EP0052261B1 - Container for flowable materials with a reclosable opening device - Google Patents

Abstract

Two-piece containers having a one-piece tubular body and base and a cover molded onto the body are formed from a continuous web of thermoplastic supporting material by means of an apparatus which includes tube forming, cover molding, container filling and container base sealing stations. The web of material is initially formed into a strand of partially assembled tubular container bodies having fold impressions for the base and then severed into separate tubular bodies for further processing, filling and sealing.

Description

The invention relates to a package for flowable fillings with a tube formed by at least one longitudinal seal seam, at the ends of which bottom and lid are attached, of which the lid is made of thermoplastic material without carrier material, is injection-molded along its outer edge on the tube and one towards the inside Has the outer contour of the folded pouring device, the tube made of at least one side coated with thermoplastic plastic carrier material, for. B. cardboard, and the bottom is square.

The type of pack that has currently become the most popular for the transport of liquids, particularly milk and fruit juices, is a parallelepipedic pack, which consists of a tube made of a plastic material coated on both sides, which is closed at the ends by cross-sealing ribs in the area of the end walls and is brought into a parallelepiped shape, so that there are two opposite, double-walled triangular flaps on each end wall, which first protrude outwards from the end walls of the pack and are finally folded over against adjacent side walls or the end walls of the pack.

Many such packs are also used for powdery and granular contents. In some known packs, the pouring opening is formed by punching perforation lines or other lines of weakness in the outer pack layer, which are torn off after the corresponding triangular flap has been unfolded. Also known is an opening which has already been punched out of the packing material and is covered in a liquid-tight manner by a strip. The cover strip is grasped and pulled up via a free grip section which is not fastened to the side wall, and the tear-open opening arranged on the inside of the triangular tab is then exposed in the form of a round or elongated hole. In a disadvantageous manner, the pouring in this known package does not take place in the desired jet in order to avoid the filling material being spilled.

In another type of pack, attempts have been made to provide a rectangular slot, covered by a sealing strip, as a pouring opening, which is located on one side of the end wall next to the transverse sealing seam. Sealing a cover strip is generally associated with problems of tightness on the one hand and easy tearing off on the other hand. Similar problems also exist if the pouring opening previously punched out and then closed with the cover strip is arranged in the upper wall of the triangular tab. Various different opening devices have therefore been developed, solely in the field of parallelepipedic packs, in which the transverse sealing seam closing the end wall is partially broken open or in which tear aids such as e.g. welded threads can be used.

The manufacturers of superplasticizer packs, in particular since the price of petroleum has become more expensive, use as little plastic as possible, especially as a coating for the carrier material, and make the packaging machine as simple as possible, preferably without using one from the inside and possibly even cover strips to be sealed separately from the outside. Compromises had to be made again and again between the reliability of the sealing on the one hand and the easy opening on the other.

In contrast, from DE-OS 2210013 a liquid pack is known, in which the side walls are also made of thermoplastic-coated and very stable, thick cardboard, whereas the lid and base are made of thermoplastic material without a carrier material. When ready for filling, this pack is designed such that the lid is injection molded along its four edges, but the bottom is only molded onto the side walls along one edge to fill the pack. Such a pack is still relatively expensive because the structure is very strong and heavy.

The package known from the publication mentioned is, so to speak, upside down for filling; because the one-piece lid provided with the opening device is initially arranged at the bottom, while the base, which is only molded on along its one side edge, is arranged at the top with the tube of the ready-to-fill pack open next to it. In the manufacture of such an opening device, either complicated injection molds with a tool head for injecting both thermoplastic end walls are required, or two tool heads, one for the lid and one for the bottom, are required. If you only use one spray head, you need long and warm connecting flow channels, and the tool is space-consuming. Higher closing pressures are also required on the colder side. With two spray heads, the manufacturing costs are obviously high.

After filling, the well-known package is closed on its bottom. Difficulties in the centering and exactly liquid-tight welding can sometimes arise here, or at least the mechanical engineering effort is also not insignificant when closing the end wall forming the base.

The invention is therefore based on the object of creating a pack of the type specified in the introduction, in which an optimal saving of material and a stable pack with good sealing properties can be produced using thinner cartons, which can be easily opened and closed by the end user without special instructions. The aim of the invention is also to provide a method for producing such a package and an apparatus for carrying out this method.

To solve this problem, the new package according to the invention is characterized in that the bottom of the folded tube of the package is designed as a folding closure and has a transverse sealing seam with triangular flaps folded over onto an adjacent wall and that the lid and the cross section of the package are at least in the area of the lid are round. For the first time, a plasticizer pack is created here, in which a previously unusual combination of completely different closure walls is used on the end walls. In contrast to the known package described last, only the end wall forming the lid should consist of pure thermoplastic material; the floor, on the other hand, should be closed by a transverse sealing seam, as in the conventional packs, and formed in a manner known per se by folding the triangular tabs into one of the usual flat end wall designs, the opening of which has repeatedly been difficult in the past.

This combination of the two completely different bulkhead manufacturing systems is by no means obvious, especially since there are no manufacturing machines that promise to solve the above-mentioned problem when using such a principle.

