EP0348960B1 - Thermally shaped tray with a zip-fastener - Google Patents

Description

The present invention relates to improvements in packaging in plastic trays and, in particular, to an improved tray construction and a method for producing the trays, the lid being closable as in the molded tray considered in the preamble of claim 1 according to FR-A-2 618 411.

A variety of items, including food, such as B. cheese, bacon, prepared meat are sold in bowl-shaped containers or packaging. These packages are generally made of semi-flexible thermoplastic material which is inexpensive to manufacture and which provides certain rigidity and protection for the product. Such trays are usually closed with a lid which is placed over it and which can be torn off the tray in order to access the contents. However, for products such as food that may only be partially removed from the bowl, it is desirable to be able to close the bowl or container again, and this is often done by the consumer by having a Replacement cover, e.g. B. made of foil or Saran. With a view to attractive distribution and the safety and integrity of food, it is nevertheless desirable to be able to tightly seal the original packaging, preferably in a manner that is secured against tampering, so that dealers or customers can see if the original closure was opened.

In order to keep the contents fresh without sacrificing taste or texture, it is often necessary to repack the product completely if the provisional replacement cover is not sufficient.

Accordingly, it is an object of the present invention to provide an improved tray for the distribution of products which has a lid which can be closed again to protect the products after the tray has been opened. Another purpose of the invention is to provide a reclosable shell, the lid of which is provided with tamper evident features, so that the shell can be reused and reclosed until it is purchased by the customer, but is completely sealed and opens every time, thereby the contents would be exposed to the air, would be recognizable.

Another purpose of the invention is to provide an improved method of closing a reclosable package with the aid of a repeatable, fast-running one Process.

Another purpose of the invention is to provide an improved packaging tray which is suitable for food and has a moisture-resistant, reclosable zipper on the lid, the arrangement and construction of the lid and the zipper offering improvements over previously known methods and arrangements.

According to the principles of the invention, it is a reclosable shell that has an outwardly bent edge at the edge. The bowl is made of a semi-rigid but flexible thermoplastic material, which means that the lid can be attached either by hot gluing or with the help of adhesives. The lid is preferably made of a transparent material such as polyethylene or, if necessary, a layered film with barrier properties suitable for food preservation. With a view to reducing the production costs, these can be very thin and can only be provided with an opening and reclosing feature.

The reclosable feature results from the attachment of a continuous flexible zipper with stripes along which interlocking profiles consisting of ribs and recesses run. The strips are constructed to be flat in one embodiment lie and thereby adjust the horizontal cover and run parallel to it and stand upright in another embodiment and are provided with vertical pull tabs. The lid can be attached in the simplest way so that the contents of the shell are reliably and completely sealed. The closing strips can be arranged directly above the lid without impairing its sealing effect, and nevertheless form an opening through which the content can be removed and which at the same time creates a closure which can be reliably reclosed to prevent the content from penetrating moisture and to shield air or contaminants, and this is particularly advantageous when the tray is used for food distribution.

