EP1905574B1 - Device and method for manufacturing gas-filled packing elements - Google Patents

Description

The present invention relates to a device for producing gas-filled packing according to the preamble of claim 1. Furthermore, the invention relates to a method for producing gas-filled packing according to the preamble of claim 10.

Such gas-filled - usually air-filled - filler are nowadays increasingly used as a filler, especially for the shipment of sensitive goods. Compared to conventional filling materials for packaging purposes, e.g. Foamed plastic packings, the gas-filled packings can be made in the place where they are needed from a provided on a roll half-tube by "blowing" the film in a special device, whereby the volume of the packing compared to the original Volume of the film roll increased by a multiple (typically at least a factor of 10). After use, the air from the packing can be easily let out again, so that the waste volume is reduced, with recycling of the films is of course readily possible.

An apparatus for producing such gas-filled packing is known from WO 02/26589 A1 This document is to be made by reference in particular with regard to the configuration of a suitable half-tube film to the subject of the present disclosure. In this document, a continuous filling device is described in which a one-sided open, prefabricated Folienhalbschlauch initially passed a gas filling device, deflected at an angle and then welded by the action of a heated via a welding run, Teflon-coated steel strip. Although the known device works quite satisfactorily, both the design effort and the maintenance, especially due to the use of a Teflon-coated steel strip is significant.

From the DE 203 15 643 U is a generic device is known in which the welding tool is formed as directly abutting the foil material Schweißkufe. The transport of the film half tube is carried out according to this document by belts and guide wheels. Although in the known device the need for teflonized steel strips for the welding process is eliminated, however, a relatively complicated mechanism with several drive elements is required for the transport of the film, which must be exactly synchronized with each other, so that the superimposed at the beginning of the filling process still loosely superimposed. and bottom film existing film half-hose does not run out of the machine or folds are thrown between the top and bottom film, which would make an air-tight weld impossible. The corresponding drive means with gears are therefore expensive in the known device, require a relatively large space and due to the friction and transmission losses require a drive motor with relatively high performance, although for the transport of the film by the device actually no particularly large drive power would be required.

The present invention has for its object to improve a generic device or a corresponding method to the effect that the drive with a constant quality and speed of the filler produced is structurally significantly simplified, which in turn leads to the saving of manufacturing and maintenance costs.

The solution of the above object is achieved by means of a device having the features of claim 1 and by a method having the features of claim 9.

Advantageous embodiments of the invention are described in the dependent claims.

One aspect of the present invention is to simplify the drive for the transport of the film half-hoses in that it takes place in the transport direction only behind the gas filling device and behind the place of use of the welding tool. Therefore, no conveyor belts od. Like. As required in the generic state of the art, and the drive mechanism can be greatly simplified and operated with lower drive power.

With the approach according to the invention, however, the problem arises that the film half-tube in the gas filling device can no longer be pressed firmly against them, as is to be ensured in the generic state of the art by appropriate conveyor belts. Thus, in principle, air can escape from the pockets which have just been filled and not yet welded in the region of the gas filling device and behind it. However, this can be counteracted by applying a certain tensile stress to the film half-tube by automatically braking the supply roll for the film material, as proposed in a preferred embodiment of the invention. As a result, upper and lower film are applied to the gas filling device, which reduces the air losses.

Furthermore, escape of the blown-in air can be avoided by connecting the welding process as directly as possible to the injection of air, so that certain residual leaks have no appreciable effect on the degree of filling of the filling bodies. The latter measure can be realized in a preferred embodiment of the invention by means of two along its circumference a contact region exhibiting drive rollers particularly advantageous by the two rollers are arranged offset in the horizontal direction. Particularly preferably, an upper drive roller is offset in the transport direction of the film half tube relative to the lower roller to the rear, wherein the lower roller spatially connects directly to the gas filling device.

On the one hand, this leads to the film half tube being deflected obliquely downward following the gas filling, so that an angle of typically 20 ° to 50 ° results compared with an imaginary continuation of the horizontal transport path. Such angular guidance prevents the film from migrating out of the transport direction due to the distortions that arise during the inflation process, or it may cause wrinkles between the upper and lower films which make the welding process more difficult.

At the same time it is possible with the staggered arrangement of the rollers that the first, lower roller forms the counter bearing for the welding tool. As a result, the welding tool can be arranged directly adjacent to the gas filling device, so that leakages before the welding process are minimized. Due to the moving roller as welding abutment also an excellent weld quality is achieved.

The fact that the plastic half hose is driven only in one place, wherein this drive takes place in a section in which the upper and lower film are already welded, a reliable transport without warping between upper and lower film is achieved, with problems in the exact synchronization of different Drive elements are already avoided from the outset.

The escape of air after filling and before the welding process can be further reduced by the fact that the air is injected through the gas filling device obliquely with a component in the direction of movement.

