EP3812288A1 - Method and shrinking device for shrinking a thermoplastic packaging material onto articles - Google Patents

Abstract

The invention relates to a method for shrinking a thermoplastic packaging material (4) onto an article (2) or to an assembly of articles (2) and a shrinking device for carrying out such a method. The article (2) wrapped in thermoplastic packaging material (4) or the assembly of articles (2) wrapped in thermoplastic packaging material (4) is conveyed over a transport path (TS) in a transport direction (TR) through a shrinking device (10). The article (2) wrapped in thermoplastic packaging material (4) or the assembly of articles (2) wrapped in thermoplastic packaging material (4) is acted upon from above by shrinking medium (HL) which has a first temperature (T1). Furthermore, the article (2) wrapped with thermoplastic packaging material (4) or the assembly of articles (2) wrapped with thermoplastic packaging material (4) is exposed to the side with shrinking medium (HL) which has a second temperature (T2). It is provided here that there is a temperature difference of at least three degrees Celsius between the first temperature (T1) and the second temperature (T2).

Description

The present invention relates to a method and a shrink tunnel for shrinking thermoplastic packaging material onto articles according to the features of the independent claims.

Flat material webs made of thermoplastic material are used, for example, as a film for shrinking processes in packaging technology. The respective thermoplastic sheet or the respective shrink film is provided as an endless material on rolls before shrinking, then arranged around a compilation or group of several articles, subsequently guided together with the respective articles through a shrink tunnel and there subjected to shrinkage with temperature. If the articles wrapped in the sheet or shrink film exit the shrink tunnel, a so-called packaging unit is formed from the sheet and the group of articles, in which the individual articles are held together by means of the shrunk-on thermoplastic sheet or shrink film.

In shrinking devices known from the prior art for shrinking materials, the articles, such as PET bottles, wrapped with a thermoplastic packaging material or shrink material, in particular a shrink film, are transported along a transport path through the so-called shrink tunnel. During its transport through the shrink tunnel, the shrink material is heated from the sides and / or from below by exposure to a shrinking medium, in particular with hot air or the like, and is thereby shrunk onto the respective article. Known shrink tunnels include, for example, electrical heaters for heating the thermoplastic packaging material to be shrunk.

A shrink tunnel in which an electrical heating device is used is, for example, from the laid-open specification DE 199 20 057 A1 known. The air heated by the heating devices is fed into the interior of the shrink tunnel via hot air outlets.

In order to improve the shrinkage quality, shrinking devices are known from the prior art, in which the thermoplastic packaging material already applied to the article passes through different temperature zones within the shrink tunnel in the transport direction, which is for example in the laid-open specification US 2010/0059036 A1 is described.

For this reason, one object of the invention can be seen as providing a possibility with which the shrinkage quality in the production of packaging units, in particular shrinkable packs, can be further improved.

The above object is achieved by a method for shrinking on a thermoplastic packaging material and a shrinking device which comprise the features in the independent claims. Further advantageous refinements are described by the subclaims.

The invention relates to a method for shrinking a thermoplastic packaging material onto an article or onto an assembly of articles. For this purpose, it is provided that the articles, for example beverage containers such as bottles or cans or the like, are combined into article groups or article combinations in a grouping device. These article groups or article combinations are then wrapped in a wrapping device with a thermoplastic packaging material, for example with a flat packaging blank made of a shrink material, which is also referred to as shrink film. In particular, the shrink film is wrapped around the article assembly in the wrapping device.

The compilation of articles encased in this way with thermoplastic packaging material is now fed to a shrinking device, where the thermoplastic packaging material shrinks onto the items of the compilation when a shrinking medium, for example hot air, is supplied, so that the articles are held together within the compilation. The packaging unit produced in this way is also referred to as a shrink pack.

The shrinking device comprises an interior space with at least one transport path. In particular, the shrinking device comprises a shrinking tunnel and a housing surrounding the interior of the shrinking tunnel with an entry area and an entry opening as well as an exit area and an exit opening for the articles wrapped with the thermoplastic packaging material or compilations of articles. Between the inlet opening and the outlet opening there extends at least one transport path for the articles wrapped with shrink material, on which the articles are transported in the transport direction through the shrink tunnel. The transport route is formed in particular by a transport device or a partial area of a transport device which is delimited on both sides by shaft walls. Each of the shaft walls has at least one outflow surface or nozzle surface for shrinking medium directed towards the transport path, which is applied to the articles wrapped with the thermoplastic packaging material via the nozzles of the nozzle surface or the like. The shrinking medium is preferably formed by warm air.

