EP0094077A2 - Method and machine for packaging articles - Google Patents

Abstract

Method and machine for packaging articles, in which a packaging film is removed from a stock roll at a point situated above the transport plane of the machine and is sealed by welding the edges lying next to one another and drawn in together in parallel subsequent to the stock roller, and in an application section on a conveyor belt lying in between which is moved at the same speed as the packaging film, the latter is deposited on the conveyor belt and the products to be packaged are applied. <IMAGE>

Description

The above invention relates to a method and a machine for packaging articles using the so-called "flow pack" technique.

There is already such a packaging machine has become known in the products, such as confectionery products, baked goods but, efuehrt also technical products which have a stable, defined shape on a Foerderband kontinuiertlich to ^g. For this purpose, the conveyor belt has suitable projections or ribs for feeding the products. The supplied products are then encased in a film, preferably a plastic film, the packaging film being placed on the products from above, then placed around the products and the assembled packaging edges being closed by welding them together. The welding process takes place in the known machine using welding rollers, which are located below the feed plane of the products to be packaged. The packaging tube produced is then divided into individual packages by welding at the same time at the beginning and at the end of the packaging material, which is placed around the product in a sleeve-like manner, whereby individual packaging is produced, which is generally referred to as "flow pack" packaging.

The known packaging machines of this type have proven themselves for the packaging of not too sensitive products, i.e. for the packaging of products that are not damaged during the feed movement by the movement by the feed means protruding from the transport plane.

Due to a mechanical load that is transferred by the feed devices to particularly sensitive and fragile products,. and due to the frictional action that occurs between the horizontally arranged feed plane and the product to be packaged, it is not possible to break fragile products that are sensitive to mechanical loads, such as fruit and vegetables, e.g. To pack tomatoes, peppers or pears, because the sensitive surface of these products would inevitably be damaged and would lead to an impairment and damage to the product.

In the known machines it is also not possible to pack products with a certain, uniform shape, for example carrots, cucumbers or zucchini, since these products cannot maintain their arrangement intended for packaging during the feed movement in the machine. Furthermore, it is not possible in the known In addition to the aforementioned products, packaging machines can also pack loose or piled-up products, such as small vegetables or fruit, for example cherries or plums. It is also not possible to pack loose flowers or flower arrangements with the known machines of this type, since these products cannot be moved forward using slides which protrude from the feed plane of the machine, since the extremely sensitive parts of these products, owing to the Friction that arises between the product and the support and sliding plane of the packaging machine would be damaged.

In the known machines of this type, welding is also always carried out at the beginning and at the end of the packaging film wrapped around the products, always between two conveyor belts, which are arranged at a distance from one another, and for this reason it is obvious that the packaging is loose or small, irregular Products with these known devices is not possible, since the constantly moving packaging tube would have the tendency to penetrate into the space between the two spaced conveyor belts in which the welding device is provided, which would lead to malfunctions and frequent business interruptions.

In order to create the possibility, in the conventional packaging machines of the type mentioned above, also the aforementioned products with an irregular shape or in bulk To be able to pack, these products are usually prepacked by hand using suitable trays or receptacles made in cardboard or polystyrene. The need to prepack the products mentioned by hand, as well as the need to provide suitable documents and containers, has a disadvantageous effect on the packaging costs, which increases the sales price of the packaged product.

The object of the above invention is to propose a new method and a new machine with which, using the so-called "flow pack" technique, also sensitive products, products with an irregular shape, as well as small products or loosely accumulated articles, in a safe and fast manner , can be packed automatically without the product being mechanically stressed or even being damaged due to direct contact with the conveying means or due to a frictional movement with respect to the transport level.

The object according to the invention is achieved by a method which is characterized in that the packaging film is pulled off the supply roll in a plane which is above the transport plane of the machine, and the packaging film is then welded by welding the parallel edges of the film together the supply roll is put together and that in an intermediate support section of the film on a conveyor belt that is the same The speed at which the packaging film is removed from the supply roll is when the products to be packaged are deposited on the packaging film.

With this method it is achieved in a surprising and advantageous manner that the packaging film experiences a gradual deformation from a horizontal level (take-off roll) into a tubular casing from its pull-off point on the supply roll to the welding device, with the parallel edges of the packaging film in the Welding device can be connected and that the packaging film between the horizontal take-off roll and the welding unit, in the form of a gradually preformed tube, lie on the conveyor belt, which moves at the same speed as the packaging film. The products to be packaged are advantageously deposited on the conveying line of the packaging film on the conveyor belt; this is done without mechanical stress due to the lack of relative movement between the product and the feed plane. Immediately after the products to be packaged are placed on the packaging film and the feed level of the conveyor belt, the position of the products to be packaged is definitely determined by the packaging material that has already been joined in the welding device with its parallel edges and a closing angle or a gusset between the products and forms the packaging film, stabilized.

