DE3447771A1 - Process for closing the orifice of a box and box and apparatus for carrying out this process - Google Patents

Abstract

Figure 1 shows an apparatus which is suitable for carrying out the process according to the invention and which has a ram (1) which cooperates with a die (3) and by means of which a lid blank (2) supplied can be shaped to form a suitable lid (6). This ram (1) serves at the same time as an abutment and anvil for an ultrasonic device which is designed with sonotrodes (15) and by means of which a thermoplastic, applied both to the edge (14) of an already filled, but still open box (10) and to the edge (7, 8) of the lid (6) placed onto the box orifice (3), can be heated and thereby made adhesive. <IMAGE>

Description

Method of sealing the opening of a box as well

Box and device for performing this process.

The present invention has a method of closing the opening a box by means of a lid or base covering this opening Object in which the edge of the lid or bottom at least partially on the adjacent box edge and is to be connected to the same.

In the production of folding boxes from pre-cut cardboard blanks the parts that are to be connected to each other are immediately prior to insertion the blanks are provided with a hot melt adhesive in an erecting device, the causes the connection to the other cut part resting on it. That the same also applies to the edge of a box opening, which is opened by means of a lid or the bottom should be closed.

In particular when such erecting devices are in continuous operation as well as in the event of any incorrect deformation of the box, however, cuts are made heavy soiling of the tools, which again means high maintenance costs overall has the consequence. If, on the other hand, such a hot melt adhesive is already applied to the relevant blanks are applied, special heating devices are necessary, around the hot melt adhesive that has already been applied to the relevant blanks to activate. After all, is it about box blanks that consistently consist of a weldable plastic or coated with a plastic are, so special hot air nozzles are required, by means of which the each other to connect points of the box blanks before they are introduced into a Erecting device can be heated and softened.

Apart from that, these measures listed above are quite time-consuming are, they are also quite harmful to the environment and also require one Considerable use of energy in order to make the cuts as well as the possibly provided Reheat the hot melt adhesive that has been applied to the lid or base.

The object of the present invention is to keep this up to now to avoid existing overhangs and a procedure as well as a box and a to create a suitable device for performing this method, by means of the simple and environmentally friendly the one to cover the box openings provided covers or bottoms are to be connected to the respective opening edges.

According to the invention, this object is achieved in that already at the production of the box blanks and the blanks of the lid or bottom on at least one of the two opposite sides of the box edge or the edge of the lid or base has a high solids content over the entire surface or partially exhibiting thermoplastic applied and this after curing and after Erecting the box and filling the box with the intended Packaged goods in a form that has already been published by the German Offenlegungsschrift 32 46 325 previously known way through the action of U1-traschall and the resulting Heating is again made at least viscous and thus adhesive.

This inventive type of connection of the box edge with the opposite edge of the intended cover or base is in this respect particularly advantageous as this creates a perfect and clean connection can be without any residues of an adhesive passing over the adhesive points and stain the already filled box. It also needs when using of ultrasound no special preparatory work and / or preparation times, like this when using hot melt adhesive by heating it and also are essential due to special gluing devices. In the end but, and that is particularly important nowadays, can such a connection of the box edges with the edges of the provided lids or bases safely and easily in very short Carry out working hours, which only the nowadays required high filling and Packing speeds enabled.

A dispersion varnish is expediently used as the thermoplastic, which consists, for example, of about 40% acrylic resin and about 60% solvent, wherein The preferred solvent is water with an added ammonia. Even this dispersion varnish advantageously has a high viscosity at which the throughput speed this highly viscous emulsion paint for a 4 mm DIN cup takes about 60 to 70 seconds amounts to.

Applying this thermoplastic or dispersion varnish to the individual box blanks are expediently carried out by means of offset printing that is, the amount of thermoplastic or dispersion varnish applied to the cut parts can be about 7 to 8 g / wet weight per square meter.

Should either the bottom side by means of the method according to the invention Opening of a still empty box through a bottom or the top Opening a box already filled with a packaged item by means of a Lids are closed, it is useful for such a box at least the edge of the box opening to be covered to form a flange or part flange preferably continuous to turn outwards, whereby then the edge of the lid or bottom covering the box opening roughly in this way has the same outline as the bent edge of the box opening that after the application of the lid or base, the edge of which is fed up on the side facing it of the bent edge of the box.

If, on the other hand, it is a box that consists of a lower part and an upper part covering the same, in this case both the edge of the bottom part of the box as well as the edge of the top part of the box Forming a flange to bend outwards.