Furthermore, the shrinking device comprises a lower spraying device and an upper spraying device, which are assigned in particular to the transport path of the shrink tunnel. The number of shaft walls defines the number of transport routes formed. In the case of single-lane transport over a transport path, so-called outer shaft walls are provided on both sides of the transport path on or above the transport device, each having an outflow surface or nozzle surface facing the interior of the shrinking device and a closed side surface facing the housing of the shrinking device.

In the case of two-lane transport over two parallel transport routes, three shaft walls are arranged on or above the transport device. In particular, the two transport routes in the vicinity of the housing of the shrinking device are each delimited by outer shaft walls. Arranged centrally or approximately in the middle between the two outer shaft walls is an inner shaft wall, the two essentially vertical side surfaces of which are each designed as outflow surfaces or nozzle surfaces parallel to the transport direction. The middle or inner shaft wall thus in particular feeds shrinking medium to the two parallel transport routes, wherein the application of shrinking medium to the two parallel transport routes is or can have approximately the same order of magnitude.

In the method it is provided that the article wrapped with thermoplastic packaging material or the wrapped combination of articles is at least partially exposed to shrinking medium from above and / or from below, which has a first temperature.

Furthermore, the article wrapped with thermoplastic packaging material or the wrapped assembly of articles is acted upon at least in regions from the side and / or from below with shrinking medium which has a second temperature. It is provided that there is a temperature difference of at least three degrees Celsius between the first temperature and the second temperature. There is preferably a temperature difference of at least five degrees Celsius, particularly preferably there is a temperature difference of at least ten degrees Celsius.

A preferred embodiment provides that the first temperature is higher than the second temperature, in particular that the first temperature is at least three degrees Celsius higher than the second temperature.

It is preferably provided that the difference between the first temperature and the second temperature is at least five degrees Celsius, in particular that the value of the first temperature is at least five degrees Celsius above the value of the second temperature. The temperature difference is particularly preferably at least ten degrees Celsius. For example, the value of the second temperature is approximately 180 degrees Celsius and the value of the first temperature is at least 190 degrees Celsius or higher. According to a preferred embodiment, the value of the second temperature is approximately 180 degrees Celsius and the value of the first temperature is approximately 230 degrees Celsius.

In one embodiment of the method, warm air is sucked out of an interior of the shrinking device, in particular from the interior of the shrink tunnel, and is divided into at least one first partial flow and at least one second partial flow. The first partial flow is then heated by a heating device. The article wrapped with the thermoplastic packaging material or the compilation is at least partially exposed to the heated first partial flow from above.

In contrast, the second partial flow is fed directly to the shaft walls and to the at least one lower spray device of the shrinking device. In particular, in the method described here, the article wrapped with the thermoplastic packaging material or the compilation is thus at least partially exposed to the side and from below with a second partial flow of warm air, which has a lower second temperature than that from above onto the article or the Compilation directed first substream.

The method can in particular be carried out in a shrinking device which comprises at least one first device for supplying a shrinking medium subjected to a first temperature to an upper spraying device and / or a device for supplying a shrinking medium subjected to a first temperature to a lower spraying device. The upper spraying device is formed, for example, by what is known as an upper hood, which is arranged above the transport path and has spraying openings on its underside through which the shrinking medium is sprayed downwards into the interior of the shrink tunnel and thus onto the top of the article or article combination wrapped in thermoplastic packaging material can.

The lower spraying device is formed, for example, by a so-called floor chamber which is arranged below the transport path. In particular, the bottom chamber is arranged below the transport device, which is formed, for example, by an endless conveyor belt. The bottom chamber has nozzle openings on its upper side, via which the shrinking medium, directed upward, through openings in the transport device, can be sprayed onto the lower side of the article wrapped with thermoplastic packaging material.

Furthermore, the shrinking device comprises at least one second device for feeding a shrinking medium subjected to a second temperature to lateral spraying devices and / or a device for feeding a shrinking medium subjected to the second temperature to the lower spraying device, in particular to the shaft walls and / or the bottom chamber of the shrinking device or to areas of the chess walls and / or the bottom chamber of the shrinking device.

For the provision of shrinking medium, the shrinking device preferably comprises at least one suction device for sucking in or sucking off air from the interior of the shrinking device. The suction device is preferably formed by a fan. A distribution device can be assigned to the fan, which divides the sucked-in air into at least two partial flows, wherein in particular a first partial flow is assigned to the first device and a second partial flow is assigned to the second device. Alternatively, it can be provided that each device is assigned its own fan for supplying air from the interior of the shrink tunnel.