The device for carrying out the method according to the invention is characterized by the provision of a receiving device for a roll of packaging material, to which a horizontal and height-adjustable take-off roll is assigned, which is provided above the feed plane of the machine so that a continuous conveyor belt runs on the feed plane, and a positionable welding unit is arranged above the conveyor belt. With a device designed in this way it is possible that the pull-off roll of the packaging film can be adjusted in height and that the welding device can be adjusted in a corresponding manner so that the packaging film can be moved from an extended position arranged in a horizontal plane with the two parallel wheels of the packaging film at a maximum distance (horizontal take-off roll), gradually, due to the mutual approach of the parallel edges of the packaging film, sinks down, is supported on the conveyor belt of the feed plane of the machine, and is then present in the manner of a pre-formed packaging sleeve, and there are no folds irregularities are still caused in the packaging film and immediately following this support zone forms a closing angle (triangular sealing gusset) between the parallel edges which are connected in the welding unit. As a result, the packaging film is increasingly deformed into a closed shell Merging and stabilizing the products to be packaged, especially in the case of irregularly shaped products.

Further advantages and features of the invention can be found in the following description, the subclaims and the drawings.

The subject matter of the invention will now be described in more detail and shown schematically on the basis of an exemplary embodiment in the accompanying drawings.

• Fig. 1 schematisch die erfindungsgemaesse Verpackungsmaschine in Ansicht;
• Fig. 2 die Maschine gemaess Fig. 1 in Draufsicht;
• Fig. 3a und 3b schematisch in Draufsicht sowie teilweise im Querschnitt die Ablagezone der zu verpackenden Erzeugnisse;
• Fig. 4a und 4b in einer Draufsicht, sowie teilweise im Querschnitt, den Beginn des Umhuellens, sowie den Beginn der Bildung des sogenannten Verschlusswinkels (Zwickel);
• Fig. 5a und 5b schematisch in Draufsicht, teilweise im Querschnitt das fertig verpackte Erzeugnis, zusammen mit dem Verpackungsfilm in der Verschweisseinrichtung;
• Fig. 6 eine einstellbare Fuehrungs- und Spanneinrichtung fuer den Verpackungsfilm, die vor der Schweisseinheit vorgesehen ist; und
• Fig. 7 die Vorrichtung nach Fig. 6 in Draufsicht.

Show it:

• 1 schematically shows the packaging machine according to the invention in view;
• FIG. 2 the machine according to FIG. 1 in plan view;
• 3a and 3b schematically in top view and partly in cross section the storage zone of the products to be packaged;
• 4a and 4b in a plan view, and partly in cross section, the beginning of the sheathing and the beginning of the formation of the so-called closure angle (gusset);
• 5a and 5b schematically in plan view, partly in cross section, the finished packaged product, together with the packaging film in the welding device;
• 6 shows an adjustable guide and tensioning device for the packaging film, which is provided in front of the welding unit; and
• Fig. 7 shows the device of FIG. 6 in plan view.

As can be seen in FIG. 1, the packaging machine 1 consists of a base frame, which has a horizontal support surface 3 has, which extends over the entire length of the machine. At the beginning of the horizontal plane, holding, guiding and running rollers 4 are provided, which are driven, for example, directly via a motor or a drive wheel 5 and thus drive the supply roller 6 in the direction of the arrow f and ensure that the packaging film 7 at the same speed , with which the conveyor belt moves along the horizontal plane 3, is driven.

Immediately following the supply roll 6, the frame 2 of the packaging machine has two vertical supports 9, which receive a guide roll 10, via which the packaging film 7 drawn off from the supply roll 6 runs off. The supports 9 have elongated holes 11 in order to enable adjustment of the horizontally arranged take-off roller 10 in the vertical direction.

At a distance from the supply roll 6, the machine frame 2 has a welding device, which is designated 12 in its entirety.

Said welding device has holding supports 13 which can be displaced along a horizontally arranged guide 14 and along vertically arranged guide rails 155 in order to be able to make an adjustment with respect to the machine plane. Welding rollers 15, which are driven by a motor, are rotatably mounted in the holding supports 13.

