CZ9902945A3 - Welding apparatus, sealing plate and welding process - Google Patents

Abstract

Welding equipment for welding containers (2) with non-circular, especially polygonal like four, six, octagonal or with elliptical holes, it has conveyor belts on which the container is placed (2) with holes for welding moves and feed device for sealing plates (15) that connect to the openings of containers (2) and there it is inductively welded and further has one or more inductive ones loops (11) to induce current in the sealing plates (15). The induction loops (11) are adapted to the shape and dimensions the welding edges (14) of the container openings (2) and form homogeneous field and move parallel to movement conveyor belts. Means for controlling the speed of movement The induction loops (11) are arranged parallel to the motion of the belts, and the apparatus further comprises means for time regulation the belts conveying the containers (2) and the downward pressure a welding. The containers (2) move during the induction process to create a delay either with stops or with the induction loops (11) and the welding edge (14) move in same time or at the same speed. Sealing plate (15) for use in welding equipment is non-circular, in particular polygonal or elliptical and has at least one metal foil (16) and on the underside of the container (2) the layer (9) s sealing material adapted to the container material. Upper the sealing plate part (15) is arranged in the closure (3) of the container (2), and the metal foil (16) for the closure (3) is covered with a layer (17) of paper or a thin foam sheet or wax layer (17) adhesive material or polyethylene and is bonded to the top panel sealing plates (15).

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a welding apparatus for welding containers with non-circular, in particular, rectangular, such as four, six, octagonal or elliptical openings, conveyor belts on which the container with welding openings is moved and a feeder for sealing plates connecting to the container openings; there inductively welds, and with one or more induction loops to induce current in the sealing plates. The invention further relates to a method for welding apertures in containers and a sealing plate used therein.

BACKGROUND OF THE INVENTION

For economical storage of the boxes, these are preferably non-circular containers, in particular multi-purpose containers, for example for cocoa powder. Therefore, more rectangular containers can be stored on the same storage area than when using circular containers. Finally, they are also preferred in production.

It also proves that the closing of the rectangular containers is more difficult than the closing of the circular containers. Therefore, rectangular containers are often provided with circular upper openings. In this case, it is particularly advantageous to have a plurality of glass containers whose upper open flange can be sealed.

However, these glass containers are not suitable for storing light-sensitive products such as cocoa powder or espresso powder. Decomposition or other harmful effects could be triggered in the glass container when light is incident. It is therefore known to use some kind of opaque plastic containers directly for such products. However, sticking the film to the upper edge of these plastic containers proves to be problematic. For example, the bonding of known films to HDPE (high density polyethylene) is not sufficiently or at all reliable.

It is known to weld containers of this kind with light-sensitive products or also with dairy or protein products by means of thermal conduction. The heat is then fed directly into a suitable foil, which is then fused to an opening in the plastic surface of the container. The heat may be obtained in the film by means of a current or other means, for example by thermal conduction. For example, products such as crab salad are cooked in this way using aluminum foil or plastic foil or metal foil plastic foil. However, conduction welding proves in most cases to be complicated and frequent. It is therefore unsuitable for a variety of uses, for example in containers with light-sensitive products such as cocoa or espresso powder or HDPE containers with dairy or protein products, as welding through layers that aluminum foil upwardly closes the container isolates it is almost impossible.

Further, it is known to inductively weld containers with round filling holes. EP 0 223 517 B1 discloses a device by which it is possible to inductively weld containers of plastic material with a closure cap also of plastic as well as with a metal layer. The induction loop used in the device has a shaping corresponding to the weld edge. It comprises at least one square shape. A ferrite coupling unit is arranged therein. When welding, an induction loop occupies the? · 9 9 · * · · · · · ····· * _Λ · · · · · 4

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with lid surface. The ferrite coupling unit is arranged next to the induction loop.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for welding containers with non-circular, in particular multilateral, such as four, six, octagonal or elliptical apertures.

SUMMARY OF THE INVENTION

This object is achieved by a device for welding vessels with non-circular, in particular multilateral, such as four, six, octagonal or elliptical holes, with conveyor belts on which the vessel with welding holes moves and with a supply device for sealing plates which are connected to the vessel holes; there inductively welds, and with one or more induction loops for inducing current in the sealing plates, according to the invention, the essence of which is that the induction loops are adapted to the shape and dimensions of the welding edges of the container openings and create a homogeneous field, induction loops movable parallel to the conveyor belts and the means for controlling the speed of movement of the induction loops is arranged parallel to the direction of movement of the strips, and means are provided for temporally regulating the strips conveying the containers and the course of the downforce and welding.

