EP0203079A1

EP0203079A1 - Method and device for producing sheet cushion-bags as well as cushion-bag obtained thereby

Info

Publication number: EP0203079A1
Application number: EP85904091A
Authority: EP
Inventors: Wilhelm Heisig
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-11-20
Filing date: 1985-08-13
Publication date: 1986-12-03
Also published as: WO1986003163A1; DE3442396A1

Abstract

Le coussin-sachet (2) est constitué de deux feuilles (3, 4), qui sont partiellement soudées entre elles pour constituer des chambres à air dans lesquelles un volume d'air déterminé est retenu. Conformément à l'invention, les chambres à air vides communicantes sont reliées à une pompe à air au moyen d'une seule ouverture de gonflage qui est scellée après le gonflage du coussin-sachet.The bag cushion (2) consists of two sheets (3, 4), which are partially welded together to form air chambers in which a determined volume of air is retained. According to the invention, the communicating empty air chambers are connected to an air pump by means of a single inflation opening which is sealed after the inflation of the bag cushion.

Description

Method and device

for the production of foil bag pillows

such as

Foil bags for treatment by the method and the device

The invention relates to a method and an apparatus for the production of foil pouch cushions and to a foil pouch for treatment by the method and the apparatus, consisting of at least two foils which are partially connected to one another, preferably by heat sealing, to form air chambers a predetermined volume of air or a gas-like medium is enclosed in the air chambers.

Such foil bag pillows are used to fill voids, for example in packaging, as shock-absorbing pads, as Protection of packaging for easily fragile or prone to damage goods and the like. Protective cushions are known, consisting of a foil bag filled with foam or shredded cellulose material, which is closed after filling. Furthermore, bubble wrap films are known whose deep-drawn knobs fill with air before sealing a cover film, which is then enclosed in a potty shape by the sealed cover film. These air cushion films, which are manufactured in wide webs exclusively in the film manufacturing company, are cut to size according to the desired formats, the air bubbles lying in the cutting line losing their stored air, as a result of which the cushion loses its cushioning ability in all peripheral zones. However, all these known foil bags or cushions have the disadvantage of a large volume, so that their transport to the user is made more difficult because volume is essentially transported in air and the user incurs considerable costs with regard to the storage of such voluminous cushions.

The invention has for its object to provide a method, an apparatus and a film bag treated with it, whereby the transport, storage and last but not least the production of such film bags is significantly improved.

This object is achieved by a method with the features specified in the characterizing part of patent claim 1. Advantageous further developments of this method result from patent claims 2 to 7.

In contrast to the prior art, in the method according to the invention pre-fabrication, that is to say at the film manufacturer, an air-empty film bag or a large number of such rolls lenman trained, coherent foil bag created and this extremely low-volume intermediate product is sent to the user, for example in roll form. In contrast to such known foil bags or packaging materials, no air needs to be transported and kept in stock. This is made clear by a comparison: with a cushion height or cushion thickness of, for example, 10 mm per pillow, a stack height of 10 m unfilled, ie empty pillows compared to filled pillows according to the prior art, results in a volume ratio of approx. 1: 1250, whereby only a pillow thickness of twice the film thickness results for unfilled pillows. The customer for such upholstery material no longer purchases pre-filled cushions with a large volume, but unfilled, flat-lying or foil bags wrapped on rolls. These foil bags are only filled with air using a device described below, for example directly at the user's packing station, and then immediately used for packaging or the like. This eliminates the need for a welded-in valve plug or valve hose, which is otherwise customary for air cushions. As is known, this has a disruptive effect on many consumer goods that have to be packed and that are packed in boxes, for example, in boxes.

Advantageously, the method steps specified in claims 1 to 7 can be synchronized and carried out with a single, relatively simple device. The central part of the device is a cutting mandrel, which has a preferably pyramid-shaped or square-shaped cutting tip, the edges of which are sharpened, whereby the injection opening is created very precisely with the formation of burr-free and pinch-free cutting surfaces. This cutting mandrel also serves Supply of compressed air or another gas-like medium into the existing air chambers of the foil bag, which communicate with each other in terms of flow. In order to create clear positional relationships between the cutting mandrel and the foils, a hold-down device is provided which partially presses the foils of the foil pouch lying on top of one another in the area of the blowing opening onto a work surface, for example a worktop, so that there are still flow openings for the air to be blown in. In this case, the injection opening is preferably arranged at the edge region of the film bag, as a result of which the device for carrying out the method and the entire process sequence are considerably simplified.