In order to generate shrink medium with the at least two different temperatures, it can be provided according to one embodiment that the at least one first device is a first heating device or comprises a first heating device. For example, the first heating device can be a first heating register. A part of the air sucked in from the interior of the shrink tunnel is heated to the desired first temperature via the first heating register and fed to the upper spraying device and / or the lower spraying device. The air heated to the first temperature is introduced as a shrinking medium into the interior of the shrink tunnel, the shrinking medium at the first temperature being directed, in particular, to the top and / or the bottom of the article or article combination wrapped with thermoplastic packaging material.

Furthermore, it can be provided that at least one second device is a second heating device or comprises a second heating device. For example, the second heating device can be a second heating register. Via the second heating register, part of the air sucked in from the interior of the shrink tunnel is heated to the desired second temperature and fed to the shaft walls and / or the lower spraying device and fed back into the interior of the shrink tunnel as a shrinking medium, the shrinking medium in particular affecting the Manhole walls directed towards side surfaces and / or the bottom surface of the article wrapped with thermoplastic packaging material is guided. In this embodiment described above, the provision of shrinking medium at a first temperature and shrinking medium at a second temperature takes place independently of one another.

According to a further embodiment it can be provided that the air sucked out of the shrink tunnel can be used directly as a shrinking medium for application from the side and / or from below via the shaft walls without further heating. In this case, the second device is formed by the line system between the fan and the shaft walls and the second partial flow is sucked out of the interior via the fan. Air is introduced directly into the shaft walls and / or the floor chamber.

In order to generate shrinking medium with the at least two different temperatures, it can be provided according to an alternative embodiment that the shrinking device comprises a first heating device which is assigned to the first device and the second device and wherein the Shrink device comprises a second heating device which is assigned to the first device. Here, the air sucked out by the fan is first brought to the second temperature by a heating device. A second partial flow of the air heated in this way is introduced directly into the shaft walls and / or the lower spray device.

Another part of the air heated in this way is further heated to the higher first temperature in a further heating device and then fed to the upper spraying device and / or the lower spraying device. In this embodiment, the provision of shrinking medium at a first temperature and shrinking medium at a second temperature takes place via a step-by-step heating of the air sucked out of the interior.

According to one embodiment it is provided that the application of shrinking medium of a first temperature from above and / or below and the application of shrinkage medium of a second, in particular lower, temperature from the sides and / or from below take place at the same time. An alternative embodiment, on the other hand, provides that the articles or article combinations wrapped with thermoplastic packaging material are first acted upon from above and / or from below with shrink medium of the first temperature and then from the side and / or from below with shrink medium of the second, in particular lower, temperature . Another embodiment can provide that the articles or article combinations wrapped with thermoplastic packaging material are first acted upon laterally and / or from below with shrinking medium of the second, in particular lower, temperature and then are acted upon from above and / or from below with shrinking medium of the higher first temperature .

Furthermore, the formation of at least two different temperature zones can be provided within the shrinking device. In a first temperature zone it is provided, for example, that the articles or article assemblies wrapped with thermoplastic packaging material are simultaneously exposed to shrinking medium at the first temperature and shrinking medium at the second temperature, while the wrapped articles or article assemblies within a second temperature zone from above, in particular via the upper spraying device, and / or from below, in particular via the lower spray device, as well as laterally, in particular via the shaft walls, or all around, with shrinking medium of a third temperature.

Another embodiment can provide that the articles or article combinations wrapped with thermoplastic packaging material are acted upon in a first temperature zone from above and / or from below with shrinking medium of the first temperature. In a subsequent, second temperature zone, shrink medium of the second, in particular lower, temperature is introduced into the interior of the shrink tunnel from the side and / or from below, while in a third temperature zone shrink medium with a third temperature is introduced from above and / or from below and from the side. In this arrangement, the first temperature zone and the second temperature zone can also be interchanged. The third temperature is preferably above the second temperature. According to one embodiment of the invention, the third temperature can be higher than the first temperature or else lower than the second temperature. However, the third temperature is preferably between the first temperature and the second temperature.

In the case of a shrink device comprising at least two temperature zones, it can be provided in particular that each of the temperature zones has a first device for providing a shrinking medium to which a first temperature is applied and / or a second device for providing a shrinking medium to which a second temperature is applied and / or a third device for Providing a shrinking medium etc. to which a third temperature is applied. In the case of a shrinking device which provides shrinking medium at a third temperature in a temperature zone, a device for providing a shrinking medium to which a third temperature is applied is preferably provided, which device is in particular assigned to the corresponding temperature zone.

It is preferably provided that the different temperatures in the different temperature zones are each generated and / or controlled independently of one another.