With the new principle according to the invention, which create a front wall as a purely plastic cover and the base in the classic square shape, it is possible to produce flux packs in the form of cubes, cuboids or other designs. For example, it is expedient according to the invention if the shape of the cover is the use form during and immediately after the spraying process. This means that the lid, which is only made of thermoplastic, is injection molded in the shape of its use. So of course he has the spraying process and also up to the next processing stage, which e.g. includes deforming the lid, the form of use, d. H. the form in which the end user opens the pack, pours out the contents and, if necessary, closes the pack again. The advantage of this measure lies in the fact that, as a rule, thermoplastic plastic tends to return to its production mold after it has been deformed. In contrast to this, in the known packs, for example, end walls forming the lid with an opening device are injection molded in such a way that the form of transport results immediately. Then, after filling and closing, the package can be immediately transferred to a collecting container and handed over to the transport. However, it has been shown, and particularly in the case of packs in the household, that opening a lid which has been sprayed in this way is difficult. It is much easier and more pleasant for the housewife, for example, if she deforms an opening device from a deformed design into the production injection mold by pulling or pressing. In the present case, the lid molded onto the side walls is folded in immediately before and then after filling and during transport with respect to its opening device such that the outer contour is not disturbed by protruding parts of the opening device. Therefore, the end user has to pull out the opening device in the lid before use, and this process is considerably facilitated because the thermoplastic tends to return to the manufacturing mold anyway.

The round cover and the round design of the cross-section of the pack in the area of the cover make it possible to produce particularly simple tools, and yet the pack equipped in this way still has the advantages of stability, good use of space, combination in collecting containers and tightness.

It is also advantageous according to the invention if the pouring device has a ring collar which projects upwards outwards, the upper edge of which is connected to a sealing plug with a welded-on gripping ring and lies within the outer contour of the package for transport. The gripping ring also protrudes somewhat from the sealing plug in the manufacturing spray design, so that the user can easily grasp it, use it to pull the pouring device up into the use form and open the opening by tearing off the sealing plug along the upper edge of the ring collar. Before opening, the gripping ring preferably protrudes laterally by 180 ° against the sealing plug.

In the case of a special packaging form, it may be expedient if at the connection point of the gripping ring on the sealing plug, a bulge protruding from the ring collar is formed in the latter and the hinge is formed on the diametrically opposite side of the sealing plug. The bulge allows a first small air inlet opening to be formed when the gripping ring is torn up and after reaching the shape of use, whereby the opening, i.e. tearing off the sealing plug along the upper edge of the ring collar is facilitated. On one side of the upper edge of the ring collar there is the weakening for tearing and for the formation of the air inflow opening, while diametrically on the opposite side there is a thickening that does not allow the sealing plug to be completely torn off even when carelessly tearing up, so that it closes the thickening or reinforcement sticks and is articulated around a hinge.

Further advantageous refinements of the pack according to the invention are given in claims 3 to 6.

In the process for producing the pack, the coated carrier material is first pre-grooved, fed to bending and folding stations by a roll in the form of a web, and pulled against an outer ring under tension to produce a tube. Only then is the tube closed by longitudinal sealing. There are already some development proposals to create a tube, which will later be closed by longitudinal sealing, in such a way that a pre-embossed material web, after being cut accordingly, is passed through an outer ring with such tension that it is formed, so that this tube can be passed through puts the material web on the ring and thus gets a circular cross-section. If one uses these development suggestions to solve the problem according to the invention, then the tube is expediently drawn onto a calibration mandrel. According to the invention, the longitudinal sealing takes place between the latter and the outer jaws. In each case, a section length of the tube is withdrawn from the calibration mandrel in cycles, transferred to an injection mold lower part and moved to the side out of the feed direction into position relative to an injection mold upper part. The round lid is injected and cooled while being connected to the end of the tube section. This tube section, which is closed on one side, is then pulled off the lower part of the injection mold. After the lid has finally been pressed into the transport shape, the pack is closed after filling by welding the block bottom to the bottom.

While according to the older proposals the path to form the tube is drawn from the inside against an outer ring and thereby brought into the shape of a circle in cross-section, the above features additionally provide for the tube thus formed to be drawn onto a calibration mandrel. Due to the special type of the new packing with the two different types of closures on the end walls of the respective tube section (corresponding to a packing), the filling takes place later, so that the space in the tube is available for the calibration mandrel. The longitudinal seal seam is created in batches between the calibration mandrel and one or more outer jaws, so that the tube to be sealed lengthways is arranged between the mandrel and the jaws. For further processing, including for separating the tube from the web into the respective section lengths, the tube is pulled off the calibration mandrel and transferred to another mandrel, which is simultaneously designed as an injection tool. To increase the processing speed, the section length of the tube is moved out of the feed direction and into the injection molding machine, where the end wall forming the lid is molded onto the still open edge of the tube section. This spraying technique is mastered in technology, and in this way a good adhesion between the thermoplastic plastic of the cover and the side walls coated with plastic and thus a perfect seal are guaranteed. The freshly sprayed lid, which is in the shape of the use form, is now cooled, after which the tube section is pulled off the lower part of the injection mold. This is preferably done via a transport conveyor in such a position that after the tube section has been pulled down from the lower part of the injection mold and when the now cooled cover is placed on the conveyor, the cover is immediately pressed into its transport configuration. In other words, after being pressed in, the opening devices, which are integrally molded and molded together with the lid, no longer protrude from the entire outer contour of the package. At the same time, the new package is closed on the lid and standing with the lid on the conveyor, i.e. upside down, so to speak, with an open bottom for further conveying, filling and subsequent closing. This closing takes place by the welding known per se along the transverse sealing seam in the manner of the block bottom welding to form the end wall forming the bottom.