• Fig. 1 ist eine perspektivische Ansicht einer Reihe von Schalen, die entsprechend den Grundzügen der vorliegenden Erfindung hergestellt und verschlossen wurden.
• Fig. 2 ist eine vertikale Schnittansicht, im wesentlichen entlang der Linie II-II aus Fig. 1.
• Fig. 2A ist eine geschnittene Teilansicht, die eine weitere Form der Befestigungsvorrichtung aus Fig. 2 zeigt, und wobei der wieder zu öffnende Verschluß an der Kante einer Schale liegt.
• Fig. 2B ist eine geschnittene Teilansicht, die eine weitere Form einer Befestigungsvorrichtung ähnlich der aus Fig. 2 zeigt, wobei der wieder zu öffnende Verschluß an der Kante einer Schale liegt.
• Fig. 2C ist eine geschnittene Teilansicht, die noch eine weitere Form einer Befestigungsvorrichtung ähnlich der aus Fig. 2 zeigt, wobei der wieder zu öffnende Verschluß an der Kante einer Schale liegt.
• Fig. 3 ist eine perspektivische Ansicht einer Schale ähnlch derjenigen aus Fig. 1, die jedoch eine andere Form eines wieder zu öffnenden Verschlusses zeigt.
• Fig. 4 ist ein vergrößerter, vertikaler Teilschnitt im wesentlichen entlang der Linie IV-IV aus Fig. 3, der einen Reißverschluß mit aufrecht stehenden Zugflanschen zeigt.
• Fig. 5 ist eine Teilansicht einer Schale ähnlich der aus Fig. 3, die jedoch eine weitere Form der Verschlußkonstruktion zeigt.
• Fig. 6 ist ein vergrößerter, vertikaler Teilschnitt im wesentlichen entlang der Linie VI-VI aus Fig. 5.
• Fig. 7 ist eine perspektivische Teilansicht, die eine weitere Form der Verschlußkonstruktion zeigt.
• Fig. 8 ist eine perspektivische Teilansicht, die noch eine andere Form der Verschlußkonstruktion zeigt.
• Fig. 9 ist eine perspektivische Teilansicht, die noch eine andere Form der Verschlußkonstruktion zeigt.
• Fig. 10 ist eine geschnittene Teilansicht durch einen wieder zu öffnenden Verschlußabschnitt eines Deckels, der eine Form des Verschlusses zeigt.
• Fig. 11 ist eine geschnittene Teilansicht ähnlich derjenigen aus Fig. 10, die eine weitere Form eines Verschlusses zeigt.
• Fig. 11A ist eine geschnittene Teilansicht ähnlich der aus Fig. 11, die eine ähnliche Form einer Schließvorrichtung wie in Fig. 11 zeigt.
• Fig. 11B ist eine geschnittene Teilansicht, die einen weiteren wieder zu öffnenden Verschluß zeigt, der in etwa dem aus Fig. 11 gleicht.
• Fig. 12 ist eine geschnittene Teilansicht ähnlich derjenigen aus Fig. 10 und zeigt noch eine weitere Verschlußform.
• Fig. 13 ist eine geschnittene Teilansicht, die eine Verschlußform zeigt, bei der aufrecht stehende Zugflansche verwendet werden.
• Fig. 14 ist ein vertikaler Teilschnitt ähnlich dem aus Fig. 13, der jedoch eine andere Verschlußform zeigt.
• Fig. 15 ist ein vertikaler Teilschnitt ähnlich dem aus Fig. 13, der eine weitere Verschlußform zeigt.
• Fig. 16 ist ein vertikaler Teilschnitt ähnlich dem aus Fig. 13, der eine weitere Verschlußform zeigt.
• Fig. 17 ist ein schematischer Seitenriß, der eine Art und Weise zeigt, in der eine Reihe miteinander verbundener Schalen verschlossen werden.
• Fig. 18 ist eine perspektivische Ansicht, die das Verfahren gemäß Fig. 17 weiter veranschaulicht.
• Fig. 19 ist eine perspektivische Ansicht, die die Abdichtung zwischen einem einzelnen Deckel und einer Schale sowie das für die Abdichtung benutzte Gerät zeigt.
• Fig. 20 ist eine perspektivische Ansicht, die ein weiteres Gerät zeigt, wie es für das Verschließen einer Schale verwendet wird.
• Fig. 21 ist ein Seitenriß, der einen Schritt des Verschluß- und Abdichtverfahrens einer Schale zeigt.
• Fig. 22 ist eine perspektivische Teilansicht, die eine Konstruktion für die dichte Anbringung eines Deckels mit den Merkmalen gemäß Fig. 21 auf der Oberseite einer Schale zeigt.

In the following, embodiments of the invention are scanned using the drawings, which show the following:

• Figure 1 is a perspective view of a series of trays made and sealed in accordance with the principles of the present invention.
• Fig. 2 is a vertical sectional view taken substantially along the line II-II Fig. 1.
• Fig. 2A is a partial cross-sectional view showing another form of the fastener of Fig. 2, and with the reopening closure located on the edge of a shell.
• Fig. 2B is a partial cross-sectional view showing another form of fastener similar to that of Fig. 2, with the re-opening closure located on the edge of a shell.
• Fig. 2C is a partial cross-sectional view showing yet another form of fastener similar to that of Fig. 2, with the reopener located on the edge of a shell.
• Fig. 3 is a perspective view of a tray similar to that of Fig. 1, but showing a different form of re-opening closure.
• Fig. 4 is an enlarged, vertical partial section taken substantially along the line IV-IV of Fig. 3, showing a zipper with the flanges upright.
• Figure 5 is a partial view of a shell similar 3, but which shows a further form of the closure construction.
• FIG. 6 is an enlarged, vertical partial section substantially along the line VI-VI from FIG. 5.
• Fig. 7 is a partial perspective view showing another form of the shutter construction.
• Fig. 8 is a partial perspective view showing still another form of the shutter construction.
• Fig. 9 is a partial perspective view showing still another form of the shutter construction.
• Fig. 10 is a partial sectional view through a re-opening portion of a lid showing a shape of the closure.
• Fig. 11 is a partial sectional view similar to that of Fig. 10, showing another form of closure.
• Fig. 11A is a partial sectional view similar to that of Fig. 11, showing a similar shape of a locking device as in Fig. 11.
• Fig. 11B is a partial sectional view showing another re-opening shutter which is approximately the same as that of Fig. 11.
• Fig. 12 is a partial sectional view similar to that of Fig. 10 and shows yet another form of closure.
• Fig. 13 is a partial sectional view showing a closure shape using the upright tension flanges.
• Fig. 14 is a partial vertical section similar to that of Fig. 13, but showing a different form of closure.
• Fig. 15 is a partial vertical section similar to that of Fig. 13, showing another form of closure.
• Fig. 16 is a partial vertical section similar to that of Fig. 13, showing another form of closure.
• Fig. 17 is a schematic side elevation showing a manner in which a series of interconnected trays are sealed.
• 18 is a perspective view that further illustrates the method of FIG. 17 illustrated.
• Fig. 19 is a perspective view showing the seal between a single lid and a tray and the device used for the seal.
• Fig. 20 is a perspective view showing another device used for closing a tray.
• Fig. 21 is a side elevation showing a step of the shell sealing and sealing process.
• Fig. 22 is a partial perspective view showing a construction for tightly fitting a lid having the features of Fig. 21 on top of a tray.

