Note: Descriptions are shown in the official language in which they were submitted.
'~ 3 !~ ~r/Auso/
- 1 -
PACKAGING F~R PERISHABLE GOOD~
5 Field of the Invention
This invention relates to .improved packaging for
perishable goods and relates particularly but not exclusively
to improved packaging for meats such as red meats.
Description of Prior Art
10~ Hitherto, there have been many proposals for
: : packaging good in a clear plastics material. With meats and
: other perishable type goods, the shelf life i5 limited because
of the ~rowth of bacteria within the packaging and because of
discolouration of the packaged goods particularly red meats.
lS It has been known to provide certain gases within the package
to enhance the keeping properties of the packaged goods. In
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WO91/03407 ~ ^
- 2 - PCT/AU90/0038 ~
the case of meats, a combination of 2 and CO2 is used.
Generally, the volume of gas is equal to the volume of the
meat. Typically 2 is present in the proportion of 80% whilst
the CO2 is present in the proporlion of 20~. in red meats.
Examples of known packaging for this purpose are
disclosed in PCT Patent Application PCT/AU86/00339,
~ PCT/AU87/00243, PCT/AU87/00297 and PCT/AU88~00424 all in the
.; name Garwood Limited... The subject matters of the above
applications are hereby incorporated by reference.
It is considered that the construction of the
packaging in the aforementioned patent specifications is
unnecessarily expensive and that the resulting equipment which
is required to manufacture the packaging is also unnecessarily
expensive. The packaglng is considered to be unnecessarily
15 expensive because of the requirement to provide for
multi-layered webs of plastics material for the base and for
the lid and for the skin wrapping membrane. Multi-layered
webs are required in order to provide for the required gas
permeability and/or non-permeability whilst at the same time
; 20 allowing sealing of the various packaging components together.
The machines used for producing the above packaging are
considered unnecessarily expensive because, as an example,
complicated drive arrangements are required to advance all the
~ebs of plastic material at a controlled rate so that one or
25 more webs will not rupture prior to sealing o~ the package.
The packaging in the above patent applications
relates generally to providing a clear plastics base, goods
positioned within the base, a plastics material skin wrapping
the goods relative to the base, a lid sealed over the base,
30 and a space under the lid and above the skin wrapping
material. A gas is retained within the space ~or enhancing
the keeping properties of the packaged goods. The skin
wrapping-materia:L is gas permeable so that the gas can pass
through the~skin wrapping material and contac-t the goods.
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WO9l/034n7 - 3 - PCr/AU')0/On3~X
Additionally, gases which may generate or exude from the
packaged goods can, in some cases, pass -through the sXin
wrapping web and into the space.
The skin wrapping material is used to physically
5 support and hold the goods relative to the base so they do not
flop around within the package.
It has been realised that improved packaging can be
obtained without the use of a skin wrapping web, but instead
wllere strand means are used to hold the goods relative to the
10 packaging. The strand means may comprise individual filaments
which extend across the upper surface of the goods or may
comprise a mesh which is held over the top of the goods.
; Alternatively, the strand means may comprise a web of plastics
material which has heen slit and stretched so that it
15 represents an expanded mesh arrangement where the remaining
portions of the web material between the slits form strand
means.
- The strand means are of a size which will permit
easy viewing of the upper surface of the packaged goods
20 without obstructing direct viewing of a major portion of the
upper surface of the goods. The strand means also does not
significantly interfere with the gas contacting the surface of
the packaged goods. The strand means is such that it is
stronger than the skin wrapping webs and hence complicated
25 feeding means for permitting the strand means to be corr~ctly
placed within the packaging as needed for the skin wrapping
webs is not required. This contrasts significantly with the
-feed means in packaging machines used for the packaging in the
aforementioned patent specifications, where the s~retch skin
30 wrapping web has to be controlled precisely thereby so that it
will not rupture or buckle or fold.
Object and Statement of Invention
_ . . .. . . _. . .... __..__ .