The advantage of the method according to the invention over the production of the known package with the two end walls, which consist only of thermoplastic, is that it is easier to close after filling. While in the known case the welding of the three free edges of the end wall forming the bottom is difficult because, among other things, the machine elements have to grasp the package precisely and the individual tools have to be manufactured and moved very precisely, and furthermore the space inside the package above the filling level is very scarce, in order to ensure the correct engagement for the machine elements and welding jaws and still too much air space must remain in this area of the pack next to the filling material, the measures according to the invention result in significantly better conditions and premises. Although the liquid level or the upper level of the filled bulk material can be brought up to a desired upper edge, the fluid level is far enough away from the welding point that with certainty no filling material gets between the tools or the surfaces to be welded when cross-sealing. In accordance with the block bottom shape, the sides are folded together at the relevant edge of the tube without touching the filling material, so that the weld seam can be easily applied after folding. After this transverse sealing seam has cooled, the triangular flaps are then folded over in a known manner and onto an adjacent wall, preferably the end wall itself, which forms the bottom, welded on. It goes without saying that in order to carry out the block bottom molding and then the block bottom welding, the cross section of the packing in the region of this end wall which later forms the bottom must be square.

On the other hand, as mentioned above in connection with the description of the package itself, it is very advantageous to round-shape the end wall which later forms the lid and the adjacent cross-section of the tube. If, for example, the larger part of the tube cross-section is round in the direction of the longitudinal sealing seam or in the direction of the tube, a maximum filling volume, based on the packaging material used, can be achieved. In addition, the stability is the best, so that even in comparison to the known parallelepipedic packs, the thickness of the carrier material and / or the thickness of the plastic coating of this carrier material web are reduced without the stability being affected.

The invention is advantageously further developed in that the axis of the tube is provided in the conveying direction. Although it is entirely conceivable and in practice even customary to arrange the axis of the tube transversely to the conveying direction, the production of the package according to the new method according to the invention allows a higher production speed and fewer relative movements of the individual tube sections from one work station to the next when the tube axis is in the conveying direction. Experiments with the device according to the invention have particular advantages in that the paper web rolled up on the reel is pre-embossed with such a width that two or even three pack blanks could be produced next to one another if only two or three devices for carrying out the method described above be arranged side by side. However, this is easily possible and even expedient, while working from a paper roll or web wrap, because this web is pulled through roller-shaped separating knives, so that each of the two or three manufacturing devices arranged next to one another is fed with a web with the appropriate package cutting width . In this way, a machine having two of the devices described below arranged side by side can have an output of, for example, 3600 packs per hour.

According to the invention, the device for carrying out the method described above is characterized in that in alignment with and coaxial with an outer form ring, a calibration mandrel is attached, next to which a longitudinal sealing jaw is movably provided, that at least one transport jaw oscillates cyclically in the conveying direction behind it and a cutting device is arranged behind the calibration mandrel, next to which a rotatable mandrel wheel with at least three radially protruding mandrel-shaped injection mold lower parts is provided, an injection device with an injection mold upper part is arranged at an angular distance from the axis of the calibration mandrel, and a conveyor with spaced-apart, open-top conveyors is arranged under the mandrel wheel Mold drivers, a filling and a closing station are provided, the mold driver having at least two parts which can be moved relative to one another, which in the moved-together state at least in the region specify a round cross-section at one lower end and a square cross-section at the other upper end. The device constructed in this way can be set up in a relatively narrow space; because all embossing, cutting and longitudinal sealing stations can be arranged in front of or behind deflection rollers, so that the calibration mandrel in the desired position, e.g. arranged at an inclination of 45 ° to the horizontal, next to the mandrel wheel and yet can be fed in the desired conveying direction without difficulty. In an expedient embodiment of the invention, one or two pairs of rollers in the form of circular knives are provided between the web roll and the calibration mandrel for separating the web into two or three partial webs, so that during continuous or pushing. operation, the web pulled off the winding is continuously separated into the correct width. Further folding stations can optionally be arranged behind these circular knives, for example in order to impress package edges.

So far, there has been no talk about the internal protection of the longitudinal seal seam. The relevant station can also be arranged in front of one, possibly the last deflecting roller in front of the calibration mandrel. In this station, a sealing strip is placed on the inside of the. coated paper web placed in the area of the later longitudinal sealing seam, so that an uncoated surface due to the cut on the side edge of the web does not come to lie opposite the filling material, in particular the liquid. Otherwise the liquid could penetrate the cut edge, which is not protected by plastic, and soften the package there. For this reason, cover strips or sealing strips have been provided for the cut edge so that these are also coated with plastic and the difficulties mentioned above are avoided. After this station, the coated paper web treated in this way is expediently guided through a deflection roller in such a way that the finished paper web can be fed into alignment with the calibration mandrel described and also coaxially with the outer form ring.

Because in the preferred embodiment of the packaging manufacturing machine the individual processing operations are carried out batchwise and consequently the paper web and thus the tube are also conveyed batchwise or intermittently, one or two longitudinal sealing jaws are movable arranged. The longitudinal seam is sealed with the aid of this from the outside or this from the outside acting longitudinal sealing jaws on the calibration or form mandrel.

Sealing the cut edge, the so-called LS protection, can not only be done by applying a corresponding cover strip, as described above, but can also be done later on the mandrel wheel, namely when the end wall that later forms the cover is molded on. So that the correct welding of the longitudinal seam and the correctly positioned further processing can be carried out, an annular stop is provided on a mandrel-shaped injection mold lower part, against which the tube section is pushed when the longitudinal sealing seam is finished when it is pushed down from the calibration mandrel and transferred to the mandrel-shaped injection mold lower part. This pushing in takes place by means of transport jaws arranged behind the longitudinal sealing jaw in the conveying direction, one or more transport jaws being able to be provided here, which oscillate in cycles.