The method of welding non-circular, especially multilateral, such as four, six, octagonal or elliptical container openings is solved by the invention such that the containers to provide constant spacing between the welding edges and the induction loop during the welding process are moved either with stops to create a delay or induction loop and the welding rim moves at a coordinated tact or at the same speed such that the induction loop or induction loop pressure element is lowered precisely from above onto the seal plate closure, * 9 9 «··· * 9 · * ft» ···· «· * · · ·. ft

And that the induction welding takes place under the effect of a predetermined pressure or without pressure, that the induction loops or the pressure element are lifted up after the induction welding and that the vessel is further guided out from the welding equipment.

For a sealing plate used for welding having a non-circular shape, in particular a polygonal or elliptical shape and at least a metal foil and a layer of welding material adapted to the container material on its underside, the object is solved by arranging a laminated top in the container cap and that the metal foil has a layer of paper or a thin foamed film on the side facing the closure or is covered with a layer of wax, adhesive or polyethylene and is connected to the top of the sealing plate. Further embodiments of the invention are described in the appended claims.

Preferably, the distance between the induction loop and the welding edge is adjustable or selectable depending on the shape, size and material of the welding edge and / or the sealing plate. For induction welding, the induction loops are preferably bent in the same shape and dimensions that correspond to the upper peripheral welding edge of the container. The welding process takes place either under pressure or under pressure. In the latter case, the sealing plate is pressed against the weld edge either by the container closure or by the pressure element.

This provides a device and a method for welding non-circular holes in the containers, in which uniform induction occurs. This eliminates the tanning of the longitudinal surfaces of the rectangular or elliptical container openings or the lack of welding at the corners. By either unscrewing screwing or connecting the caps to the neck of the canisters or the thrust available, it is advantageous to save the additional cost of the thrust device, which is otherwise to ensure error-free operation. • 4 4 9 4 • 4 4 9 4

999 ···· «·· 444 99 9» Welding conventional. There is also no prolongation of the welding process time, because either the induction loop and the container closure move in parallel at the same clock or at the same speed or by parallel guidance of multiple containers during the welding process can eliminate the time loss created when the welding containers stop. In the actual filling process of the containers, such parallel guidance is already common in the food industry.

By providing a double winding or simply double-running winding of the induction loop, there are no more inhomogeneities of current in the winding in the region of the inlet and outlet. An exactly matched homogeneous field is created. Welding of non-circular containers is thus done in an optimal way, especially also in corners.

The induction loops are preferably arranged in the pressure element or elements. However, they can also be arranged next to or outside the pressing elements, also without additional pressing elements. Preferably, a large thrust element is arranged in the welding device with the induction loops arranged side by side in the induction process preferably in a manner corresponding to the spacing between the parallel guided vessels. However, for this embodiment, a plurality of thrust elements with an induction loop dimensioned correspondingly can be arranged side by side or one after the other. Preferably, the induction loops are arranged sequentially when they move at the same beat and / or at the same speed as the containers on the conveyor belt.

The welding edges of the containers are already preferably provided with sealing plates and a closure, which are sized accordingly. However, they can also first be provided with a closure and a sealing plate in the region of the welding device.

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For welding with a pressure element, the pressure element with an induction loop is lowered under a certain pressure on the container. By means of the closure, the pressing element advantageously pushes the metal foil disposed on the sealing plate as a so-called antenna or inductive welding means in connection with the welding layer on the upper peripheral edge of the container. By applying current in the induction loop, the metal foil is attached to the upper peripheral edge of the container. The connection of the metal foil and the peripheral welding edge is the same at each point of the upper peripheral edge of the container. Also at the corners of the opening in the container, the foil welding is optimal since the field formed in the induction loop is precisely matched to the dimensions of the upper peripheral welding edge of the container and is homogeneous.

In order to create complete homogeneity of the field, an induction loop double winding is preferably used.

Also, the distance between the induction loop and the welding edge can advantageously be selected depending on the shape, size and material of the welding edge and / or the sealing plate.

Adapting to the different dimensions and shapes of the openings in the containers is accomplished by arranging an assortment of different, in particular, induction loops of the integrated induction loops with corresponding dimensions and shapes. If the container rim shape and dimensions change, the induction loops or induction loops with the thrust element are replaced completely. After the welding process is finished, the induction loop with the pressure element or the pressure element is pulled up from the container. The drive device transports the container out of the welding device, in particular along the previous parallel guide, to create a delay and to equalize the production speed, again in one row.