- Accordingly it is an object of the present invention
to provide an improved packaying, a method oE production and
35 apparatus therefore. - :
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WO 91/U3407 i, i~ PCI`/AU90/0038:1
Therefore, in accordance with a first broad aspec~
of the present invention there may be provided improved
packaging for perishable goods comprisi~g:
a b~se over which said goods are placed,
strand means over said goods holding said goods
relative to said packaging,
~ a lid positioned over t:he top of said base and
sealed to said base,
a space above said goocls and under said lid,
:~ 10 a gas in said space, said gas selected for enhancing
preservation of the packaging goods by contacting the surface
of said goods,
said strand means not substantially inhibiting said
gas from contacting said goods and permitting. viewing of a
15 major portion of the upper surface of said goods.
In this way, the strand means will hold the goods
relative to the packaging such as the base, and i~ the
packaging base and lid are of a clear plastics material, then
substantially the whole of the surface of the packaged goods
20 can be inspected by an intending purchaser. Thus, the
~. packaging will be pleasing to an intending purchaser.
Brief Desc.ription of Drawings
; In order that the invention can be more clearly
ascertained, preferred embodiments will now be described with
25 reference to the accompanying drawings, wherein:
Figure 1 is an exploded perspective view of one ..
preferred packaging;
Figure 2 is an end sectional view of the packaging
shown in Figure l;
Figure 3 is a part sectional perspective view.of the
packaging shown in Figures 1 and 2 showing how strand means ..
engage with the upper surface of the packaged goods~ 'rhe
packaging of Fi~ure 3 is.shown just prior to the lid and the
base being sealed together;- - :. :: . .
Flgure 4 shows strand means in:the form of:a mesh:
; ~ WO')l/03407 ~ ' PCrtAU~)0/003~2
Figure 5 is a side view of a typical packaging
rnachine for producing packages shown in accordance ~i-th the
embodiments of Figures 1 through 3;
Figure 6 is a perspecti~e view of a preferred plate
5 means for use with the packaging rnachine of Figure 5;
Figures 7a and 7b show a form of web material which
is slitted and subsequently expanded to provide strand means;
Figure 8 is ,a side cross-sectional view of a further
embodiment of packaging;
E`igure 9 is a side view of a further embodiment of
packaging;
Figure 10 is a side view of an even further
embodiment of packaging; and
Figures lla and llb show side views of a further
15 embodiment of packaging where strand means are integrally
attached to a lid prior to closing and sealing of the lid
relative to the base.
Figure 12 is a side view of an even further
embodiment.
20 ~
Referring now to Figure 1, there is shown improved
packaging for packaging perishable food stuffs and in this
embodiment red meats. The packaging comprises a base 1 and a
'~ lid 3. In the embodiment shown, each of the base 1 and lid 3; 25 are of shallow tray-like configurations. The lid and the base
are both made from PVC which may have a polyethylene coating
on the inside faces. The PVC is therefore a subs~antially gas
impervious gas barrier material. The polyethylene coating may
be treated with an anti-fogging agent or material. Typically
30 the lid has the PVC of 200um thickness and the polyethylene
coating of 80um thickness. Typical size ranges ~or the lid
- materials could be for the PVC, 100 to 400um thickness and for
the polyethylene coating, 20 to 200um thickness. The base 1
,has the PVC of about 400um with a polyethylene~'coating'of
35 about 80um thickness. Typical,ranges'for the'PVC in the'base
1 are 200um to ,800um and~for the polyethylene coating 50um to
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W09l/034~7 ;.~ ~J ~ 6 ~ PC~/AU90/00382
lOOum. Thicknesses outside these limits are possible but the
above appears to represent desirable thickness ranges. The
base 1 is shaped and sized to neatly receive goods 5 such as
red meat therein.
A plurality of strand means 7 are provided between
the base 1 and the lid 3. In the embodiment shown there are
three strand means 7 although the number used can be
determined to some ex~tent by the aesthetics o~ the finished
package. The strand mean is preferably of polyethylene of a
10 diameter of about lmm. A typical size range for the strand
means in the embodiment of Figure 1 may be from 0.05mm to 5mm.
