Note: Descriptions are shown in the official language in which they were submitted.
The present i~vention relates ts~ packa~3:ing, and
ha~ app~ic~tion ~o ~;e~ supportirl~c product contain~rs,
often o~ tra.y-like type.
crea.sing at~ention ~s b~ing paid to the
packaging o~ ~ood procluc~s for 6ale to con~umer~ to
~nsure t:hat the food reache~ the consumer in the best
po~sible cs~ndition. That h~s l~d to vacuum paclcing,
and more resen~ly to coll~roll~d or modl~ied a-~lnospher~
pack~in~ ~ T~ere i~ al ~o ~n increa~ing demandL Por ~uch
pa¢ka~;ed food to b~ supplie~ in ~el~ upp~rting
tray-llke container~; In which the ~ood can b~ heated-up
or cooked in either o~ converltion~l or ~ics~owave o~n~;~
lS Clearly, ma~erial~ used should nvt c~ theme;elv~.~ o:r
otherwise lead to ~ontami.n~tion o-f :~ood prodllcts
therein. Als~, mat~rials whlch e~sh~bi-~ suitahl~
~hysical ri~idity ~nd the~ a~ y ten~ ~o be
cli~ lcult for con~entional diI:~e:renti~l pressure
thermoXormin~, and often clo noi provide su~f:icient
~rrier, at least ~or ~ontrol. led or motllPied atmosphere
,
.4 p~c~aglng. Ac~ordingly, pro~ucin~ containerf~ which
meet all the desired re~uireme~ts i~ par-ticular~y
difficult at re~sonable cost, if not impossibleO The
pre~ent invention aim~ t least irl ~iome pr~:~er~ed
embodir~e~tæ, to help ov~r~ome Ithe abo~re mentioD~d
dl~:Eiculties ~or Iood pac~sa~ln~.
In packaging in general J not necessarily l Lmlted
to Iood proc,uct~3, there ~g o~ten a requireme:n'c ior
- a~ording ~hock or lmpac1~ l~e~i~t~nce and/or ~ibration
protect~on, and embodiment~; o;~ the in~ention c~n be
use~ul ~o tk~Lt end.
~ccorc.ing to one ~spe~t o~ the preser~t inv,. ntion
there is provided a 6el~-~uppor-tin~ pre~erably
tray-l ike product container c~mprisi~g an inner ~i~hed
part Iormed with a peripher;~l edge p~rtion there~bout
and ~ iirst w~ eceiving said produ~, and an outer
dished part ~ormed wi th a p~-~lphe~l ed~ portion
thereab~ut and ~ sec~nd well intc~ which ~aid ~irst well
1~ entrarlt, the inner ancl ~u~er pal t~: co~t,~cting ~nd
. il
b~?in~ jolrlecl to ea~h other a~ t,heir re~p~c~ive
peripheral e~dge por-tions, o~herwi~e with their well~ :ln
round mLltUa 1 1 y -spaced re :l at lon,
Use~ul therma:L and/or~.~hoc~ or impac~ insulation
can resul~ from that ~paced r~lation ~v~ th ~n
in~ul~ing/~ushionln~ fluid, usually a ga~ at or ne~r
normal ~1;mo~pheric pres~ure ~nd of~erl wit;h alr,
betw~en the inner aTld ou~er parts, which can be o~
di~Perent m~ter~als c~nt~ibuting also ~o eco~o~y o~
~ manu~a~ture. Pref~rahly, th~ peripheral edge portlons
: o~ the inner ~nd out~r part~, which may ~e as ~lan~es~
lipR or a~u~ent ~u~ces, a~e join~d to~ether by a
G ~ontinuou~ ~eal ~hereabaut.