A component of the device for carrying out the method according to the invention is furthermore a welding stamp or heat sealing stamp which at least partially moves around the cutting mandrel and which, after the blowing opening has been created and the cutting mandrel has been positioned, is automatically pressed onto the foils, which are now filled with air, and a e.g. U-shaped welding of the foils causes. Before the welding ram is lowered, a special hold-down device is lowered onto the cushion, which has the task of keeping the air pressure in the air cushion away from the welding zone area during the welding phase. All parts of the device can be controlled by a simple control device with e.g. only two switches, which are operatively connected to a sensor element which scans the cushion thickness, are synchronized with one another and can be designed for fully automatic operation.

On the basis of the measures according to the invention, there is the possibility of combining a large number of film bags with one another to form a roll material or a roller conveyor, with separating seams, for example perforation seams, being provided between the individual film bags, by means of which the individual film bags can be separated from one another, for example by hand. The individual air chambers of each foil bag can be formed by nub-like welds within the area enclosed by the hermetically sealed edges of each foil bag, the mutual spacing of which determines the maximum pillow height. Instead of welding nubs, differently designed connection points can be provided, for example in the form of elongated welding points, through which tubular air chambers result, as is customary, for example, with air mattresses.

Further advantageous embodiments of the invention result from the exemplary embodiment shown in the drawing and described below.

It shows

FIG. 1 several foil bags connected in a roller conveyor,

FIGS. 2-6 the device for carrying out the method according to the invention in different working positions,

Figure 7u.8 enlarged representations of parts of the device in different working positions.

Figure 1 shows a plurality of foil bags 2 connected to each other to form a roll-up roller conveyor via separating or perforation seams, the roller conveyor and thus also each individual foil bag 2 consisting of two thin foils made of plastic, namely a bottom foil 3 and an upper foil 4 as illustrated in Figure 5, for example. These two foils are prefabricated at the outer edges 5 and at the abutting cross edges 6, so that they are airtight, for example welded or heat-sealed. In Figure 1, the Weld seams 7 along the transverse edges 6 on both sides of the separating seams 1 are shown. The thickness of each individual film 3/4 is, for example, 0.4 mm. This coherent roller conveyor is wound as a roller 8 for transport and storage. Welding studs 9, on which the lower film 3 is partially connected to the upper film 4, are evenly distributed over the area within the outer edges 5 and transverse edges 6, with the formation of intermediate air chambers 10 which are filled with air in the manner described below. The distance between these welding nubs 9 determines the thickness of the filled foil bag cushion 3/4. All air chambers 10 communicate with one another in terms of air technology, ie are connected to one another. An example in general form in FIG. 1 shows the manner in which the method for producing or filling the foil bag cushion 3/4 takes place. Air is filled into each individual foil bag 2 by means of a cutting mandrel 11, with which an injection opening is created in the immediate vicinity of an outer edge 5 of each foil bag 2 by inserting the cutting mandrel 11, which is provided with a sharply ground cross cut, into both foils 3 and 4 to facilitate the positioning of the cutting mandrel 11, a holding-down device 12 which circularly surrounds the cutting mandrel 11 and which only partially presses the two foils 3 and 4 against a work surface (not shown here) so that air coming from a compressed air source can flow into the individual air chambers 10, which is made possible by the fact that the individual air chambers 10 communicate with one another in terms of flow. After the air has been filled in, a U-shaped hold-down device 13 is then pressed against the foils 3, 4, likewise a U-shaped welding punch 14, which likewise moves the blowing opening, with the holding-down device 13 and welding punch 14 projecting beyond the outer edge 5, as shown in FIG. 1. Through the hold-down 13 ensured that the air pressure prevailing in the air chambers 10 is kept away from the welding point during the welding or heat sealing process by means of the heated welding stamp 14. Subsequently, all parts of the device are lifted off the finished foil bag cushion and the roller conveyor is transported by a grid dimension to carry out the filling process for the next foil bag 2.