As shown in Fig. 1, there is a series of preformed trays (11) which have a hollow or recessed central part for receiving food, upright side walls and an edge (12) which is around the edge at the upper end of the side walls runs continuously. A lid (13) is placed on the bowl to protect the contents and the edges of the lid material are sealed off from the bowl edge. As shown in Fig. 2, the lid (13) is all around Periphery, as shown at (14), sealed at the edge (12). As shown in Fig. 1, this can be done in a continuous manufacturing process, with the flexible cover material being advanced as indicated by the arrow in Fig. 1 to cover the tray, and the trays are joined together at the ends and the covering material is made in one piece to join adjacent trays as shown by the dotted line (20). After the individual shells are covered, they are separated from one another, as indicated by the separating cut (19). The lid (13) is sealed at the edge (12) of the shell by suitable means, e.g. B. by joining the plastics by ultrasonic waves, glue, vibration welding, HF welding or by other known sealing methods.

1 and 2, a reclosable locking device is separated from the covering material, the locking device being formed on the edge of the shell (11) with an upper strip (15) and a lower strip (16). Between the strips are pressure resealable and openable rib profiles with the rib element at (17) and the receiving element at (18). If you grasp the upper tear-open flange of the strip (15), the lid can be opened along the edge and the contents are exposed. If you push the upper tear-open flange of the strip (15) downwards, the rib and groove elements become reassembled and seal the contents against penetrating air and moisture.

Figures 2A, 2B and 2C illustrate different forms of the locking device shown in Figures 1 and 2, which is arranged on the shell edge. The locking devices in FIGS. 2A, 2B and 2C can be made in one piece with the film of the covering material (such as, for example, with the lid shown in (13) in FIG. 2 or separately as shown in FIG. 1), or it can a re-opening zipper made separately and attached to the lid.

With particular reference to Fig. 2A, the shell lid can be seen at (13a) and a strip (8a) of the locking device is shown as being made in one piece with the cover, although the strip (8a) could also be glued to the cover. The locking device has a rib profile element (17a) which can be pressed into a receiving groove element (18a) by means of an interference fit. The groove fastening device rests on a strip (16a) which is connected to an edge (12a) of a shell (11a).

The foot strip (16a) of the locking device consists continuously of one piece with a strip (15a) of the upper fastening part with a weak point (9a) which is formed in the material (15a and 16a). The continuous material (15a and 16a) leaves neither Air still penetrate moisture so that a complete protective seal for the shell (11a) is present until the contents are to be used. The shell can be designed in such a way that the rib element (17a) and the groove element (18a) engage in one another, or this engagement can be effected only after the shell has originally been opened

FIG. 2B illustrates yet another form of closure for the side of a shell, as shown in FIGS. 1 and 2. A bowl (11b) has an edge (12b). A cover (13b) lies above the bowl and is to be firmly connected to the edge. A foot strip (16b) is shown as a permanently integrated extension of the lid. The closing device, consisting of the foot strip (16b) and an upper strip (8b), can however be connected to the cover (13b) in such a way that it can be manufactured separately. The locking device is provided with the lower strip (16b) and a groove profile element located thereon. The upper part of the locking device has a rib element (17b) which engages in the groove element (18b). The upper strip of the closing device has a tear-open flange (15b) which starts from the upper strip (8b).