It is expedient according to the invention if the conveying device has two transport jaws arranged diametrically opposite one another outside the hollow-shaped calibration mandrel and an inner part which can be moved in the middle therebetween in a longitudinal slot of the calibration mandrel. In this way there is no disadvantageous trace of friction on the outer surface of the packing wall, preferably the side wall, namely by traces of transport jaws on the side wall, because it is not this friction that causes the tube section to move forward, but a clamping effect.

A cutting device is arranged behind the calibrating mandrel — when looking in the conveying direction of the tube — which, in a special embodiment of the invention, preferably has a rotary ring that carries cam-controlled knives and is distributed around the circumference. The packaging machine therefore works in such a way that the longitudinal weld seam is first created on the calibration mandrel, then the tube is moved a section length further towards the mandrel wheel, so that the longitudinal seal seam can cool and harden. During this movement, the next front section length was transferred from the calibration mandrel to the lower part of the injection mold, specifically via a gap in which the cutting device described is arranged. At this point at the latest, of course, the tube must be separated or separated into the individual section lengths, because otherwise the mandrel-shaped injection mold lower part cannot move laterally out of the transport device on the mandrel wheel by rotation.

The rotatable mandrel wheel arranged next to the cutting device has at least three, preferably eight radially protruding, mandrel-shaped injection mold lower parts which are arranged at a corresponding angular distance from one another. The mandrel wheel rotates in cycles, just as the entire device works in cycles. The described tube section length, which is separated by the cutting device, is moved by a certain angular rotation of the mandrel wheel under the injection machine, in particular under the upper part of the injection mold, so that the lower part and the upper part of the injection machine are exactly aligned with one another. In this state, the end wall that later forms the cover can be injected. This spraying work is mastered technically perfectly, and in particular by the if only thin coating of the carrier material web, i. H. of the upper edge of the tube section, the plastic material applied by the injection molding machine adheres well while ensuring an absolutely secure seal between the side wall and the lid of the subsequent pack.

The mandrel wheel and thus the tube section under consideration continues to move intermittently until the conveyor, which is preferably arranged horizontally under the mandrel wheel, is reached. This can be one of the known chain conveyors, which offers sufficient rigidity and resistance so that the stop described above, ie the ring that is movable relative to the mandrel-shaped injection mold lower parts, can strip off the tube section under consideration with the meanwhile hardened lid and place it down so firmly, that all parts protruding beyond the end line perpendicular to the tube axis at the end of the tube, in particular the opening device on the cover, are pushed in in the transport configuration. After stripping, the scraper ring, which was also a stop, moves on the mandrel-shaped injection mold lower part during the next intermittent rotation in the direction of the center of the mandrel wheel in order to stop the next tube section as a stop once the angular position described above has been reached. In the meantime, the package, which is initially still upside down, is placed with the lid on the conveyor and with the bottom open at the top by the conveyor, for example the so-called station chains, under a piston filler or the like, in which the package is filled with the filling material. For stabilization and at the same time for forming or creating the prerequisites for the subsequent block bottom molding, there are mold drivers on the conveyor, which are preferably open at the top and, in a further other preferred embodiment, have at least two parts which can be moved relative to one another and which, according to the invention, at least in the retracted state specify a round cross section in the area of one lower end and a square cross section at the other upper end. In this way, the prerequisites for block bottom forming and then block bottom welding are specified. These form drivers are expediently attached to the conveyor at a distance from one another in such a way that they move with it and are always flush with it the mandrel-shaped injection mold lower parts for taking over the tube section which is closed on one side. In addition, these form drivers, together with the packages that are then open at the top, are in alignment under the filling station and, accordingly, later under the various stations for closing the end wall that will later form the bottom, preparing the triangular tabs for fitting, heating the triangular tabs and under the corner pressure stamp.

An expedient embodiment of the device has a cycle of two seconds and eight mandrel-shaped injection mold lower parts evenly distributed on the circumference of the mandrel wheel. In this special and preferred device, the axis of the calibration mandrel is inclined at 45 ° to the horizontal, the longitudinal axis of the injection mold is at an angular distance of 45 ° to the calibration mandrel such that the lower and upper injection mold parts are arranged approximately vertically under the injection machine, and after Leaving the injection molding machine, the freshly sprayed cover has a time of 3 work cycles from its next position, which is rotated 45 ° out of the injection molding machine, to the stripping position and transfer of the tube section into the mold driver open at the top. H. 3 x 2 seconds, for cooling the lid a total of 6 seconds.

Since individual parts of the device described above are known per se, it is possible to create the device for carrying out the method according to the invention with the know-how of the relevant industry without undue effort. Even in known systems, such a device can therefore be set up relatively quickly after appropriate conversion. Different units form the device as a whole, so that by exchanging one unit for a corresponding other, the overall device is highly adaptable, e.g. to different shapes of desired packs, round, square, rectangular pack cross sections and the like. The device works perfectly with thinner paper to create a pack of the same stiffness. The paper web, i.e. the backing material only needs to be provided with a thinner plastic layer, and the longitudinal welding and also the application of the transverse sealing seam are nevertheless perfectly guaranteed; because it is a dry weld when welding the bottom of the block. The simple processing and the small number of structural units in the device is further favored by the pre-stamping of the material web to be processed during its manufacture. Due to the thinner plastic coating of the carrier material web, a higher extruder running speed is advantageously possible. You can draw on many years of experience in material production.

