CA2021036C

CA2021036C - Packing container

Info

Publication number: CA2021036C
Application number: CA002021036A
Authority: CA
Inventors: Walter Schellenberg
Original assignee: Rundpack AG
Current assignee: Rundpack AG
Priority date: 1989-07-14
Filing date: 1990-07-12
Publication date: 1997-07-15
Anticipated expiration: 2010-07-12
Also published as: ES2047900T3; DK0408516T3; DE59003852D1; CA2021036A1; CH678936A5; ATE98596T1; EP0408516A1; EP0408516B1

Abstract

The packing container has a lid deep drawn from a thin plastic film and in which is positively and non-positively inserted at one point a sealing plate, so that it forms there a reinforced ring area which sealingly presses against the wall of the container body. As the sealing of the packing container is solely ensured by said ring area, an additional sealing connection merely serves as a guarantee closure and has a corresponding weak construction, so that the container can be opened particularly easily. The locally bounded reinforcement of the otherwise flexible lid contributes to this. An undercut on the opening rim of the container body makes it possible to snap the lid in again so as to ensure tight resealing.

Description

PACKAGING CONTAINER

The invention relates to a packing container having a "single-use" security seal and which is also resealable.
In known packing COll~ used, for example, for dairy products such as curd, cottage cheese and yoghurt, the secure and air-tight seal between the container body and the lid is solely provided by the sealing connection, which is located between the marginal flange of the container body and the edge of the lid. For opening purposes the flexible lid is torn from the marginal flange by an upward peeling and tearing movement. The relatively strong sealing cormection required due to the need for a reliable sealing effect is very disadvantageous and the lid is unesthetically perm~nently deformed. As a result of its flexibility, also in the marginal area, it is unsuitable for the tight resealing of the packing container. Therefore, for dairy products, resealable packing containers are also known, whose lids have an adequate rigidity and a suitable edge construction, so that the lid can be snapped back into the container opening. However, the necessary rigidity has hitherto required the production thereof by very expensive injection moulding with the additional disadvantage that such a container cannot be provided with a secure closure by heat sealing in the conventional manner.
The object of the present invention is to provide a packing container of the aforementioned type which can be m~nl-f~ctured more easily with low material expenditure through the deep drawing of its lid and which does not suffer from the aforementioned disadvantages in that it can be more easily opened and tightly resealed.
More particularly, a packing container with a lid, comprises a p~c~ing containerhaving a bottom, an open top defined by an opening rim, and a side wall portion having an inner surface; and a deep drawn lid comprising a bottom portion, a side portion ext~n(1inp around the circumference of the bottom portion and having an upper edge portion and an outwardly directed bulge formed around its circumference. The bulge forms a sealing ring on its outside and a reception groove on its inside. The reception groove accommodates a rigid sealing plate tightly fitting into the reception groove and forcing the sealing ring outward, such that when said lid is snappedly engaged to cover the .~p, open top of said container, the lid, by its sealing ring, sealably and frictionally engages with the inner surface of the side wall portion of the container, thereby allowing the lid to be repeatedly sealably engaged with the container. The upper edge portion of the lid is located above the bulge, and the upper edge portion is sealed for a single use to the opening rim of the container, whereby when the lid is removed from the container for the first time, the single-use seal is destroyed.

- la-.,'p, -The invention will now be described further by way of example only and with reference to the accompanying drawings, wherein:
Fig. 1 is a cross-section through a packing container with a lid according to the invention;
S Fig. 2 is a plan view of part of the lid of Fig. l;
Fig. 3 is a larger-scale partial cross-section through the p~cking container of Fig. l;
Fig. 4 is a cross-section through part of a lid corresponding to a further ~ ~o~i - t of the invention;
Fig. 5 is a plan view of a marginal area of the lid of Fig. 4;
Fig. 6 is a larger-scale partial cross-section of another embodiment of the invention; and Fig. 7 is a partial cross-section in the bottom area of another embodiment of the invention.
According to the embodiment of Figs. 1 and 3 the packing container 1 has a stackable, conical body 2 which, like its lid 3, is produced by deep drawing a plastic film, e.g. of polyester, or a composite film whereas in the embodiment according to Figs. 6 and 7 the body 2' is produced cylind-rically in a winding process from a relatively thick cardboard material.
Referring firstly to Figs. 1 to 3, the lid 3 is deep drawn from a plastic film with a thickness of, for example, 0.2 to 0.4 mm, preferably 0.2 to 0.3 mm. The lid has a sealing plate 5 fixed positively and non-positively therein and made, for example, from a cardboard material with a thickness of approximately 400 to 500 g/m2. The plate 5 engages a narrow sealing ring area 6 of the lid 3 approximately having the thickness of the sealing plate 5, and presses the ring area in a permanently sealing manner outwardly against the wall of the container body 2. For this purpose the largest external diameter of said ring area 6 is somewhat larger than the internal diameter of the container body 2, at the point at which said ring area sealingly engages the body following the complete insertion of the lid 3, so that with a force fit, it has a firm seating in the body 2.
For a good seal, comparable with a so-called 0-ring seal, the aforementioned sealing ring area 6 preferably has a rounded cross-sectional shape, such as can be produced by an Annlll~rly grooved radially outwardly 5 directed bulge or convexity of the plastic film of the lid 3.

