Note: Descriptions are shown in the official language in which they were submitted.
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CONTOUR SEALED HEAT-SHRINKABLE TURKEY PA_KA OE
FIELD OF THE INVENTION
The invention disclosed hc~_in relates to the packaging of msat
pieces and more particularly to vacuum packaging of discrete pieces of
turkey meat in a contour-sealed, thermoplastic flexible bag. Then, the
open neck end of the bag is closed such as by hea-t sealing or clip-
ping. At this point the package may be frozen or refrigerated for
storage. The bag material is oriented, i.e. heat-shrinkable, as the
resultant packaged product is oEten intended for cook-in, during which
the material shrinks about the product for a tight fit. Due to the
shape of the contour seal, the shrunken bag has a specific desired
contour shape, and in the event where the product is turkey, -the appear-
ance of a whole turkey breast. The bag of cooked turkey is then soId
in the retail stores.
~BACKGROUND OF THE IN~ENTION
When discrete pieces of meat, such as comminuted turkey meat or
turkey emulsion, are packaged, it is aesthetically appealing for -the
resultant packaged article to look more like a whole turkey breast.
Problems have occurred in the past with packaging because the bag was
made from a cylindrical tube of hea-t-shrinkable plastic film. Thus,
the shrunken packaged product was cylindrical in shape and looked like
a log rather than a whole turkey breast. Also, the prior art resultant
packaged produc-t often looked `wrinkled. With -the ins-tan-t contour
shape, any desired contour can be obtained. Contour shapes are known
for items such as gloves or toy balloons (i.e. the inflated balloon
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looks like a cartoon personage) but speclfic contour shapes for heat-
shrinkable packaging of comminu-ted meat are unknown.
Many apparatus for vacuum stuffing or packaging are well
known. One is the Belam vacuum meat press marketed by Belam, Inc., Oak
Brook, Illinois. Many patents disclose such apparatus, for example US
Patents 3,563,764, 3,703,064, 3,760,556, 3,853,999, 3,g28,938,
3,950,919, 4,132,048, 4,251,976, 4,586,320 and 4,672,793 and UK Pub-
lished Patent Specification 1,516,498, the disclosures of all of which
are incorporated herein b~ reference.
Also, some patents are specific to the bag closure means of the
vacuum packaging apparatus, the closure of the bag, mouth or neck being
accomplished by heat sealing with a heat seal bar such as tha-t de-
scribed in US Patent 3,673,041 or being accomplished by clipping the
bag neck with a clipper apparatus such as that described in US Patent
3,740,921. The disclosures of these two patents are incorporated here-
in by reference.
The package of comminuted meat can be frozen or refrigerated
for storage. Either before or after storage, the package can be sub-
jected to cook-in. For turkey, cook-in is a long slow process, typical-
ly about 1 to 4 hours, and can be up -to 12 hours, at a temperature
typically of about 160F (71C) to 200F (93C) and can be from about
131F (55C) to 212F (100C). Heat-shrinkable, cook-in films are
described in US Patents 4,411r919, 4,606,922, and 4,469,742 and common-
ly assigned published European Patent Application No. 269325, publica-
tion date of ~une 1, 1988 (counterpart of commonly assigned copending
USSN 932,138 filed November 17, 1986), the disclosures of all of which
are incorporated herein by reference. When the meat has been packaged
in a bag of heat-shrinkable film (i.e. oriented film, which is further
discussed below?, then during coo~-in the heat-shrinkable bag will
shrink about the meat to form a tightly fitting package. For certain
cook-in applications, such as oven roast, the bags are perfora-ted, for
instance with round perforations from needles or with oblong perfora-
tions from pointed-end knife blades. A perforating appara-tus is de-
scribed in US Patent 3,038,198, the disclosure of which is incorporated
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herein by reference. Oblong perforations are disclosed ln Australian
Published Patent Application No. 67078/~36, published April 3, 1987,
corresponding to USSN 7~5,419, the disclosure of which is incorporated
herein by reference.
STATEMENT OF INVENTION
It is an object of the present invention to provide an improved
method for the packaging of comminuted meat, wherein the heat-shrink-
able, flexible, thermoplastic packaging bag is contour-sealed whereby
when it shrinks about the meat, the shrunken package has a specific,
desired contour appearance. When the meat is turkey, the shrunken
package has the appearance of a whole -turkey breast. It is an advan-
tage of the invention that the packaged mea-t is substantially wrinkle
free.