• Fig. 1 perspektivisch die verschlossene, gebrauchsfertige Packung einer bevorzugten Ausführungsform der Erfindung,
• Fig. 2 ebenfalls perspektivisch die gleiche Pakkung, jedoch mit dem Boden nach oben, wobei der hier unten angeordnete und nicht sichtbare Dekkel so eingedrückt ist, dass keinerlei Teile der Öffnungsvorrichtung über die untere Kante des Deckels über die Gesamtkontur der Packung herausstehen,
• Fig. 3 eine perspektivische Ansicht des Bodens nach der Klotzbodenfaltung und vor dem Fertigstellen der Quersiegelnaht,
• Fig. 4 die mit den Prägelinien für das Klotzbodenformen versehene obere Ende der Packung, an dem später durch das Klotzbodenfalten der Boden gebildet wird,
• Fig. 5 schematisch eine Querschnittsansicht desjenigen Zustandes des Deckels in der Transportform, bei welchem keine Teile der Öffnungsvorrichtung über die Gesamtkontur der Packung überstehen,
• Fig. 6 eine Schnittansicht durch den fertig gespritzten Deckel, allerdings ohne Seitenwandungen,
• Fig. 7 im Schnitt Spritzwerkzeugober- und -unterteil der nicht dargestellten Spritzmaschine bei abgebrochen dargestellter Packung und
• Fig. 8 schematisch den Gesamtaufbau der Vorrichtung zur Herstellung der erfindungsgemässen Packung.

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

• 1 is a perspective view of the closed, ready-to-use pack of a preferred embodiment of the invention,
• 2 likewise in perspective the same package, but with the bottom facing upwards, the cover arranged here and not visible being pressed in so that no parts of the opening device protrude beyond the lower edge of the lid over the overall contour of the package,
• 3 is a perspective view of the bottom after the block bottom folding and before the completion of the transverse sealing seam,
• 4 the upper end of the pack provided with the embossing lines for the block bottom molding, at which the bottom is later formed by the block bottom folding,
• 5 schematically shows a cross-sectional view of the state of the cover in the transport form in which no parts of the opening device protrude beyond the overall contour of the package,
• 6 is a sectional view through the finished molded cover, but without side walls,
• Fig. 7 in section injection mold upper and lower part of the injection machine, not shown, with the pack shown broken off and
• 8 schematically shows the overall structure of the device for producing the pack according to the invention.

The package is first described with reference to FIGS. 1 to 6, then the device for producing the package with reference to FIGS. 7 and 8 and finally a possible mode of operation of the device.

The finished pack for flowable filling goods shown in FIGS. 1 and 2 consists of a total of 1 side walls, because in the embodiment shown here a round cross-section is provided in the area of the cover 2 (because the cover 2 is circular in plan view), so that one could differentiate between four side walls at most on the end wall side forming the base 3. For the sake of simplicity, the side walls 1 are referred to in the present description. These are shaped into a tube as shown in FIGS. 1 to 4 and connected along the longitudinal sealing seam 4 for the final formation of the closed tube. 2 that the longitudinal sealing seam 4 extends into the bottom 3. This results from the cutting, as can also be seen in FIG. 4. This tube has the height H in the form of FIG. 2, which, taking into account the shaping shown in FIG. 4, is evidently smaller than the section length A from the free upper edge 5 of the tube to the upper edge 6 of the cover 2 before completion of the base 3 .

The upper edge of the finished package results from the line labeled 7, which is shown in FIGS. 2 to 4. Due to the different folding not shown and shown in Fig. 4 or embossing lines, the double cardboard strip 8 (FIG. 3) is formed when the block bottom is formed, in which the transverse sealing seam 9 which is barely visible in FIG. 2 is located. The triangular lobes 10 are also formed here. The floor 3 is created from the state of FIG. 4 via that of FIG. 3 to that of FIG. 2. First, the corners, the later tips of the triangular lobes 10, in the direction of the arrows 11 (FIG. 4) in the direction shown moved outwards and pulled until the state of FIG. 3 is reached. Then the double cardboard strip 8 is pressed together, the transverse sealing seam 9 is applied, the triangular flaps 10 are folded onto the floor and attached there, for example by point-like heating, so that the state of FIG. 2 is then reached.

This closing on the side of the bottom 3 occurs after the pack has been filled, as will be described below. In other words, the lid 2 is already sealed liquid-tight on the lower side of the pack in FIGS. 2 to 4. In contrast to the square bottom 3, the cover 2, which is preferably, but not necessarily, round in the new pack is constructed only from thermoplastic material and without a carrier material. Therefore, the cover can be injection molded along the outer edge 12 of the tube or the side walls 1 shown in FIG. 5, in the form of the use form, as shown in FIG. 1. In contrast, the transport configuration is shown in FIG. 5, in which the pouring device, generally designated 13, is folded inward within the outer contour of the package such that no individual parts of the pouring device 13 protrude beyond the outer edge 6. This ensures perfect stability and good outer packaging (using shrink films or the like).

The pouring device 13 is seated centrally on the lid 2 in the form of an annular collar 14 which stands upwards outwards, as shown in FIG. 1, the upper edge 15 of which is connected to a sealing plug 16 with a welded gripping ring 17.

The exact shape after the cover 2 has been sprayed can be clearly seen from FIG. 6. The top edge 6 of the cover 2 is practically only a ring, on the outside of which a support wedge 18 is molded in such a way that the top of the tube or the side wall 1 is below the edge 12 shown in FIG. 5 comes to lie around this support wedge 18. This provides a particularly strong and rigid connection between cover 2 and side wall 1. Between the outer edge of the lid and the annular collar 14 is a truncated cone surface 20, which in the state of Figs. 1 and 6, i.e. in the use form, protrudes outwards and inwards at approximately the same angle in the transport form according to FIG. 5. At the top of the edge 15 of the ring collar 14, apart from the point designated 21 on the right in FIG. 6, a weakening line 22 is arranged in a ring, which forms an almost 360 ° weak point around the sealing plug 16 so that it can be easily torn out to open the package . In addition to the point designated 22 on the left in FIG. 6 on the weakening line, there is the connection point 23 (FIG. 1) of the gripping ring 17, next to which a bulge 24 projecting inward from the ring collar 14 toward the center is provided such that the wall of this bulge 24 extends inwards according to FIG. 6 and is separated from the surroundings only by the weakening line 22. If the user then tears open the weakening line 22 by tearing the gripping ring 17 (according to FIG. 6 upwards), then this breaks first in the region of the bulge 24, so that air can advantageously get into the space under the cover 2.