Figs. 4 and 5 illustrate a further embodiment of the invention, wherein lid 3~, sealing plate 5' and ring area 6' of lid 3' correspond to and co-operate in similar manner to elements 3, 5 and 6 of Figs. 1 to 3. Fig. 6 illustrates yet a further embodiment of the invention, wherein lid 3", sealing plate 5~ and ring area 6N of lid 3" correspond to and cooperate in similar manner to elements 3, 5 and 6. Fig. 7 illustrates a bottom closure 4 having a sealing plate 5~" with a sealing ring area 6'n cooperating with container body 2' in similar manner to the lid 3", sealing ring area 6" and container body 2' of Fig. 6.
Thus, in the foregoing description, the respectively corresponding elements between Figs. 1 to 7 are 2 and 2'; 3, 3', 3" and 4; 5~ 5~ 51' and 5~n; and 6, 6', 6" and 6"'.
In the embodiment according to Fig. 7 the sealing ring area 6"' is obtained by a radially inwardly directed Annl~lAr bulge 7, which is located at a distance from the closure diaphragm 8 of the bottom closure 4 corres-ponding to the thickness of the sealing plate 5~n In the embodiments with the annular groove-like bulge, on the inside of the sealing ring area 6, 6', 6", 6"', there is provided a reception groove 10,10",10' n~ for the positive anchoring of the sealing plate at the predetermined position.
In the embodiment according to Figs. 4 and 5, the sealing ring area 6' is formed by the rounded cross-sectional edge of an AnnlllAr shoulder 12 of the lid 3', which is located between oppositely sloping conical circumferen-tial wall areas 13, 14. In order to improve the location of the sealing plate 5~ in lid 3~ at this point, there are provided at regular intervals on the inside of the circumferential wall area 14 tapering conically away from the sealing plate 5~ individual toroidal shaped locating protuberances 15, which engage over the sealing plate 5~ and therefore hold it down on the shoulder 12.
The rigidity of the lid 3,3',3~ on the sealing ring area 6,6',6" permits its further use after the packing container 1,1' has been opened, because the ring area 6,6',6" forming an outwardly directed protuberance of the cover edge can be located in the container opening, so that the cover snaps in place to form a seal. For this purpose, the container body 2, for example, 5 has towards the opening edge or rim a conical constriction 16. For the same purpose, the embodiment of Fig. 6 utilizes a locating groove 17, for exarnple, corresponding to the cross-sectional shape of the ring area 6' locked therein and which is, for example, press-formed in the body 2'.
Apart from the tight resealability, the packing container has the important advantage that, as a result of the rigidity of its ring area 6,6', 6", it can easily be opened on the first occasion with the destruction of a single use security seal, without requiring any great tearing forces. This is achieved in that in the marginal area 18, 18', 18" (see Figs. 3 and 6), coextensive with the ring area 6, 6', 6"of the lid edge and engaging the container body, a low strength sealing connection is provided at certain circumferential points or over the entire circumference between the lid and the body, so that it is easily destroyed on tearing off the lid 3, 3', 3", for example by pulling on gripping tab 21 (Fig. 2), which for example projects laterally over the container body 2, 2'. Such a particularly easily destructible connection is adequate, because compared with the known sealing closures it does not have to fulfil any gas-tight sealing function. The secure seal is, for example, located in conventional manner between outwardly projecting flange edges 19, 20 of the container body 2 and the lid 3,3', so that the initial opening can be initiated by a peeling movement, which emanates from lateral gripping tab 21.
As the security seal does not have to fulfil any gas-tight sealing function, it is not necessary for the gripping tab to project laterally over the flange l9 of the body 2 to enable a peeling, tearing movement and it can instead be formed, for example, by an area of the flange edge 20 of the lid 3, 3' identifiable by a colouring effect and at which the security seal connection is interrupted.
It is obvious that the bottom closure 4 also has a secure seal or some other secure connection to the container body 2'. However, in this case easy destruction is unimportant, unless for separate waste utilization of the cardboard body 2', the bottom closure is also to be easily removable.
Thus, in surnmary, it can be understood that the packing container l,1' has a lid 3,3', 3"deep drawn from a thin plastic film and in which a sealing plate 5,5',5" is form-fittedly and press-fittedly inserted at one point, so that it forms a reinforced ring area 6, 6', 6", which is sealingly pressed against the wall of the container body 2,2'. As the sealing of the packing container 1,1' is enured solely by the said ring area 6,6',6", the additional sealing connection merely fulfils the function of a security seal and has a corresponding weak construction, so that the container can be particularly easily opened. The locally limited reinforcement of the otherwise flexible lid 3,3' 3" also contributes to this. An undercut 16 on the opening rim of the container body 2 of the embodiment of Fig. 3 makes it possible to snap the lid 3 in again and therefore permits a tight resealing.