As can be seen particularly from FIG. 1, it is advantageous that the take-off roller 10, which guides the packaging film 7, and the Welding rolls 15 are arranged approximately at the same height. The set height positions are primarily dependent on the dimensions of the product 29 to be packaged and inevitably on the width of the packaging film 7, as well as on the dimensions of the line section in which the bulged part 7a of the film is to lie on the conveyor belt 8, that is horizontal support level 3 of the packaging machine 1 runs.

Advantageously, a storage device 16 known per se is provided in the storage zone in which the packaging film 7a rests on the conveyor belt 8a and can advantageously be moved up or down in the direction of the arrow g. This loading or dosing device is able to deposit the product 29 to be packaged carefully and automatically in the bulged storage zone 7a of the packaging film 7, which rests on the driven conveyor belt 8.

As can also be seen in FIG. 1, the conveyor belt 8 has no interruptions, not even in the vicinity of the dividing device.

The dividing device 17, which is designed as a cutting and welding device, consists of a double arm which is pivotally mounted about the point 18, which is provided in the lower part of the machine frame. The pivotable double arm 17 crosses the conveyor belt 8 in a yoke-like manner and has a cross strut or a transversely arranged welding bracket 19 which, for example, also extends over the piston rod of a pneumatic cylinder or the like 20 marked drive means is operatively connected.

To adjust the double arm 17, taking into account the thickness of the product to be packaged, the arm 17 is displaceable in height and for this purpose, for example, an adjusting screw or an automatic transmission known per se is used.

Under the conveyor belt 8, the double arms 17 are advantageously connected via a transverse, rotatably arranged roller 21, which serves as a counterpressure surface for the welding bracket 19 during the closing movement of the bracket 19, ie during the execution of the welding and cutting process at the beginning and at the end of the Packaging. During the welding and splitting phase, the double arm 17 follows the movement of the conveyor belt 8 in the direction of the arrow h. During this movement, the conveyor belt and the packaging sleeve to be welded are raised slightly. If one takes into account that the radius between the pivot point 18 and the counterpressure roller 21 is very large in comparison to the pivot angle of the double arm 17, it is understandable that the slight lifting of the conveyor belt 18 is fully compensated for by its elasticity. Furthermore, 8 deflection rollers 22 are provided on the lower strand of the conveyor belt, which can carry out a compensating movement if necessary. The conveyor belt 8 is followed by a further conveyor device 23, which only has the task of separating the finished packs 29 and feeding them to other devices which operate independently of the packaging machine 1.

2 that a known folding and welding bracket 24 can be provided at the height of the closing angle (gusset) between the side edges 7b of the packaging film 7, which is by a certain amount in the packaging film which has already been deformed into a tubular packaging sleeve can occur to enable, for example, that Using rolls with a horizontal axis (not shown for reasons of clarity), the production of a weld with overlapping edges becomes possible. This was previously not possible in the packaging machines already known, since in these devices the packaging film was placed on the product 29 to be packed from above and the welding was carried out below the horizontal feed plane of the machine.

The mode of operation of the packaging machine according to the invention will now be described in more detail below with reference to the schematic representations according to FIGS. 3a-5b.

3a shows the product 29 to be packaged in the lay-up line in which the packaging film 7 lies fully on the conveyor belt 8 and in which zone the formation of the closure angle (gusset) between the two approximated edges 7 of the packaging film has already begun .

In the schematic sectional view according to FIG. 3b, it is shown that the packaging film 7 with its bulged part lies flat on the conveyor belt 8 and that in this zone the packaging film 7 drawn off the take-off roll 10 has already started to wrap around the product to be packaged in the form of a sleeve or a tube. During its advancing movement in the direction of arrow (i), as can be seen in FIG. 4a, the product 29 to be packaged is enveloped by the packaging film 7 and stabilized in the packaging film 7 due to the tension that occurs; in this case there is an increased formation of shells in the packaging film due to a further convergence of the edges 7b of the film, which are fed to the following roll welding unit 12.

4b shows that in this case the packaging film is already applied to the sides of the product 29 to be packaged and that the tension present in the packaging film 7 already leads to an automatic stabilization of the product 29 to be packaged.

It can be seen from FIG. 5a that the product 29 is already completely enveloped by the packaging film 7, the edges 7b of the packaging film are completely joined together and firmly connected by the rollers 15 of the welding unit.