Acco~d~n~ to another aspect o~ th~s inventio~,
~here is provided a n~thod o~ produci:ng a
: sel~-supportin~ produc~ cont~iner~ comp~ising the steps
o~ ~rmin~ a ~irst part having ~ p~ripher~l edge
portion thereabout and a product~receiving well~
~ormin~ ~ second part having ~ peripheral edge portion
thereabout ~nd a well accommod~ing ~he
product-rec~!iving wèll in all-round mutually-sp~ed
relatlon, ~c.d uniting -the ~irst and sec~nd par~ t
lS their p~ripheral edge port.:Lon~ with ~he ~lr~-t p~rt
inner ~nd th~ ~econd part ou~er relati~e to the
c4nt~iner as a whole J pre~ra~ly w~th ~n
Ln~ ting/c~ushioni~K ~luid therebetw~en.
Accorclin~ to ~ ~urther aspect G~ thl~ Lnv~nt~on,
there is pxovlded apparatu~ ~or mak~ suppor~ing
product c~ntainers, compr:i~in~ mean~ ~or f~rming
~ir~t ~nd ~econ~ par-ts each wlth peripheral
edge portions ~herea~out ~nd re~eiving wells, the
rec~ivin~ Y1ell of the fir~t part bein~ ~or product and
the recei~ing well o~' the ~econ~ p~rt a~com~no~atin~ the
- product-re~ivin~ well oi the first pal~ in ~ round
~utually-space~ rel~ n, arld mean~ ~vr ~olrliQg khe
~irst arld second p~rt~ at their peri~h~ral edge
portion~, pr.e:~erably wi~h an in~3ulating/cu~3hionlng
~lul~ therehetween.
S The ~ ner and 4ut,er p~rts ca~ be mad.e, ~s~Ly by
di~feren~ pressure aided th~rmoforlning ~ ~he~t
material, as open-top containers or traye, e~ch ha~ing
a b~se and upstandin~ ~ide walls e~tending the:re~rom
and out-t~rned to ~orm re~pective periph~r~ ngiQg~
F4~1n~ may b~ do~e separatçl~ and the p~rt~ brou~ht
: to~ther a~erwa~ds, or ~ub~tantially sim~ltan~vusly
~nd oppositely with the well o~ the inner part the~
illverted into the wel l o$ the otber part ~
Using di~Iererlt materials, the outer part c~n be
: .
. 15 o~ a relatively inexpensive m~erial mainly to provide
desired ph~,ical properties, includin~ rigidlty ~ the
container, even ~s a board or pape~-b~sed materia.l,
. whlls~ the inner 6~in i~ v~ a ~on-contaminati~ bar~ie~
m~terial, e.g. ln allowi~g a c~ntrolled/mor~lPied
~0 atmo~phere to be eskablishecl in the ~!ead ~pa~e abov~ a
~ood produc-t. Thermal d~ormatlon re~ n~,es c~n be
di~fer~nt, whether for mi~rowavirlg ~requ~rlng ~i~her
~uch ~esi~tan~e (say 120 d~grees C) for the inne~ p~r~
than ~or the ou~er part ~say 50 to Ç0 de~rees ~, or
Z5 ~o~ conventional o~en coo~ng requiIin~ higher ~uch
re~iatance lor the outer p~r~ ~s~y 200~0 de~r-es C)
.
; .. ~
than for the inner part (say 120 degre0s C)r
Physically strong and rigid outer parts allow
inner parts to be of ~lexible material. However, the
opposite is feasible, say for conventional o~en use,
i.e. where the inner part is physically supporting and
the outer part is physically weaker, even flexible, but
of high thermal distortion resistance as applies to
polycarbonate. Generally, thic~ness of material o~
each part can be kept to a sensible minimum, also
reducing costs. Clearly, flexibility of either part
can contribute to shock/impactlvibration resistance.
There will normally be a cover for a product
container hereoP, generally extending over its inner
part, conveniently sealed thereto, often preferably
continuously about the container.
Such cover may be of sheet, say a web or ~ilm,
and cooperation with the inner partl can give close
restraint of product then ef~ectively trapped as well
as suspended by the inner part in the outer part. An
alternative is to use two uncovered containers hereof
in confronting relation. Suitable connection or
securement can include hinging together at effectively
common edge portions.
