DE19921032A1 - Method and device for wrapping a good with a plastic film - Google Patents

Abstract

A method and device for wrapping a good with a plastic film is proposed. The plastic film wraps itself around the goods as flexibly as possible. During the closing movement of the closer, which interacts with the sealing unit, a clamping device is used at the same time in order to pull the film taut in the area of the goods.

Description

The invention relates to a method and an apparatus for Wrapping a good with a plastic film, the Driving in or out of the film well against a film curtain is enclosed on several sides and in the import area next to the goods a first and a second film curtain part remains and a the middle part of the film, the goods one or more encloses on one side. A closer is provided, which the Afterwards, the import area is at least almost completely closed, wherein at least one of the two film curtain parts by one  Clamping device is tensioned so that the thing lying around Foil middle part fits tightly. The closer positions here in the two film curtain parts such that these by a Sealing unit to be welded together and each severed ends of the film middle part ver are welded, after which the finished goods are removed admit.

The aforementioned methods and devices are used for the purpose play previously grouped goods with an art, for example to connect fabric skin film firmly to one another to make bigger solid unit of goods.

For example, a stack of boxes is piled up that by the above-described method and the device be connected relatively firmly, if so Individual boxes are needed to open the plastic film is separate.

In known methods and devices for Example a film roll above and below the Surface of the goods. These two slides are together welded and thus form the foil curtain against which the Is well promoted. Through the conveying movement of the goods a film middle part around the goods and divides the films curtain in a first and a second film curtain part, which remain firmly connected. With the known A hold-down device is then moved to the estate in order a slipping of the goods or that of different individuals Avoid packs of existing pile of goods. The closer which ultimately interacts with the sealing unit becomes Example pneumatically controlled closed, while still Abge film material from the film roll or the film stock is pulled.  

To the film and in particular the film middle part, which around the good is looped to be as tight as possible at the state of the art as soon as the closer enters the import area has closed, used a clamping device in front of one Welding the film to the goods tightens them. It becomes Example two oppositely driven rollers are used, each roller being provided for a film curtain part. The film material closes due to the opposite movement transported back and thus tightened or stretched the film. After the film middle part lies tightly against the good, the Sealing unit used, on the one hand the foil curtain severed, the ends of the film middle part ver welds and simultaneously or shortly afterwards the two, well separate foil curtain parts reconnects in order for that next following good again a closed film curtain To make available.

The number of cycles of the previously known devices and thus permitted procedure is determined by the individual time sections, the sequential order of the aforementioned Ver packing steps required.

To the performance of such methods and devices the number of cycles, i.e. the number of goods, correspondingly per unit of time with a plastic film be taken to increase. An increase in movement the good is not always usable, because the good, for example from stacked boxes or the like stands and accelerations too great to slip this Stacking or even toppling over, inevitably leads to a failure of the machine.

The invention has for its object a method and to ver a device as described above improve that the number of cycles with constant reliability  is increased, thereby increasing the performance of the aforementioned device increases or procedures.

To achieve this object, the invention is based on one Method and an apparatus as described in the introduction and suggests that a clamping means as a clamp on the closer is provided for the first film curtain part and that Clamping means at least during the closing movement of the closer for part of the closing movement, the first film curtain part or the film middle part clamps and so taut.

The configuration according to the invention ensures that the otherwise the usual sequential sequence of packaging steps runs at least partially simultaneously to accelerate of the packaging process, but without doing so impress additional forces on the goods or the stack of goods, which may lead to an undesired slipping or Would cause the goods or the stack of goods to fall over.

As a clamping device for the first part of the film curtain a clamping means is provided which is movable with the closer is arranged. The closer who, while the good against the The film curtain moves as far up, so that Can drive through well afterwards closes the previously clear given import area. The state of the art afterwards The clamping process is now at least partially in the Integrated closing movement, which creates a time advantage. At the same time, the movement of the closer is part of the Take advantage of the clamping process. Through the inventive combination put these two activities it is possible to order the number of measures increase about 20 to 40%.