Therefore, the present invention provides a method to package
discrete pieces of meat, said method comprising:
~a) providing a bag comprising a contour-sealed, flexible
thermoplastic, heat-sealable container having an open neck
end and opposing bag panels;
(b) extruding via a vacuum stuffing apparatus meat pieces under
pressure into the bag through the open neck; `
(c) vacuumizing the bag of meat pieces; and
(d) closing the open neck end of -the bay.
Then, the bag of meat can be heat shrunk, resulting in a specif-
ic desired contour appearance.
The invention also provides a package of discrete pieces of
meat, said package comprising:
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(a) a bag comprising a contour-sealed, flexible, thermoplas-tic,
heat-shrinkable container having a r.eck end, and opposing
bag panels;
(b) meat pieces disposed between opposite bag panels;
(c) the bag of meat pieces having been vacuumized; and
(d) the neck end of the bag having been closed.
The invention also provides this package of meat wherein it has
been heat-shrunk thereby providing a desired contour appearance.
The invention also provides a package of discrete pieces of
turkey meat, said package comprising:
(a) a bag comprising a contour-sealed, flexible, thermoplastic,
heat-shrinkable container having a neck end, and opposing
bag panels;
(b) turkey meat pieces inside the bag and disposed between
opposite bag panels;
(c) the bag of turkey meat pieces having been vacuumi~ed and
the neck end of the bag having been closed, and
(d) wherein said bag of turkey meat pieces has been heat
shrunk, and has the appearance of whole turkey breast.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a heat-shrunk turkey package
according to the invention.
Figure 2 is a plan view of the turkey package of Figure 1.
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Figure 3 is a slde view of the turkey package of Figure 1.
Figure 4 is a cross-sectional view of the turkey package of
Figure 2 along the plane defined by line 2, 2'.
Figure 5 is a schematic view oE a bag containing comminuted
turkey and a vacuum stuffer apparatus.
Figure 6 is a plan view of a bag top panel and Figure 7 is a
plan view of a bag bottom panel, each in the unshrunken condition.
Figure 8 is a perspective view of an unshrunken bag formed by
heat sealing together the panel of Figure 6 and the panel of Figure 7.
DETAIT~Fn D~SCRIPTION
Thermoplastic flexible Eilms may be generalIy manufactured by
extrusion (single layer films) or coextrusion (multi-layer films) of
thermoplastic resinous materials heated to or above their flow or mel-t-
ing point from an extrusion or coextrusion die in, for example, either
tubular or planar (sheet) form, followed by a post extrusion cooling.
To make the film heat-shrinkable, stretching typically is conducted at
some point during the cool down and while the film is still hot and
within its orientation temperature range followed by completing -the
cooling. Alternatively, after the post extrusion cooling, the relative-
ly thick `'tape" extrudate is then reheated to a temperature within its
orientation temperature range and s-tretched to orient the material and
then cooled. This is colloquially referred to as the "double bubble"
technique, and is described in US Patent 3,45~,044 (July 15, 1969~ and
US Patent 3,555,604 (January 19, 1971), both to Pahlke. When the
stretching force is applied in one direction monoaxial orientation
results, and when simultaneously applied in two directions biaxial
orientation results. The term oriented is also herein used interchange-
ably with the term "heat-shrinkable" with these terms designating a
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material which has been stre-tched and se-t by cooling while subs-tantial~
ly retaining its stretched dimensions. An oriented (i.e. heat-shrink~
able) material will tend to return to its original unstretched (unex-
tended) dimensions ~hen heated to an appropriate elevated temperature.
An "oriented" or "heat-shrinkable" material is defined herein as a
material which, when heated to an appropriate temperature above room
temperature (for example 96 C), will have a free shrink of about 5% or
greater in at least one linear direc-tion. Free shrink is measured in
accordance with ASTN D2732, and shrink tension is measured in accor-
dance with ASTM D2838.
With material of the hea-t-shrinkable type, then after wrapping,
the enclosed product is subjected to elevated temperatures, for e~am-
ple, by passing the enclosed product through a hot air tunnel or plac-
ing the enclosed product in hot water. This causes the enclosing heat
shrinkable film to shrink around the product to produce a tight wrap-
ping that closely conforms to the contour of the product. In the prior
art the film tube is formed into bags or pouches and thereafter uti-
lized to package a product and shrink it. Since the film has
been formed as a tube, the shrunken packaged product has a tubular or
cylindrical shape and appears like a log. In contrast with the instant
invention, the film is cut to a contour shape and then with a contour
seal bar, two sections of film are heat-sealed together.
The resultant contour shape of the present invention may be a
combination of the free shrink, the shrink tension, and the comminuted
meat's density. All 3 factors should work together to produce the
desired contour shape when the package is heat-shrunk. The resultant
desired shape should be an equilibrium condition achieved, for instance
when the comminuted product solidifies from cook-in. There should be
balanced force distribution of the product, bag shrink force, bag
strength and bag shape.