As can be seen each of the strand means 7 in the embodiment
of Figure 1 comprises individual filaments.
Figure 2 shows the arrangement in end cross-section.
15 It also shows that the base 1 has a plurality of upstanding
ribs 9 which space the bottom of the goods 5 above the bottom
of the base 1.
Figure 3 shows the arrangement just prior to sealing
closed of the base 1 relative to the lid 3. Here it can be
20 seen that the strand means 7 engage with the upper surface of
the goods 5 as the goods 5 stand somewhat above the upper
surface of the base 1 and in particular a lip 11 thereof.
The strand means 7 are tensioned over the goods 5 so they
deform the upper surface of the goods 5 slightly by partly
25 embedding into the upper surface. The strand means 7 are
sealed to the base 1 under such tension to firmly hold the
goods to the base 1.
A gas for enhancing the keeping qualities oE the
packaged goods is provided between the base 1 and the lid 3
30 and retained within the packaging when the lid 3 and strand
means 7 are sealed relative to the base 1. Typically the
sealing can be by heat seaJ.ing although it may be by gluing or
by other means known in the packaging arts such as RF or sonic
bonding. The gas which is provided in--the packaging for red
35 meats is typically 80% O2 and 20%- CO2. It is noted that there
is a space 13 provided above the goods S and under the lid 3.
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-- W091/03407 - 7 - PCr/AU90/00382
The volume of the gas retained within the packaging is
substantially eq~al to the volume of the meat or goods 5.
Thus, the volume of gas will be sufficient to permlt for a
shelf lift of at least several days. Typically, the base 1
5 and the lid 3 are made of a clear plastics PVC and the coating
of polyethylene is also clear. Accordingly, a purchaser will
be able to view the goods 5 by looking through the packaging.
The strand means 7 is of a size which does not substantially
inhibit said gas from contacting the goods. It is also of a
10 size and spacing to permit viewing of a major portion of the
upper surface of the goods.
If desired, the base 1 may be made of a
non-transparent material. Thus, juices which may exude from
the packaged goods 5 may be able to se-ttle on the bottom of
15 the base 1 and not be observed by an intending purchaser
because of the opaque nature of the material fro~n which the
base 1 is made. A paper or like pad may be used under the
meat to soak up any such juices.
- The strand means 7 is sufficient to hold the goods 5
20 within the base 1 so that it does not flop around if the
package is inverted or otherwise moved. The strand means 7 is
particularly preferred to be st~etched under tension across
the goods 5 prior to sealing of the lid 3 relative to the base
1. Thus, when the lid 3 is sealed relative to the base 1, the
25 strand means 7 will be sealed and secured relative tc the
packaging and will always act to hold the goods 5 relative to
the packaging without flopping.
The packaging described above has the base 1 and the
lid 3 of a material which substantially inhibits against the
30 gas within the package fxom escaping and also substantially
inhibits other gases from entering the packaging. The
polyethylene coating on the inner faces of the base 1 and the
lid 3 provides a convenient means to effect heat sealing of
the lid 3 relative to the base 5 and to hold the stxand means
~5 7 sealingly-retained relative to the packaging. ~-
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wo 91/03~07 ~ 3 !~ PCr/~U90/0038~
Figure 4 shows a different version of strand means 7
which comprises a web of netting like material. Each of the
- strands in the strand means 7 can be of the same size as
previously described for the embodiment of Figures 1 through
S 3, and the mesh size can be in the range of 5~n2 to 40mm2.
Referring now to Figure 5 there is shown a
particularly preferred embodiment of packaying machine for
producing the packagin~g shown in the embodiments of Figure 1
through 3 with the strand means described therefor or as
10 depicted in Figure 4. Here the apparatus comprises a pair of ~.
spaced conveyor chains 15 which pass over driven sprocket
wheels 17. Each of the chains 15 supports a respecti.ve side
of a plurality of plate means 19 which are pivotally supported
relative to the chains 15 by brackets means 21 and pins 23.
