EP3253568A1

EP3253568A1 - Method and device for forming at least one bottom on a hose piece

Info

Publication number: EP3253568A1
Application number: EP16700554.5A
Authority: EP
Inventors: Uwe Köhn; Thomas Hawighorst
Original assignee: Windmoeller and Hoelscher KG
Current assignee: Windmoeller and Hoelscher KG
Priority date: 2015-01-30
Filing date: 2016-01-12
Publication date: 2017-12-13
Also published as: BR112017014757A2; US20180022053A1; CN107405854A; DE102015201691A1; WO2016120059A1

Abstract

The invention relates to a method for forming at least one bottom on a hose piece (20), which comprises plastic material, wherein at least one end of the hose piece is pulled open along at least one first folding edge (21), a bottom rectangle (22) and triangular pockets (23) thus being formed; wherein side tabs (25, 26) of the bottom rectangle are folded back along two folding edges (24) spaced apart from the first folding edge in order to close the bottom, wherein the two side tabs then contact each other; and wherein a bottom cover sheet (31) is applied to the bottom and is connected to the side tabs and at least one triangular pocket by application of heat or by means of a glue. The surfaces of the side tabs that come into contact and the triangular pockets are connected to each other at least in the region of the two folding edges, a connection (32) thus being formed.

Description

Method and device for molding at least one floor

hose Connector

The invention relates to a method for molding at least one base to a piece of tubing, which comprises plastic material, according to the preamble of claim 1 and a device for molding at least one bottom to a piece of tubing comprising plastic material according to the preamble of claim 10 Production of sacks, in particular cross-bottom sacks, is raised to bottom at least one end of the hose piece to form a bottom rectangle and triangular pockets along at least one first folded edge. Thereafter, the two resulting side flaps of the bottom rectangle are folded back along second folding edges, which are spaced from the first folding edge, wherein the two side flaps then contact each other.

In the case of pieces of hose which comprise material in the main, these contact points or surfaces of the two side straps remain unconnected. An attachment of the soil is now carried out by applying a bottom cover sheet, which is connected to both side flaps. The bottom cover sheet is thereby also connected to the part of the triangular pockets which it covers and which is not covered by the side flaps, as long as no filling valve is present. In the case of the presence of a valve, the bottom cover sheet is connected to the valve. This method is particularly efficient because the bottom is completely fixed with only one step, so that the bag is ready for receiving a filling and above all fully loaded with a product. However, it has been found in practice that along the second folded edges often so-called trickle channels arise, along which in particular dusty filling material can escape to the outside. The reason for this is that because of the tolerances in the sacking process, the bottom face sheet must be slightly smaller in size than the rectangle inscribed in the folded bottom to reliably avoid sticking over the edges of the bottom after application.

The object of the present invention is therefore to propose a method and a device for avoiding the discharge of contents from the finished bag.

According to the invention this object is achieved by all features of claim 1. In the dependent claims, possible embodiments of the invention are given.

According to the present invention it is provided that the contacting surfaces of the side flaps and the triangular pockets are connected together at least in the region of the second folded edges to form a connection. This area includes parts of the second folded edges. If the Settenlaschen folded back, thereby arise - also triangular - contact surfaces between each side flap and each triangle pocket, wherein the respective contact surface of the side flap and the contact surface of the triangular pocket are connected to each other over a portion of the second folded edge. At least in part of the contact surface in the region of this folded edge side tab and triangular pocket are now connected to each other, so that a possible trickle channel is interrupted. A complete connection along this contact surface is not necessary to avoid giant channels. Preferably, even only along a small part of this contact surface, a connection is produced, wherein a smaller Part is understood as less than 20% of this contact surface, whereby the method is particularly efficient feasible.

However, the joined portion advantageously extends to an area of the surface spaced at least 1 cm from the seaming edge. With this measure, a trickle canal can be avoided very well, wherein the compound also has sufficient strength, without having to fear that this compound dissolves again. In a further embodiment it is provided that the connection is arranged in or at the folded edge, that at least the region of the intersection of the folded edge with the diagonal comprises the triangular pocket. At this point, in sacks of the prior art, the contents come out, so providing the connection at this point brings a great advantage.

In order to create a solid and thus permanent connection, it is expedient if the connection extends from the point of intersection extends at least 1 cm in the direction of the folded edge. In particular, in connection with the above-mentioned advantageous feature, according to which the connection extends over a surface which starts at the seaming edge and extends to at least 1 cm distance from this, results in an area which is so large that it safely extends below a later applied ground cover sheet, even if this is shifted due to manufacturing tolerances compared to the desired position. The leakage of filling material is thus avoided particularly well.