In both cases, the surface of the edge of the box opening or the lower part of the box is either perpendicular to the vertical axis of the box directed or inclined.

Another design of one for carrying out the invention Process suitable box is characterized according to the invention in that the Edge of the lid or bottom covering the box opening to form a outwardly open and the engagement of a stamp enabling trough-like Recess protrudes perpendicular to the outside of the lid or the bottom over this and one open towards the edge of the box opening and full around the latter has encompassing U-profile, of which after the application of the cover or Soil on the edge of the box opening of the outer leg the outside of the box edge, the web on the face of the box edge and the inner leg rests against the inside of the box rim. This invention The design of such a box enables a two-sided connection the edge of the lid or bottom with the edge of the box, whatever is special The advantage is if the closure of the box should be very tight.

To carry out this method according to the invention during the closure of the boxes indicated above is expediently a stamp as well to use a device having a tool that interacts with this punch, the at least one slidably mounted, one welding the cover or bottom edge with the box edge causing ultrasound and with the aforementioned stamp cooperating device is equipped, which over the entire area of the two edges or edge parts to be connected to one another extends, can be advanced against these edges or edge parts and back into their starting position is retractable.

Is it a matter of the box edge forming a Annular flange is bent outwards and with the edge of a lid or floor is to be welded, so extends the device causing the ultrasound expediently over the entire edge of the box opening, this facility then mounted displaceably in the direction of the vertical axis of the box and can be lowered towards the edge of the box and lifted off the same again. at this inventive design of such a device is the ultrasound an effecting device whose design is assigned an adapted counter stamp, which then serves as a counter bearing for this ultrasonic device.

If, on the other hand, the lid or the bottom indicates that the as The trough-like recess that enables the thrust bearing to serve the counter bearing is the Edge of the lid or bottom covering the box opening in cross section as U-shaped profile and should the two vertical legs this on the edge of the box opening upturned U-profile on the one hand with the outer surface and on the other hand the inner surface of the box edge are connected, so are in in this case at least two devices producing the necessary ultrasound to be provided, which are then each along a portion of the box edge extend, mounted displaceably perpendicular or parallel to the vertical axis of the box and to be pushed towards the edge of the box and withdrawn again.

A particularly useful device for carrying out the invention The method is characterized, for example, by one of the continuous feed of boxes that have already been filled with the packaged goods but are still open Conveyor table, above it one step by step around a horizontal one axis swiveling work device with a multitude of rotating on a circular path Stamp is arranged, one after the other when pivoting this work device several fixed workstations for providing the lid blanks, for Deforming these cover blanks and for applying and welding the on Pass the lid attached to the box openings. Here you can use the pivotable Work equipment at the same distance from each other four punches be arranged, which pass four workstations one after the other, each offset by 900 to one another, of which the first station has a dispenser for the prepared lid blanks has, the second station with a deformation of the lid blanks causing, equipped with a tool that can be displaced against the respective punch opposite it, the third station with both a device for lifting the filled and fed Boxes as well as a device for welding the from the boxes each opposing stamps supplied, placed on the box openings Lids equipped with the respective box edge and finally the fourth Station is designed as a teaching station.

Further details of the present invention emerge from the following description of an exemplary representation of the method, various example embodiments of the box to be closed as well as the subsequent claims.

1 shows a schematic representation of a first form of the method with process steps A to F, FIG. 2 shows a partial section from the 1 on an enlarged scale, FIG. 3 a representation corresponding to FIG. 2 a second type of method, FIG. 4 another, also corresponding to FIG. 2 and FIG. 5 shows a third type of method and FIG. 6 shows the schematic diagram an apparatus for performing the method shown schematically in FIG. 1.

Fig. 1 shows the schematic representation of a method with the individual process steps A to F. According to this representation is a for Implementation of the method according to the invention is more necessary, with one not particularly illustrated suction device provided punch 1 provided, which in vertical Direction is shifted and by means of which an existing cardboard box Lid cut 2 lifted from a stack, not specifically shown, and one that interacts with it Tool 3 is fed. As soon as the stamp 1 together with the cover blank 2 has reached its position shown in station A above tool 3, the stamp 1 according to method step B in the direction of arrow 4 by the Dimension a lowered, with the deformation of the lid blank shown in FIG. 1 2 takes place. This deformation of the cover blank 2 creates a trough-like shape Recess 5 of the thereby formed cover 6, its vertical edge 7 and its on this cover edge 7 molded, outwardly protruding horizontal cover flange 8 surround the punch 1 engaging in the trough-like recess 5.