The footer (16b) is provided with a weak point at (9b). The weak point allows the tread strip to be broken open at (9b), but is impermeable to moisture and air, so that the contents of the shell remain completely sealed until the Shell should be opened by the user. The user thus has a tamper-proof cover, so that he can visually recognize whether the shell was opened before he bought it or not. If the buyer wants to use the content, he pulls the tear-open flange (15b) upwards, so that the weak point (9b) breaks and the content becomes accessible. The shell can then be resealed by squeezing the interlocking rib and groove members (17b) and (18b) to engage them.

2C illustrates yet another form of a reclosable closing device for the edge of a shell (11c). The bowl has an edge (12c). A closing strip is connected at the shell edge to a lower foot flange (16c) which is glued to the edge (12c). The upper closing strip (8c) can either consist of one piece with a cover (13c) for the shell or can be glued to it. This allows the locking device to be manufactured separately, if desired. The upper closing strip has a rib element (17c) which, due to its design and size, can snap into a groove element (18c). The upper strip has a tear-open flange (15c) which at the end, as shown at (15'c), is bent downwards. The foot flange for the lower closing strip is bent upwards at the end, as in (16′c), and a flexible sealing film (7c) is between the ends (15'c and 16'c) attached and glued to seal the space between the ends. This continuous sealing film (7c) comes to lie between the profiles (17c and 18c) and forms an air- and moisture-tight seal to protect the contents, which must be broken open in order to access the shell contents so that the buyer and user know that the bowl was not opened before the purchase.

Thus, each of the arrangements shown in Figs. 2A to 2C can be designed so that the top strip is integral with the lid or can be separately manufactured and attached to the lid to form a tamper evident closure for the bowl

Figures 3 and 4 show a modified version of the reclosable shell closure. A shell (21) has a continuous edge (22) on its upper edge and a flexible cover (23) is placed over the shell and sealed against the edge. In this arrangement, the lid (23) can consist of a continuous one-piece film, which has a uniform thickness and is inexpensive, and can also consist of thin transparent material so that the contents of the shell can be seen. With the shell base made of a flexible thermoplastic material and the lid made of a light thermoplastic material, suitable materials are available for both the lid and the shell, each of which has particularly optimal properties, and yet these can Elements are easily heat-sealed using a mandrel or other heat transfer element that is continuously applied to the edge of the material.

A locking device (24) can be attached to the lid (23) in advance or attached to it after the lid is in place. In the type of closure shown, the closure is preferably heat-sealed with the lid, so that such a heat seal takes place before the lid is placed on the shell. The locking device can be attached to the lid by means of various known connection or attachment methods, such as. B. by ultrasonic welding of the plastic, with the help of glue by vibration welding, HF welding or the like. It will be understood that such known attachment methods can be used to connect the various fastener structures to the lids as described below.

In Fig. 4, the closure (24) of a one-piece, folded-over unit is shown, which contains laterally upright closing strips (25 and 26), which run downwards and are joined to a spread foot (27) which is heat-sealed to the cover (23) becomes. The zipper (24) has matching, engaging, reclosable rib and groove profiles (28 and 29) on the inner surfaces of the closing strips (25 and 26). In order to first attach the zipper (24) to the lid material, the rib and groove can be separated by pulling the closing strips apart and performing a heat seal, whereby the foot (27) is attached to the lid surface. If desired, a continuous weak point (30) can also be provided so that the lid can be opened during use and releases the contents. A preferred embodiment of the weak point (30) is that one can use the tool with which the feet (27) are sealed on the cover to simultaneously produce the continuous weak point. Alternatively, a perforating wheel can be used, which is moved downwards in the longitudinal direction between rib and groove profiles after they have been separated in order to cut through the foot (27) and the cover (23). In order to maintain the air and moisture tightness of the container, these perforations were sealed by heat sealing a strip over the perforations, no sealing strip is required for products that do not require a barrier film. If desired, an additional seal can be made to cause accidental opening in the store by means of adhesive elements which are arranged either at (25a) above the profiles or at (25b) below the profiles. The adhesive elements are not shown in the assembled state, but would be connected to one another when filling and closing the shell in order to adhere to one another and thereby additionally separate the rib and groove prevent and to further seal against moisture and air.

4, a closing strip (25) is shown so that it is longer than the other closing strip (26), so that it is easier to grip and rib and groove can be pulled apart at the beginning, so that the lid along the Perforation line (30) can be opened and the content becomes accessible. Once the contents have been removed, the rib and groove (28 or 29) can be pressed together, so that the packaging is resealed with a different content until further use and for removing further parts of the contents or for the purpose of using the packaging.