15 This is more clearly shown in Figure 6. Each of the plate
means 19 is mounted relative to the chains 15 so that the
plate means 19 are almost in abutting end-to-end relationship
as shown. The sprocket wheels 17 are indexed in their angular
rotation so that the plate means 19 index to various work
20 stations along the apparatus.
A first work station 25 comprises a tray 1 loading
station where trays 1 are loaded into an aperture 27 therefor
in the plate means 19. Two such apertures 27 are shown in
each plate means 19. The apertures 27 are of a size to
25 receive the lowermost portion of the hase 1, and so that the
lip 11 'supports the base 1 from the upper surface of the plate
means 19. Two such apertures 27 have been shown, represen~ing
a preferred arrangement where two packages are produced
simultaneously. Other numbers of apertures 27 may be provided
30 so that desired numbers of packages can be produced
simultaneously by the apparatus.
- , -, The plate means 19 index to a second work station 29
where goods 5 are loaded into the trays 1. -
,- - The plate means 19 then next index to a third work
35 station 31 where.l.ids 3 are placed over the'top'of'the'goods 5
in the trays 1. The lids 3 are stacked in a holding column 32
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WO91/03407 _ 9 Pf~/AlJ~0/003B2
in upside down relationship relative to the base ~.. An arm 34
carrying pneumatically operated suction cups 36 swings about
pivot 38 so the cups 36 enyage with the lowermost lid 3 in the
column 32. Suction is applied so the lowermost lid 3 is then
5 held by the suction cups 36. The arm then swinys to the
position shown in dotted line inverting the lids 3, and
~' suction is released. Thus, the lids 3 fall. onto the plate
means 19 directly over the bases 1 and in the correct inverted
relationship thereto. Figure 6 shows how there are a
10 plurality of upstanding pins 33 on the upper surface of the
plate means 19. The pins 33 are spring biased to extend
upwardly as shown. Each of the pins 3 around each of the
respective apertures 27 aligns the lids 3 relative to the
bases 1 carried by the plate ~eans lg as the li.ds 33 fall from
15 the suction cups 36.
The plate means 19 then index to a fourth work
station 35 where gas flushing and sealing of the lids 3 to the
~ base 1 is effected. The fourth work station 35 has an upper
platen 37 and a lower platen 39 which respective chambers 41
20 and 43 therein. The platens 37 and 39 can be move~ by
suitable means such as by air bags which are inflated or ~ '
deflated,. The platens 37 and 39 are shown spaced apart as the
relevant plate means 19 index into the fourth work station 35.
The platens 37 and 39 are then moved to seal on the upper
25 surface and under surface of the plate means 19 respectively.
Thus, the chambers 41 and 43 seal relative to the plate means
19. Suitable "O" ring seal means 45 are provided on the outer
edges of the upper platen and lower platen 39 to effect such
seal ing .
When the upper platen 37 and lower platen 39 are
sealed relative to the plate means 19, air can be evacuated
through air evacuation passageways 47, and a suitable gas for
.enhancing the keeping properties of the goods 5 can be
admitted through gas inlet passageways 49. -Thus,'each'of the
35 chambers 41 and 43 has air removed therefrom and a desired gas ¦
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W091/03407 - 10 - PCr/AU~O/003B2
introduced thereto~ This, in turn, means that air undernea~h
the lid 3 and in the base 1 is exhausted and replaced with the
desired gas.
Impulse heat sealing means 51 is provided on the
5 undersurface of the upper platen 37. The impulse heat sealing
means 51 may conveniently comprise a known electrical heating
strip of flat stainless steel hel.d to the undersurface of the
platen 37. An electric current can be supplied to the strip
to cause it to heat to, in turn, cause heating of the plastics
10 material around the lip 11 of the base and the corresponding
-: portion of the lip on the lid 3. It will also cause heating
of the strand means 7. Thus, because the platens 37 and 39
are applied with pressure against the respective upper and
lower faces of the plate means 19, the lid 3 will be forced
15 towards the base 1 around the lip portions at least and will
then cause sealing of the lid 3 to the base 1 with ~he strand
means 7 stretched across the goods 5 and held relative to the
packaging.