Claims

1. A packing container with a lid, comprising:
a packing container, said packing container having a bottom, an open top defined by an opening rim, and a side wall portion having an inner surface; and a deep drawn lid having a sealing ring adapted to engage said side wall portion inner surface of said container in a sealing region, the external diameter of said sealing ring prior to engagement of said lid with said container being larger than the internal diameter of said container inner wall in said sealing region, said lid comprising a bottom portion and a side portion extending around the circumference of said bottom portion, said side portion having an upper edge portion and an outwardly directed bulge formed around the circumference of said side portion of said lid and said bulge forming said sealing ring on its outside and a reception groove on its inside, said upper edge portion of said lid being located above said bulge, and a rigid sealing plate having an outer peripheral edge, said outer edge of said sealing plate tightly fitting into said reception groove of said bulge and forcing said sealing ring outward, such that when said lid is snappedly engaged to cover said open top of said container, said lid, by its sealing ring, frictionally engages the inner surface of said side wall portion of said container to form a gas tight seal which is under tension against the inner surface of said side wall portion of said container, thereby allowing said lid to be repeatedly sealably engaged with said container, said lower edge portion being connected to said opening rim of said container, by means of a single use security seal, whereby when said lid is removed from said container for the first time, said single-use security seal is destroyed.

2. A packing container according to Claim 1, wherein said bulge has a U-shaped cross-section and said sealing ring defined thereby has a semi-circular cross-section.

3. A packing container according to Claim 2, wherein said bulge is bounded by a radially inwardly directed ring-like bulge, said ring-like bulge being positioned at a distance from said bottom portion of said lid equal to the thickness of said sealing plate, thereby tightly retaining said sealing plate in said retaining groove against said bottom portion.

4. A packing container according to Claim 1, wherein said bulge on said lid is bounded at its lower portion by a shoulder, and said sealing plate seats on said shoulder.

5. A packing container according to Claim 1 further comprising a plurality of circumferentially distributed protuberances formed on the inside of said side portion of said lid above said bulge, whereby said protuberances engage with said sealing plate and act to positively retain said sealing plate within said reception groove.

6. A packing container according to Claim 1, wherein said lid further comprises a gripping tab provided on said upper edge portion of said lid, whereby said single-use seal is destroyed by pulling said gripping tab to remove said lid from said container.

7. A packing container according to Claim 6, wherein said gripping tab is provided on said iid adjacent said side wall portion of said packing container.

8. A packing container according to Claim 6, wherein said gripping tab is defined by an interruption in the sealing of said upper edge portion of said lid to said opening rim of said container.

9. A packing container according to Claim 1, wherein said lid is constructed from a plastic material having a thickness of 0.0079 to 0.0016 inches (0.2 to 0.4 mm).

10. A packing container according to Claim 1, wherein in the vicinity of said opening rim, said inner surface of said side wall portion widens slightly outward from its opening rim, thereby acting to draw said lid downward onto said container.

11. A packing container according to Claim 1, said container further comprising a locating groove defined around the inner side wall portion near said opening rim in which said sealing ring snaps into place.

12. A packing container with a lid, comprising:
a packing container, said packing container having a top, an open bottom defined by an opening rim, and a side wall portion having an inner surface; and a deep drawn bottom lid having a sealing ring adapted to engage said side wall portion inner surface of said container in a sealing region, the external diameter of said sealing ring prior to engagement of said lid with said container being larger than the internal diameter of said container inner wall in said sealing region, said lid comprising a top portion and a side portion extending around the circumference of said top portion, said side portion having a lower edge portion and an outwardly directed bulge formed around the circumference of said side portion of said lid and said bulge forming said sealing ring on its outside and a reception groove on its inside, said lower edge portion of said lid being located below said bulge, and a rigid sealing plate having an outer peripheral edge, said outer edge of said sealing plate tightly fitting into said reception groove of said bulge and forcing said sealing ring outward, such that when said lid is snappedly engaged to cover said open bottom of said container, said lid, by its sealing ring, frictionally engages the inner surface of said side wall portion of said container to form a gas tight seal which is under tension against the inner surface of said side wall portion of said container, thereby allowing said lid to be repeatedly sealably engaged with said container, said lower edge portion being sealed for a single use to said opening rim of said container, whereby when said lid is removed from said container for the first time, said single-use seal is destroyed.