In a preferred embodiment of the invention is pre see that a hold-down holds the good before filming middle part by stretching one or both of the foils  curtain parts is stretched. This ensures that the good, while the film middle part wraps around the good, does not slip or fall over.

Furthermore, it is proposed that during the tensioning of the first film curtain part also the second film curtain part is excited. By simultaneously executing the tensioning device another time advantage is achieved. It is natural also possible, the clamping sequentially one after the other to expire. It is also possible to use the low halter to continue to act on the property, in particular pulling away the top or bottom packs Avoid multiple packs of existing stacks of goods.

The invention also relates to a device for one beating a good with a plastic film, in particular which is suitable for carrying out the aforementioned method ren. According to the invention it is proposed that the Closer is movably mounted on a rail guide and a positioning unit is provided which the position of the NO contact monitors and controls, depending on the Position of the closer, which controls the clamping means to a Tearing the film curtain and / or slipping of the To avoid good things. The conditions that are met must be safe and reliable with a good as described to enclose the plastic film are relatively narrow dimensioned. It is usually possible to use the ones described above Devices not just a format of goods or stacks of goods to pack, but they are also for different formats applicable. This also changes the conditions, ins in particular the necessary stroke distances of the NO contact and thus interacting clamping means, which at the same time tightening of the film material results. Through the use according to the invention a positioning unit that detects the movement of the closer wakes up, it is possible on the relatively narrow  To make room for conditions to exist, to be sure make that on the one hand the film curtain not unintentionally is torn or such a great force on the good is exercised, which cause the goods to slip would. The respective conditions, in which clamping the clamping means during the closing movement of the closer acts on the first part of the film curtain, for example determined on the basis of experiments or experience is available for this tion values available, which result in particular from the strain derive the behavior of the plastic film used.

In a further development according to the invention, that a servo motor serves as the positioning unit, which has a Drive means, for example a toothed belt or an an drive spindle, on the slide-like guided closer works. The positioning unit takes on two functions nen. On the one hand, a motion drive is provided, on the other hand enables the positioning unit to read out the exact Position of the element driven by the positioning unit tes, here the closer. The use of a servo motor he allows the implementation of the above two functions. The servo motor is capable of being relatively high Accelerate to run in the short time segments perform the desired movements. The connection of the Servomotors with a drive means, for example a tooth belt or a drive spindle with which sled-like ge led closer results in a safe transmission of the locking movement from the servo motor to the slide on the one hand and at the same time a high level of security when determining the position the closer. According to the invention it is provided that the clamping means may not be along the entire length Movement path of the closer the first film curtain part stuck, but only after a certain, just of additional Conditions dependent path is used. This exact way Monitoring is possible with the posi proposed according to the invention  tioning unit possible and is controlled accordingly by the control monitors the when the corresponding position is reached Clamping device actuated.

According to the invention it is also proposed that on the rails guide on which the closer is already sledge-like is arranged, also the hold-down device and / or the sealing unit is arranged.

The further development according to the invention makes it possible to to create a modular unit, in which all moving elements, the closer, the hold-down and also the sealing unit are arranged. This makes it easier Maintenance, because in the case of maintenance, for example, this com Complete unit removed and pre-selected by a corresponding holding exchange unit is replaced to in any case Ensure continued operation of the machine, then in the out built condition on the one hand the hold-down or the seal unit or to check the closer. Allowed at the same time the proposed summary of various assemblies in one unit easier adjustment and adjustment of the Parameters as these are no longer separate on their own leadership lanes must be aligned.

In a preferred embodiment of the invention is provided see that the clamping means is arranged on the closer and moving with it. Alternatively, it is possible that a device is selected in which the clamping medium is fixed and the closing movement of the closer Tightening the film around the well results. Please note doing that the load on the film at a fixed Clamping means is higher and the control correspondingly more precise must be switched.