During this deformation of the lid blank 2 is on one with 9 designated conveyor track already with a packaged item not specifically shown filled box 10 has been fed, according to method step C below of the die 1 carrying the already formed cover 6 is placed.

In the course of the further process step D, this box 10 by means of a pneumatic lifting device 11 as far in the direction of the arrow 12 raised by the amount b that the trough-like lid 6 in the opening 13 of the box 10 reaches into it and the box edge 14 surrounding this opening 13 on the underside of the outwardly protruding cover flange 8 abuts. Does the box of 10 have these reached raised position, so are in Course of the process step E several arranged in a ring around the stamp 1, causing an ultrasound Sonotrodes 15 lowered so far in the direction of arrows 16 that the cover flange 8 is bent down by 900 and is fed up with the outside 17 of the box edge 14 creates. As soon as the sonotrodes 15 are lowered as shown in step E of the method Have reached the working position, these are in the direction of arrows 18 against the downwardly bent flange 8 of the cover 6 moved and at the same time this Lid flange 8 pressed against the outside 17 of the box edge 14. Once the The cover flange 8 rests snugly against the box edge 14, the action of the sonotrodes 15 generated ultrasound both on the box edge 14 and the full on that The lid edge 7 resting against the stamp 1 and the edge 7 resting against the outside of the box edge 14 Lid flange 8, which causes these box parts 7, 8 and 14 to heat up Has. This in the interaction of the sonotrodes 15 with the serving as an anvil The heat generated by the stamp 1 makes both sides of the box edge 14 as well that applied to the outside of the lid edge 7 and the inside of the lid edge 8 Thermoplastic or dispersion varnish can be glued again, which means intensive gluing of the lid flange 8 and the lid edge 7 with the box edge 14 on both sides has the consequence.

Is this process of gluing the lid edge 7 and the lid flange 8 closed with the box edge 14, the lifting device 11 is lowered again and the stamp 1 against the direction of arrow 4 in his Starting position A shown in FIG. 1 is raised. The one with the packaged goods filled box 10 is now closed by the lid 6 and is then fed to a collecting station not specifically shown.

Is also on the underside of the in Fig. 2 on an enlarged scale shown, the lid edge 7 with the bent cover flange 8 connecting web 19 a thermoplastic or a dispersion varnish is applied, the with the punch 1 cooperating sonotrode 15 also heated the web 19 and with the Front side 20 of the box edge 14 glued. But that means that it is U-shaped in profile Lid edge 7 along its two vertical legs and these with one another connecting web 19 is firmly and sealingly connected to the box edge 4.

The following Fig. 3 shows another possibility in which the in In this case, the box labeled 21 is used, the side wall 22 of which is used has a cross-sectionally U-shaped, downwardly open profile, in which the two vertical legs with 23 and 24 and the web of this U-profile with 25 are.

To close this box 21, a flat lid 26 is provided, which sits snugly with its edge 27 on the web 25 of the box side wall 22. In order to now also close this cover 26 with the continuous web 25 of the side wall 22 connect, are provided with a thermoplastic above the underside Edge of the lid 27 a plurality of sonotrodes 28 arranged in a ring, with one serving as an anvil Cooperate punch 29. This punch 29 protrudes from below between the two Legs 23 and 24 of the side wall 22 into it, the web 25 of which on its surface likewise a thermoplastic is applied on the surface 30 of the stamp 29 sits up. As soon as the cover 26 is in its position shown schematically in FIG has reached, the sonotrodes 28 in the direction of arrow 31 against the edge of the cover 27 lowered and a heating of the lid edge 27 and the side wall web 25 causing ultrasound, which also causes the side wall web to stick 25 with the underside of the lid rim 27 results.

A similar process is shown in the further FIG. 4, in which the same a fixed punch 32 and several sonotrodes which can be lowered in the direction of arrow 33 34 are provided. In this case the box 35 has a flange-like one Edge 36 on which a box opening 37 to be covered cover 38 is placed is. As soon as this cover 38 has assumed its position shown in FIG. 4, the sonotrodes 34 are in turn lowered against the stationary punch 32 and this causes the box edge 36 to stick to the lid edge 39.

A variant of this is shown in FIG. 5, according to which the box 40 consists of a lower part 41 and an upper part 42 and both the box lower part 41 as well as the top of the box 42 each flange-like, according to have outwardly protruding edges 43 and 44. Isn't that particularly depicted When packaged goods are placed in the box bottom part 41, this is the box top part 42 so placed on the box bottom 41 that the edge 44 of the box top 42 comes to rest fully on the edge 43 of the box base 41. Has the box top 42 assumed this position shown in FIG. 5, the with the punch 32 cooperating sonotrodes 34 in the direction of arrow 33 lower and to generate a U1-traschall that a warming of the two box edges 43 and 44 and thus also causes them to stick together.