The inner and outer parts can be fused or sealed
together at the same time as a cover web is applied.
Where a controlled or modified atmosphere is cal~ed
Ior, a suitably impermeable material will be used for
the cover web. It may be advantageous t at least ~or
food products, if the cover web has a peelable fixing
to the inner part,say for "cook-in" packs to allow
openi~g up a corner, for escape of steam during
cooking, and/or for easy removal after cooking. Seal
strength can also provide a safety mechanism9 by
breaking if excessive pressure builds up in unpuctured
packs.
Peeling of a cover web can be aided if loose at
a corner o~ the pack whereat inner and outer parts are
sealed together. Cutting or heavy scoring o~ the inner
~ and outer parts, at a corner or along an edge, can also
: '
aid Gover web removal, i.e. in "crack-peel" manner.
Continuous production can be b~ thermoiorming two
':
sheets or webs in one machine, but pre~ormed parts
could be used, or a combination. Feasibly, product can
be loaded into the inner part alone and a top web
~0 sealed over before inserting the loaded inner part
into the outer part.
In one suitable apparatus, web materials ~or
inner and outer parts are held together, at least up to
sealing thereto of a cover, conveniently by a chain
conveyor which grips opposite overlying edge portions.
~ .,
Covering webs impermeable to gas, vapour, aroma ~r
: flavouring are generally pre~erred ~or ~ood packs, and
may be of clear or opaque or printed material, normally
polymeric.
In connection with applying and/or sealing the
covering web, the inner part may be gas flushed, or gas
introduced where a controlled or modified atmosphere is
called for in the head space between the inner part and
the covering web, and at least the inner part may
exhibit controlled permeation properties, say where the
space between the inner and outer parts also contains
an atmosphere helpful in conjunction with or relative
to the head space atmosphere.
Speci~ic implementation of the present invention
will now be described, by way oP example, with
re~erence to the accompanying drawings; in which:-
Figuxe 1 is a broken away perspective view of a
container for food according to the present invention;
Figure 2 is a schematic sectional view of the
con-tainer;
Figure 3 is a diagrammatic illustration showing
the various parts of a ~achine and illustrating the
s-tages in a method of producing a ~ood package;
Figure 4 is a simplified sectional view through a
container providing protection against physical damage
D~ j 7 ~'
. 8
to product therewithin;
Figure 5 is a schematic view o~ the process o~
forming a container with material of in~er and outer
parts brought together before formation; .-
Figure 6 is a schematic view of another system
forming filled containers; and
.. Figure 7 illustrates diagrammatically provisions
for allowing passage of gas to and from both sides of
inner parts; and
Figure 8 illustrates reversal o~ inner parts
within the thermoforming station.
A container for food, generally indicated at 1,
has inner and outer parts 3 and 57 respectlvely, the
inner part 3 having wells 13 accommoda-ted substantially
within a well space 11 o~ the outer part 5. The parts
are in the ~orm of open-top trays, as illus-trated and
each has a peripheral flange 7, g. The ~lange 7 o~ the
inner part 3 overlaps and contacts the flange 9 of the
outer part 5 so as to support the part 3. The wells 13
are then accommodated within the outer part well space
11 and spaced therefrom all-round in -that space 11.
Different materials are usual for the parts 3 and 5.
~ One of the parts 3 and 5, which can be preformed
:: ~ to shape, can be physlcally robust, basically
: 25 substantially rigid and form-sus-taining in ovens, and
~he othçr can be physi~ally weaker, even ~lexibl~,
altho~gh ~hat is b~ no means e~,enti~l~ It i~,
however, pre~erred ~h~t th~ inn~r p~t have
; character~stic~ ~g~in's~ ~ontamination and l~s o~
S de~ired atm~sphere, say an ~nti-cont~minant ma~eri~l
imper~eable ~o co~trolled/mcdi~ied atmo~pheres. We ~re
particularly interested ln the use o~
plastl~s/polymeric ma~erials ~ha~ c~n be ~haped by the
technique~ o~ thermo~orming usin~ erential
pressure~.
