EP0424649A1 - Package for flowable products - Google Patents

Abstract

A device is described for the tearable sealing of a lid (1') to a base part, both of which are joined together by a first weld (3), a first tearing line (5) being provided extending parallel to the first weld (3). <??>In order no longer to have to tear the lid up or even bend it and to be able to provide a package with such a tearing device, provision is made according to the invention for a second tearing line (4) to be arranged in the lid (1') with spacing (a) from the first tearing line (5) at least along a first portion thereof (5) and extending in such a way that a tear-off strip (6) can be formed between the two tearing lines (4, 5). <IMAGE>

Description

The invention relates to a device for the detachable fastening of a first plastic part to a second plastic part, both of which are connected to one another by a first weld seam, a first tear line being provided running parallel to the first weld seam. The invention further relates to a use of this device for attaching a lid to a package and relates to a package for liquid and / or solid contents, consisting of a bowl-shaped lower part and a cover, the cover and at least the upper edge of the lower part being made of plastic material. The shape of the lower part can of course also be understood as a cup, sleeve or plate. The term "bowl-shaped" should be used representatively for these forms of lower parts.

In general, there are a wide variety of fastening options, types and problems in the case of parts made of plastic material, plastic part in the sense of the present invention being understood to mean a sheet or sheet material.

The usual way of connecting a first plastic part to a second one is of course welding or sealing. If one then wishes to separate one part from the other, one naturally provides a first tear line, which generally runs parallel to the first weld mentioned. In this way, the first plastic part can be gripped and separated from the second plastic part along the tear line, the first weld seam remaining on the second plastic part.

In many cases it has proven to be disadvantageous to have to bend the first plastic part relative to the second at least in the area of the first tear line, but otherwise the first plastic part cannot be torn off the second. In particular in the case of plastic parts provided with profiles, bending may either be impossible or lead to damage, so that remedial measures must be taken here.

The object of the invention is therefore to provide a device for detachable fastening of the type mentioned above, in which the second plastic part no longer has to be pulled up or even bent in order to enable tearing along the first tear line; and the task also consists in creating new uses and in particular in the new design of a packaging of the type already mentioned, in which the bending of a lid is particularly undesirable.

With regard to the device for detachable fastening of a general type, the object is achieved according to the invention in that a second tear line is arranged in the first plastic part at least along a first section at a distance from the first tear line such that a tear strip can be formed between the two tear lines. The tear-off strip requires only small amounts of material and can be provided as waste without significant losses, be it that the tear-off strip is separated after the tear-off process and is thrown away or gets stuck on one of the two plastic parts. Since it is inevitable and indispensable to bend one part along a tear line with respect to the other, the measures according to the invention have taken the tear-off strip, which is in any case intended as waste, as the part which can then be bent without further damage and the separation of one Part of the other enables.

It has turned out to be advantageous that the first tear line runs on the strip-side edge of the first weld seam and the second tear line is formed at least along a first section of the first tear line by a separate weakening line in the first plastic part. In addition to the first weld seam, a separate weakening line can also be formed so that it forms the first tear line. This work and material expenditure is not necessary, because on the side of the tear-off strip the edge of the first weld seam also forms a tear line. If the user tears up the tear-off strip, it will separate along the strip-side edge of the first weld. This allows you to separate the first plastic part from the second part, be it hinged up or separate. The tear strip is preferably narrow and elongated and is delimited on one side by the strip-side edge of the first weld seam, while on the other side it abuts the second tear line, which is, for example, a separate line of weakness in the first plastic part.

It is also expedient according to the invention if the second tear line is formed along a second section of the first tear line by a second weld seam which extends approximately in the extension of the second tear line. In this case, the second plastic part is held in a hinge-like manner on the first plastic part, while in the remaining part, following the respective end of the second weld seam, the second tear line runs along which the first plastic part can be separated from the second part.