According to one embodiment it is provided that the air sucked in from the interior is divided into a first partial flow and a second partial flow, the first volume of the first partial flow being greater than the second volume of the second partial flow. The amount of shrinking medium that is applied over the shaft walls and from below onto the article or the article assembly that is at least partially encased with thermoplastic packaging material is thus significantly reduced compared to known shrinking devices. In particular, the first partial flow is inflated from above over a large area, so that the shrinking medium of the first partial flow also has a the lowest possible flow velocity flows into the interior of the shrinking device.

An alternative embodiment can provide that the first partial flow and the second partial flow are designed to be approximately the same in terms of volume. For other applications, however, it can also be advantageous if the first partial flow provides a smaller volume than the second partial flow.

According to one embodiment of the invention, it is provided that the air is sucked out of areas behind the outer shaft walls, which areas are assigned to the side surfaces of the shaft walls that are not facing the transport path. For example, the suction device of the shrink device has at least one suction opening arranged above the transport path and above the at least two outer shaft walls.

Associated with the suction opening is at least one suction panel above the transport path, which extends across a width transverse to the transport direction, which is greater than a width of the suction opening and which extends in particular over a width between the outflow surfaces of the two outer shaft walls. In the case of multi-lane transport, the suction panel preferably extends transversely to the transport direction over the total width of all transport routes subdivided by inner shaft walls and beyond.

The air is thus sucked in from an area between a housing delimiting the interior of the shrinking device and the, in particular closed, side surface of the outer shaft walls facing away from the transport path. In particular, the air can thus be sucked out of an area in which no articles wrapped with packaging material are arranged. There is thus also no risk of the packaging material being blown and not shrinking onto the articles or article combinations in the desired manner.

According to one embodiment it is provided that the shrinking device comprises a control device and at least one sensor assigned to the upper spraying device and / or at least one sensor assigned to the lower spraying device and / or at least one sensor assigned to the shaft walls. In particular, the sensors are in each case temperature sensors that determine the temperature of the shrinking medium which is applied to the thermoplastic via the respective spraying device or shaft wall Packaging material wrapped articles or article assemblies is applied. In particular, an actual value of the supplied shrinking medium is determined in an upper and / or a lower area and / or in a lateral area of the shrinking device.

The data determined by sensors are transmitted to the control device and the first device and / or the second device are regulated and / or controlled on the basis of the data determined by sensors. The control device compares in particular the at least one measured actual value with a defined setpoint value. When determining a deviation between the actual value and the target value, the heating of the sucked in air via the first heating device and / or the second heating device can be adapted accordingly. One embodiment provides, for example, that the heating device through which the first partial flow is passed is regulated and / or controlled on the basis of the data determined by sensors in order to adapt the temperature of the air of the first partial flow accordingly.

By using shrinking agents with different temperature levels, the shrinking process takes place in the reverse order than with conventionally known shrinking processes. In particular, the shrinkage takes place from the center of the film outwards in the direction of the edge of the film. In particular, the side spraying and / or the spraying from below takes place with shrinking medium, the temperature of which is lower than the mean process temperature in the interior of the shrink tunnel, while the spraying takes place from above and / or below with shrinking medium, the temperature of which is above the mean process temperature or interior temperature.

The mean process temperature or interior temperature represents a mixed temperature between the first and the second temperature Shrink material applies wrinkle-free around the article or since the formation of wrinkles when shrinking the shrink material is significantly reduced compared to known processes. A clean design of the foil eye is also guaranteed here.

The packaging units produced in this way are then sent for further processing. It can be provided that the packaging units After leaving the shrink tunnel, a coolant, for example cooling air, can still be applied in order to cool the packaging units more quickly, which further increases the stability of the shrunk-on thermoplastic packaging material. A plurality of packaging units are put together, for example in a layer formation module, to form a palletizable layer. The layers are preferably formed by means of at least one suitable manipulator, for example by means of a gantry robot, a tripod or the like. The layers prepared in this way can be stacked on top of one another in a palletizing module for subsequent storage and / or transport.

An alternative embodiment, which also serves to optimize the shrinking process, can provide that the different areas of the articles or article assemblies wrapped with packaging material are each acted upon with different volume flows of shrinking agent in order to achieve a different energy input. The different energy input can also be achieved, for example, if, for example, IR radiation or the like is used as the shrinkage means. It can be provided here that the different areas of the articles or article combinations wrapped with packaging material are each irradiated with different IR radiation.