Figures 5 and 6 illustrate another form of closure, wherein the zipper consists of individual, separate strips and the zipper (35) is shown to have strips (33 and 34) with upstanding tear flanges. Again, one of the strips (33) is longer than the other strip (34) in order to facilitate gripping to pull the rib (39) and the receiving groove (38) apart. Each of the strips is L-shaped and has a foot web (36 and 37) which extends laterally outwards, parallel to the surface of a cover (32). The lid (32) is sealed along the edge with the edge of a shell (31), on which the lid is placed.

The lower webs (36 and 37) are with the flat Material of the lid (32) connected in the manner shown in Fig. 6 by adhesion or heat sealing. Again, a continuous vulnerability such as B. a perforation (40) between the zipper strips along the lid so that when the rib and groove are pulled apart by means of the tear flanges, the lid can be opened along the line (40) and the content is accessible.

Figures 7, 8 and 9 respectively show different ways in which the ends of the zipper can be sealed between the zipper strips for convenience, appearance or reliable protection against leaks.

Fig. 7 shows a shell (41) with a continuous flat lid (42) which is attached to the edge thereof. The strips (43 to 44) protrude above the lid and are fastened to the flat lid surface with web parts (45 and 46). In general, the web portions (45 and 46) on the lid would be sealed in one operation and the end flanges in a second, earlier operation, offset from the first, sealed together at predetermined locations depending on the size of the shell to which the lid is attached . The ends of the strips (43 and 44), as shown at (47 and 48), are sealed together and form a flat web which cannot be separated and which prevents air from entering at the end between the strips (43 and 44), if the ribs and groove profiles are attached, which are not shown here, but which are located on the inner surface and interlock.

8, a bowl (49) has a continuous, flat, thin lid (50) which protects the contents and is sealed to the edge of the bowl. An upright zipper strip is provided with closing strips (51 and 52), on the opposite inner surfaces of which there are interlocking rib and groove profiles. At the lower part of the strips there are webs (53 and 54) which are sealed with the cover (50). The ends of the strips are sealed together at (55 and 56) and then flattened and sealed flat with the cover (50) at the ends, so that leaks between the strips are additionally avoided when the container is closed. With this arrangement, access to the shell is more limited. In each of the cases described in FIGS. 7 to 9, the content is accessible by separating the strips and opening an opening in the lid between the strips so that food or other materials located in the bowl become accessible.

According to FIG. 9, a bowl (57) has a flat lid (58) which is sealed to the bowl edge. A zipper extends in the longitudinal direction parallel to the side edges at the middle of the shell and the zipper has stripes (59 and 60). At the foot of the strips there are webs (61 and 62) which are sealed to the surface of the cover (58), as in FIG. 8, but which are then cut along the line (63) so that they stand upright . The arrangement would be used when barrier properties to protect the shell contents are not required.

While the shell is shown in each case to have a rectangular shape and the zipper extends downward at the edge or at the center parallel to the side edges, it will be understood that shells or containers of different shapes can be used and that an arrangement of the zipper parallel to the side edges is not essential, but that they can form an angle or adopt another arrangement. In the arrangement according to Figures 1 and 2, the zipper is formed separately from the lid and shown as being on the edge of the shell, but it can also be arranged on the inside of the edge. If the opening is in the middle, as shown in the arrangements according to FIGS. 3, 5, 7 to 9, the semi-flexible shell is opened by forces acting at the end, so that the contents are easily accessible. Of course, the zipper strips must be separated before the end forces are exerted to open the lid, and the continuous weak point must be broken. Alternatively, the contents of the shell can also be accessed by pulling the zipper strips apart.

Fig. 10 illustrates a construction in which the closing element is part of the lid and arranged so that an unwanted separation of the profiles is prevented. 10, the cover at (64 and 64a) is shown in two parts, an opening being present between the parts mentioned and the upper part of the cover extending over the opening, so that an upper strip (65) is formed. The lower part below the opening is folded over at (68) so that a strip (69) is created. On the mutually opposite inner surfaces of the strips (65 and 69) there are rib and groove elements (66 and 67) which engage with one another. The lower strip, which is folded at (68), has a hinge function and the folded part (68) forms the hinge that prevents opening by bending the lid or the shell. Lids and profiles can be made in one piece, and in this case the embodiment shown in Figures (14 or 15) occurs.