The invention is shown schematically in the drawing. It demonstrate:  

Fig. 1 to Fig. 4 in a side view of the sequence of the inventive method in an inventive apparatus.

The good 1 lies on a support 11 and is transported along the conveying direction 10, for example by a grouper or the like. The good 1 consists here, for example, of one or more pieces, which are arranged one above the other and next to one another for example and thus form a pile of goods or a stack of goods, for example. The goods 1 are conveyed against a film curtain 20 in the import area 12 .

The film curtain 20 , better shown for example in FIG. 4, extends essentially transversely to the conveying direction 10 in the entry area 12 . The film curtain 20 is formed here from two films which are welded in the central region and are held on the film rolls 29 , 29 '. In the exemplary embodiment shown here, the film rolls 29 , 29 'are located above half (film roll 29 ) and below (film roll 29 ') of the layer 11 . However, it is also possible in the same way to arrange the film roll 29 , 29 'or the film supply 28 , 28 ' laterally, left and right next to the conveying path 10 of the goods 1 in order to implement the proposal according to the invention.

The film 2 , 2 'is held in front of the film roll 29 , 29 ' and is carried out in a meandering manner through a film supply 28 , 28 'in order to allow a sufficient film material run-up at short notice during the rapid packaging movement. For this purpose, the film supply 28 is pivotally mounted and thus enables light to quickly remove short pieces of film without having to accelerate the great inertia of the heavy film rolls 29 , 29 '. For a uniform pulling movement of the film 2 from the film roll 29 , 29 ', a drive wheel drive not shown is provided.

In Fig. 1 to be packaged 1 consists essentially of a cuboid body. The (in the direction of conveyance 10 ) first side surface 13 of the goods 1 first touches the film hanging 20 , which is transported in the conveying direction 10 with. The film 2 begins to lay around the side surface 13 and around the roof and floor surfaces 14 , 15 and folds the foil curtain 20 downright. The folding area of the film curtain 20 now forms the film middle part 23 , which further divides the film curtain 20 into a first film curtain part 21 and a second film curtain part 22 .

In the embodiment shown in FIG. 1, the first film curtain part 21 is located essentially above and the second film curtain part 22 and essentially below the support surface 11 .

In Figs. 1 to 4 of the packaging process is shown for a good 1 respectively. It is clear that 11 additional goods are transported to and from the edition, which are not shown here for the sake of clarity.

Due to the conveying movement of the goods 1 into the film curtain 20 , film material 2 is drawn off from the film supply 28 , 28 ', this is indicated by the pivoting movement 27 , 27 ' of the film supply 28 , 28 '.

The additional necessary for packaging or enclosing the goods 1 with a film 2 , such as the closer 5 , the hold-down 7 and the sealing unit 8 , are located on a common rail guide 50 which extends essentially at right angles to the conveying direction 10 . According to the invention, these elements can also be gela individually.

In Fig. 2 it is shown that the cross-sectionally substantially square material 1 on three of the four side surfaces, in particular on the roof surface 14 , floor surface 15 and a first side surface 13 , is already surrounded with the film material 2 . The support 11 , which is formed, for example, as a movable conveyor belt, can be controlled intermittently here, with no feed in the conveying direction 10 taking place in the sequence shown in FIG. 2. In contrast, in the position shown here, the hold-down 7 , which is stamp-like, by the working cylinder 70 , which is driven pneumatically or electrically, for example, from above against the good 1 to hold the good 1 with the underlying film middle part 23 . The closer 5 is still in an open position. The holding movement of the hold-down 7 against the good 1 is indicated by the arrow 72 .