It has proven to be particularly advantageous if the device of the type explained above is used to fasten a plastic cover on a packaging in which at least the upper edge is made of the plastic material of the Cover is made of weldable plastic material. Such packaging can then be produced inexpensively using simple means and is also easy to handle by the end user. Either the cover can be removed completely from the packaging by the tear-off strip or folded up like a hinge. In the latter case, the reclosure option is particularly simplified.

The teaching of the invention is therefore also directed to a packaging for liquid and / or solid filling goods, which consists of a bowl-shaped lower part and a cover, the cover and at least the upper edge of the lower part being made of plastic material. Such packs can be used, for example, for foods that contain solid and liquid components. Such a pack is inexpensive to produce in large quantities, suitable for transport and storage due to good tightness and strength properties, and also inexpensive for the end user, especially if it is provided according to the invention that a first weld seam approximately along the upper edge of the lower part between the Edge and the lid is attached and that for the formation of a tear-off strip towards the center of the lid at a distance from the first weld seam a weakening line and / or a second weld seam is arranged, which is / are provided all around the upper edge of the lower part. It is expedient if the first weld seam, which is the main fastening of the cover on the circumferential edge of the lower part of the pack, runs on the outside and, except for an approximately thumb-wide exception, runs around the upper edge. This exception is intended for a grip tab, which is described in more detail below. The cover is thus firmly connected to the pack by the first weld seam, so that the pack can be described as closed. The lid is opened using the tear-off strip in the manner described is formed, with the cover being completely separated after opening when the line of weakness runs at a distance from the first weld seam without being replaced along a certain section by a second weld seam. Since the line of weakness forms the second tear line, it is understandable that the lid can be removed after opening if this line of weakness runs around the entire upper edge of the lower part. However, if the weakening line is replaced by a weld seam along part of this line course, then the hinge effect already described above results with the advantage of a good reclosure possibility.

With such a packaging, it is particularly advantageous if the first tear line runs on the strip-side edge of the first weld seam and the second tear line along a first section of the first tear line through a separate weakening line in the lid and along a second section of the first tear line through a second weld seam is formed. This then extends or joins the second tear line. In the area of the second section, the hinge is formed, via which the lid sticks to the edge of the lower part of the pack.

It is also particularly favorable according to the invention if, for the packaging described here, the tear-off strip is connected to the upper edge of the lower part via a welding tack and if this welding tack preferably connects the first weld to the second weld. The tear-off strip is then not completely separated and thrown away after being torn up, but remains on the edge of the lower part. This can be done using the above mentioned welding booklet. This is a welding area of approximately 0.5 to 4 cm², preferably 1 to 3 cm². Alternatively, this sweat but also an extension of the first and / or the second weld, because according to the above teaching, the welded joint should create a connection between the two welds. If the first weld seam, which is arranged on the outside with respect to the center of the lid, is followed in a top view of the lid and the upper edge of the lower part of the packaging, then the first weld seam is interrupted in the handle tab area to be described; ie if you follow it from the beginning in the direction of tearing behind the handle tab to be described, it runs around the upper edge of the lower part to the mentioned welding tackle and ends there or is transferred to the second weld seam, provided that in the particular embodiment one ( to form a hinge). In this case, the first weld passes over the weld tack into the second weld and runs from the weld tack (still in the tear direction) at a closer distance to the center of the lid. If you were to follow the web in the tear-open direction at the end of the hinge or at the end of the second weld seam, then you would find the subsequent second tear line here, which rotates in the manner described and also ends in the weld tacking point when further tear-open.