Due to the swivel-mounted bracket 19, welding takes place in the closing station at the beginning and at the end of the packaged product, and a division into individual packages. While in FIGS. 3a-5b only a packaging and sealing method by directly connecting the edges 7b of the Packaging film 7 was shown, the machine according to the invention is also advantageously suitable for producing overlapped welds of the joined edges 7b. For this purpose, it is only necessary that a back pressure bracket 24 is provided in the joining zone of the edges, which is introduced into the interior of the sleeve-shaped packaging 7 and works with an already known welding and folding device which is arranged above the back pressure bracket 24.

Particularly advantageous are provided along level 3 of the packaging machine 1 touch devices and measuring devices 30 and 31 (photocells, interrupters and similar devices), with which it is possible to start and end the product 29 to be packaged and the end of the product to be packaged To record or measure product 29. These probing and measuring devices 39 and 31 can via a suitable electrical or electronic control circuit, which, for. B. is equipped with microprocessors, determine the length of the packaged product 29, process this value and send 8 control pulses depending on the feed speed of the feed belt to drive the welding and dividing device 17-21 accordingly and the welding and separation of the packaging film 7 am Carry out beginning and end of the product. This fact makes it possible to pack products with different lengths.

In the case of products of constant length, it is possible to use a switch that e.g. on the control panel of the machine, the automatic buttons 30, 31 are to be switched off, as a result of which the welding and dividing device (17-21) is driven with a constant partial step.

As can also be seen from FIGS. 6 and 7, a holding device 50 is provided on the front of the welding unit, which is identified overall by 12, which receives two horizontally arranged parallel holding rods 51 and 52. The rods 51 and 52 are inserted into recesses in the holder 5 and, after loosening a corresponding locking screw 53, the rods can be adjusted in their position in order to then be tightened again.

Each rod 51, 52 has a blind hole 54 on the front, which receives the tapered end of a further rod 55 and 56, respectively. The rods 55, 56 can also be adjusted in the direction of the arrow (a) in order to be able to adjust the rod 55 or 56, a corresponding adjusting screw 57, with which clamping is also possible, being provided.

In a slot which is worked into the front ends of the rods 55, 56, a pivot lever 59 or 60 is mounted via a horizontally arranged transverse bolt 58, which ends in a handle 61 or 62 at its upper end and at its lower end Guide and guide rollers 63, 64 has.

By actuating the handles 61, 62, the levers 59, 60 and therefore the guide rollers 63, 64 can be pivoted in the direction of the arrow (s). On the underside of the rods 51, 52 there is also a flat cutout 65 or 66, and in this cutout a corresponding mounting plate 67 or 68 is inserted, which can be pivoted about a locking screw 69. Each plate 67, 68 receives on its underside rotatable guide rollers 70, 71 and 72, 73 with a vertical axis of rotation and, by pivoting the corresponding holding plate 67, 68, the rollers can be pivoted in the direction of the arrow (o).

With the device shown in FIGS. 6 and 7, the angle of inclination of the roller 63, 64 in the direction of the arrow (s) with respect to the vertical can be changed, and thus the edges of the packaging film B can be given an increasing component of motion or a decreasing component of motion.

A further division can be made by pivoting the rods 55, 56 about their horizontal axis and finally, by pivoting the roller groups 70, 71 or 72, 73 about the vertical axis in the direction of the arrow (o), it is possible to make a larger or to transmit smaller tension to the edges of the packaging film, whereby there is a further adjustment possibility, which can also be completed by a pivoting movement of the rods 51, 52 about the horizontal axis; the locking screw 53 solved.

By providing these adjusting means, which are provided in front of the welding rollers 51, the edges of the packaging film P can be acted upon and these can be adjusted in their position precisely in relation to the welding rollers 15, furthermore according to the material properties or the deformation state of the packaging film P, e.g. in the case of corrugated or wrinkled edges, a compensating division can take place, whereby it is achieved that the edges of the packaging film in the desired position are fed exactly with straight edges to the welding unit and in particular to the welding rollers 15.