The hold-down 7 is located here above the closer 5 also on the rail guide 50 , but the hold-down 7 due to the separately provided working cylinder 70 is able to attack the goods. In a variant of the invention it is provided that the positioning of the Niederhal age 7 by the provided for the closer 5 positioning unit 6 is possible. For this purpose, the fixation of the hold-down 7 on its slide part 71 , on which the hold-down 7 is mounted on the rail guide, is released and then the positioning unit 6 is controlled such that the closer 5 repositions the slide part 71 in accordance with a new format of a good 1 . The slide part 71 is then fixed again. This can be done automatically, for example, with a pneumatic or electro-magnetic latch, or manually. Such a further development according to the invention makes it possible to automatically position the hold-down device 7 when the material 1 is changed in format. This saves makeready times when changing formats.

The good 1 is almost completely surrounded by film material, but at least on three side surfaces. It is of course also possible to pack a good 1 with the device according to the invention which has fewer side surfaces.

In Fig. 3 it is indicated that the film middle part 23 is tensioned and tightened by the activated tensioning means 4 so that it fits as closely as possible to the good 1 .

As clamping means 4 for the film 2 , a clamping means 40 on the closer 5 for the first film curtain part 21 and a slotted roller 41 are provided for the second film curtain part 22 .

First, the clamping means 40 is actuated. This is indicated by the arrow 42 , by means of which the clamping means 40 , which is designed like a strip, is set against the first film curtain part 21 . This movement of the clamping means 40 is controlled as a function of the position of the closer 5 . It should be noted that, on the one hand, the clamping means 40 is not actuated too early with respect to the closing movement 51 of the closer 5 , in particular in order not to tension the film middle part 23 so much that it tears, on the other hand it must not be actuated too late, since otherwise the film middle part 23 is tightened too little and thus no tight-fitting film packaging 3 is reached on the goods 1 . The Klemmbewe movement 42 is provided by a drive monitored by the controller, which is controlled depending on the position of the closer 5 , which is monitored by the positioning unit 6 . By clamping the film part 21 and the closing movement 51 of the closer 5 an attempt is made to pull further film material from the film roll 29 . At the same time, however, the film middle part 23 is pulled taut by the downward movement, this also happening with the hold-down device 7 placed on it, which only ensures that the good 1 remains in shape, that is, for example, it does not slip laterally over boxes stacked on top of one another.

In this sequence it is shown that the closing movement of the closer takes place simultaneously with the tensioning or tightening of the film middle part 23 around the material 1 and ensures that the film 2 is in close contact with the material 1 . This saves time in the packaging sequence, which allows the packaging cycle to run at a higher cycle speed. As a result, the performance of such a device or machine or such a method is increased.

Simultaneously with the clamping of the clamping means 40 , the roller 41 is also rotated about its longitudinal axis. The roller 41 is slotted longitudinally, the second, lower film curtain part 22 being carried out through this slot 43 . The rotary movement 44 (clockwise) tightens in particular the film center part 23 arranged in the area of the bottom surface 15 , whereas the clamping means 40 causes the film material in the area of the roof area 14 to be tightened.

The forces impressed by the clamping means or clamping means 4 , 40 , 41 in the film are expediently the same size in wesent union to achieve even tightening of the rear part on the side surface 13 of the good 1 and not to deform the good 1 .

During or after the lowering movement 51 of the closer 5 , the working cylinder 70 of the holding-down device 7 is reversed, and the holding-down device 7 is lifted upwards from the good 1 in accordance with the arrow 73 .

The closing movement 51 of the closer 5 is brought about by the positioning unit 6 . The positioning unit 6 in this case consists of a drive, for example a servo motor 60 and a drive means 61 , here for example an endlessly rotating toothed belt, which is connected via the terminal block 62 to the closer 5 , which sits on the rail guide 50 like a slide. The positioning unit 6 also simultaneously determines the position of the closer 5 . The control monitors both the function of the positioning unit 6 and the clamping or clamping movement of the clamping means 4 , clamping means 40 or roller 41 .