In an advantageous further embodiment of the invention, the first weld next to the welding tack for the tear-off strip is interrupted along a grip tab, the length of which is 0.5 to 3 cm, preferably 1 to 2 cm, seen in the tear-open direction. This grip tab can even protrude beyond the outer edge of the lid edge so that the end user immediately recognizes the function of the grip tab. In the case of food packaging, the person skilled in the art could recognize that the inside of the package is not theoretically completely separated from the outside by a weld seam or a plurality of weld seams. In fact, it is expedient, according to the invention, in the case of a grip tab to provide the second weld next to the first in the so-called second section, so that a narrow long channel is formed in the area of the second section between the two welds, so to speak, which is pressed during the welding process and thus when the edge of the lid is pressed onto the edge of the lower part in such a way that even without the mentioned theoretical welded connection, a liquid-tight packaging - according to practical tests even a gas-tight packaging - is created.

It is particularly expedient according to the invention if the cover is approximately square in plan view, with rounded corners also being conceivable, as a result of which four more or less straight edges of the same and / or different lengths are formed. Along a certain one of the four straight edges, along which the above-mentioned second section then extends, the two weld seams run at a distance from one another between the cover and the lower part such that, according to the invention, the first weld seam also extends from a first end of the grip tab all the way to its other second end runs. The first weld seam ends, so to speak, in the welding tack at this second other end of the grip tab. Furthermore, it is useful if the second tear line from the second end of the tab to the opposite end of the certain straight edge of the cover stripes along the second weld seam running there and then along the other three edges all around in one piece to the welding tack for the Tear strip stretches. The tear-off strip sticks to the lower part due to its attachment to the welding tacking point after being torn up and forms when torn up by the two tear lines running parallel to one another, the first tear line being understood as being outside the center of the lid and the second tear line lying further inside. The second tear line runs approximately like a beginning weft line, because one of them End located with respect to the lid center in plan view of the lid within the other end.

The situation is similar for the first weld seam, which, starting from the first end of the grip tab in the tear-open direction, runs around the edge to the other second end of the grip tab and there in the embodiment with the second weld seam in the area of the weld tacking point to a narrower radius or a smaller distance from the center of the cover is diverted and transferred into the second weld seam, which in the area of the second section, which is practically also the area of the hinge, on the other side of the tear-off strip runs parallel to the first weld seam until the second weld seam stops at the hinge end and from there to the second tear line. In the area of the hinge of the packing, the course of the two weld seams can be regarded as approximately spiral, because the second weld seam is arranged within the beginning of the first weld seam.

It has proven to be particularly advantageous when using the fastening device for packaging if the lower part of the pack or the so-called second plastic part is thicker and stiffer than the lid or the first plastic part. In a particularly preferred embodiment, it is expedient if the lower part is made of a 1.0 mm thick plastic material and the cover or the first plastic part is made of a 0.4 mm thick plastic material. For example, it is also expedient if the lower part of the packaging and / or the lid is / are deep-drawn. The packaging and the fastening device when used on such a packaging are particularly interesting in connection with two plastic films or sheets or sheets to be sealed, as already indicated above. These plastic materials preferably form one piece, the respective film, web or Sheet, which enables particularly reusable parts such as packaging to be created (in contrast to composite materials). A particularly expedient plastic material is polypropene, which in turn can be filled in a particularly preferred embodiment, for example can be filled to 60%. Fillers are chalk, mica, talc, plaster or the like. Such filled plastics are also thermoformable and sealable. It has been shown that filled plastic materials are even more tearable.