It can be seen that the strand means 7 is fed from a
~20 suitable roll to the upper surface of the bases 1 prior to the
-lids 3 being applied over the bases 1. A suitable tension can
be applied to the stand means 7 to cause it to be sealed under
tension relative to the packaging thus causing the goods 5 to
be tightly held relative to the packaging in the base 1.
The strand means 7 may comprise individual filaments
as shown in the embodiment of Figures 1 through 3 or it may
comprise mesh as shown in Figure 4.
The sealed packages then i~ldex from the fourth work
station to a fifth work station 53 where a pair of guillotines
30 55 will sever the strand means 7 which interconnects each of
the packages passing from the fourth work station 35. As the
packages index to the fifth work station 25 they draw the
strand means 7 over the package in work s~ation 31. The roll
of strand means ? is controlled so that a required tension is
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WO91/03407 ~ 3'~31~ Cr/~U')0/00382
imparted to the strand means 7. A guide roller 54 applies to
the strand means 7 directly over the top of the goods 5 at
work station 31.
As the relevant plate means 19 move over the end
5 sprocket wheel 17 at the left-hand side of Figure 5, the
completed sealed package can fall therefrom as by gravity.
Suitable electrical and mechanical control means are
used to index the plate means l9 -to the relevant work stations
and to cause operation of the various loadings and operations
lO at the relevant work stations. These are all considered known
in the packaginy arts and have not be detailed herein. It
should be noted that as the upper platen 37 and the lower
platen 39 close on the plate means l9 at the fourth work
station 35, the pins 33 will be depressed by the undersurface
15 of the upper platen 37 engaging therewith. The lids 3 will,
however, be located relative to the bases l at this point of
time and thus there will be no expected movement of the lids 3
- relative to the base which would cause misalignment of the lid
3 relative to the base l.
~ 20 In the embodiment shown herein, the first ~ork
- station 25 may be replaced by a sheet extruder which extrudes
the desired plastic material to a thermoforming station which
directly feeds bases l in csntinuous strip-like form into the
relevant apertures 27 in the plate means l9. Similarly, a
25 further extruder and thermoformer may be used to provide lids
3 at the third work station 31. The embodiment shown herein
represents a very economical machine or apparatus for
producing packaging according to the present invention. By
using the extruders and thermoformers as suggested above~ more
30 sophisticated apparatus can be developed to assist throughput.
All this is consiclered within the skills of the packaging arts
and therefore has not been disclosed in detail herein.
Referring now to Figures 7a and 7b, there is shown a
web of plastics material 57 which is used to provide the
35 strand means 7. Here the web is of the required thicknéss and
of the required material. It is first slitted in a series of
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WO91/03407 "'~
- 12 ~ PCT/AU90/0038
rows as shown by numerals 59. The web 57 is then elongated
both longitudinally and transversally or in only one direction
if required, so that the web 57 assumes an expanded mesh
; arrangement as shown in Figure 7b. Th~s, the portions of
5 material 61 which remain between the openings 63 provide
strand means which will engage wi.th the goods 5. In this
embodiment the web 57 may be of a suitable transparent
material but desirably the dimensions of the strand means 61
: are such that they will not substantially inhibit a person
10 observing the upper surface of the goods 5 or will act to
inhibit the gas within the packaging from contacting the
goods. In the embodiments shown herein the web 57 may be made
from a polyethylene sheet.
The strand means depicted in the embodiments of 7a
- 15 and 7b can be used to replace the strand means previously
described and may also be incorporated into the apparatus
shown in Figure 5 so that packaging with strand means of this
type will be produced.
~igures 8 through lQ show further embodiments of
20 packaging within the scope of the present invention, which can
be produced by suitably modifying the apparatus shown in
Figure 5.