As already described at the outset, the invention relates to hose pieces comprising plastic material. In particular, it is hose pieces that consist exclusively of plastic material and just do not have other materials, such as paper. Such Schiauchstücke may consist of plastic film material, as it can be produced in film extrusion equipment. Apart from a hose formation, further processing steps are unnecessary here. However, plastic pieces comprising hose pieces may also include a fabric which For example, has stretched plastic tape. This fabric can also be coated. In a further variant, such a piece of tubing may comprise non-woven material, which is also referred to as non-woven material. A nonwoven material is characterized in that individual plastic fibers are joined together under pressure and / or heat. Such a nonwoven material may also be provided with a coating or form a laminate using at least one plastic film. In order to be able to form a compound according to the method of the invention, a hot-air sealing method is advantageously used. The advantage of this is that it is a very efficient process with which it is also possible to produce sufficiently durable compounds. In addition, the material is not overstressed because only near-surface areas are involved in the sealing process. In a hot air sealing process, the regions of the two connection partners to be joined, in this case parts of the triangular pocket and parts of the side flaps, are heated at their mutually facing sides by injection of hot air until plastification and immediately brought into contact with each other. Preferably, a subsequent pressing in a press nip, which may be formed by two rollers.

In a further advantageous embodiment of the method according to the invention it is provided that the connection takes place by means of an ultrasonic welding. The ultrasonic welding process is a welding process in which high-frequency mechanical vibrations cause molecular and boundary surface friction in the bonding zone. This creates heat at this interface, so that the material is plasticized here. Compression or compression of this area leads to a tight connection, so that no filling material can escape.

In another embodiment, it is provided to produce an adhesive application on the areas provided for the connection. It is useful to apply the adhesive before or at the latest when folding back the side flaps. It is particularly advantageous, however, to apply the adhesive before opening the floor, since it is then avoided that the adhesive gets onto the side wall of the later bag and possibly an unwanted bonding of the triangular pocket to the side wall takes place.

The adhesive is preferably applied with an adhesive nozzle. The adhesive trace emerging from the adhesive nozzle can be introduced directly into the already formed or later occurring folded edge.

As adhesives known cold adhesives can be used. Preferably, however, heat-activated hotmelt, which is inexpensive, is applied. The latter is particularly advantageous in the case of an adhesive application which takes place before the floors are opened. This hotmelt solidifies after the job, so that the bottom opening or bottom closure can be done without the hotmelt adhering to the bottom opening or bottom closing tools, which could otherwise interfere. During or after bottom pounding, the hotmelt can be reactivated by a heat input so that the connection between the triangle pocket and the side flap is now established. If hot air is used in the ground production for permanently closing the bottom, as is well known, for example, for applying a cover sheet, then the heat input caused thereby already suffices to activate the hotmelt. A separate heater is therefore not necessary.

A further advantageous variant of an adhesive entry is the introduction of a plastic extrudate into the second folded edge shortly before or during the folding over of the side flap. The plastic extrudate is a liquefied plastic material, in particular the same or a similar plastic material as at least the surface of the hose piece. Again, this is a cost effective way of applying glue. The further turning of the side flap takes place before the curing of the Extrudates, so that by pressing or pressing a connection is formed, which prevents leakage of the filling material from the bag interior.

All of the abovementioned processes for preparing the compound have in common that they preferably work in cycles. This means that they are only put into the active state if they are just opposite the areas to be connected. In this case, the corresponding tools are usually arranged stationary within the machine, while the hose piece is guided with a - preferably uniformly moving - transport device to the tool over. It is of course provided that the region of the second folded edge, in which the side flap is folded back directly onto the hose piece wall and not on the surface of the triangular pocket, is recessed. A missing recess in this area would lead to unwanted bonding, which could make the bag useless.

The above object is also achieved by a device for molding a floor to a ski piece, which comprises plastic material, according to claim 10. The feature essential to the invention is a device with which the surfaces of the side flaps coming into contact and the triangular pockets can be connected to one another, at least in the region of the second folding flaps, to form a connection.

Such a device may be a hot-air sealing device, which is arranged in the region of a respective folding device, with which a side flap can be folded back onto the corresponding triangular pockets along the second folded edges.

In another embodiment, an extrusion nozzle can be arranged at the same location, with which an extrudate can be placed in or immediately adjacent to the folded edge.