The device suitable for carrying out the method outlined above is explained below with reference to FIGS. 2 to 8. The central part of this device is the cutting mandrel 11, likewise mentioned, which has a pyramid-shaped cutting tip 15 which is sharply ground in a cross-cut. Following this cutting tip 15, the cutting mandrel 11 is slightly conical, as shown in particular in FIGS. 7 and 8. Also following the cutting tip 15, the cutting mandrel 11 has a roughened surface 16, for example with a file effect. Up to the cutting tip 15, the cutting mandrel 11 is traversed centrally by a longitudinal bore 17 which is connected to a compressed air source or to an air pump in the manner described below. Immediately behind the cutting tip 15 are laterally in the cutting mandrel 11 several circumferentially distributed blow-out openings 18, through which the compressed air is blown into the air chambers 10 of the foil bag 2. The cutting mandrel 11 is fastened to a holding bush 19, which in turn is firmly connected to the axially Movable piston 20 of a first lifting cylinder 21, which is electrically actuated to carry out lifting movements and can then perform a lifting movement pneumatically or hydraulically. An L-shaped air path 22 is provided in the holding bushing 19 and is connected via a connecting piece 23 to an adjustable and controllable compressed air source or air pump 24. In The figures show the air flow by arrows. Attached to the cutting mandrel 11 is an adjusting ring 25 on which a compression spring 26 is supported. This compression spring 26 presses a hold-down device 12 which is displaceably mounted on the cutting mandrel 11 against a work base 27. As shown in particular in FIGS. 7 and 8 in connection with FIG. 1, this hold-down device 12 has a circular cross-section and dome-like recesses 28 distributed between the periphery and at the free end Support webs 29, with which the hold-down device 12 is supported on the work base 27 or on the foils 3, 4, leaving airways free in the area of the recesses 28. In alignment with the cutting mandrel 11, a bore 30 is provided in the work base 27, the clear width of which is slightly larger than the outer diameter of the cutting mandrel 11 in the area of the cutting tip 15 plus twice the thickness of the two foils 3 and 4, as illustrated in FIGS. 7 and 8. On the piston 31 of a second lifting cylinder 32, which can be connected to the first lifting cylinder 21 via a plate 33, a plate-like, extended support 34 is rigidly fastened by means of a screw connection, to which welding punches 14 and hold-down devices 13 are fastened in the manner described below. The U-shaped welding stamp 14 is directly and firmly connected to the carrier 34. This welding stamp 14 is moved outwards by the hold-down device 13, which is relatively displaceably mounted on threaded rods 35 with respect to the carrier 34 and is pressed against the working base 27 by compression springs 35. In the rest position, the free pressure end of the holding-down device 13 slightly projects beyond the free welding end of the welding punch 14, ie when the carrier 34 is lowered after the lifting cylinder 32 has been actuated, this holding-down device 13 leads the welding punch 14. 37 denotes a float plate serving as a sensor element of a sensor and control device, which is of relatively large area and plate-like design and which is firmly connected to an elongated, rod-like switching plunger 38. This switching plunger 38 is slidably mounted in guide tubes 39 of a support plate 40 of the lifting cylinder 32 and is pressed in the direction of the work pads 27 by a compression spring 41 which is supported on the support 3 on the one hand and on the float plate 37 on the other hand. In the form of a limit switch is at the upper end of the switching plunger 38, the switching contact 42 of a first electrical switch is arranged, while below an actuating projection 43 of the switching plunger 38, the switching contact 44 of a second electrical switch is arranged. The function of these two switches is illustrated below. The first switch is operatively connected to a timing element or timing relay, not shown.

The mode of operation of the above-described device for carrying out the method is explained below:

In Figure 2, the device is in the rest position, with the pistons 20 and 31 of the two lifting cylinders 21 and 32 being moved upward. For the sake of clarity, the films of the film bag to be treated are not shown in FIGS. 2 to 4. Now an unfilled, i.e. air-empty film bag 2 is pushed onto the work surface 27 to below the device after a film bag filled with air has previously been removed from the work surface 27. The float 37 thus falls down onto the empty foils 2 and 3, with the switch contact 44 being actuated by closing the contact elements. The lifting cylinder 21 is activated via the associated switch. The following filling process is based on the figures