Figure 8 shows àn embodiment where the goods 5 are
totally suspendèd within the packaging within a mesh bag 65
25 The bag 65 is stretched and held relative to the packaging by
~ being sealed between the lid 3 and the base 1 as shown. The
bag 65 may have mesh of the same size as that previously
disclosed in Figure 4. The bag may not be a hag as such, but
~ . may.be two separate webs of mesh material which are brought
- 30 together as the lid 3 is closed relative to the base 1 so that
the goods 5 are enclosed within a bag-like mesh. In the
embodiment.of Figure ~ it can be seen that there is a space 67
above the goods 5 and a further space 69 below the goods 5.
- The gas, which is in the package, can freely circulate between
~ 35 spaces~67 and 69.through:the mesh and can also contact the
~ surf~ces of the goods 5. : -
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WO91~03'107 ~ ~,3~ ,'A ~'~ ('J PCr/~U90/00382
Figure 9 shows ~ different embodiment where a rnesh
web of the same type as that sho~n in Figure 4 is used, but
here the mesh web is brought down and sealed to the bottom of
the base l at positio~s 71 by a s11itable heat sealing member
5 or other sealing member (not sho~). In this way, the mesh
tightly holds the goods 5 relative to the bottom of the base l
and inhibits flopping around of the goods 5 within the
packaging.
Figure lO shows an embodiment similar to that of
lO Figures l through 3 but instead of the lid 3 being heat sealed
relative to the base l, it is sealed by having con~inuous
extending snap engaging means 71 and 73 on the lid 3 and the
base l respectively which co-operate to permit the lid 3 to be
snap-lock engaged with the base l and to effect a gas tight
15 seal therewith. A web of mesh material of the type disclosed
in Figure 4 can be provided over the goods 5 to provide the
strand means 7 to hold the goods S relative to the base l. In
this embodiment, the impulse heat sealing means which seals
the lid 3 relative to the base l can be dispensed with,
20 although it may be preferable to effect heat sealing of the
lid 3 to the base l to prevent unauthorised tampering of the
packaging which may otherwise go undetected by an intending
purchaser.
Referring now to the embodiment of E'igures lla and
25 llb, there is shown packaging where there is provided a base 1
of the type previously disclosed and a lid 3 of the type
previously disclosed but wherein the lid 3 has a downwardly
extending circumferential rib 73 to which may be bonded a web
of mesh material having the configuration as shown in Figure
30 4. Thus, a plurality of strand means 7 are provided across
the lid 3 from the rib 73. The web may be bonded at positions
75 so that it is carried integrally with the lid 3. In this
- embodiment the goods S may be placed somewhat below the lip ll
on the base l and the dimensioning of the rib 73 is such that
35 the strand means 7 are caused to still stretchingly engage
- with the upper surface of the goods 5 to hold the-goods 5
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WO91/03407 ~ i~$f~ PCr/~U)0/00382
relative to the paclcaging. This is shown in Flgure llb where
the lid 3 has been closed relative to the base 1 In this wa~
any tendency of the goods 5 to spread during closing so that
they overlie or contaminate the upp2r surface of the lip 11
5 where bonding is to occur and subsequent sealing is to be
effected, is reduced.
Referring now to Figure 12 there is shown a further
embodiment which is similar to the embodiment shown in Figure
9. Here the base 1 has the upper peripheral lip 11 plus an
10 intermediate peripheral lip 91. The strand means 7 extends
from the upper lip 11 down the inside faces of the base 1 to
the intermediate lip 11, down to the bottom of base 1 and over
the upper surface of the meat 5. The strand means is secured
to the bottom of the base 1 at positions 71 to hold the meat
15 to the base 1 to inhibit from flopping around within the
packaging. An inner web 73 of gas permeable clear plastics
material can then extend from the upper peripheral lip 11,
down the inside face of the base 1 to the intermediate
peripheral lip 91. Typically the web 73 can be held at the
20 upper peripheral lip 11 and stretched downwardly to
intermediate lip 91 so it will be stretched taught across the
base 1 over the meat 5 and secured to the intermediate lip 91
at positions 95. Typically the web 73 can be of LDPE and have
a thickness range sf from 10 microns to 1,000 microns. Other
; 25 plastics and thicknesses are possible but the above represents
an economical choice. The web 73 is preferably of a gas
permeable material although it may be a non gas permeable
material with passageways, i.e. openings'therein to allow gas
- to pass.