6 on the right-hand side of the closure plug 16, the hinge 25 for the closure plug 16 is formed in the vicinity of the location designated 21 diametrically opposite the bulge 24. The hinge 25 can therefore, according to FIG. 6, around the hinge 25 moved clockwise, ie be rotated in the opening direction without the sealing plug 16 tearing off immediately. This enables advantageous resealability, especially since the sealing plug 16 has an edge 26 which runs approximately parallel to the annular collar 14 and is only closed by the flat bottom 27.

The device for producing this pack has in detail a spraying machine 30 shown in FIG. 8, the upper part 31 and lower part 32 of which are enlarged and shown in section in FIG. With the understanding of the cover 2 according to FIG. 6, the embodiment of FIG. 7 is easier to understand. The exact contour of the two facing surfaces of the upper and lower parts 31, 32 results from machining in accordance with the design of the cover 2, so that it is sufficient to mention a few parts here: for example the funnel 33 for injecting plastic into the cavity , the holder 34 for the die 35 and the calibration and sealing pieces 36 for sealing the plastic, preferably polyethylene, against lateral squeezing out past the mandrel-shaped lower part 32 of the injection mold. It is already clear from the illustration in FIG. 7 that an injection mold lower part 32 of one length can be replaced by one of a different length without the cover 2 having a different design and the rest of the injection molding machine having different parts.

The entire device for producing the package described above can best be explained with reference to FIG. 8. On a frame 40, on the left is the winding 41 of the carrier material web 42, which is thinly coated on both sides with plastic, preferably polyethylene, and is rotatably supported here on the bearings 43. On the upper right half, an endless conveyor 44 is shown schematically, which is provided with drives in a manner known per se and can be a station chain conveyor. The upper and lower runs of the conveyor 44 are horizontal and at a distance to the right of the paper roll 41. A holder 45 is attached at a distance above the frame 40, on which knives in the form of circular knives 46 are rotatably mounted on the left-hand side, with which the webs of the carrier material 42 can be separated. 47 is a pre-bending station for creating packaging edges, behind which a first deflection roller 48 is arranged, above which a second deflection roller 49 is located. In between is schematically shown a sealing jaw 50 with a counterpart, which is not described in any more detail, with the aid of which a plastic strip 52 pulled off a roll 51 is sealed along the cut edge for LS protection so that a direct contact edge between paper and liquid is not possible there when packaging liquids is.

Between the last-mentioned LS sealing station 50-52 and the injection molding machine 30 fastened to the right on the holder 45, the tube forming station 53 is attached, which will be described in more detail below. An essential element here is the calibration mandrel 54, which is covered by the tube shown here and which is designated 54 at the location of its arrangement under the tube. The axis of this calibration mandrel 54 is below 45 ° to the horizontal. In its extension downward and to the right, the mandrel wheel, generally designated 55, with the eight mandrel-shaped injection mold lower parts 32 is arranged. Furthermore, to the right of the mandrel wheel 55, the piston filler 56 is arranged on the holder 45, and furthermore, to the right, only schematically the block bottom welding station designated 57.

Finally, on the upper run of the conveyor 44, a mold driver 58 is shown schematically only at two points, which is attached to the conveyor 44 at a distance a from the respectively adjacent mold driver and is advanced with it in the direction of arrow 59 under the block bottom welding or closing station 57.

The tube forming station 53 consists in detail of a holder 60, likewise arranged at 45 ° to the horizontal, to which the shaping or calibration mandrel 54 is fastened via the mandrel curvature part 61. The coated paper web 42 in the form of a shell which is open at the bottom is placed around this curvature part 61 on the right below the deflection roller 49. The lower right end of this shell rests under tension within the outer ring 62, which is also attached coaxially to the calibration mandrel 54. In the direction of transport, which is to be thought here from the deflection roller 49 at 45 ° downward to the right toward the mandrel wheel 55, a longitudinal sealing jaw 63 is provided behind the outer ring 62 and a transport jaw 64 is spaced further behind. The latter oscillates with the cycle of the entire device in accordance with the double arrow 65. The calibration mandrel 54 extends a section length A further in the conveying direction, namely up to the cutting device 66, which is indicated schematically here in the form of two knives, but actually a circular knife with one inside counter knife to exercise a scissor effect.

From a functional point of view, the mandrel wheel 55 is connected downstream of the tube forming station 53. It is in the direction of the arrow shown, i.e. clockwise, rotatable about the central axis, in cycles, i.e. intermittently, one cycle at a time moving a mandrel-shaped injection mold lower part 32 by 45 ° in the clockwise direction. Each lower part 32 carries an annular stop 70 which is driven in an oscillating manner in the axial direction of the mandrel-shaped injection mold lower part 32 in order to exert a scraper effect. In the lowest position, designated 111, the stop or scraper ring 70 is in its lowest position.