3, 4, 7 and 8 clarified. When the lifting cylinder 21 is actuated, the piston 20 moves downward and presses the cutting mandrel 11 into the bore 30 Hold-down device 12 pressed against the two foils 3 and 4 lying one on top of the other. The sharply ground cutting edges of the cutting tip 15 cut through the two foils 3 and 4 in a cross shape, forming and taking along the edge segments 3 'and 4' created by the cross cut (see FIG. 7). These edge segments rest loosely between the cutting mandrel 11 and the upper edge of the bore 30. Now the cutting mandrel is raised slightly from the position shown in FIG. 7 to the position shown in FIG. 8 by a renewed actuating stroke of the lifting cylinder 21, in which position the side blow-out openings are between the two foils 3 and 4. With this raising of the cutting mandrel 11, the edge segments 4 'of the upper film are carried upwards by the roughened surface, as shown in FIG. 8, so that the edge segments 3' and 4 'are turned inside out and the blow-out openings 18 of the cutting mandrel 11 are located between them. Now the actual filling process is carried out by pressing compressed air between the top film 4 and bottom film 3 until a predetermined air pressure is obtained in the air chambers 10 of the film bag 2, which air pressure can be read, for example, on the clock-like display element of the compressed air source 24. During this filling process, the float divider 37 is switched off the growing thickness of the foil bag cushion is adjusted upwards. In the upper extreme position of the floating plate 37 and thus the switching plunger 38, the switching contact 42 is closed and the associated electrical switch is actuated, which in turn causes the lifting cylinder 32 to be actuated. This actuation position of the device is shown in FIG. 5. Immediately after actuation of the switch contact 42, the piston 31 of the cylinder 32 and thus also the carrier 34 are lowered. As illustrated in FIG. 6, after a predetermined stroke distance, the U-shaped hold-down device 13 is placed on the now filled film bag 2 and against it Working pad 27 pressed, whereby the air chambers 10 of the film bag 2 are sealed airtight with respect to the injection opening. Immediately afterwards, the U-shaped welding stamp 14 also strikes the foils 3 and 4 and the actual welding process takes place around the injection opening (FIG. 1). The hold-down device 13 keeps the air pressure away from the welding point. With the actuation of the first switch 42 or the lowering of the carrier 34, a timer is actuated, for example a time relay, by which the welding stamp 14 and hold-down device 13 persist in the lowered position during a predetermined welding and cooling phase, and after this welding and cooling phase both lifting cylinders 21 and 32 adjust their associated device parts away from the work surface 27 into the raised rest positions. The now filled and finished foil bag cushion 2 is now pulled sideways away from the work surface 27 and the following, still empty foil bag 2 comes to lie below the device. This, in turn, causes the float plate 37 together with the switching plunger 38 to fall down onto the layers 3 and 4 lying on top of one another, and the switching contact 44 is actuated via the actuating projection 43 and the next filling process takes place automatically, initiated by actuating the lifting cylinder 21 and lowering the Cutting arbor 11.

In order to facilitate the insertion of the foil bag under the device, the spring plate 37, which is pressed resiliently downward, can have an angularly upwardly bent edge, onto which the foil bag 2 pushed onto the work surface 27 runs and thereby presses the floating plate 37 slightly upwards.

After all the process steps have been carried out by means of the device explained, there remains on the edge of the film bag only the small injection opening in the area of the edge segments 3 'and 4' and the U-shaped connection or welding point (see Figure 1).

It should also be mentioned that the switch contact 42 also serves to switch off the compressed air source 24 after the predetermined cushion thickness has been reached.

Claims

Patent claims

1. A process for the production of foil bag pillows, which consist of at least two foils, which are partially connected to one another to form air chambers, preferably by heat sealing, a predetermined volume of air or a gas-like medium being enclosed in the air chambers, characterized in that the prefabricated air-empty foil bag (2), the air chambers (10) of which communicate with each other with a single injection opening, is connected to an air pump (24) and all air chambers are filled with air, and then the injection opening is preferably sealed off from the air chambers by heat sealing.

2. The method according to claim 1, characterized in that the injection opening through a cutting mandrel (11) formed blowing nozzle of the air pump (24) is created by cutting out at least one film (3, 4) and by simultaneously positioning the blowing nozzle in the blowing position.

3. The method according to claim 2, characterized in that with the cutting mandrel (11) both foils (3, 4) are cut through to form two film edges bent in the same direction (3 ', 4') of the foils and that then by limited retraction of the cutting mandrel (11) the film edge (4 ') of the one film (4) is turned in the opposite direction and is lip-like opposite the film edge (3 ') of the other film (3) is formed.

4. The method according to any one of the preceding claims, characterized in that simultaneously with the creation of the injection opening, the positioning of the cutting mandrel (11) and the blowing of the air into the air chambers (10) of the film area adjacent to the injection opening by a hold-down device (12) is partially pressed against a work surface (27).

5. The method according to any one of the preceding claims, characterized in that during the blowing process, the cushion thickness representative of the air pressure prevailing in the air chambers (10) is measured by means of a float plate (37) and when a predetermined cushion thickness is reached, the air pump ( 24) is switched off automatically.