In a further advantageous embodiment of the invention, an ultrasonic welding device may be provided, which of the above Folding device is immediately downstream. With this

Ultrasonic welding device can be produced in the region of the second folded edge, if the side flap already rests on the triangular pocket,

In another preferred embodiment of the invention, a device for applying a hot melt is provided, which is also located within the folding device or this is arranged upstream. However, it is particularly advantageous if it is arranged upstream of the device for opening the bottom of the hose piece.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the figures, various embodiments are explained in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or for any combination of mentioned features. Within the scope of the entire disclosure, features and details described in connection with the method according to the invention apply, of course also in connection with the printing press according to the invention and in each case vice versa, so that reciprocal reference is always made to the disclosure of the individual aspects of the invention can. The individual figures show:

Fig. 1 schematic diagram of an apparatus for producing plastic-containing bags

Fig. 2 Essential steps for producing a bag from a

hose Connector

Fig. 3 piece of tubing with traces of adhesive on the later folding edges

Fig. 4 An embodiment with a hot air sealing device

5 shows a cross-section of an envelope element from FIG. 4

Fig. 6 shows a further cross section of an envelope element of the figure

4

FIG. 7 shows another view of the exemplary embodiment according to FIG. 4 8 is a plan view of the embodiment according to FIG. 7

Fig. 9 An embodiment with an extrusion device

Fig. 10 An embodiment with an ultrasonic welding device

FIG. 1 schematically shows individual steps for processing a plastic-containing tube, such as a film tube or a tube of coated tissue into sacks, as they take place in the sack manufacturing device 1.

First, the hose 2 is fed to the bag making apparatus 1. This advantageously takes place by unwinding the tube 3 forming a tube in an unwinding device 4. Subsequently, the tube 2 can experience the so-called opening in the optional opening station 5, which is preferably used in a fabric tube. In this case, the tube is guided around an inner tool, which separates the two layers, so that the layers, if they were glued together in one of the manufacturing steps of the tube separate. Only with separate layers can it be ensured that the following production steps can be carried out properly. Subsequently, the so separated Materia Ilagen the hose are put back on top of each other. The tube is then fed to the cross-cutting device 6, which separates the tube into individual tube pieces 20.

Subsequently, a change of the original transport direction z, in which the tube or pieces of tubing were transported in the direction of their longitudinal axes (so-called longitudinal transport), in the new transport direction y, so that the hose pieces now no longer in the direction of y tube longitudinal axis (hereinafter also extension direction of the hose pieces called), but are transported transversely thereto (so-called transverse transport), so that the ends of the hose pieces are laterally accessible for the purpose of Anformung the floors. In the following station, the bottom opening station 8, both ends of each tube piece are opened and the so-called ground rectangles are laid. In the subsequent valve station 9, a valve is placed and secured on one of the two open ends of the hose piece. The open bottoms are now closed in the bottom closing station 10, with two side flaps folded over along second folding edges and partially laid one on top of the other. The conclusion of the actual Sackherstellprozesses forms the application of a bottom cover sheet on the floors in the cover sheet station 11, wherein the cover sheet is connected to areas of the two side flaps and with areas of the triangle pockets. For this purpose, the cover sheets can be sealed or glued. The finished bags are then placed on the bag stack 12 and transported away from there on unspecified manner. FIG. 2.1 illustrates the steps for molding floors onto the hose piece 20, wherein the hose piece can be brought by means of the transport device 19 to the individual stations, with which the steps for molding floors onto hose pieces can be carried out. In the illustration a), at least one end, preferably both ends, of the piece of tubing is raised, the top layer being folded back along the bottom center line 21, so that the bottom rectangle 22 and the triangular pockets 23 form. In this illustration, the second folded edges 24 are drawn with dotted lines around which the side flaps 25, 26, with which the areas are designated beyond the second folding edges, are folded over.

The side flaps 25 and 26 are folded around these second folded edges in step c) and d), which preferably takes place slightly offset in time so as not to cause a disturbance. It has now been created a ground 27. In step b), a so-called valve pad 30 was previously attached to a triangular pocket, which later provides an opening for filling the finished bag. In the concluding step e), a cover sheet 31 is now fastened on the bottom of the bag such that both side flaps are connected to one another and to the triangular pockets adjoining on both sides. For the understanding of the present invention, in the illustration a), hatched rectangles indicate that overlapping connecting regions 32 are provided directly adjacent to the folded edges or with folded edges. These are shown only on a triangular pocket, however, such connection areas may be provided on more than one or all of the triangle pockets. If a valve is provided, connecting areas in the area of the valve are unnecessary. Figure 2.2 shows the relevant area in an enlarged view. The connection area is shown only on one side of the folding line, but it is immediately clear that after the folding of the side flaps 24, 25, the connecting surface also acts on the folded side flaps 24, 25, so that it can also be said that the connecting surface lies on both sides of the second folded edges.