It should be expressly mentioned at this point that all aspects and design variants that have been explained in connection with the device according to the invention relate to or can be partial aspects of the method according to the invention in the same way. If, therefore, at one point in the description or in the definition of claims for the device according to the invention, certain aspects and / or interrelationships and / or effects are mentioned, this applies equally to the method according to the invention. Conversely, the same applies, so that all aspects and design variants that have been explained in connection with the method according to the invention relate to or can be partial aspects of the device according to the invention in the same way. If, therefore, at one point in the description or in the definition of claims for the method according to the invention, certain aspects and / or interrelationships and / or effects are mentioned, this applies equally to the device according to the invention.

• Fig. 1 zeigt eine Schrumpfvorrichtung und einen Schrumpfungsprozess nach dem bekannten Stand der Technik.
• Figuren 2A bis 2D stellen das Schrumpfen eines thermoplastischen Verpackungsmaterials um die Artikel in verschiedenen Bereichen entlang der Transportstrecke innerhalb des Schrumpftunnels der Schrumpfvorrichtung gemäß Fig. 1 dar.
• Fig. 3 zeigt eine Schrumpfvorrichtung und einen Schrumpfungsprozess gemäß vorliegender Erfindung.
• Figuren 4A bis 4C zeigen jeweils einen Teilbereich einer Schrumpfvorrichtung gemäß vorliegender Erfindung, wobei Figuren 4A und 4C unterschiedliche Ausführungsformen gemäß vorliegender Erfindung zeigen.
• Fig. 5 zeigt in schematischer Weise eine erste Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• Fig. 6 zeigt in schematischer Weise eine zweite Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• Fig. 7 zeigt in schematischer Weise eine weitere Ausführungsform der Schrumpfvorrichtung gemäß Fig. 4C.
• Fig. 8 zeigt in schematischer Weise eine vierte Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• Fig. 9 zeigt in schematischer Weise eine fünfte Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• Fig. 10 zeigt eine Schrumpfvorrichtung analog zu Fig. 3 ohne umhüllte Artikelgruppe.
• Fig. 11 zeigt eine weitere Ausführungsform einer Schrumpfvorrichtung analog zu Fig. 3 ohne umhüllte Artikelgruppe.
• Fig. 12 zeigt in schematischer Weise eine weitere Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• Figuren 13A bis 13D zeigen den Schrumpfungsprozess zu unterschiedlichen Zeitpunkten.

In the following, exemplary embodiments are intended to explain the invention and its advantages in more detail with reference to the accompanying figures. The proportions of the individual elements to one another in the figures do not always correspond to the real proportions, since some shapes are simplified and other shapes are enlarged in relation to other elements for ease of illustration.

• Fig. 1 shows a shrinking device and a shrinking process according to the known prior art.
• Figures 2A to 2D illustrate the shrinking of a thermoplastic packaging material around the articles in different areas along the transport route within the shrink tunnel of the shrink device according to FIG Fig. 1 represent.
• Fig. 3 Fig. 10 shows a shrinking device and a shrinking process according to the present invention.
• Figures 4A to 4C each show a partial area of a shrinking device according to the present invention, wherein Figures 4A and 4C show different embodiments according to the present invention.
• Fig. 5 shows in a schematic manner a first embodiment of a shrinking device with differently tempered shrinking medium.
• Fig. 6 shows in a schematic way a second embodiment of a shrinking device with differently tempered shrinking medium.
• Fig. 7 shows a further embodiment of the shrinking device according to FIG Figure 4C .
• Fig. 8 shows in a schematic way a fourth embodiment of a shrinking device with differently tempered shrinking medium.
• Fig. 9 shows in a schematic manner a fifth embodiment of a shrinking device with differently tempered shrinking medium.
• Fig. 10 shows a shrink device analogous to FIG Fig. 3 without wrapped article group.
• Fig. 11 shows a further embodiment of a shrink device analogous to FIG Fig. 3 without wrapped article group.
• Fig. 12 shows in a schematic manner a further embodiment of a shrinking device with differently tempered shrinking medium.
• Figures 13A through 13D show the shrinkage process at different points in time.

Identical reference symbols are used for identical or identically acting elements of the invention. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures which are necessary for the description of the respective figure. The illustrated embodiments merely represent examples of how the device according to the invention or the method according to the invention can be designed and do not represent a final limitation.

The representation of the Fig. 1 shows a cross section of a shrinking device 1 and schematically demonstrates a shrinking process according to the known prior art. Article 2, in particular beverage containers, bottles 3, cans or the like are put together in article groups in a dividing module (not shown) and wrapped in a wrap-around module (not shown) with a flat thermoplastic packaging material, in particular a cut of shrink film 4.