The lid 3 is bonded to the base 1 over the web 73,
around the upper peripheral lip 11 at positions 97 so that the
lid is sealed gas tight relative to the base 1. A desired gas
is provided within the package prior to sealing the lid 3 to
the base 1. Thus, the desired gas will occupy a first space
35 101 between the lid 3 and the web 73. The desired gas may
also occupy the second space 103 between web 73 and the base
.
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WO9i/03407 - 15 - PCr/AU90/~03$2
1. The volume of the desired gas ls such that it will permit
enhanced keeping of the meat 5 for at least several days.
Thus, the volume can be substantially equal to the volurne of
the meat 5. Because the web 73 is gas permeable or can allow
5 gas to pass through openings therein, the -total volume of gas
in the packaging will be avallable for enhancing the keeping
of the meat 5.
The bonding~at positions 97 to secure the lid 3 to
the base 1 i5 preferably releasable as by peeling so that the
10 lid 3 can be removed from the base 1 without disturbing the
bonding of web 73 or strands 7 to the base 1. Thus, should
the meat 5 discolour with time - i.eO turn dark brown with
time ~ the lid 3 can be removed to allow oxygen in the
atmosphere to then permeate through the web 73 or pass through
15 the openings therein to contact the meat 5 and to bloom it to
a bright red colour. Thus, the packaging is still sealed and
the meat 5 still hygenically packaged even though the lid 3
has been removed. Accordingly, a store or shop or purchaser
is able to remove the lid 3 if the meat turns dark brown so as
20 to bloom the meat 5 to a bright red colour whilst still
leaving the meat 5 hygenically packed. If the web 73 is
without openings then the desired the gas in space 101 may be
chosen to be different to the gas in space 103. This may be
; useful where it is desired to retain the meat 5 in one gas
- 25 environment for an initial time and then subject the meat 5 to
a different gas environment for the remaining time. Thus, the
gas permeability of web 73 can be chosen so that the gas in
space 101 will permeate to space 103 to a required amount
after the initial time.
The surfaces of web 73 may ~e coated with required
plastics or adhesives to permit bonding at positions 95 and 97
so the base 1 and lid 3 will be sealed and inteyrally attached
- to one another. Typically positions 95 and 97 are continuous
peripheral seals caused by heat bonding.
Because the web 73 is stretched taught above the
meat 5 - i.e., it does not touch the upper surface ~f meat
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WO9l/03LIO7 - 16 - YCr/AU90/00382
it will appear as a substantially invlsa~le web whilst lid
3 remains attached to base 1.
The plastics material for the packaging components
described herein is preferable and may be replaced with other
5 packaging materials if desired. The materials described in
the preferred embodiment herein represent an economic material
at this point of time.
If desired the base 1 and lid 3 may be of a linear
low density polyethylene web such or the type used for
10 wrapping pallets in a shrink wrapping. Each web of p]astics
may have a partial gas barrier coating on the inside face of
the packaging to inhibit escape or introduction of gases. The
nature of the polyethylene is such that it has a natural
shrinkage which will offset to some degree the amount of
15 absorption of the gas into the goods S, and not cause the
package and in particular the lid 3, to bow inwardly as the
gas is absorbed.
Instead of sealing the strand means to the base at
the time of sealing the lid to the base, the strand means may
20 be sealed to the base at a strand sealing station and then the
base and the strands passed to a lid sealiny station where the
lid can be sealed to the base with a desired gas sealed
between the lid and the base to enhance the keeping properties
of the packaged goods such as red meats.
Modifications may be made to the invention as would
be apparent to persons skilled in the packaging arts.
These and other modifications may be made without
departing from the ambit of the invention, the nature of which
-is to be determined for the foregoing description.
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