Figures 3.1 and 3.2 now show a first embodiment of the invention, in which on the triangular pockets along the (later) second folding edges 24 an adhesive trace 34 of heat-activated adhesive (so-called hot melt adhesive) is applied. Although a hotmelt connection can not create a load-bearing connection, it is not necessary at the location mentioned and for the aforementioned sealing function, so that the cost-effective hotmelt offers cost advantages here.

In the figure 3.1, however, the soil is not yet raised, so that the traces of adhesive supposedly do not lie on the second folding edges. Nevertheless, the adhesive traces are on the projections 35 of the second folded edges 24 on the triangular pockets 23. On the back of the hose piece, not shown, the adhesive tracks are of course congruent apply. The application of an adhesive takes place in this embodiment, preferably during the longitudinal transport of the hose or a piece of tubing or in a standstill phase in the course of Longitudinal transport. Here is the period of time in which a piece of hose is separated from the hose. Since the hot applied adhesive cools quickly and thus becomes firm, a disability or even disturbance of the following processing steps can not be assumed. Providing adhesive application at this point has the great advantage of a simple system integration of an adhesive applicator.

In Figure 3.2, the soil is already raised, so that the adhesive tracks already described 34 are applied directly along the second folding edges on the triangular pockets, so after the pieces of hose have passed the bottom opening station.

The actual bonding and thus the production of sealing connections between side flaps and the triangular pockets, preferably in the areas that are not covered by the bottom cover sheet, now takes place by an entry of heat. An entry of heat advantageously takes place with a device for sealing a bottom cover sheet 31 onto the bottom 27 to be added. This takes place in the cover sheet station 11 already explained in connection with FIG. FIG. 1 of the patent DE 195 022 55 C2 and the associated description passages of columns 2 and 3 describe the components and the mode of operation of such a cover sheet station 11. The cited disclosure parts of DE 195 022 55 C2 are hereby incorporated as part of the present patent application, since they form a combination preferred in connection with the embodiment of the present invention just described.

FIG. 4 shows a further advantageous embodiment of the present invention. In this figure, an envelope element 41 is shown as an example, which is part of a bottom closing station and with which the side flap 26 is folded back along the second folded edge 24 on the open floor. At a bottom forming device up to four envelope elements are provided to convert all side flaps can. Of great advantage is when the cover member 41 has a U-shaped configuration, wherein in the further course in the direction z of the typical Arc developed to an edge to successively perform the turnover, without acting on the side flap too large forces that could lead to a misalignment of the second folded edge or other errors. The U-shape of the cover element 41 can be clearly seen in the figure 5, which represents a cross section. Evident is an advantageous embodiment in which the hose piece end between an inner guide member 42 and an outer Führungsseiement 43 is feasible or is guided. In the figure 6, which shows a cross section of the cover member 41 at a point in the further transport process, it can be seen that the two guide element now comprise a more pronounced tip for forming the second folded edge.

In FIG. 4, moreover, a hot air device 44 is shown which comprises at least one air feed 45, a heating element 46 and a tube 47 for supplying the hot air to the hot air sealing point. The tube 47 opens into a hot air nozzle 48, which is shown in FIG. The hot air nozzle is preferably a slot die, which is characterized in that its cross section has a width which is at least three times the height.

FIG. 7 now shows a perspective view of a part of the bottom closing station with an envelope element 41. It can be seen that the inner guide element 42 is shorter than the outer guide element 43 and that in the end region of the inner guide member 42, the hot air nozzle 48 is arranged so that the hot air z in direction over the end of the inner guide member 42 in the area between the Side tab and the triangle pocket can be injected directly to and / or in the fold edge. The point at which this occurs can be referred to as joint 49. The piece of hose with the soil to be zuzulegenden is not shown for better representation of the machine components. Furthermore, a nip formed by the rollers 50, 51 is visible. This is used for pressing and thus the better connection of the hot air-sealed areas. The rollers can be designed to be tempered, in particular cooled. A second pair of rollers 50 ', 51' may be provided. However, since the side flaps are to be connected to the triangular pockets, but not to the open bottom rectangle and thus to the interior of the bag, two alternatives offer advantages. On the one hand, at least the tube 47 can be designed to be pivotable together with the nozzle 48. In this pivoted position, the tube is shown with broken lines and reference numeral 47 '. On the other hand, the hot air flow can also be interrupted by, for example, a valve (not shown) being provided in the tube. In both cases, a control is provided, with which the hot air flow is cyclically injected into the joint 49.