If the term shrink film 4 is mostly used in the following, it is intended to encompass any suitable thermoplastic packaging material. The arrangements of articles 2 and shrink film 4 are also referred to as wrapped article groups 5. The wrapped article groups 5 are transported in a transport direction on a transport path TS, which is formed in particular by a conveyor belt 6, through the shrink tunnel of the shrinking device 1.

At least one heating means (not shown) is arranged in the shrink tunnel that generates hot air HL as the shrinking medium. The hot air HL with a temperature T, for example with a temperature T = 180 degrees Celsius, is blown laterally through the shaft walls 7 in the direction of the wrapped article groups 5 into the interior 8 of the shrink tunnel.

The shaft walls 7 are, for example, lateral spraying devices in the form of perforated hollow bodies. The shrinking device 1 shown shows a single-lane shrink tunnel with two lateral shaft walls 7, the side surfaces of the shaft walls 7 facing the interior 8 of the shrink tunnel being designed as outflow surfaces 9. The two shaft walls 7 are also referred to as so-called outer shaft walls 7a.

In addition, it can be provided that part of the shrinking medium generated by the heating means is blown onto the wrapped article groups 5 from below in the form of hot air HL. In particular, the conveyor belt 6 is designed to be correspondingly permeable, for example in the form of a mat chain conveyor or the like. The shrinking medium, in particular the hot air HL, causes the shrink film 4 to shrink around the article 2. The shrinking process starts in particular from the edge of the film and runs in the direction of the center of the film. The starting areas are marked in the drawing by the reference symbol "S", while the center of the film is marked by the reference symbol "M".

The Figures 2A to 2D represent the shrinking of the shrink film 4 around the bottles 3 of the wrapped article group 5 in different areas along the transport route TS within the shrink tunnel of the shrinking device 1 according to Fig. 1 represent. Figure 2A shows the situation in the starting area of the shrink tunnel 1. The shrink film 4 was wrapped around the bottles 3 by means of a film wrapping device or a wrapping module (not shown), for example.

In the shrink tunnel, hot air HL at temperature T or another suitable shrinking medium is sprayed laterally onto the wrapped article groups 5 via the outflow surfaces 9 of the shaft walls 7. The further the wrapped article group 5 is transported in the transport direction through the shrink tunnel, the more the shrink film 4 shrinks around the bottles 3 according to its properties. The so-called film eyes are formed on the side surfaces with the film protrusions FÜ that initially overlap freely at the sides. In particular, the shrinking process begins at the laterally freely overlapping film protrusions FÜ, which is identified by "S", and continues in the direction of the film center "M", which is particularly evident in FIG Figure 2D can be clearly seen.

Initially, there is a small distance between the outflow surfaces 9 and the shrink film 4 (cf. Figure 2A ). The distance between the outflow surfaces 9 and the shrink film 4 has already been increased to a mean distance in the middle area of the shrink tunnel due to the shrinking of the shrink film 4 (cf. Figures 2B and 2C ). Before the wrapped article group 5 leaves the shrink tunnel of the shrink device 1 (cf. Fig. 1 ), the shrink film 4 lies largely completely close to the outer surfaces of the bottles 3, whereby there is a maximum distance between the outflow surfaces 9 of the shaft walls and the bottles 3 of the wrapped article groups 5 (cf. Figure 2D ).

The schematic view of the Fig. 3 Fig. 10 shows a shrinking device 10 and a shrinking process according to the present invention. It is provided here that shrinking medium, in particular hot air HL, at a first temperature T1 is applied from above to the wrapped article group 5 and that further, in particular simultaneously, via the shaft walls 7, shrinking medium, in particular hot air HL, of a second temperature T2 from the sides forth is applied to the wrapped article group 5.

In particular, it is provided that there is a temperature difference of at least three degrees Celsius between the first temperature T1 and the second temperature T2. For example, it is provided that the first temperature T1 is at least three degrees Celsius higher than the second temperature T2.

For example, the shrinking medium from the shaft walls 7 has a second temperature T2 of approximately 160 to 180 degrees Celsius, while the shrinking medium supplied from above has a first temperature T1 that is at least five degrees Celsius above the second temperature T2. The first temperature T1 is preferably at least ten degrees Celsius above the second temperature T2.

