PACKAGE AND A METHOD FOR SEALING THE PACKAGE

CONDITIONNEMENT ET METHODE DE SCELLEMENT CONNEXE

English Abstract

1990-05-30 14:26 L A GROTH & CO AB 46 8 316767 05




ABSTRACT

A package comprising a tray and a removable lid, which
tray is made of plastics material and is especially intended
for keeping and heating of ready-cooked food, and which lid is
made of cardboard and/or plastics material. The package
includes a plastic film (3) the area of which is at least as
large as that of the lid (2) and which is heat-sealed to the
lid and to the edge (la) surrounding the opening of the tray
(1) and the characteristics of which are such that the lid and
the plastic film are removable from the edge without the lid
or the tray being destroyed.
The invention also comprises a method for sealing the
package.

Claims

CLAIMS
1 A package especially for keeping and heating of ready-
cooked food, comprising
a tray having an opening and being made of plastics
material,
a removable lid made of at least one of cardboard and
plastics material,
a plastic film, the area which is at least as large as
that of the lid, the plastic film belong heat-sealed to the lid
and to the edge surrounding the opening of the tray,
the lid and plastic film being removable from said edge
without the lid and the tray being destroyed.
2 A package according to claim 1, in which the tray is
made of thermoformed CPET and the plastic film is made of
polyester.
3 A method for sealing a package comprising a tray and a
lid, the tray being made of plastics material and especially
intended for keeping of ready-cooked food and healing of same
in a microwave oven, and the lid being made of cardboard
and/or plastics material, wherein
a) the tray with contents is placed on a support,
b) a plastic film, the area of which is larger than
that of the tray opening, is placed over the tray,
c) the lid, the area of which is larger than that of
the tray opening, is placed on top of the plastic film,
d) the plastic film is welded to the tray and the lid
is welded to the plastic film in one and the same operation.
4 A method according to claim 3, wherein the area of the
plastic film is essentially larger than that of the lid when
the plastic film is placed over the tray and is given substan-
tially the same length-width dimension as the lid in connec-
tion with its being welded to the tray.
A method according to claim 4, wherein the plastic film
in the form of a band is advanced to a position over the tray
in which the plastic film is given substantially the same
length-width dimension as the lid through separation by means
of heat.

Description

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"DES~RIPTION

Technical field
The pre~ent i~ventlon relate~ to a package and a method
for sealing $he pac~age. The package comprlse~ a tr~y
e~peclally lntended or keep1ng and heating ready-c~o~ed food,
and a lld which i~ removable from the tray.

PriQ~ art
It iB known to keep and to heat ready-cooked Pood in
packages con~isting of a tray provided wlth a lld. it i8
essential that the food ~hould not be affected by the
packaging materlal and that the lld should be ea~lly removable
from the tray.
A package fulSllllng the8e requlrement~ comp~l~e8 an
aluminium tray wlth a cardboard and/or alumin1um llq which ~8
attached to the tray by fol~ing the ed~e~ surroundl~g the
opening of the tray inwardly over the lld, and whLch, can be
removed therefrom after sald sdges have b en folded ,~way from
the lid. Di~adva~tage~ of thls package are that seal~ng ls
carried out manually, that the fo~d'cannot ~e heate~!ln~lde
the package ln a microwave oven and that the ~eallng wlll not
be liquldproof. ,'
A package ln which the ~ood can be neated ln a micro-
wave oven and whlch can be sealed mechanlcally compr~e~ atray of plastic~ material such as aPET and a lld made of
plastic-coated cardboard, which ~ld can be welded ~heat-
sealed~ to the edges of the trsy opening. A dlsadv~n,tage o
this kind of package iA that the lld i8 dlfflcult to re~ove
from the tray and often break~ when beinq removed.
Further, lt i~ ~nown to weld a plastic film to a CPE~
tray. Wit~ thl~ ~$nd of packa~e lt i8 difficult to tear and to
remove t~e film without touchln~ the food. Moreover,,it i9 not
po~slble to provlde the film with informatlon in tho,form of,
for example, advertislny or a text statln~ the contents of the
package, and packages of th$a,kind are theFefore often
supplied ln cardboard cases provided;~w$t~-" uch infor~ation.-


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Desc~lption of ~he inv,e,~o,n
It 1B an ob~ect of the pre~ent lnventlon to lmprove
packages of the above-mentioned klnd and to seal these ln a
~lmple, nonexpen~ive and efflcient way.
Thls o~ect i~ accompl~hed by provldinq the p,ackage of
the inventlon with the features tated in the charac!terlzlng
portions of the claims.