Figur 1a

eine schematische Seitenansicht einer erfindungsgemäßen Vorrichtung;

Figur 1b

eine Draufsicht auf eine erfindungsgemäße Vorrichtung;

Figur 2

eine im Rahmen der Erfindung einsetzbare Rollenhalterung mit einem Bremsmechanismus; und

Figuren 3 und 4

Ansichten der im Rahmen der Erfindung verwendbaren Folienhalbschläuche im flachen (Figur 3) und im gefüllten Zustand (Figur 4).

The invention will be explained in more detail by way of example with reference to the drawings. Show it:

FIG. 1a

a schematic side view of a device according to the invention;

FIG. 1b

a plan view of a device according to the invention;

FIG. 2

a usable within the scope of the invention roll holder with a braking mechanism; and

FIGS. 3 and 4

Views of the usable in the invention foil half-tubes in the flat ( FIG. 3 ) and in the filled state ( FIG. 4 ).

In FIG. 1a is a generally designated 10 device according to the invention for producing gas-filled packing in a partial side view is shown schematically. The figure shows the essential elements for air filling, welding and transport of the (in FIG. 1a not shown) Folienhalbschlauchs.

The per se known film half-tube 40 may, for example, according to the FIGS. 3 and 4 be educated. According to these illustrations, the film has 40 pairs of transverse welds 42, between each of which a perforation 44 is provided. The transverse welds 42 terminate at a predetermined distance from the open end of the half tube. Punches 46 in the space between the transverse welds 42 serve to control the device, in particular to detect the position of the welds or to control the film welding process depending on the film material or the film materials in multilayer films or the film thickness.

Preferably, the film half tube is made from two layers coextruded, e.g. an outer layer of more thermally stable plastic (e.g., a melting temperature of about 120 to 130 ° C) over a more easily fusible, thinner inner layer (melting point, e.g., about 85 ° C), thereby greatly improving the welding properties.

The foil is covered by an in FIG. 2 supplied supply roll 54 which is rotatably locked relative to a roller holder 52. The rotation of the roll holder 54 is decelerated by a brake, the strength of which is automatically controlled via a driver arm 50, via which the film is guided in a loop (not shown). As a result, the film of the device is always supplied under a defined tension.

The film enters the device 10 according to FIG. 1a from the left and is first passed over a free-running guide roller 22 (see, the feed direction marked with an arrow) and then enters an inlet slot formed by guide plates 32 of the device 10, which initially runs substantially horizontally. The inlet slot 32 has (as well as an outlet slot 30) a depth of only a few centimeters, so that only the edge region of the film tube is guided therein. The remaining area of the film tube (typical width about 20 cm) is not detected by the slots 30, 32, but grinds over a horizontal support surface 36, so that the filling pad unfold unhindered in the gas filling and the width of the filling pad can be chosen flexibly can.

A shallow gas filling device 16 then engages between the upper and lower film initially not connected to one another at the edge, by means of which upper and lower film are lifted off from one another at both ends and brought together again at the other end. In FIG. 1a transverse to the plane of the drawing passes through the gas filling device 16, an air duct, which is supplied by a behind a base plate 26 arranged (not visible) fan with air. This air duct extends obliquely or is designed such that the outflowing air receives not only a component of movement transverse to the plane, but also a component in the direction of movement of the film, the latter indicated by the arrow 24. As a result, air losses in the area of the welding tool are additionally compensated.

The transport of the film by means of two synchronously driven rollers 12 and 14, which are provided with a rubber coating. The electromotive drive of the rollers 12, 14 is also located behind the base plate 26 (not visible). In this case, a first, from below to the foil fitting roller 12 is relatively close adjacent arranged on the gas filling device. This first roller 12 serves at the same time as an abutment for a welding tool 18, which is pressed from the top side onto the film and has a relatively relatively small welding punch, which produces a weld seam of typically about 2 to 3 mm width.

The welding tool 18 is attached to a lever arm 20 (whose bearing 48 in FIG FIG. 1b is shown in the operating position, the welding tool 18 spring-biased against the film, is lifted in a standby state at standstill, however, from the film to avoid a melting of the film, wherein the pivoting of the lever arm 20 is manually via an eccentric, the over a switch simultaneously activates the film drive.

The welding tool 18 is heated electrically via a heating cartridge and held by an electronic control within a predetermined temperature range.

Relocated to the rear relative to the first roller in the transport direction, a second roller 14 is provided, which rests in a contact region 28 against the first roller. Due to the staggered arrangement of the second roller 14, the film is first guided along a partial region of the circumference of the first roller 12 and then at an angle α relative to the horizontal obliquely downward, this direction by an appropriate design of guide plates to an outlet slot 30th is maintained until the output of the filled filler. The contact area 28 between the rollers 12 and 14 is thus lower than the original film transport plane. By means of this angled arrangement, the problems mentioned in the introduction of the foil tube and in the formation of the weld seam are minimized. Furthermore, it is even possible by the staggered arrangement of the second roller 14 that the welding tool can use the first roller 12 as an abutment. As a result, the welding tool can be arranged relatively close to the gas filling device 16 be minimized so that the air losses are minimized by leaks, the air losses are additionally reduced by the oblique blowing.