FIG. 11 illustrates a further embodiment, which is approximately the same as that of FIG. 10, but the closing strips, instead of being made in one piece with the lid material, are separated from one another and attached to the lid. The lid has a part (70) and a part (71) which run towards each other and form an opening between them.
Closure strips include an upper strip (72) attached to the top cover layer (71) and a lower strip (73) attached to (74) on lower cover part (70) is attached. The point (74) where the strips are attached is offset from the profiles of the strip so that a hinge is created at (74), which prevents accidental separation of profiles and opening.

FIGS. 11A and 11B show modified embodiments of a closing strip for sealing a shell cover, approximately similar to the embodiment according to FIG. 11.

In the arrangement from FIG. 11A, a closing device, consisting of an upper strip (72a) and a lower strip (70a), is attached such that the upper strip with a cover (71a) for the shell and the lower strip (70a) is glued to the edge of the shell. The closing strips have mating profiles and between the ends of the upper strip (72a) and the lower strip (70a) there is a sealing film (5a) which seals the ends. This seal creates a moisture and air seal to protect the shell contents. When the user buys the bowl, he is provided with a tamper-evident fastening device so that he can visually determine whether the bowl was opened before it was purchased. For use, the seal (5a) is broken to make the contents of the bowl accessible and the fastening strip is then closed and opened in the usual way to close the bowl again or to make it accessible. There can be a continuous one in the sealing strip Weak point (6a) may be provided so that the sealing strip can still be combined with a fastening element in order to achieve an even better air and moisture seal.

11B shows another form of the locking device, this having a lower strip (70b) and an upper strip 72b) which are connected by interlocking rib and groove elements. Upper and lower strips are connected by a web part (4b) joined together, which is glued to the lid (71b) of the shell. The lower strip (70b) is then glued to the edge of the shell. The lower strip has a continuous weak point (6b), which can be broken open to access the contents of the bowl. In use, the buyer pulls the top strip up and breaks the weak point (6b). By lifting the top strip, the user can visually determine whether the closure has been opened so that the arrangement forms a tamper evident closure. After the weak point has broken open, the shell can be opened and closed again by pulling the fastening strips apart and putting them back together.

FIG. 12 shows a further arrangement in which a closing device is connected to cover material (76) on one side of the opening and to cover material (75) on the other side of the opening.

There are stripes (77 and 78) in the opening. The closing strip (77) is attached to the upper cover material (75). The lower cover material (76) is folded over at (80) so that a flap (81) is formed. This is attached with the other edge to the lower closing strip (78). This creates a hinge at (79), which is offset from the profiles of the closing strips to provide resistance when opening. The lower folded part also forms a second hinge at (80), which essentially forms a further pull-out fold which allows additional material which counteracts an unintentional separation of the profiles by loading the cover or the shell.

Figure 13 shows the concept of a hinge zipper strip with the locking device in an upright position. A lid has an opening at (130) and edges that extend upward on the sides of the opening. A fastening element for the opening has a lower web part (133) and an upper web part (134), which are to be fastened on both sides of the opening to the folded surfaces of the cover. The upright closing strip (131) extends upwards and has a profile on the inner surface. The closure has an additional strip part (136) with a profile that matches the profile of the strip (131). The strip (136) is on the upper edge part (134 at 135) with an upright part (132) of the Lid connected so that at (135) a hinge is created, which is offset from the profiles and counteracts an opening when the sides of the lid are stressed near the opening (130).

Fig. 14 shows another arrangement in which a one-piece zipper device (82) is constructed so that it can be attached to a flat lid on a tray. The shell cover can be provided with a continuous weak point, which is not shown here, such as e.g. the perforation line (30) according to FIG. 4 or the perforation line (40) according to FIG. 6.

The zipper device has lateral web parts (83 and 84) which can be attached to the lid surface. In some embodiments, the zipper may be integral with the lid, a lid originally being formed from a pressed material so that rib and groove profiles (86 and 87) are integrated therein. The strip runs continuously and is folded over at the top edge. The folded part has continuous weak points, such as B. the perforations (88 and 89) so that the upper part of the strip can be torn off in use. This creates a tamper evident closure in that the buyer can see that the container has not been opened before purchase. In use, the upper part is torn off so that upright strips remain to separate the rib and groove elements from one another and the interior of the shell to make it accessible.

15, a construction similar to that of FIG. 14 is used, but at (96) there is a fragile seal or connection under the rib and groove elements (93 and 94) on the closure (90) . The sole sealing strips have lower web parts (91 and 92) which either consist of one piece with the lid or are attached to it. The closure is folded over and continuous on the outer edge (95), and the outer edge is torn open for use, so that upright tearing flanges are formed, as a result of which the rib and groove elements are torn apart.