Finally, FIG. 6 shows a schematic representation of a for Implementation of the method shown schematically in FIGS. 1 and 2 is suitable Device 45, which with one of the supply of one of the plurality of filled boxes 46 serving table 47 is equipped. Above this table 47 is located a shaft 49 pivotable in the direction of arrow 48, on each of which by 900 to each other offset, four with 50 designated support arms are arranged. At the free ends 51 of these support arms 50 are four each designed with a suction device 52 Stamp 53 to 56 arranged. With a cycle to be carried out in four sub-steps the shaft 49 these punches 53 to 56 pass the four each by 900 to each other Staggered stations G to K. In the area of the first station G is a designated 57 Dispenser arranged in which a plurality of lid blanks designated 58 provided are. The second station H, on the other hand, has a displaceable in the direction of arrow 59 mounted tool 60 on. The third station above table 47 J can be lowered with a wreath in the direction of arrows 61, alternating with Stamping 53 to 56 cooperating sonotrons 62 equipped. At the station Finally, K is an empty station.

The mode of operation of this device 45 is as follows: First once from the plunger 53 opposite the dispenser 57 by means of the suction device 52 a cover blank 58 located in this dispenser 57 is removed. Is this happen, the shaft 49 with the support arms 50 performs a pivoting movement by 900 so that now the punch 53 with the cover blank 58 is the one shown in FIG Position H with respect to the tool 60 assumes. Then the tool 60 a feed in the direction of arrow 59 issued, which the required partial deformation of the cover blank 58 and thus also the design of the cover 63 with the cover edge 64 and the cover flange 65 results. Then the shaft 49 leads another Pivoting movement by 90 °, so that now the already preformed cover 63 carrying punch 53 assumes its position J above table 47. In the In the meantime, below this stamp 53 is one of the boxes that have already been filled 46 raised so far in the direction of arrow 66 that the cover 63 with its trough-like Middle part 67 in the opening 68 of the raised Box 46 engages and the box edge 69 abuts the underside of the box flange 65. is If this happens, the sonotrodes 62 are moved so far in the direction of the arrows 61 lowered so that they bend the cover flange 65 downwards by 900 and this in the manner already shown in Fig. 2, full on the outside of the box edge 69 is present. The sonotrodes 62 are then countered in the direction of the arrows 70 the outside of the bent cover flange 65 is guided and an ultrasound is generated, what a mutual gluing of the lid edge 64 and the lid flange 65 with the box edge 69 results. If this process is also completed, so the sonotrodes 62 are retracted into the starting position shown in FIG. 6, the filled box 46 against the direction of the arrow 66 on the table 47 lowered and in the direction of arrow 71 of a collecting station not specifically shown fed. During the following pivoting movement of the shaft 50, the punch 53 arrives first to the empty station R, to then after a further pivoting movement of the shaft 50 to assume its starting position G shown in FIG. 6 again.

Since the other punches 54 to 56 are the same one after the other at the same time Go through stations G to H, with each pivoting movement of the shaft 49 and the Support arms 50 are closed by 900 each one of the boxes 46 by means of a cover 63.

In the three methods shown schematically in FIGS. 3 to 5 can instead of the sonotrodes arranged in a ring along the edge of the box 22 28 and 34 only a single sonotrode can be provided, the shape of which then the is adapted to the respective outline of the box edge.

Claims (18)