For induction loops, in particular, means for regulating the desired current to produce an adapted homogeneous field are preferred, for the pressure element means are provided for regulating the desired pressure acting in the induction process. In particular, control devices are provided for the timing control of the conveyor belt, the pressing and welding process and the possible adjustment of the pressure during the welding process. In particular, thermoplastic materials, in particular polymers such as polypropylene, polyester, PVC or the like, or in particular HDPE (High Density Polyethylene), or also glass, can be used as the container material.

The sealing plates have an additional layer of paper, thin foil or wax, glue or polyethylene in the direction towards the container closure on the metal foil, in particular the aluminum foil and the welded layer which is arranged towards the product in the container. board that is inserted into it. It is preferably made of polyethylene or polypropylene foam, laminated or made of laminated cardboard.

Overview of the drawings

In order to further illustrate the invention, the following examples illustrate a device for welding non-circular apertures of containers for light-sensitive products according to the figures, in which Fig. 1 is a sectional view of a container with sealing plate, closure and induction loop according to the invention; Fig. 2 is a top plan view of a partial section of the induction loop pressing element of Fig. 1; Fig. 3 is a top view of another embodiment of an induction loop according to the invention, with a container; 5 shows a perspective basic diagram of a welding apparatus according to the invention with a branching of conveyor belts to create a delay.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a cross-sectional view of a first embodiment of an induction loop in the pressing element 10 of the invention. The pressure element 10 is adapted to receive the induction loop 11. The induction loop 11 is formed as a double winding. This eliminates the disadvantage that arises in an induction loop with only one winding in the region of the inlet and outlet of the current, namely a slight inhomogeneity. For the double winding of the induction loop 11, inlets 12 and outlets 13 are provided. A sealing plate 15 is provided as a welding edge 14 of the container 2 at the upper edge of the container. The sealing plate 15 has three layers. Adjacent to the upper edge 14 of the container is a welding layer 9 above which a metal foil 16, for example an aluminum foil, is arranged. The welding layer 9 preferably covers the entire metal foil 16. During the welding process it melts in the region of the welding edges 14, and therefore consists of welding material coordinated with the material of the container. Above the metal foil 16, a sealing material layer 18 is provided as an upper part of the sealing plate 15. This layer 18 abuts the closure. It consists mainly of

Polyethylene or propylene foam and is preferably laminated at least on the metal foil side. However, the layer 18 may also be composed of laminated cardboard.

This layer 18 is inserted directly into the closure 1 and deposited on the inner surface 19. A layer 17 is arranged between the metal foil 16 and the layer 18. It preferably consists of a thin layer of paper and a thin foamed film. Alternatively, it may also consist of wax, adhesive or polyethylene. The layer 17 serves as a connection with the layer 18.

The container 2 is filled with the product 20. It may be, for example, a cocoa powder or an espresso powder, a milk or protein product or the like. The welding layer 9 should be made of a material that does not damage the quality of the product in the container 2. In order to protect the product also after the first opening of the container, i.e. after the metal foil 16 has been torn off the upper peripheral edge 14 of the container, layers 17 and 18 are provided in the container closure 3. Also these layers are therefore preferably made of material which does not react with the product in a container or has no other negative effects on the product.

In order to ensure optimum welding of the peripheral rim 14 of the container at each location thereof, the induction loop 11 is adapted to align precisely with the upper rim of the container or the welding rim 14. It is integrated into the thrust element 10 such that the foil 16 bonds to the top edge 14 of the container by fusing. In order to ensure a secure laying of the film 16 without wrinkling on the upper edge 14 of the container, the pressing element 10 is pressed at a given pressure p. This pressure can be adjusted by a control means not shown here in a predetermined size range. The current down pressure is also entered. The pressure element 10 is then displaced

♦ · Switching off the power supply to the induction loop extends upwards from the container 3 closure.

Giant. 2 shows a top view of the pressing element 10 according to FIG.

1. The pressure element 10 is shown in cross-section to visualize the position of the induction loop 11. The induction loop 11 lies as a double winding in one plane on the upper edge 14 of the container, highlighted in broken lines. Inductive welding of plate-shaped inductive fields is usually used for circular container openings. These plate-shaped induction fields arise in the plate by means of a coil bent to the shape of a wavy line. Since the same means are now available for circular openings for the outer edge of the container opening, welding takes place uniformly over the entire region of the upper peripheral edge of the container.