The ~ap all-round be~ween th~ two par~s 3 and 5
can be particularly advant~.geous as a thermal barrier
in~ulat~on feature, or as a ~hock/i~pact protection.
In Fi~ure 1, the inn~r past 3 has two wells 13,
al~hough ~ sin~le well m~y be more usual ~aF3 ~h~wn
dotted in Figu~e 2).
~ n one application, suitable ~vr use in a
mi~rowave o~eD I ~he inrler par-t 3 i~ ~ormed o~
~ lexible ~b o~ material which 'is capab`i.e o~
ZO wi~ths~t~ndin~ the cooking ~e~.peratures ~nerated in ~oo~
products, typically up to 120 ~egree~ C. A suitable
mat~rial ls a ¢oextruded multilayer ~ .rn 0~
polyethylena/~dhe~ivzfnylonf~dhe~ive/poly~thylene~ with
a thicknes~ o~ 5ay 50-100 rnicrons. The out~r par~ 5
~5 can he m~de o~ a ~ateri~l w~ich has a lower re~stance
to ~h~rmal dis~ortio~, ~hich may be as low as 50 or
, 60 d~gr~e~ C. ~ ~ulta~le ma-~erial ~s a multilayer b~se
¦ web oi ~t~r~ne/~dhe~lve/polye~hylen~ extruded tv~e~her
' ~ay with ~ ~eb ~hicknes6 ~ 500 mi~ron~.
In prs~c~c~, the temperatur~ o-E th~ outer p~rt 5
. is ~sually sUch ~hat i~ ca~ ~e h~ld in kh~ h~nd
com~or~a~ly, even whil~t the inner ~ki~ contalns
produ~t at boiling point i.eO in ex¢ess o~ 100 degre~
C.
Use of a hi~h gr~det r~la~ivel~ expensive,
b~rrler material te,g. non-~ontamin~nt and ga~
imperme~ble~ for ~he inne~ par~ 3 need not contribute
~gni~icant.ly to phy~ical robu~ness, thou~h the outer
: p~rt 5 can ~o so, and be o~ ~ mu~h le~$ expe~sl~e
mate~ial ~vho~e non-~onta~niIlan~ ~ature i3 1~
importan~ nd May even be g~ permeable. The barrier
m~t,erial ~h~ld act to block ~ny o~ ~s, ~la~our, aroma
and vapour p~rmeation.
In ancrther ~mbodi~ent, ~or u~e in a co~ventional
20 oven, the outer part ~ is o~ a m~-~erlal which will
withs-tand ~verl-shel~ ~ontac-t-temperatures of 200-22~
~ d~grees C, ~vhil~t the ~ap 11 allows the inner pa~t 3 to
.~ b~ mad~ of a materi~l which needs only to withstand the
temper~ure of the ~ood, typically 120 de~ree~ C 3ince
~5 the ~ood ~cts as a h~at ~ink. In this case, for
econo~y, it, rnay be preferred to ~orm the inner p~rt 3
11
from a physically strong or robust material, and:to
have the outer part 5 o~ a weaker, even flexible,
material. A suitable material for the inner part is a
polypropylene/adhesive/nylon/adhesive/polypropylene
laminate, say of 500 microns thickness. A suitable
material for -the outer part is a thin ~lexible
polycarbonate/sealant web with a thickness of 50-100
microns. Gas pressure between the inner and outer
parts can inflate a flexible outer part and assure
spacing it from the inner part, typically by heat
generated in the cooking process expanding gas in the
gap 11, so ensuring spacing of inner and outer parts.
It can be advantageous for shapes o~ the par-ts and
amount of gas within the gap 11 -to be such that the
outer part in~lates just suf~iciently on heating.
Ridges or dimples in the inner part can be employed,
say relative to a plain outer part.