• Figur 1 perspektivisch zwei aufeinander befestigte Folien mit einem teilweise hochgerissenen Abreißstreifen in der oberen dünneren Folie, die das erste Kunststoffteil genannt wird,
• Figur 2 eine schematisch und abgebrochen gezeigte Schnittan­sicht entlang der Linie II-II in Figur 1,
• Figur 3 eine ähnliche Ansicht entlang der Schnittlinie III-III,
• Figur 4 die Draufsicht auf eine große untere dickere Folie, welche zweites Kunststoffteil genannt wird und eine daraufliegende kleinere dünnere Folie, welche das erste Kunststoffteil genannt wird mit gebogenem Abreißstrei­fen und Schweißnähten bzw. Reißlinien,
• Figur 5 eine abgebrochene Schnittdarstellung entlang der Ansicht der Linie V-V in Figur 4,
• Figur 6 eine Draufsicht auf den Deckel einer rechteckigen Fließmittelpackung mit Andeutung der Schweißnähte und Reißlinien,
• Figur 7 eine Schnittansicht entlang der Linie VII-VII der Figur 6 zur Veranschaulichung der Form der Verpackung,
• Figur 8 eine schematische und abgebrochene Schnittansicht entlang der Linie VIII-VIII der Figur 6,
• Figur 9 eine ähnliche Ansicht wie Figur 8, jedoch nach dem Entfernen des Aufreißstreifens mit Grifflasche,
• Figur 10 eine ähnliche Schnittdarstellung entlang der Linie X-­X in Figur 6,
• Figur 11 eine ebenfalls abgebrochen und im Schnitt dargestellte Ansicht wie bei Figur 10, wobei jedoch der Abreißstrei­fen hochgezogen gezeigt ist,
• Figur 12 eine ähnlich angebrochene Schnittdarstellung durch den Randbereich des Unterteils der Verpackung gemäß der Schnittlinie XII-XII der Figur 6,
• Figur 13 die gleiche Darstellung wie bei Figur 12, bei welcher jedoch der Abreißstreifen hochgezogen ist,
• Figur 14 ein Werkzeug zur Erstellung der ersten Schweißnaht und der Reißlinien und
• Figur 15 eine nach Einwirkung des Werkzeuges gemäß Figur 14 verformte und abgebrochene Querschnittsdarstellung zweier Kunststoffteile in vergrößertem Maßstab.

Further advantages, features and possible uses of the present invention result from the following description of preferred exemplary embodiments in conjunction with the drawings. Show it:

• FIG. 1 is a perspective view of two foils fastened to one another with a tear strip that is partially torn up in the upper thinner foil, which is called the first plastic part
• FIG. 2 shows a schematic and broken sectional view along the line II-II in FIG. 1,
• FIG. 3 shows a similar view along the section line III-III,
• FIG. 4 shows the top view of a large, lower, thicker film, which is called the second plastic part, and a smaller, thinner film, which is called the first plastic part, with a curved tear-off strip and weld seams or tear lines,
• FIG. 5 shows a broken sectional view along the view of the line VV in FIG. 4,
• FIG. 6 shows a plan view of the lid of a rectangular plasticizer pack with an indication of the weld seams and tear lines,
• FIG. 7 shows a sectional view along the line VII-VII of FIG. 6 to illustrate the shape of the packaging,
• FIG. 8 shows a schematic and broken sectional view along the line VIII-VIII of FIG. 6,
• FIG. 9 shows a view similar to FIG. 8, but after removing the tear strip with a grip tab,
• FIG. 10 shows a similar sectional illustration along the line X-X in FIG. 6,
• FIG. 11 shows a view, likewise broken away and in section, as in FIG. 10, but with the tear strip shown pulled up,
• FIG. 12 shows a similarly opened sectional view through the edge area of the lower part of the packaging according to the section line XII-XII of FIG. 6,
• FIG. 13 shows the same representation as in FIG. 12, but in which the tear strip is pulled up,
• Figure 14 is a tool for creating the first weld and the tear lines and
• FIG. 15 shows a cross-sectional view of two plastic parts deformed and broken off after the action of the tool according to FIG. 14 on an enlarged scale.

A in the drawings generally larger in plan view and thicker in cross section of plastic material is referred to here as the second plastic part 2, which corresponds to the lower part 2 'in the packaging shown in Figures 6 to 13'. A first plastic part 1 is to be fastened to this second plastic part 2, which is the film part which is generally smaller in plan view and generally thinner in cross section. The packaging according to Figures 6 to 13 is the lid 1 '. These two plastic parts 1 and 2 or cover 1 'of the packaging and its lower part 2' are connected to each other by a first weld 3. This can be straight as in Figures 1 to 3 or curved and straight, as shown in Figures 4 and 6. Parallel to the first weld 3, ie in Distance a runs a second tear line 4. More specifically, the second tear line 4 runs at a distance a parallel to a first tear line 5, which is shown in FIGS. 2 and 15 by a broken line. This first tear line 5 forms at the center 20 of the lid 1 'lying edge of the first weld 3, because when tearing up the tear strip 6 located between the two tear lines 4 and 5, this is automatically cut off next to the first weld 3. For this reason, the first tear line 5 runs in the strip-side edge of the first weld 3.