6. The method according to any one of the preceding claims, characterized in that after completion of the blowing process, the foils (3, 4) are connected to one another preferably by heat sealing along a connecting point moving around the blowing opening.

7. The method according to claim 6, characterized in that before and during the connection process, the foils (3, 4) are compressed airtight along a moving the blowing opening, located between the connection point and the air chambers (10) pressure point.

8. Device for carrying out the method according to any one of the preceding claims, characterized in that a compressed air source (24) is connected in terms of flow to a cutting mandrel (11) which forms the injection nozzle of the air pump and is preferably connected by a lifting cylinder (21) to one of the foils ( 3, 4) supporting work surface (27) can be lowered and raised, which has at the free end a preferably pyramid-shaped cutting edge having cutting edge (15) and is partially traversed by a hole (17) connected to the compressed air source to the side immediately adjacent to the cutting tip Blow out openings (18).

9. The device according to claim 8, characterized in that the cutting mandrel (11) in the region of the blow-out openings (18) has a roughened surface (16) and is conical at least in this region.

10. The device according to claim 9, characterized in that the cutting mandrel (11) with the material thickness of the two foils corresponding game in a bore (30) in the work surface (27) insertable and taking the film edge or the edge segments (4 ') a film (4) can be returned by a short actuation stroke, which actuation stroke is dimensioned such that the blow-out openings (18) come to lie between the film edges of both films.

11. Device according to one of claims 8 to 10, characterized in that on the cutting mandrel (11) a resilient, this at least partially moving hold-down (12) is mounted, which resiliently and partially on the foils when the cutting mandrel (11) is lowered ( 3, 4) supports.

12. Device according to one of claims 8 to 11, characterized in that a heatable welding stamp (14), which at least partially moves around it and is preferably concentric to the cutting mandrel (11), is provided, preferably by means of its own lifting cylinder (32) on the working base ( 27) and can thus be lowered onto the foils.

13. The apparatus according to claim 12, characterized in that a cutting die (14) at least in the region of the air chambers (10) moving down device (13) is provided, which together with the welding die and preferably through its lifting cylinder (32) on the film spring. is lowerable and leads the welding stamp.

14. Device according to claims 12 and 13, characterized in that the welding stamp (14) and hold-down (13) on a with the piston (31) of the lifting cylinder (32) connected to the carrier (34) and are adjustable together with this.

15. The device according to one of claims 12 to 14, characterized in that the welding stamp (14) and hold-down (13) are substantially U-shaped and protrude with their free legs over the film edge (5).

16. Device according to one of claims 8 to 15, characterized in that it has a sensor and control device, with a preferably designed as a floating plate (37), the respective cushion thickness sensing sensor member, which as an actuating element for the two lifting cylinders (21st , 32) assigned electrical switches (42, 44) is used.

17. The apparatus according to claim 16, characterized in that the sensor member has a with the float divider (37), by the force of a spring (41) against the work pads (27) pressed and movable perpendicular to the work pad switching plunger (38), in the The contacts (42, 44) of at least two switches controlling the lifting cylinders (21, 32) are located on the path of movement.

18. The apparatus according to claim 17, characterized in that the first switch (42) can be actuated by the switching plunger (38) in its extreme position lifted from the work surface (27) and the actuation of the lifting cylinder (32) to lower the carrier (34). of welding stamp (14) and hold-down device (13) on the filled cushion, and that the second switch (44) through the switching plunger (38) when falling from said extreme position against the empty films (3, 4) of the next film bag (2 ) can be actuated and serves to actuate the lifting cylinder (21) for lowering the cutting mandrel (11) and the associated hold-down device.

19. The apparatus according to claim 18, characterized in that with the actuation of the first switch (42) or the lowering of the carrier (34), a timing element, preferably a timing relay, is actuated by the welding stamp (14) during a predetermined welding and cooling phase ) and hold-down device (13) persist in the lowered position and by means of which after this phase both lifting cylinders (21, 32) are adjusted into their rest position lifted from the work surface (27).

20. Foil bag for treatment by the method and the device according to the preceding claims, characterized in that it consists of two at the edges (5, 7) air-tightly interconnected foils (3, 4), in the area enclosed by these edges partially e.g. are connected to one another by stud welding to form air chambers (10) which communicate with one another.

21. Foil bag according to claim 20, characterized in that a plurality of foil bags (2) are combined to form a roll-up roller conveyor, with separating seams (1) between the individual foil bags e.g. Perforation seams are provided.