In producing a packaged food product, usually
there will be sealing of the inner and outer parts 3, 5
together continuously about their peripheral flangings
7, 9, whether before or at sealing on of a top cover
; 20.
In one method of manufacture, see Figure 3, two
webs of material 51, 52 are fed into respective
thermoforming uni-ts 55, 57 to form inner parts 59 from
12
web 51 and outer parts 61 from web 52~ Typically, each
thermo~orming unit 5S, 57 comprises a heater 56 to heat
up a web urged against it and render the web
deformable, and a ~ould 58 to which hea~ed web is
indexed and where differential pressure urges it into
contact with the mould 58. The formed shape will be
retained on cooling. The plate 56 and mould 5B may
move up and down during indexing of the web. After
thermoforming, the two formed webs are brought together
at a combining stage 63 so that inner parts 59 are
inserted into respective outer parts 61 of tray-like
form.
The assembled parts then pass to a product
loadin~ station 64. Conveyance may be by pairs o~
chain conveyors or the like (not illustrated) engaging
overlying edge flanges o~ the two ~ormed webs.
conveyor with spring loaded side-engagers for grlpping
edges of the web 52 can also pick up the web 51 at the
station 63, and may serve to pull both webs of~ and
through thermoforming, etc. However, a separate
conveyor section may be employed for transporting the
web of the inner part through its thermoforming unit.
The product loading station is ~ollowed by a
~ sealing station applying a covering web 65 unwound from
- 25 a reel 67 over the open top of the container. This is
i7~7
likewise preferably drawn through by said first
conveyor. ~echanical means can be used to hold the
covering web and two parts as required whilst the
compartment accommodating the product, at least if
food, is gas flushed where desired before sealing of
the covering we~ in position, usually by heat. All
required evacuation and gas flushing is preferably done
at the sealing station. Thus, unwanted distortion o~
the inner parts can be assured by reduction of pressure
in the space between the inner and outer parts.
Flushing of that space could use different gases from
those for the product compartment. Figure 7
illustrates diagrammatically provisions for allowing
evacuation to both sides of the inner skin 3 and/or for
introduc-tion of any desired atmosphere prior to final
sealing, for which purpose the webs of the inner and
outer skins are pierced so as to align with respec-tive
passages represented by respective larrows X and Y
leading to spaces above and below the inner part. Webs
are then severed to give complete packages 71.
Spaced skin containers made as herein described
can be useful for products other than food, whether as
packaging for transportation~ including shock/vibration
resistance, or for display, say using transparent
material at least for covers.
,~ ,
- ' '
7~
14
~ . Figure 4 shows a spaced skin container 90 that
suspends and restrains a product or iproduc-ts 92, 94
with a considerable degree o~ protection ~rom impact
shock and/or vibration. That may be done by a
contacti~g cover web or, as illustrated by a ~lam-shell
type container with top and bottom components 96, 98
~ formed as above and hinged along one edge 99~ The top
is shown hinged apart in dotted outline at A. Each
component has an outer part 100, usuall'y this would be
made of a relatively rigid material, and an inner part
; 102 both possibly transparent.
The two components 96, 98 can be separate spaced
skin containers brough-t together and secured in any
convenient way. Alternatively, a continuous series of
alternating components 9Z, 94 can be severed in
end-to-end pairs. Multiple ~ormation with the
components side-by-side can also be,praduced and, at
least then, adjacent ~ormations ~or top and bottom can
readily be ~ormed with dif~eren-t desired well shapes.
Figure 5 shows simultaneous formation of inner
and outer parts from webs 130, 132 ~ed together ,into a
~orming machine 134 in overlying relation, preferably
with slight sepa.ration into which pressurised gas may
be fed. The webs are moved simultaneously to a heating
and forming station 110 where both webs are heated,
then the webs are indexed and thermoformed. There are
two moulds, one (llZ) for the outer we~, conveniently
as a female mould9 a~d the other (114) also as a female
mould ~or the inner web. Pressure applied be,tween the
webs, such as from pipe 115, can help the webs to
conform to the shape of the respective moulds, usually
in conjunction with vacuum applied to interiors o~ the
moulds. The webs preferably cool on contact with
surfaces of the moulds.