Irradiation of the bag film, if desired, may be accomplished by
the use of high energy electrons, ultra violet radiation, X-rays, gamma
rays, beta particles etc. Preferably, electrons are employed up to
about 20 megarads (Mr) dosage level. The irradiation source can be any
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electron beam generator opera-ting in a range of about 150 kilovolts to
about 6 megavolts with a power output cap-~ble oE supplying the desired
dosage. Many apparatus for irradiating films are known -to those of
skill in the art. The irradiation is usually carried out a-t a dosage
between about 1 Mr (lO kilogrey~ and about 20 Mr ~200 kilogrey~, with a
preferred dosage range of about 2 ~r (20 kilogrey~ -to about 12 Mr ~120
kilogrey). Irradiation can be carried out conveniently at room tempera-
ture, although higher and lower temperatures, for example, 0 C to 60 C
may be employed.
Many polymers are suitable for the bag films. For instance
polyolefins such as polyethylene, polypropylene, ethylene/butyl
acrylate copolymer, linear low density polyethylene, very low density
linear low density polyethylene, or ethylene/vinyl acetate copolymer
may be employed. Also, nylon may be employed. Also may be employed
(A) a copolymer of (i) a major amount of mol %-of an alpha-olefin of
the formula RCH=CH2 wherein R is H or C~ to C8 alkyl and ~ii) a
minor amount by mol % of an alpha, beta-ethylenically unsaturated
carboxylic acid, or (B) a metal salt neutrali~ed ionomer of (A); such
materials are commercially available as Primacor or Surlyn, respec-tive-
ly, from du Pont. ~lso blends of these may be employed. Also the film
may have an o~ygen barrier layer such as a layer of polyvinylidene
chloride copolymer or ethylene vinyl alcohol copolymer. Typical
comonomers for the polyvinylidene chloride copolymer are vinyl chloride
or methyl acrylate.
DETAILED DESCRIPTION OF THE DRAWINGS
The following discussion centers on the preEerred embodiment of
comminuted turkey. It is to be understood that other comminuted meats
may be used.
Figure 1 is a perspective view oE a turkey package showing a
heat-shrinkable bag 1 that has been packaged with turkey emulsion 3.
The package was cooked so that bag 1 is shown here in its shrunk condi-
tion forming a tight fit about the emulsion 3. The neck or mouth end S
of the bag 1 has been clipped closed.
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Figure 2 is a top plan view of the turkey package of Figure 1.
Shown is turkey emulsion 3. The bag is contour heat-sealed all the way
around by contour seal 9, and the mouth end 5 of the bag has been
clipped closed by mou-th ena clip 7.
Figure 3 is a side view of the turkey package of Figure 1.
Shown is turkey emulsion 3. The bag 1 has contour seal 9, and mouth
end 5 clipped closed by mouth end clip 7.
Figure 4 is a cross-sectional view oE the turkey package of
Figure 2 along the plane defined by 2, 2'. Seen is the top panel 11 of
the bag 1 and turkey emulsion 3 fills the bag from the top panel 11 to
the bottom panel 13 of the bag. The bay has contour seal 9, and mouth
end 5 clipped closed by mouth end clip 7.
Figure 5 is a schematic view of a vacuum stuffer apparatus 21
and a bag 23. The bag is of heat-shrinkable material. Also, the bag
material may be mono-layer or multi-layer (not illustrated here). Bag
23 is shown vertically disposed with its open mouth end 27 directed
upwards and disposed about discharge end 43 of the stuffing horn 29
part of vacuum stuffer apparatus 21. Stuffing horn 29 is shown in its
lowered position inside bag 23 between bag panel 39 and bag panel 37.
The two panels 37 and 39 are joined by contour heat seal 9. Via flex
hose 31, discrete pieces of turkey meat product 41 are pushed form
vacuum stuffer apparatus 21 in the direction of product flow arrows
33A, 33B, 33C, 33D, and 33~ into bag 23. Clean out piston 35 moves up
and down to help push the discrete pieces oE turkey meat product 41 out
of stuffing horn 29 into bag 23. The stuffing horn 29 retracts during
the stuffing process (not illustrated hera).
Figure 6 is a top plan view of top panel 11 of Figures 3 and 4,
but in its unshrunk condition llA so that the contour shape can be
viewed, and likewise Figure 7 is a bottom plan view of hottom panel 13
of Figures 3 and 4, but in its unshrunk condition 13A so that the con-
tour shape can be viewed.