Now, if a coil bent in the shape of a wavy line has been provided in the plate at the non-circular, i.e., polygonal, opening of the container, there would be a tanning opening in the region of the longitudinal sides 21.22.23.24. In the corner area 25., 26., 27.28. an opening in the container would result in incomplete welding. By arranging the induction loops 11 which correspond to the dimensions of the weld edges 14, the corners 25 to 28 weld as well and securely as the longitudinal sides 21 to 24.

By arranging the assortment of thrust elements 10 of different sizes with induction loops 11 of different dimensions, in a manner corresponding to the actual dimensions of the sealing plates 15, which are dimensioned correspondingly to the weld edges 14, rapid adaptation is possible by replacing the corresponding thrust elements 10 during operation. Likewise, the thrust elements with multiple induction loops arranged side by side can also be arranged in different dimensions. For a faster exchange, for example, a latching mechanism can be provided in the welding device to the "4" "4" "9" · 9 · 9 · 9 · 9 · 9 · 9 · 9 »·« «» »» »» »» »» »» »» »» »» »» »» »» »» »» »» »» »»

Giant. 3 shows a plan view of a second embodiment of an induction loop according to the invention with a receptacle inserted underneath. The container 2 has an octagonal shape as well as its upper peripheral welding edge 14. This is highlighted in FIG. 3 by a line.

The induction loop 38 is mounted on this welding edge 14 on the container closure 3. The sling is provided with an induction loop. In contrast to the embodiment according to FIG. 1 or FIG. 2, a pressure element is not provided in the embodiment according to FIG. The induction loop 38 is provided without a thrust element. It is arranged above the container closed by the closure and welds the welding edge 14 with the sealing plate without applying pressure to the closure. The required pressure is already adjusted by the cap screwed onto the opening in the container. The application of additional pressure is no longer necessary for the welding process. Alternatively, the induction process can also be completely depressurized. The sealing plate is not pressed against the welding edge by the closure. Nevertheless, its welding layer melts to the welding edge of the container during the welding process. For this purpose, the induction loop is arranged at a suitable distance from the welding edge and a homogeneous field which forms them appropriately adapted to the shape, size and fusible material.

Figure 4 shows the corresponding welding process with the containers and induction loops of Figure 3. Figure 4 shows two containers with the induction loops 38 arranged above them in the holder 29. The containers 2 are seated on the conveyor belt 30 and move with him. The direction of movement is indicated by arrows. The containers reach the welding device according to the invention during movement on the conveyor belt 30. There, the holders 29 with the induction loops 38 are lifted above the closures 3 of the cans 2.

They then follow the movement of the vessels in parallel during the welding process. This is also highlighted by the arrow in Fig. 4.

During the welding process, it should be noted that the distance from the induction loop and the welding edge does not change. The distance should remain constant throughout the welding process.

If an induction loop pressure element is to be used for the welding process, as shown in FIGS. 1 or 2, in the welding device according to the invention the receptacles, upon their entry into the device, are lowered with the closure pressure element 3. The pressure on the closure begins to act simultaneously with the movement parallel to the movement of the containers. The welding process then takes place as previously described.

Before the containers leave the welding device, either the induction loop 38 in the holder 29 or the pressure element 10 with the induction loop 11 is lifted upwards from their closures so that the fully welded container can be further used in the manufacturing process.

Giant. 5 shows a perspective diagram of the principle of an induction welding apparatus according to the invention with a branched feeder strip

31. Three containers 2 are arranged in succession on the supply belt 31. The containers are already provided with a closure 3. At the upper peripheral edge of each container, i.e. below the closure, sealing plates are provided, which in this case are not visible.

The supply belt 3 is divided at the point A of the branching into three belts 34. 35,

36. On the three belts 34, 35, the three containers 2 with the associated closures 3 are arranged in parallel. A thrust element 37 is provided above the three containers. This is indicated by a broken line in FIG.

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Induction loops 41 are arranged above each receptacle in the pressure element 37. The induction loops 41 have dimensions corresponding to the receptacles 2 and their closures 3. The induction loops 41 are also indicated by broken lines in FIG. During the welding process, the thrust element 37 is lowered onto the shutters 3. They are then pressed against the shutters by a predetermined pressure. At the same time, current is fed into the induction loops. This ensures optimal welding of the containers 2.

After a predetermined time, the pressing element 37 is lifted up again from the container closures. The induction loops are no longer energized.

The welding device actuates the containers which have been stopped on the belts 34, 35, 36 during the welding process. In a manner corresponding to the speed control of the individual belts, the containers 2 at the branching point B are again brought in line on the conveyor belt 3 9. The current conveying direction of the belts 31, 34, 35, 36, 39 is indicated by arrows. The containers 2 arrive at the feed belt 1 from the filling device and the device in which they are provided with sealing plates and closures. After leaving the welding device, the finished, welded containers for the conveyor belt 39 reach, for example, the packaging department.