Bringing the overlying peripheral edge portions
of the webs together, say after initial shaping o~
inner and outer parts, whilst still in the mould, can
serve in joining the two webs at their edges. Where a
~lexible material is used for the inner part, it can be
inverted after ~ormation, shown at 121, either by
application of pressure (mechanical or ~luid) or at
introducing product~
Perhaps preferably, such inversioln can be done in
the mould by the introduction o~ pressure between the
part 120 and its mould 114, see dashed,arrow in Figure
5, and Figure 8 where the inner part is shown solid at
120 in the forming position, and chain dotted at 120 in
its reversed position ready for introducing o~ product.
Gas pressure input by way of passageway 121 can serve
to invert the part.
16
'
The so-formed spaced~skin component then moves to
successive stations in the ~achine (unless producing
; simple product container parts for later filling), see
; filling station 123, to~ web applying and sealing
station 125, and severing station 127. Any desired
atmosphere may be established in the final package,
whether in the head space above the product or between
the inner and outer skins. The inner,and outer parts
can be apertured to allow evacuation and/or gas
flushing and/or atmosphere introduction as illustrated
with reference to Figure 7.
Figure 6 shows a further alternative for
~;~ manufacture. There, the inner and outer parts are
brought together a~ter the inner par-t has been Rilled,
even, as shown, after the ~illed inner part has been
covered. The outer part can then be sealed to the
filled inner part at station 1400 Inner part web
thermoforming is shown at 141 progressing to a ~illing
station at 142 with a covering web then being sealed to
the filled container at 143. The Pilled conta-iner may
be gas flushed prior to final sealing. This is
followed by brlnging together with the thermoformed
outer part 150, pre~erably after the filled inner part
is severed from its web, indeed the filling may take
place completely separately e.g~ at a remote location
17
Xrom the ;Einal ~om~ination with th~ outer web.
Alte~na~ively, po3itioning and ~ealin~ o~ the co~er c~n
k~ done a~ter brin~ing tog~her the ~illed inner part
with the outer par-t ~u that on0 s~l in~ ~p~r~kion can
5 su~ice to ~eal all three we~. The other ~tatio~s c~n
be ~s ~escribe~ previou~ly.
8y use o~ suitable web ~ormation~ the top web can
pro~lde a peelabIe seal wlth the inner web. More
e~pe~ially, with all three ~eb~ ~ealed to~ether, we
propose to c:ut ~hrou~h the inner and auter we~s, ~y
across a ~o~ner ~lange o~ t,he packa~e, to provide
cra~k-peel ~y~tem.
In the foregolng, we de~cribe use o~ a ~rrier
material ~c,r the i~n~r part, and re~er ~o i~ being
15 ~hosen ~or lts impermeabili-ty, It will be appr~olated
~hat many, i~ not all, ~o-ca].led ~mpermeabl~ m~ rial~
do possess some permea~ility, even i~ very low.
.~vreover, lt i~ ~ore~een that ad~antag~ can ~rise from
~ u~ing a innqr pa.rt material tha~ has ~n intentionAl
~ 20 ~ de~ired per~e~bili~ty, ~or ex~ple in ex~ange o~ ~a.~e~
khrough the inner part.
~ oreover, contain~rs h~reo~ c~n ~e sh~pe~d a~
desired, including deeper, ~ay ~or drlnk~ or #OUp~
etc., even tria~gular ~ay ~or sand~iches etc. Presence
25 o~ ~ ~luiclt ~sually ~ ~s but possibly ~ liqllid,
between the inner and outer parts i~ a sl~ni~lcan~
aspect of inventio~ contributin~ to advant~geous
combinations o~ heat ln~ulatio~ and phy~ical
cushioning, especially ~or ~icrowavable ~ood product~