In the arrangement according to FIG. 16, a continuous, one-piece zipper (97) is again provided. The closure has lateral web parts (98 and 99) which are part of the lid or are attached to this. The closure is folded over at (100). The profiles (101 and 102) are located on the inner surface of the closing strips. A bridge-shaped seal (103) is attached to the inner surfaces of the sealing strips below the profiles to form a moisture and airtight connection point. So even if the outer part (100) of the closure is removed and the rib and groove elements are torn apart, the buyer can determine whether the container was tightly sealed and the bridge-shaped part (103) can get to the shell contents, be cut open or torn open.

The bridge-shaped part (103) can be made in one piece with the closing strips or can be used separately, and the bridge-shaped strip can be used instead of the folded part (100) of the closure, which can be cut open by the end user before use, the part ( 103) then forms the tamper evident seal.

Figure 17 shows a manner in which a continuous series of trays are handled and sealed. The semi-flexible shells (104) are continuously manufactured and fed from right to left, as shown in Fig. 17. A covering material is drawn off from a drain roller (106), and the material to be placed over the tray is fed in at (105). Zipper elements (108) arranged at intervals are already attached to the cover material, and a pressure roller (107) presses the cover material onto the top of the shells. The closures are shown in separate units (108) so as to fit the tops of the shells. As the trays and lids continue to move, a heat seal mandrel (109) is pressed onto the top of the cover to seal the edges on the edge of the tray. As the bowl continues to move, a knife (109a) separates the bowls from the continuous feed, creating a single, separate bowl on which the lid is already in place. The contents are probably filled into the bowl immediately before the lid is put on.

Fig. 19 illustrates in detail the pressing of the mandrel (109). The mandrel is shown with a rectangular shape that matches the shape and size of the shell edge (104). The unique feature of the mandrel is the slots (110 and 111) which are arranged to match and receive the upright zipper elements (108).

Fig. 20 illustrates a similar process in which the zipper is to be flattened so that it takes the form shown in Fig. 8 or 9. In this case, a mandrel (122) is also rectangular in shape to match the shape and size of the edge of a shell (117) and a heat seal cover material (118). An upright zipper element (119) is flattened and sealed at the points (120 and 121) with the lid.

Figure 18 illustrates the application of the principles to trays pressed in double rows with one row of trays at (112) and a second row at (113).

Covering material (114) is fed above the tray after it is filled and advanced with the material, and the trays move in the direction indicated by arrow (128). The upright zipper elements (115 and 116) are already attached to the cover material (114).

In some cases it may be desirable to feed the cover material laterally, as indicated by the arrow (128a), the cover material (114a) being pushed laterally over the trays (112 and 113).

21, heating rods (125 and 126) move in the directions indicated by arrows to achieve a good seal and are shown in their final position by the dotted line (124). A bowl (122) has a lid (123) which is provided with an upright zipper element (127), and the bars (125 and 126) heat seal the lid (123) to the edge and also provide the end seal on the vertical zipper element so that the final seal finally looks like that in Fig. 7 shown.

The heating rods (125 and 126) are shown in more detail, but rather schematically, in FIG. 22. Suitable devices, such as. B. an embedded heating element, heat the rods, and to seal the lid with the top of the shell, the rods are lowered vertically onto the lid to connect this by heat sealing with the edge of the shell. The rods are U-shaped and have a size that corresponds to the size of the bowl edge. The bars are brought together laterally so that the base surfaces of the U-piece (128a and 129a) on one side of the shell and (128b and 129b) on the other side come to rest against the upright closing strips of the closing element in order to glue the ends.

Suitable mechanical devices are provided to move the U-shaped heating elements vertically downwards against the shell, as is schematically indicated by the vertical line (130). Suitable mechanical devices are also provided for laterally moving the U-shaped sealing bars, as indicated schematically by the horizontal arrows (131). Alternatively, the rods can be positioned diagonally in one step.

With a reclosable zipper that extends along the top of the shell, the contents of the shell are easily accessible by opening the zipper and removing some or all of the contents. If only a part is removed, the tray can be used for storage by reclosing the zipped rib and groove, resulting in an air and moisture tight seal on the tray, except for the case shown in Figure (9) is shown. An advantage of this construction is that the semi-rigid nature of the shell allows the side walls to bend when the ends are pressed inward. This separates or bulges the opposite sides of the flange, creating an elongated opening through which you can reach into the shell. For example, considering a construction like that in Fig. 3, the upright stripes move when the user separates the top closure member (24) and then the end walls pushes inwards, apart, so that an opening is created and the user can remove the contents from the tray or insert new contents into the tray. This type of shell normally has sufficient spring force to cause it to spring back when released, so that the strips on the side of the flexible closing element move towards one another again so that the profiles can be put together again. Alternatively, the zipper strips also cause one when pulled apart Opening to the bowl.