Claims (12)

PATENT CLAIMS 1. Welding equipment for welding vessels with non-circular, in particular, rectangular, such as four, six, octagonal or elliptical holes, with conveyor belts (30,3 1,34,35,36,39) on which the vessel with welding holes moves and s a feeder plate for sealing plates which are coupled to the container openings and inductively weld there, and with one or more induction loops (11,38,41) for inducing current in the sealing plates, characterized in that the induction loops (11,38,41) ) are adapted to the shape and dimensions of the welding edges (14) of the container openings and create a homogeneous field that the induction loops are movable parallel to the movement of the conveyor belts, the means for controlling the speed of movement of the induction loops (11,38,41) is arranged parallel to the movement of the belts and that means are provided for temporally regulating the bands (30,3, 1,34, 35, 36, 39) conveying the containers and during the pressing and welding process. 2. Welding equipment for welding containers with non-circular, especially multilateral, such as four, six, octagonal or elliptical openings in a container with conveyor belts (30,3 1,34,35,36,39) on which the container with openings for welding and with a sealing plate feeder that connects to the holes in the container and inductively welds there, and with one or more induction loops (11,38,41) to induce current in the sealing plates, characterized in that the induction loops (11, 38, 41) are adapted to the shape and dimensions of the welded edges (14) of the container openings and create a homogeneous field that means are provided to compensate the conveyor belt travel speeds relative to the induction loops; 15 • 9 9 9 9 9 9 9 999 9 · 9 že 9 prostředky 9 časové 9 · 9 · 9 · 9 · 9 · 9 · 9 being arranged to temporally control the bands (30,3 1,34,35,36,39) conveying the container and the pressing and welding process. Welding device according to claim 2, characterized in that the speed compensating means has on the conveyor belt (39) a means for creating a delay in the form of dividing the supply belt (31) into several belts (34,35,36) with a subsequent return supply. onto a conveyor belt (39). Welding device according to one of the preceding claims, characterized in that the distance between the induction loops (11,38,41) and the welding edge (14) is adjustable or selectable depending on the shape, size and material of the welding edge and / or the sealing and that the sealing plate (15) is pressed against the welding edge (14) during the welding process by either the container cap (3) or the pressing element (10,37), or that the welding process occurs without pressure. Welding device according to one of the preceding claims, characterized in that the induction loops (11,38,41) are designed as double spirals or as double loops to create a homogeneous field. Welding device according to one of the preceding claims, characterized in that means are provided for temporally controlling the pressure setting during the welding process. • 0 • 0 0 • · 0 0 0 0 • 00 00 0 0 0 0 0 0 0 000 · 000 0 Ί. Sealing plate for use in a welding device according to one of claims 1 to 6, wherein the sealing plate (15) is non-circular, in particular polygonal or elliptical, and has at least one metal foil (16) and a layer (9) on the underside of the container (2). ) of a sealing material adapted to the container material, characterized in that an upper part of the sealing plate arranged in the container closure (3) is provided, and that the metal foil for the closure (3) is covered with a paper or thin foil layer (17); a layer (17) of wax, adhesive or polyethylene and is connected to the top of the sealing plate (15). Sealing plate according to claim 7, characterized in that the upper part (18) of the sealing plate (15) consists of polyethylene or polypropylene foam which can be laminated. Sealing plate according to claim 7, characterized in that the upper part (18) of the sealing plate (15) consists of laminated cardboard. A method of welding non-circular, especially multilateral, such as four, six, octagonal or elliptical holes in containers by induction, wherein the containers (2) move to provide equal spacing between the welding edge (14) and the induction loops (11,38,41). during the induction process to delay either the stops or the induction loops (11,38,41) and the welding rim (14) move at the same clock or at the same speed, the induction loops (11,38,41) are lowered exactly from the top to the shutters (3) the vessels (2) with the sealing plates (15), • inductive welding is performed, the induction loops (11,38,41) are raised up after the induction welding, and that the vessels (2) are further removed from the welding device. Method according to claim 10, characterized in that the cans (2) are occasionally grouped and welded simultaneously to form a delay to equalize the production rate, and that the cans (2) are passed through point (B) after leaving the welding apparatus. branching back in line on one conveyor belt (39). Method according to claim 10, characterized in that the induction loops (11,38,41) move parallel to the closures (3) of the containers (2). Method according to claim 12, characterized in that the induction loops (11,38,41) move next to the pressure element