The second tear line 4 can be formed by a separate weakening line 7 in the first plastic part 1 or in the cover 1 ', so that when the tear-off strip 6 is pulled up, it is torn off along the second tear line 4, as shown by the dashed line in FIG. 15 or is also shown in Figures 3 and 13. The second tear line 4 can also be formed by a second weld 8, which is located in a so-called second section 9. On the other hand, there is only one in the first section 10, namely the second tear line 4, which therefore begins at the end of the second section 9 and ends at the beginning of the second section 9. In the embodiment of FIG. 4, the lower straight piece which adjoins it at the top within the double line without cross hatching is this first area 10, which is continued upward behind the bent area on the right into the second section 9 with the cross hatching. It is understood that the sharp tear edge next to the inner second weld 8 as well as on the strip-side edge there forms the first tear line 5 here, the second tear line 4 in the second weld.

If one looks at the packaging shown in FIGS. 6 to 13, one recognizes in particular to the above in general Fastening device described additionally the upper edge 11 of the lower part 2 ', which deteriorates in all enlarged sectional views in Figures 8 to 13.

In the embodiment of Figure 6, the lid 2 'is approximately rectangular in plan view with rounded corners. It has three straight edges 12 and a straight edge 12 ', which is on the left in Figure 6 and tears open the second section 9. In this section, i.e. along this particular straight edge 12 'of the four straight edges of the lid 2' are both welds 3 and 8 at a distance from each other that here in this second section 9, the hinge for the lid 1 'is formed. In FIG. 6, the grip tab 14, the upper end of which is called the first end 15, is arranged at the bottom left in the tear direction of the arrows 13. From this end 15 upwards in the direction of the left arrows 13, i.e. in the tear-open direction, the first weld 3 extends over the entire second section 9 then above the first curve to the right into the next straight side edge 12, at the top right again down into the next straight side edge 12 and at the bottom right in a clockwise direction along the curved arrow 13 in the lower straight edge 12, so that there is an extension all around the outer edge of the lid 1 'to the other second end 16 of the handle tab 14. This second end 16 is located in Figure 6 bottom left of the handle tab 14, ie with respect to the handle tab 14 opposite the first end 15 thereof. Here at this second end 16 of the grip tab 14, the first weld seam 3 opens into a welding tack 17. It can be seen from FIG. 6 how the welding tack 17 extends over the distance a from the outside in, i.e. creates the connection between the first weld 3 with the second weld 8.

What is important for the opening process is the beginning of the second tear line 4, which is shown on the inside in FIG. 6 with the dashed line is reproduced and results in the second section 9 on the strip-side edge of the second weld 8. This edge begins at said second end 16 of the grip tab 14 and runs upward from here in the illustration in FIG. 6 on the left side of the welded joint 17, always on the left edge of the second weld 8 to the upper end 18 of the second section 9 , That is to the end 18 of the second weld 8, which then passes without interruption into the second tear line 4 above and continues in the manner described, until after a round trip along the three side edges 12 of the lid 1 ', the welding tack 17 is reached at the bottom left where the second tear line 4 ends.

From the handle tab 14 bottom left in Figure 6 to the upper end 18 of the second section 9 or the end of the certain straight edge 12 'of the lid 1' extends from the outside inward channel between the two welds 3 and 8, the in practice after welding or welding the cover 1 'to the upper edge 11 of the lower part 2' is closed and even proves to be gastight.