In the plumb line above position 111, i.e. H. in the position designated by 11, the respective injection mold lower part 32 stands vertically under the injection machine 30, as in the arrangement according to FIG. 7. The injection mold upper part 31 can move vertically up and down with one stroke (so that it releases the freshly sprayed one Lid 2 can be lifted from the respective lower part 32), which is greater than the oscillation stroke of the injection cylinder 80 with dosing plunger 81 and granulate container 82. A more detailed description of the spraying machine 30 appears to be as unnecessary here as the closing station 57 with the device 90 for closing the bottom side, the device 91 for preparing the triangular tabs 10 for contacting the bottom 3, the device 92 for heating the triangular tabs 10 and the device 93 with the pressure stamps for the triangular lobes 10. The package shown on the upper run of the conveyor 44 is, so to speak, upside down; because the cover 2 can be seen below, while the end wall which later forms the bottom 3 is located above. For this reason, after the filled and closed package has been removed, the package is turned in the direction of arrow 59 so that the top side comes up.

The machine is operated in such a way that the paper web 42 is separated, for example by the roller knives 46, into three separate webs lying next to one another, each of which is fed to the same device as shown overall in FIG. 8. To understand the operation and method according to the invention, however, the description of the functioning of a machine is sufficient. The paper web 42 is pre-bent by the device 47 into the edges which have not yet been pre-embossed, then deflected by the roller 48 and guided into the edge protection station 50, where the plastic strip 52 pulled off the roller 51 is pulled off the plastic edge on the edge 42 of the web 42 is sealed with the help of the sealing jaw 50. The paper web prepared in this way is deflected via the deflection roller 49 to the bottom right so that the direction of transport now points from the upper outer circumference of the deflection roller 49 through the axis of the calibration mandrel 54 to the center of the mandrel wheel 55. By the train tension, which is generated by the transport jaws 64, the paper web 42 initially lies like a shell open at the bottom in a semicircle around the mandrel extension 41, in order then to completely enclose the calibration mandrel 54 with the inner ring against the outer ring 62. This enclosing provides the tube shape and takes place in such a way that the two free edges of the tube overlap to a certain extent, so that the longitudinal sealing seam 4 can be applied at this overlap point with the aid of the sealing jaws 63. During this sealing process, the tube section with the length A is stationary. After the sealing jaw 63 has been opened, the transport jaws 64 pull the next front tube section towards the mandrel wheel 55 by a section length A, as a result of which the tube section under consideration, in which the longitudinal sealing seam has just been completed, comes to the lower right end of the calibration mandrel 54. Here, the cutting device 66 now separates it from that part which has just been pushed onto the mandrel-shaped injection mold lower part 32 as far as the stop 70 by the activity of the transport jaws 64 described last.

At the next cycle, the tube section under consideration is now pushed past by knife device 66 onto mandrel-shaped injection mold lower part 32 in position I. The lower part 32 has a diameter that is approximately 0.5 mm smaller than the calibration mandrel 54.

The mandrel wheel 55 now rotates by one cycle, i.e. 45 ° clockwise so that the tube section under consideration now reaches station II under the spraying machine 30. Now the injection mold upper part 31 moves into the position shown in FIG. 7 while gripping around the upper edge of the tube or the side wall 1. In this way, the cover 2 is molded directly onto the upper edge 12 of the side walls 1. The injection mold upper part 31 or the further injection mandrel 35 then moves off the cover 2, and the mandrel wheel 55 can then move through 180 ° to the position 111, the cover being cooled with the fresh molded part at the same time.

The mandrel wheel 55 is set and synchronized with the other stations 52, 30 and with the form driver 58 in such a way that the individual stations, in particular stations I, 11 and 111, have exactly identical positions between the axes of the opposite parts. In the station 111, the annular stop 70 works as a scraper and pushes the tube section under consideration, which is closed on one end side by the cover 2, downwards in the direction of the conveyor 44, specifically into the form driver 58. This is initially in the embodiment as shown in Fig.1, i.e. with a round lid and square bottom, opened to allow the more protruding or larger area 2 to pass by, and then closes on the smaller square area. When pushed down, the ring 70 presses the lid with the aid of the rigid side wall 1 onto the upper run of the conveyor 44 such that the lid 2 folds into the transport form shown in FIG. 5. This folding in is no problem because the package is still empty.

The station chain conveyor 44 now conveys the package, which is still open at the top and ready to be filled, in the direction of the arrow 59 to the right, one form driver 58 being at a distance a from the next. The pack passes under the filling station 56, which is designed as a piston filler, and is filled up to the upper edge 7. In the device 90, the bottom side of the state of FIG. 4 is closed in that of FIG. 3. In the schematically indicated device 91, after the transverse sealing, the triangular flaps 10 are then prepared for application, heated in the station 92 and attached to the floor 3 by means of pressure stamps so that the shape of FIG. 2 results.

The triangular tabs mentioned can be folded over onto the floor itself or a side wall, depending on the design of the block bottom closure.

On the opposite side, the lid, which is only made of thermoplastic, is arranged, the ring collar of which can be circular, oval, polygonal or the like and stands out on the outside. In the truncated cone shape of the cover shown in the figures, it is expedient if the ring collar is arranged in the center. With other lid shapes, the ring collar can also be arranged laterally near the edge, so that the pouring edge has to be closer to the edge of the lid when pouring.

After the lid has been folded from the manufacturing injection mold into the transport shape, all parts of the opening device, including the welded gripping ring, are preferably located within the outer contour of the package, because this provides an optimal design for transport. The embodiment shown in the figures shows a gripping ring which is inclined at an angle of 30 ° and is molded onto the sealing plug. However, an embodiment which is not shown in the figures and in which the gripping ring is molded around 180 ° is particularly expedient. In other words, the main plane in the gripping ring lies parallel to the outer edge of the pack or parallel to the plane which runs through the edge of the lid. Nevertheless, the grip ring is still in its transport configuration within the outer contour of the pack. The arrangement of the gripping ring in the position rotated by 180 ° out of the sealing plug is expedient because the injection mold for creating the cover can be made simpler in this way.