The roller 41 is advantageously designed to be essentially round in cross-section, in order thereby to avoid an excessive notching effect on the film 2 as far as possible. In this case, the provided edges of the roller 41 lying at the slot ends are also bevelled, for example, in order not to inadvertently cut through the film 2 during a tensioning movement 44 .

In Fig. 4 the last packaging sequence is shown. The sealing unit 8 , which is also mounted on the rail guide 50 , for example, moves from below, along the arrow 80 , upwards, against the now overlapping foil curtain parts 21 , 22nd The design of the sealing unit is known and designed in such a way that, for example, in a common sealing process, the material 1 is welded to the finished film middle part 23 to form a finished film packaging 3 , and the film curtain 20 , which was initially separated, is joined and welded again to be available again for the next good as packaging material, as described.

During the movement of the sealing unit 8 , the clamping means 40 is opened (see arrow 45 ), and the clamping action of the roller 41 is loosened by turning it in the direction of the arrow 46 (counterclockwise).

The good 1 is closed with a film packaging 3 on four sides and is transported to the outside on the support 11 .

The claims now filed with the application and later are attempts to formulate without prejudice to achieve further protection.

The backward relationships mentioned in the dependent claims point to the further training of the subject of the main claim by the features of the respective sub-claim there. However, these are not considered a waiver of achievement an independent, objective protection for the characteristics to understand the related subclaims.

Features previously only disclosed in the description can in the course of the process as of essential to the invention Significance, for example to differentiate it from the prior art be claimed.

Claims (9)

1. A method for wrapping a good with a plastic film, the good against a film curtain being enclosed on one or more sides by the film and in the import area next to the good a first and a second film curtain part and an intermediate film middle part of the good remain - Or encloses more than one side and a closer then closes the import area at least almost completely, whereby at least one of the two film curtain parts is tensioned by a clamping device so that the film center part lying around the good fits tightly and the closer positions the two film curtain parts so that they pass through a sealing unit are welded together and the respectively separated ends of the film middle part are welded to one another in order to then output the finished goods, characterized in that a clamping means is provided on the closer as a clamping means for the first film curtain part and d he clamping means during the closing movement of the closer, at least for part of the closing movement, clamps the first part of the film or the middle part of the film and thus clamps it. 2. The method according to claim 1, characterized in that a hold-down holds the goods in place before foiling middle part by tensioning one or both of the Foil curtain parts is stretched. 3. Method according to one or both of the preceding An sayings, characterized in that during tensioning the first film curtain part also the second film curtain part is tensioned. 4. Device for wrapping a good with a plastic film, in particular for carrying out a method according to one or more of the preceding claims, characterized in that the closer ( 5 ) is movably mounted on a rail guide ( 50 ) and a positioning unit ( 6 ) is provided is, which monitors the position of the closer ( 5 ) and a control, depending on the position of the closer ( 5 ), the clamping means ( 40 ) controls so as to tear the film curtain ( 20 ) and / or slipping Avoid good ( 1 ). 5. Apparatus according to claim 4, characterized in that a servo motor ( 60 ) serves as the positioning unit ( 6 ), which acts via a drive means ( 61 ), for example a toothed belt or a drive spindle, on the slide-like guided closer ( 5 ). 6. Device according to one or both of claims 4 and 5, characterized in that the hold-down device ( 7 ) and / or the sealing unit ( 8 ) is / are arranged on the rail guide ( 50 ). 7. The device according to one or more of claims 4 to 6, characterized in that a slotted roller ( 41 , 43 ) is provided as tensioning means ( 4 ) for the second film curtain part ( 22 ) which about its longitudinal axis for tensioning the second film curtain part ( 22 ) is pivotable. 8. The device according to one or more of claims 4 to 7, characterized in that the clamping means ( 40 ) on the closer ( 5 ) is arranged, and moves with it. 9. The device according to one or more of claims 4 to 8, characterized in that the position of the hold-down ( 7 ) on the rail guide ( 50 ) by the positioning unit ( 6 ) and the closer ( 5 ) is adjustable.