15% by
weight of Quantum EA719-009 ethylene n-butyl acrylate copolymer, a first
lS inner layer of a blend comprising 80% by weight Dowlex 2045 from Dow
Chemical, plus 20% by weight of EZ705-009 from Qn~ntllm Chemicals, a second
inner layer of saran, and a second outer layer comprising 92.5% by weight of an
EVA copolymer (LD 318.92 from Exxon) plus 7.5% by weight of Dowlex 2045.
Patch materials suitable for use in the present invention may comprise
20 the same compositions as the heat shrinkable film or may be different. The
patch material preferably also have the necessary oxygen barrier properties to
~lev~llt oxygen cont~min~tion of the product. The patch may or may not be
heat shrink~hle since it is applied to the packaged product after hot air shrink-
ing of the film cont~ining the product. Further, the patch may be applied us-
25 ing any known ~tt~.-hing means including adhesives and heat sealing. A pres-
ently preferred patch material comprises the same m~teri~l composition as
used for the heat shrinkable thermoplastic material.
Optionally, the present invention may have an oxygen scavenging agent
introduced into the package before sealing. Suitable oxygen scavenging agents
30 are well known in the art and include, for example, AGELESSTM oxygen
scavenging packets supplied by W. R. Grace & Co., Conn. through its p~- k~ inE
division.
Although the illu~ alive embodiments of the present invention have
been described herein with reference to the accompanying drawings it is to be
35 understood that the invention is not limited to those precise embodiments,
213'q~2~
PATENT
Case No. 341900
and that various other changes and modifications may be effected therein by
one skilled in the art without departing from the scope or spirit of the inven-
tion.
For example, although the preferred tray to be used in connection with
S this invention is an "oxygen barrier" tray, i.e., a tray having either inherently
low oxygen transmission properties, or having e.g., an oxygen barrier film or
lAminAte adhered to one or more surfaces of the tray, other trays or supports
can be used in connection with the invention. Those skilled in the art will
understand that the selection of the tray or support type will depend in part on10 the type of product to be packaged, and the desired shelf life ( in the case of
food products).
Also, various olefinic and other thermoplastic polymer materials can be
used in suitable proportions as the component of a heat shrinkable film or
lAmin~te useful in the present invention. Again, the skilled routineer will
15 select such materials on the basis of desired functionalities, intended end use,
and other considerations.