The above explanations show that the choice of the lid shape can be subjected to certain variations according to the injection mold. For example, the pouring opening could be formed on an accordion or bellows-shaped device. The main thing is the «under-deck form» for transport of the pack or the “cover form” when pouring. The invention provides, in particular for the lid, which is only made of thermoplastic, the possibility of creating many desired opening arrangements and also utilizing the cold deformation possibilities in order to give the lid different shapes, for example the optimal shape for transport on the one hand and the optimal shape for the pouring process on the other hand. In this sense, cold deformation can be understood as pushing the lid into the transport shape or pulling it out into the use form.

Claims (12)

1. A pack for filling materials which are capable of flow, comprising a tube (1) which is formed by at least one longitudinal sealing seam and at the ends of which are disposed a bottom (3) and a cover (2), of which the cover (2) comprises thermoplastic material without a carrier material, is injection moulded on the tube (1) along its outside edge and has a pouring means (13) which is folded inwardly of the outside contour of the pack, wherein the tube (1) comprises carrier material, for example cardboard, which is coated on at least one side with thermoplastic material, and the bottom is quadrangular characterised in that the bottom (3) is formed from the folded-over tube (1) of the pack, in the form of a fold closure, and has a transverse sealing seam (9) with triangular flaps (10) which are folded over on to an adjacent wall (3), and that the cover (2) and the cross-section of the pack at least in the region of the cover (2) are round.

2. A pack according to claim 1 characterised in that the configuration of the cover (2) in and directly after the injection operation is the form of use thereof.

3. A pack according to claim 1 or claim 2 characterised in that the cover (2) has a cover wall (20) which extends taperingly towards the centre and which leaves a central opening, with a cetrally disposed upstanding annular collar (14) with closure (16) secured thereto.

4. A pack according to one of claims 1 to 3 characterised in that the taperingly extending cover wall is a frustoconical surface (20), with a cylindrical edge portion as the annular collar (14).

5. A pack according to one of claims 1 to 4 characterised in that disposed at the outer periphery of the frustoconical surface (20) is a further wedge-shaped support portion (18) in the form of a cylindrical peripheral portion, said support portion (18) being disposed at a position displaced inwardly from the outside edge.

6. A pack according to one of claims 1 to 5 characterised in that the edge (12) of the tube (1), which is towards the cover, is completely covered by the outer edge of the cover (2), which extends outwardly thereover.

7. A pack according to one of claims 1 to 6 characterised in that the pouring means (13) has the outwardly upwardly extending annular collar (14) whose upper edge (15) is connected to a closure stopper (16) with a gripping ring (17) welded thereto, and is disposed within the outside contour of the pack for transportation purposes.

8. A method of manufacturing the pack according to one of claims 1 to 7 wherein the coated carrier material (42) is pregrooved, fed from a roll (41) in web form to bending (47, 49) and folding stations (53) and for the purposes of manufacturing a tube (1) is drawn under tension against an outer ring (62) whereafter the tube (1) is closed by longitudinal sealing (63) characterised in that the tube (1) is drawn on to a calibration mandrel (54); the longitudinal sealing operation is effected between said mandrel and outside jaws (63); a respective portion (A) of the tube (1) is cyclically drawn off the calibration mandrel (54), transferred on to a lower injection moulding tool portion (32) and moved in position laterally out of the direction of forward feed movement to an upper injection moulding tool portion (31); the round cover (2) is injected and cooled, being connected to the end (12) of the tube portion (1); the tube portion (1) which is closed at one end is drawn off the lower injection moulding tool portion (12); the cover (2) is pressed in, into the configuration for transportation; and the pack, after the filling operation, is closed by block bottom welding at the bottom (3).

9. A method according to claim 8 characterised in that the axis of the tube (1) is disposed in the direction of conveying movement.

10. Apparatus for carrying out the method according to claim 7 or claim 8 characterised in that disposed in alignment with an outside shaping ring (62) and in coaxial relationship therewith is a calibration mandrel (54) beside which a longitudinal sealing jaw (63) is movably disposed, that arranged downstream of the latter in the direction of conveying movement is at least one conveyor jaw (64), oscillating cyclically in the direction of conveying movement, and arranged downstream of the calibration mandrel (54) is a cutting means (66) beside which there is disposed a rotatable mandrel-bearing wheel (55) having at least three radially outwardly projecting mandrel-like lower injection moulding tool portions (32), disposed at an angular spacing relative to the axis of the calibration mandrel (54) is an injection means (30) with an upper injection moulding tool portion (31, 35), and disposed below the mandrel-bearing wheel (55) are a conveyor (44) having upwardly open shaping entrainment members (58) which are arranged at a spacing (a) relative to each other, a filling station (56) and a closure station (57), wherein the entrainment members (58) have at least two parts which are movable relative to each other and which, in the condition of being brought together, define at least in the region of the one lower end a round cross-section and at the other upper end a quadrangular cross-section.

11. Apparatus according to claim 10 characterised in that the conveyor means (64) has two conveyor jaws (64) which are arranged in mutually diametrally opposite relationship outside the calibration mandrel (54) which is of a hollow configuration, and an inner portion which is movable centrally between said conveyor jaws with same in a longitudinal slot in the calibration mandrel (54).

12. Apparatus according to claim 10 or claim 11 characterised in that the cutting means (66) has a rotary ring carrying blades which are cam- controlled and which are disposed in a distributed arrangement at the periphery.

Images