In FIG. 1b a device 10 according to the invention is shown in a sectional view with sectional plane in the transport plane of the film, wherein the in FIG. 1b illustrated embodiment only in principle, but not in terms of their dimensions with FIG. 1a matches. The location of the film 40 is in Figure 1 b indicated by dashed lines. The contact surface of the welding tool 18 on the roller 12 is denoted by 17. Out FIG. 1b In particular, a possible shape of the air duct 13 can be seen, in which a bevel 15 directs an air flow with a flow component in the direction of the weld 17. This design ensures that the air duct 13 extends into the region of the circumference of the first roller 12. Taking into account that the upper and lower film are already almost one above the other just before the welding tool, an optimal filling without leaks before the welding process is ensured by means of the illustrated design of the air duct 13. In an alternative embodiment, it is also possible to obliquely guide the entire air duct 13 in the mouth region, as indicated by the dashed line in the region of the air duct 13.

Claims (10)

1. Apparatus (10) for manufacturing gas-filled packing elements, in which a prefabricated film half-tube (40) of plastic, which is at least partially open on one edge side, is divided up into individual pockets by welds (42) that are transverse to the transporting direction and is stored on a roller (34), is first guided past a gas filling device (16), by which air is blown into the film half-tube, and subsequently guided past a welding tool (18), which welds the opening on the edge side of the film half-tube to form closed packing elements, the transporting of the film half-tube through the apparatus taking place by means of a drive device, characterized in that the drive device (12, 14) is formed in such a way that it exerts a force on the film half-tube (40) substantially downstream - with respect to the transporting direction - of the gas filling device (16) and downstream of the location at which the welding tool (18) is used.
2. Apparatus according to Claim 1, characterized in that no belt that is moved along with the film half-tube (40), or other transporting elements, are provided in the region of the gas filling device (16), and in that the drive device acting downstream of the gas filling device (16) is the only device that exerts a force on the film half-tube.
3. Apparatus according to either of Claims 1 and 2, characterized in that the drive device has two electromotively driven rollers (12, 14), which lie one against the other in a circumferential region, are provided with a friction lining and between which an edge region of the film half-tube (40) is guided and drawn through the apparatus (10) when the apparatus is used in the way intended.
4. Apparatus according to Claim 3, characterized in that it is formed in such a way that the transporting of the film in the region of the gas filling device (16) takes place in a substantially horizontal plane, and in that one of the rollers (12) is formed as a counter bearing for the welding tool (18), the axes of rotation of the rollers (12, 14) being arranged offset horizontally with respect to each other.
5. Apparatus according to Claim 4, characterized in that, when the apparatus is used in the way intended, directly downstream of the region of the gas filling device (16) in the transporting direction, a first roller (12) lies against the underside of the film half-tube (40), and offset horizontally downstream in the transporting direction, a second roller (14) lies against the upper side of the film half-tube (40) and against the first roller (12), so that the film half-tube is guided in a direction that is angled away downwards with respect to an imaginary extension of the substantially horizontal transporting direction at an angle (α) of less than 90°, preferably of 20° to 45°, and in that, adjacent to the region of the gas filling device (16), the welding tool (18) lies against the upper side of the edge region of the film half-tube, the first roller (12) acting as a counter bearing for the welding tool (18).
6. Apparatus according to Claim 5, characterized in that the welding tool (18) and the axis of rotation of the first roller (12) are located vertically one above the other.
7. Apparatus according to one of Claims 1 to 6,
   characterized in that the gas filling device (16) is formed as a shallow channel (13), into which air is blown by a blower, and which narrows on both sides in the transporting direction, so that the upper film and the lower film of the film half-tube (40) are initially lifted away from each other and then brought together again, and/or in that the air is blown out of the gas filling device (16) obliquely in such a way that the air stream has in addition to a movement component transverse to the transporting direction a movement component (24) in the transporting direction of the film half-tube (40).
8. Apparatus according to one of Claims 1 to 7,
   characterized in that the unwinding of the film half-tube (40) from the storage roller (34) is braked in such a way that it is kept taut between the storage roller (34) and the drive (12, 14).
9. Method for manufacturing gas-filled packing elements, in which a prefabricated film half-tube (40) of plastic, which is at least partially open on one edge side and is divided up into individual pockets by welds (42) that are transverse to the transporting direction is first unwound from a storage roller (34) and guided continuously along a gas filling device (16), by which air is blown into the film half-tube, and subsequently guided past a welding tool (18), which welds the opening on the edge side of the film half-tube in an airtight manner, characterized in that the transporting of the film half-tube takes place by means of a force applied to the film half-tube (40) downstream in the transporting direction of the gas filling device (16) and downstream of the location at which the welding tool (18) is used.
10. Method according to Claim 9, characterized in that a sealing of the open edge of the film half-tube (40) with respect to the surroundings is brought about during the gas filling operation by the film tube being subjected to a tensile stress, acting in the transporting direction, between the storage roller (34) and the drive device (12, 14), so that the upper film and the lower film are in close contact with the gas filling device (16).

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