FIG. 8 shows the situation of FIG. 7 in a plan view and with a hose piece 20 which is located in the envelope element 41 immediately before the inlet.

9 shows a further embodiment of the invention is shown, which is configured similar to the embodiment in Figure 7. However, here the hot air nozzle is replaced by an extrusion die 60, with which an extrudate is directly on or in the second fold edge gebbar. The extrudate can also be fed via a tube 61. The extrudate is fed from an extruder, not shown, in which plastic is liquefied. Also in this embodiment, the tube 61 in the position 61 'can be swung off to prevent any unwanted connection, for example between side flap and Boden rectangle, arise. Below the extrusion nozzle 60 ', a collecting element 62 may be provided for collecting possibly dripping extrudate. As in the embodiment of FIG. 7, a pair of rollers 50, 51 can be provided following the joint, which additionally compresses the interconnected side flaps and triangular pockets, while the hot and thus liquefied material cools.

FIG. 10 shows a further advantageous embodiment of the invention, in which an ultrasonic welding device 70 for welding provided by side flaps and triangular pockets. This ultrasonic welding device comprises a combination of a sonotrode 71 and an anvil 72. In Figure 10, these two elements are shown as rollers, but it is also possible to form them differently. If the welding is to take place during the transport, at least one of the two components mentioned may, for example, be circumferential or oscillating. In the cycle advance of the hose pieces, at least one of the two components can be stationary. However, even with a continuous transport of the hose pieces, a component may be stationary. The further components of the bottom closing station can be configured as in the exemplary embodiment of FIGS. 4 to 9. In particular, the roller pair 73, 74 can in turn serve for pressing and / or cooling the connection point 32. In the above description, various features have been disclosed in connection with individual embodiments. However, it is possible or even advantageous to combine such features with other embodiments. The above description is thus not limited to the feature combinations disclosed therein.

LIST OF REFERENCE NUMBERS

Sackherstellvorrichtung

tube

reel

unwinding

Offnungsstation

Transverse cutting device

Bottom opening station

valve station

Bottom closing station

Cover Station

bag stack

transport means

hose Connector

Bottom center line

bottom square

triangle bag

folding edge

side flap

Approved ground

valve List

Bottom cover sheet

connecting area

adhesive track

projection

envelope element

Inner guide element

Extra guide element

Hot air device

air supply

heating element

Claims

claims

Method for molding at least one base onto a piece of tubing comprising plastic material, in which

- At least one end of the hose piece is raised to form a bottom rectangle and triangular pockets along at least one first folded edge,

- To close the bottom side flaps of the bottom rectangle along second folding edges, which are spaced from the first folding edge, are folded back, wherein the two side flaps then contact

a bottom cover sheet is applied to the floor and bonded by heat or by means of an adhesive to the side flaps and at least one triangular pocket,

characterized in that

the contacting surfaces of the side flaps and the triangular pockets are joined together at least in the region of the second folded edges to form a connection.

Method according to claim 1,

characterized in that

the connection extends at least over a region which differs from the second folded edge is 1 cm away.

3. The method according to any one of the preceding claims,

characterized in that

the connection of the contacting surfaces of the side flaps and the triangular pockets comprises at least the region of the respective intersection of the second folding edges and the diagonals of the triangles.

4. Method according to the preceding claim,

characterized in that

the connection extends from the point of intersection at least 1 cm in the direction of the respective second folded edge.

5. The method according to any one of the preceding claims,

characterized in that

the connection is produced by means of a hot air seal.

6. The method according to any one of the preceding claims,

characterized in that

the connection is produced by means of an ultrasonic welding.

7. The method according to any one of the preceding claims,

characterized in that

the connection is produced by an adhesive application.

8. Method according to the preceding claim,

characterized in that

the adhesive application is produced prior to the folding back of the side flaps, preferably before the bottom is raised.

9. Method according to one of the two preceding claims,

characterized in that

as adhesive application, a heat-activated hotmelt is applied. , Device for molding at least one bottom of a piece of tubing, which comprises plastic material, with

a bottom opening device for mounting at least one end of the hose piece to form a bottom rectangle and triangular pockets along at least one first folded edge,

- A bottom closing means for closing the bottom, with which side flaps of the bottom rectangle along second folding edges, which are spaced from the first folding edge, are folded back, wherein the two side flaps then contact

a cover sheet application device for applying a bottom cover sheet to the bottom and for bonding the bottom cover sheet to the tabs and at least one triangular pocket by means of heat or by means of an adhesive,

characterized in that

a device is provided for producing a connection, with which the contact surfaces of the side flaps and the triangular pockets can be connected to each other at least in the region of the second folded edges to form a connection.