Claims 1. A method for closing the opening of a box by means of a cover or base covering this opening, the edge of which is at least partially rests against the adjacent box edge, characterized in that already during the manufacture of the box blanks and the blanks of the lid or bottom on at least one of the two opposite sides of the Box edge or the lid or base edge over the entire surface or partially into one applied high solids content thermoplastic and this after Curing and after erecting the box and filling the Box with the intended packaged goods in a known manner by the Effect of ultrasound and the resulting heating again at least is made viscous and adhesive. 2. The method according to claim 1, characterized in that as a thermoplastic a dispersion varnish is used. 3. The method according to claim 1 or 2, characterized in that the Dispersion varnish consists of about 40% acrylic resin and about 60% solvent. 4. The method according to claim 3, characterized in that as solvent Water with added ammonia is provided. 5. The method according to claim 3 and / or 4, characterized in that the dispersion varnish has a high viscosity. 6. The method according to claim 5, characterized in that the throughput speed of the highly viscous dispersion varnish for a 4 mm DIN cup about 60 or 70 seconds amounts to. 7. The method according to one or more of claims 1 to 6, characterized characterized in that the thermoplastic, in particular the dispersion varnish, by means of varnishing or printing processes of all kinds are applied to the box blanks. 8. The method according to one or more of claims 1 to 7, characterized characterized in that the amount of thermoplastic applied to the box blanks, especially the dispersion varnish, about 7 to 8 gr wet weight per square meter amounts to. 9. Box for carrying out the method according to one or more of claims 1 to 8, characterized in that at least the edge (25, 36, 43) the box opening to be covered, forming a flange or partial flange is preferably continuously bent outwards and the edge (27, 39, 44) of the lid (26, 38, 42) or bottom covering the box opening approximately in this way has the same outline as the bent edge (25, 36, 43) of the box opening, that after applying of the lid (26, 38, 42) or the bottom thereof Edge (27, 39, 44) is full on the side of the bent box edge facing it (25, 36, 43) is applied. 10. Box according to claim 9, consisting of a base and a the same covering upper part, characterized in that both the edge (43) of the Box bottom (41) and the edge (44) of the box top (42) below Forming a flange are each bent outwards. 11. Box according to claim 9 and / or 10, characterized in that that the surface of the edge (25, 36, 43) of the box opening or the box base (41) and also the top or bottom wall (27, 39, 44) opposite the vertical one The axis of the box is either perpendicular or inclined. 12. Box for carrying out the method according to one or more of claims 1 to 8, characterized in that the edge (7) of the box opening (13) covering lid (6) or bottom for forming an outwardly open Trough-like recess perpendicular to the outside of the lid (6) or the bottom protrudes over this (6) and one against the edge (14) of the box opening (13) has a U-profile that is open and fully engages around the latter (14), from after applying the lid (6) or bottom of the outer leg (8) to the Outside of the box edge (14), the web (19) on the end face (20) of the box edge (14) and the inner leg (7) on the Inside of the box edge (14) is applied. 13. Device for performing the method according to one or more of claims 1 to 8, which has a tool cooperating with a punch, characterized by at least one displaceably mounted, one welding of the lid or bottom edge (7, 8, 27, 39, 44) with the box edge (14, 22, 36, 43) causing ultrasound and interacting with the stamp (1, 29, 32) Means (15, 28, 34, 62) that extend over the whole area of the two with each other to be connected edges (7, 8, 27, 39, 44, 14, 22, 36, 43) or edge parts extends, can be advanced against these edges (7, 8, 27, 39, 44, 14, 22, 36, 43) or edge parts and can be retracted back into its original position. 14. Apparatus according to claim 13, characterized in that the means (28-34) over the entire edge (14, 22, 36, 43) of the box opening extends, mounted displaceably in the direction of the vertical box axis and against the box edge (14, 22, 36, 43) can be lowered and raised again from the same, this device (28, 34) having a design adapted to its design as a counter bearing serving counter stamp (29, 32) is assigned. 15. Apparatus according to claim 13, characterized in that at least two devices (15, 28, 34, 62) are provided, each extend along a partial area of the box edge (14, 22, 36, 43), perpendicularly or mounted displaceably parallel to the vertical axis of the box and against the The box edge (14, 22, 36, 43) must be pushed forward and withdrawn again. 16. The device according to claim 13, characterized by one of the continuous Feeding of boxes that have already been filled with the packaged goods, but are still open (46) serving conveyor table (47), above the same one gradually to a horizontal one Axis (49) pivotable work device (49, 50) with a plurality on one Circular orbit circumferential stamps (53 to 56) is arranged, which when pivoting the Work equipment (49,50) several fixed workstations (G to K) for providing the cover blanks (58), for deforming these cover blanks (58) as well as for applying and welding those applied to the box openings (68) Pass the cover (63). 17. The apparatus according to claim 16, characterized in that on the pivotable working device (49, 50) equidistant from one another three Stamp (53 to 55) are arranged, successively three work stations (G to J) happen, of which the first station (G) is a dispenser (57) for the provided Has cover blanks (58), the second station (H) with a deformation the lid blanks (58) effect against the each facing him Stamp (53 to 56) equipped with a movable tool (60) and the third station (J) both with a device for lifting the filled boxes (46) and means (62) for welding the of the boxes (46) respectively opposing stamps (53 to 56) fed to the box openings (68) fitted lid (63) equipped with the respective box edge (69) is. 18. Apparatus according to claim 17, characterized in that on the Work device (49, 50) four stamps (53 to 56) and these in addition to the three workstations (G to J) a fourth empty station (K) is assigned.