It can be seen from this that an improved method for producing an arrangement has been created which is well suited for fast-running packaging processes, in particular in the packaging of foodstuffs and other products which have a limited shelf life, and which causes low costs. The resulting bowl is resealable and offers advantages over other bowls that can only be opened by destroying the lid. The bowl and the lid according to the present invention do not incur any significant additional costs compared to bowls of the previously available type and are nevertheless useful and attractive for the consumer in a way which has not been possible previously. The method and construction correspond to the objectives and advantages outlined above and include several arrangements that are within the spirit and spirit of the invention that can be used to manufacture improved protective packaging.

Claims (11)

1. Shaped tray, particularly a plastic tray as reclosable, sealed tray (11, 21, 31, 41, 49, 57, 104, 112, 113, 117, 122) for food stuffs and the like as a semi-rigid container having a depression for the acceptance of the contents and surrounded by a flange at the upper edge of the tray that proceeds continuously at the ends and sides of the tray, as well as having a flexible plastic cover (13, 23, 32, 42, 50, 58, 64, 64a, 70, 71, 75, 76) over the tray that is sealed at the tray edge, characterized in that the cover comprises a pair of closing strips (24, 35, 90, 92, 97, 108, 127) that have rib or groove elements (17, 18, 28, 29, 39, 38, 43, 44, 51, 52, 59, 60, 66, 67, 77, 78, 86, 87, 93, 94, 101, 102) that engage into one another, so that the said cover can be parted between these said strips so that an access opening arises and the opening can be reclosed by the said interlocking elements.

2. Shaped tray according to claim 1, characterized by a tear line as weak point or, respectively, rated break location (30, 40, 9a, 9b, 6a, 6b, 88, 89, 96) in the cover material between the closing strips.

3. Shaped tray according to claim 2, characterized in that the weak point is formed by perforations extending transversely through the material, and whereby the said perforations are sealed with sealing means (25a, 25b, 28, 29, 39, 38) that prevent the emergence of air and moisture through the said perforations.

4. Shaped tray according to one or more of the preceding claims 1 through 3, characterized by tear flanges that extend from the said closing strips in outward direction and whereby the said tear flanges are joined such at the outside edge that a juncture (85, 95, 100) secure against misuse arises, this having to be parted in order to separate the profiles from one another for the access.

5. Shaped tray according to one or more of the preceding claims 1 through 4, characterized in that the dimensions of tray and cover are of such a nature that the said, interengaging rib and groove elements are separated from one another and, thus, the tray contents becomes accessible by pressing onto the tray ends, an outward movement of the tray sides ensuing.

6. Shaped tray according to one or more of the preceding claims 1 through 5, characterized in that one of the said closing strips has a doubled layer secured only along one edge, said doubled layer being offset from the profiles such that a hinge (68, 74, 79, 80) that prevents an unintentional separation of the profiles arises.

7. Method for closing a shaped tray having a depression for the contents and a continuous rim proceeding along the edge according to one or more of the preceding claims 1 through 6, characterized by the method steps

a) covering the shell contents with a flexible plastic cover and sealing the cover at the said edge rim,

b) laying an elongate closing element onto the cover and having rib and groove profiles that lie opposite one another and engage into one another at two closing strips having fastening webs at the base, and

c) sealing the said fastening webs at the outside surface of the cover in such a way that the closing strips and profiles can be separated from one another and thus provide access to the tray contents through an opening in the cover.

8. Method for closing a shaped tray having a depression for the contents and a rim proceeding continuously along the edge according to one or more of the preceding claims 1 through 6, characterized by the method steps of covering the shell contents with a flexible plastic cover having an integrated closing element composed of two zipper strips and sealing the cover at said edge rim.

9. Method according to claim 7 or 8, characterized in that cover and fastening element are hot-sealed to the rim of the tray by applying a hot-sealing bar whose configuration corresponds to the shape of said rim.

10. Method according to one or more of the preceding claims 7 through 9, characterized in that a plurality of trays are joined at the edge rims and a flexible plastic cover having a plurality of closing elements is placed over the said plurality of trays and is sealed onto the trays.

11. Method according to one or more of the preceding claims 7 through 10, characterized in that lower web parts extend laterally outward from the closing strips and proceed parallel to the cover and are connected to the cover in face-to-face seals at the surface.

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