The opening process now takes place in such a way that the user grips the grip tab 14 and tears up the tear-off strip 6 in the direction of the arrow 13. The sectional view along the line VIII-VIII in FIG. 6 then changes from the illustration in FIG. 8 to that in FIG. 9. When the tear-off strip 6 is torn up further, the state in the edge region along the line XX then changes from the closed state in FIG 11 when opened further. The state of FIG. 12 then changes accordingly at line XII-XII of FIG. 6 to that of FIG. 13. The tear-off strip 6 is torn further in a clockwise direction and finally remains at the welding tacking point 17 hang. This forms in the second section 9 along the second weld 8 Hinge, around which the axis of rotation of the lid 1 'can be folded up and can be closed again after the packaging has been completely or partially emptied.

Claims (9)

1. Device for the detachable fastening of a first plastic part (1, 1 ') to a second plastic part (2, 2'), both of which (1, 2; 1 ', 2') are connected to each other by a first weld seam (3), A first tear line (5) running parallel to the first weld seam (3), characterized in that at a distance (a) from the first tear line (5) at least along a first section (10) of the same (5) a second tear line (5) 4) so arranged in the first plastic part (1, 1 ') that a tear strip (6) can be formed between the two tear lines (4, 5). 2. Device according to claim 1, characterized in that the first tear line (5) on the strip-side edge of the first weld seam (3) and the second tear line (4) at least along a first portion (10) of the first tear line (5) through a separate line of weakness (7) is formed in the first plastic part (1). 3. Device according to claim 1 or 2, characterized in that the second tear line (4) along a second section (9) of the first tear line (5) is formed by a second weld seam (8), which approximately in extension of the second tear line ( 4) runs. 4. Use of the device according to one of claims 1 to 3 for fastening a plastic cover (1 ') on a package in which at least the upper edge (11) consists of plastic material which can be welded to the plastic material of the cover (1'). 5. Packaging for liquid and / or solid contents, consisting consisting of a shell-shaped lower part (2 ') and a cover (1'), the cover (1 ') and at least the upper edge (11) of the lower part (2') being made of plastic material, characterized in that a first weld seam (3rd ) is attached approximately along the upper edge (11) of the lower part (2 ') between the edge (11) and the cover (1') and that for the formation of a tear-off strip (6) towards the center (20) of the cover (1 ' ) towards / at a distance (a) to the first weld (3) a line of weakness (7, 4) and / or a second weld (8) is / are arranged around the entire upper edge (11) of the lower part (2 ') is / are provided. 6. Packaging according to claim 5, characterized in that the first tear line (5) on the strip-side edge of the first weld seam (3) and the second tear line (4) along a first portion (10) of the first tear line (5) by a separate line of weakness (7) in the cover (1) and along a second section (9) of the first tear line (5) is formed by the second weld (8). 7. Packaging according to claim 5 or 6, characterized in that the tear-off strip (6) via a welding tack (17) with the upper edge (11) of the lower part (2 ') is connected and that this welding tack (17) preferably the first weld (3) connects to the second weld (8). 8. Packaging according to one of claims 5 to 7, characterized in that the first weld (3) next to the welding tacking point (17) for the tear strip (6) is interrupted along a grip tab (14), the length of which is 0.5 to 3 cm , preferably 1 to 2 cm. 9. Packaging according to one of claims 5 to 8, characterized in that the lid (1 ') in plan view approximately is square and along a certain (12 ') of the four straight edges of the cover (1') both weld seams (3, 8) at a distance (a) from one another such that the first weld seam (3) from a first end (15) of the grip tab (14) all the way to its other, second end (16), and that the second tear line (4) extends from the second end (16) of the grip tab (14) to the opposite end (18) of the particular straight edge ( 12 ') of the cover (1') on the strip side along the second weld seam (8) running there and then along the other three edges (12) all around in one piece up to the welding tacking point (17) for the tear-off strip (6).

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