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Then panels 11A and 13A are heat sealed together alon~ the pe-
riphery of the contour shape by hea-t seal g -to form heat-shrlnkable bag
lA, shown in a perspective view in Figure 8, with the mouth end 5A
open, and unstuffed with emulsion. Not shown, alternatively, two essen-
tially rectangular panels could be placed together, or a tube of film
could be laid flat, then the heat seal could be effected in the desired
contour shape and then after sealing the material could be cut along
the periphery of the seal.
In an alternative embodiment not shown in the drawings, the
mouth end of the bag could be heat sealed closed.
The following Examples are intended to illustrate the preferred
embodiments of the invention and comparisons thereto. It is not intend-
ed to limit the invention thereby.
MATERIALS EMPLOYED IN THE EXAMPLE
Vestamid L1801 is the trade-name of a nylon 12 type of
polyamide, herein abbreviated as PA, supplied by Nuodex.
Surlyn A-1650 is the trade-name of a zinc metal salt neutral-
ized ionomer of ethylene methacrylic acid, herein abbreviated as MSNI,
supplied by du Pont.
Bynel E20~ is the trade-name oE an adhesive supplied by du
Pont. It is herein abbreviated as Adh-l.
Bynel 3062 formerly CXA E-162, is the trade-name of an adhesive
supplied by du Pont. It is herein abbreviated as Adh-2.
Dowlex XU61512.08 is a linear very low density linear low densi-
ty polyethylene, herein abbreviated as VLDPE, supplied by Dow Chemi-
cal. It has octene as the comonomer; the density is 0.905 g/cc; and
the melt index is 0.80.
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EVA~ is the trade-name o-~ an e-thylene vinll alcohol copol~lmer,
herein abbreviated as EVOH. Such materials are also referred -to as
saponi-Eied ethylene/vinyl acetate copolymer. It is supplied by EVh~
Company of America.
NPE-4771 is the -trade-name of an ethylene/butyl acrylate
copolymer, herein abbreviated as EBA. It is supplied by USI. It has
about 5% butyl acrylate units by mol %; the melt index is 3.0; and
melting point is about 107 to 108 C.
EXAMPLE
All percentages in the film layers were by weight unless indi-
cated o-therwise. Co-extruded 6-layer tubular film was made by the
double bubble process as described above. Prior to the stretch orienta-
tion step, the tube was irradiated at 8 MR (80 Kgrey) +0.S MR
(5 Kgrey). The layers comprised the various polymers as recited below:
Sealing Abuse
Layer l Layer 2 Layer 3 Layer 4 Layer 5 Layer 6
Polymer75% PA 75% A~h-l Adh-2EVOH Adh-2 60% VLDPE
25% MSNI 25% VLDPE ~0% EBA
Thickness*
mils 2.9 4.7 1.1 1.1 1.1 5.6
(micrometer) (74) ~119) (28)(28) (28) 1142)
*Total thickness of tube wall before orientation was about 16.5
mils (419 micrometer), and after orientation was about 2.2 to 2.5 mils
(56 to 64 micrometers).
The oriented tube was laid flat, then heat-sealed in the con-
tour shape and then cut along the periphery of the contour seal so that
two panels were together, thereby forming contour sealed bags about 11
inches (28 cm) wide by 18 inches (46 cm) long, with the sealing layer
as the bag inside and the abuse layer as the bag outside. The mouth or
neck was left open for stuffing.
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Individual bags were placed ver-tically up against the ln~lation
station of a Furukawa 8150 vacuum meat stufEing apparatus. The 8150 ls
described in US Patent 4,586,320, the disclosure of which is incorporat-
ed herein by reEerence. With -the bag vertical, the open mouth end of
the bag was placed around the discharge end of the horn assel~ly oE the
apparatus. Then through the stuffing horn nozzle of -the apparatus,
turkey emulsion was filled into the bag between the bag panel. ~he
filled bags were vacuumized and then the mouth end clipped closed.
Alternatively, the mouth end could be heat sealed on the seal bars oE
the apparatus. Several pounds of turkey emulsion was put up in bags
and then the bags were heat shrunk at 200F (93.3C), by placing in hot
watex for 1 to 5 seconds. This was followed by cooking a-t 140 to 145F
(60 to 62.8C) for abou-t 1 to 1.5 hours, then at 160F (71.1C) for
about 2 hours, then at 17S to 180F (79.4 to 82.2C) till the internal
meat temperature reached 160F ~71.1~C) which was about 2 hours..
Product appearance was very impressive, similar to that of
whole breast packaged turkey. No wrinkles were observed.
While cer-tain representative embodiments and details have been
shown for the purpose of illustration, numerous modifications to the
formulations described above can be made without departing from the
invention disclosed.
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