It is preferably provided that the shrinking medium of the first temperature T1 is inflated from above onto at least in a middle area between the two shaft walls 7 delimiting the transport path TS for the wrapped article group 5, so that the shrinking process does not begin at the film protrusions FÜ, but in central areas in which the shrink film 4 rests above the article 2 of the wrapped article group 5. This ensures that the shrinking process takes place from the inside out, i.e. the shrink film 4 first shrinks in the middle area and attaches itself firmly to the article 2 from above before the shrink film 4 shrinks in the lateral area, especially in the area of the film protrusions FÜ. This achieves a particularly nice shrink result. In particular, the formation of wrinkles is reduced or completely prevented, and particularly uniform film eyes are formed.

Furthermore, it can be provided that shrinking medium, in particular hot air HL, at a first temperature T1 is applied to the wrapped article group 5 from below. Alternatively, it can be provided that shrinking medium, in particular hot air HL, at a second temperature T2 is applied to the wrapped article group 5 from below. Thus, the shrink film 4 below the article 2 is also shrunk from the inside out. Alternatively, the shrinking medium fed in from below can also be a third one Have temperature T3. The third temperature T3 is preferably also above the second temperature T2. According to one embodiment of the invention, the third temperature T3 can be higher than the first temperature T1. However, the third temperature T3 is preferably between the first temperature T1 and the second temperature T2.

Due to the supply of shrinking medium at different temperatures, an average process temperature or interior temperature is obtained in the interior 8 of the shrink tunnel of the shrinking device 10, which is between the first temperature T1 and the second temperature T2.

According to one embodiment it can be provided that at least two temperature zones are formed within the shrink tunnel. In a first temperature zone, the wrapped article groups 5 are acted upon from above and / or below with shrinking medium of a first temperature T1 and laterally and / or from below with shrinking medium of a second, in particular lower, temperature T2. In a second temperature zone, the wrapped article groups 5 are exposed to shrinking medium of the same temperature on all sides before they exit the shrink tunnel, i.e. there is no temperature difference between the shrinking medium supplied from above and / or below and the laterally supplied shrinking medium.

The Figures 4A to 4C each show a partial area of a shrinking device 10 according to the present invention. Here the Figure 4A in particular an upper portion of a shrink device 10 according to the present invention, which Figure 4B shows a lower portion and Figure 4C shows an upper portion of a further embodiment of a shrink device 10 according to the present invention.

In particular, in Figure 4A the upper hood 11 of the shrinking device 10 is shown. Three shaft walls 7 are arranged on this so that wrapped article groups (not shown) can be processed in two lanes within the shrinking device 10 shown. In particular, two outer shaft walls 7 a and a central inner shaft wall 7 i are arranged on the upper hood 11.

The inner shaft wall 7i has outflow surfaces with shrink medium outlet openings on both side wall surfaces arranged parallel to the transport direction TR, so that shrink medium flows into the interior of the shrink tunnel on both sides and thus for the lateral application of the Item with hot air or similar. The known shaft walls 7 are walls with an inner cavity into which the shrinking medium is blown. For this purpose, the shaft walls 7 each have at least one air inlet opening, preferably arranged in the upper area, through which the shrink medium is blown into the shaft wall 7 from above and then flows through the shrink medium outlet openings of the at least one outflow surface into the interior of the shrink tunnel.

The shrinking device 10 comprises a fan 12 as a suction device, which draws in air from the interior of the shrink tunnel laterally via a suction panel 13. A first part of the air sucked in by the fan 12 is fed to a heating register 14 and heated in this to a first temperature T1. The hot air HL heated to a first temperature T1 is applied via the upper hood 11 from above into the interior of the shrink tunnel and from above onto the wrapped article groups, in particular inflated. Furthermore, some of the hot air HL heated to the first temperature T1 can be inflated from below onto the underside of the wrapped article groups via the bottom chamber of the shrinking device 10.

A second part of the air sucked in by the blower 12 is fed directly back into the shaft walls 7 and thus subsequently serves to act on the enveloped article groups conveyed through the shrink tunnel from the side with warm or hot air HL at a second temperature T2, which is in particular lower than that first temperature T1 (compare Fig. 3 ).

In Figure 4B In particular, the transport path TS for the wrapped article groups can be seen, which is preferably formed by a conveyor belt 6 which is motor-driven by a suitable drive 20.

Furthermore, in the Figures 4A and 4B two different temperature zones TZ1 and TZ2 are shown. In the first temperature zone TZ1, which is for example according to Figure 4A over approximately 70 percent of the transport route TS or which extends according to Figure 4B extends over approximately 50 percent of the transport path TS, it is provided in particular that the wrapped article groups are acted upon from above and / or below with shrinking medium of a first temperature T1 and from the side with shrinking medium of a second, in particular lower, temperature T2 (cf. Fig. 3 ).