Claims (16)

1. A method for packaging products, by wrapping them using a packaging film and creating a so-called "flow pack" packaging, characterized in that the packaging film (7, P) is pulled off the supply roll (6) in a plane which located above the transport plane (8) of the machine (1), that the packaging film (7, P) is joined by welding the edges (7b) of the packaging film (7, P) joined in parallel following the supply roll (6) and, that in a Hawaiian lying support zone (X) of the film (7, P) on a conveyor belt (8) which is driven at the same speed at which the packaging film (7, P) is pulled off the supply roll (6), a deposit of the products to be packaged (16) on the packaging film (7, P). 2. The method, characterized in that the deposit zone (X) or deposit path for depositing the products to be packaged (16) immediately before the formation of the convergence angle (gusset) of the parallel edges (7b) of the packaging film (7, P) is provided and that following this deposit zone (X) the edges (7b) of the U-shaped bulging packaging film (7, P) converge due to the edges (7b) of the packaging film (7, P) being brought together in the welding unit ( 12) takes place. 3. Machine for performing the method according to claim 1 and 2, characterized in that the receiving device (4, 5) for a supply roll (6) of the packaging material (7, P) is assigned a horizontally arranged take-off roll (10) which is adjustable in height (11) and It is arranged above the feed plane (8) of the machine (1), that a continuous conveyor belt (8) runs on the feed plane, and a welding unit (12) which is adjustable in its position is arranged above the conveyor belt (8). 4. Machine, according to claim 1, characterized in that the take-off roller (10) and the conveyor belt (8) drive means (5,22) are assigned to pull the packaging film (7, P) at the speed at which the conveyor belt ( 8) runs along the horizontal conveyor plane of the machine (1). 5. Machine, according to claim 3, characterized in that the supply roller (6) assigned take-off roller (9) is adjustable in height by two vertically arranged supports (9). 6. Machine, according to claim 5, characterized in that the supports (9) have elongated holes (11) in which the hubs of the take-off roller (10) are arranged in an adjustable and fixable manner. 7. Machine, according to claim 3, characterized in that the welding unit (12) has support supports for the welding devices (13) which can be displaced along horizontal and vertical guides (14, 155). 8. Machine, according to claim 3, characterized in that the welding devices (13) are designed as driven welding rollers (15) which are designed as motor-driven roller pairs (15). 9. Machine, according to claim 3, characterized in that in the loading zone (X) in which the packaging film (7, P) U-shaped bulged U rests on the conveyor belt (8), an up and down (g) loading device (16) is provided. 10. Machine, according to claim 3, characterized in that in accordance with the convergence angle (gusset) of the packaging film (7, P), in the tubular packaging sleeve (7, 7a, 7b) a counter pressure bracket (24) is introduced, with Collapsing and welding rolls to create a package with overlapping edges (7) works together. 11. Machine according to claim 3, characterized in that after the welding device (12) a dividing and closing device (17-21) for closing and dividing the packaging (7) is provided at the beginning and the end of this device (17 - 21) consists of a double arm (17) which is pivotally mounted about a pivot axis (18) provided on the underside of the machine, that this double arm (20) is provided adjustable in height, and is bridge-like or in the manner of a yoke , the uninterrupted conveyor belt (8) and an actuating agent, for example a penumatic one Piston-cylinder unit (20), for driving a welding and cutting bracket (19) is provided that the pivotable double arms (17) below the conveyor belt (8) are connected by a cross strut (21) or a transverse rotatable roller that works as a counter pressure medium . 12. Machine, according to claim 3, characterized in that the lower run (8) of the conveyor belt (8) rolls on deflection rollers (22) and compensating rollers. 13. Machine, according to claim 3, characterized in that along the conveyor belt (8) touch devices (30, 31), e.g. Optical sensors or photocells are arranged which determine the beginning and the end of a product to be packaged (16, 29) and, with the interposition of a control unit, drive the pivotable welding and dividing device (19-21). 14. Machine, according to claims 1-13, characterized in that two parallel, horizontally arranged support rods (51, 52) are arranged in front of the inlet of the welding unit (13), the levers at their front ends about horizontal axes (58) (59, 60) take up the guide and rollers (63, 64) on their underside and that between these pivotable levers (59, 60) and the inlet of the welding unit (12), each horizontally arranged rod (51, 52) has a receiving plate (67, 68) which receives on its underside further guide and guide rollers (70, 72, 71, 73) and that each holding plate (67, 68) for adjusting and adjusting its vertical axis (69) is arranged pivotably, and can be blocked in the desired pivot position. 15. Machine, according to claim 14, characterized in that each horizontally arranged support rod (51, 52) is divided into several parts, which are mutually adjustable about their horizontal axis, and in the desired position by locking means (57, 53) can be blocked. 16. Machine, according to claim 14, characterized in that the horizontally arranged, parallel holding rods (51, 52) of holding supports (50) which are arranged at the inlet of the welding unit (12) are received.

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