~e~cr~PtiOn of the fiqure~
The one figure of the drawing 18 a schematic, explodod
perspective view showlng sealing of a package accord~ng to the
invention.

Preferred embodiment
The package according to the ~nvention comprl~s a tray
1 of thermoformed CPET with an opening surrounded by a folded,
approximately 5 mm wlde edge which extends roun~ the whole of
the tray 1, a l~d 2 of cardboard and pla~t~cq mater~al,
suitably a mater~al marketed under the name of Inver,~ote
(registered trademark) G ~ AP ~ethylene acryllc acl~?, and B
~llm or sheeting 3 of polye~ter, ~ltably a fllm mar~eted
under the name of Mylar ~reg~tered trademark) OL.
The material~ of the ~ray 1, l~d 2 and fllm 3 are heat-
~ealable to each other, however, 1f the lld were to ~e heat-
sealed (welded) straight onto the tray, it would not;~epossible to remove it from the tray without it belng,d~troyed
(torn).
The flgure shows the package ~eing sealed.
After the tray 1 has been f~lled wlth ready-co~ked
food, it ~9 placed on a support 4 prov~ded w~th a ru~b~r plate
S w~th upwardly oriented edge~ 5a ~urrounding the ba~le of the
tray. Th~ can be done manually or by mean~ of a 8ul~able
feeding device. A roll 6, on which the film 3 ~8 wou ~ in the
form of a band, i~ located over and ad~acent the ~upport 4.
The width of the roll 6 and therefore of the film 3 c,orre-
sponds to or i~ slightly wlder than the length of the~ tray 1,
i.e. the greate~t di~tance between oppos~te part~ of the edge~

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la. For each tray 1 placed on t~e plate 5, the film 3 18
intended to be advanced immed~ately over or in contact with
the tray in the dlrectlon of the arrow a dlstance whlch corre-
sponds to or i~ sligntly longer than the width of the tray, by
a sultable device not shown ln the ~igure.
The l~d 2 ~ placed, manually or by a device not ~hown,
on top of the film 2 exactly over the tray 1. The area of the
lid 2 ~9 selected such that the lid will cover the tray
open~ng and the entlre edge la.
At a distance over the plate 5 slightly exceedlng the
helght of the tray 1 there ~ 8 arrange~ a wel~lng head 7. The
head 7 i~ provided with a lower plane surface, the area of
whlch corresponds to the area of the lid 2. T~e head 7 is
movable toward~ and away from the tray 1 with the fllm 3 and
1~ lid 2 thereon, and lts temperature 18 ~uch that heat-sealing
or weldng o~ the fil~ to the tray and of the lid to the f~lm
wlll take place when the head i8 briefly pressed against
these .
After or ln connectlon wlth the above de~cribed heat-
sealinq a sleeve B wit~ a heated, lJpshaped lower edge 8B,whlch ~leeve ~urrounds the welding he~d 7 an~ i8 guided by
same, i8 carried downwardly towards the tray 1, whereby the
film 3 will melt immediately outslde the lid 2 ~o that the
parts of the fSlm ~urrounding the lid wlll be separated from
26 the now flni~hed package, which wlll then be removed from the
support 4 e~ther manua}ly or by ~ome suitable feeding-out
devlce.
Owlng to the film 3 belng ln~erted between the lid 2
and the tray 1 and owing to the properties ~f the materlal of
wh~ch they are made, there is prov~ded a package the content~
of wh~ch can be heated ~n a mlcrowave oven (also with the lld
attached), and the top s~de of which can be preprlntsd or
provlded wlth prlnt or the llke ln connection wlth ~ealing an~
the 1~ of whlch can ~e removed by the 90 called peel-off
?5 effect, i.e. the film i5 eaBlly removable from the tray
wthout the lid gettlng torn or destroyed in some other way.
Although only one embodlment of the lnvent~on has been
... , . .; . ~ . . .

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de~cribed above and ~hown on the drawlng, it will be under-
~tood that the invention i~ not limlted to ~ld embodiment but
only by the scope of the claim~.

Representative Drawing