In contrast, in the second temperature zone TZ2, which is for example according to Figure 4A over the last 30 percent or according to Figure 4B extends over 50 percent of the transport path TS, it can be provided that the wrapped article groups are exposed to shrinking medium at a first temperature or a second temperature or with shrinking medium at a third temperature on all sides. The third temperature T3 can either be below the second temperature or above the first temperature or between the first and the second temperature. In particular, it can be provided in this embodiment that each of the three temperature zones extends over approximately one third of the entire transport route.

Furthermore, in the embodiment according to Figure 4C shown that the fan 12 is assigned a distribution device 21 which divides the sucked air into a first partial flow HL1 and a second partial flow HL2. The first partial flow HL1 of the air sucked in by the fan 12 is fed to a heating register 14 and heated in this to a first temperature T1. The first partial flow HL 1 heated to a first temperature T1 is applied, in particular inflated, via the upper hood 11 from above into the interior of the shrink tunnel and from above onto the wrapped article groups.

The second partial flow HL2 of the air sucked in by the blower 12 is introduced directly into the shaft walls 7 and into a floor chamber (not shown) and is therefore subsequently used to apply hot or cold water to the wrapped article groups conveyed through the shrink tunnel from the side and from below. hot air at a second temperature T2, which is in particular lower than the first temperature T1 (cf. Fig. 3 ).

The suction panel 13 is preferably designed in such a way that the air is sucked out of areas behind the outer shaft walls 7a, which are each assigned to the side surfaces of the outer shaft walls 7a that are not facing the transport path. In particular, the suction panel extends across a width transverse to the transport direction TR, which is greater than a width of the suction opening of the fan 12 and which extends in particular over a width between the outflow surfaces of the two outer shaft walls 7a. In the case of multi-lane transport, the suction panel 13 extends transversely to the transport direction TR over the total width of all transport routes subdivided by inner shaft walls 7i and beyond. Thus, the air from an area between the housing delimiting the interior of the shrinking device 10 and the, in particular closed, side surface facing away from the transport path is the outer Manhole walls 7a sucked in. In particular, the air can thus be sucked out of an area in which no articles wrapped with packaging material are arranged. There is thus also no risk of the packaging material being blown and not shrinking onto the articles or article combinations in the desired manner.

The Fig. 5 shows in a schematic manner a first embodiment of a shrinking device 10 with differently tempered shrinking medium, in particular analogous to FIG Figure 4A . The different temperatures are generated in that part of the air sucked in is blown directly back into the shaft walls 7 of the shrink tunnel of the shrinking device 10 as a shrinking medium with the second temperature T2 without being heated again. The other part of the sucked in air is heated by a heating register 14 to an increased first temperature T1 and blown into the interior of the shrink tunnel from above via the upper hood 11.

In addition, part of the hot air HL with the increased first temperature T1 is fed to a floor chamber 15 of the shrink tunnel. The bottom chamber 15 is arranged in particular below the transport path TS for the wrapped groups of articles and has an outflow surface on its upper side so that hot air HL of the first temperature T1 can be sprayed onto the wrapped groups of articles from below via the bottom chamber 15.

The Fig. 6 shows in a schematic way a second embodiment of a shrinking device 10 with differently tempered shrinking medium. Here, only the upper hood 11 is supplied with further heated hot air HL at the higher first temperature T1, while both the shaft walls 7 and the bottom chamber 15 are supplied with hot air HL at the second, in particular lower, temperature T2. In particular, some of the air sucked in from the interior of the shrink tunnel by the blower 12 is introduced again directly into the shaft walls 7 and into the floor chamber 15.

The Fig. 7 shows a further embodiment of the shrinking device 10 according to FIG Figure 4C with shrinking medium at different temperatures. The hot air HL drawn in is divided into a first partial flow HL1 and a second partial flow via the distribution device 21. The different temperatures are generated by the fact that the second substream HL2 as a shrinking medium with the second temperature T2 directly back in without re-heating the shaft walls 7 and the bottom chamber 15 of the shrink tunnel of the shrink device 10 is blown.

The bottom chamber 15 is arranged in particular below the transport path TS for the wrapped groups of articles and has an outflow surface on its upper side so that hot air at the second temperature T2 can be sprayed onto the wrapped groups of articles from below via the bottom chamber 15. The first partial flow HL1 is heated to an increased first temperature T1 by a heating register 14 and blown into the interior of the shrink tunnel from above via the upper hood 11.

According to one embodiment it is provided that a first volume of the first partial flow HL1 is greater than a second volume of the second partial flow HL2. Thus, the amount of shrinking medium that is applied laterally via the shaft walls 7 and from below via the bottom chamber 15 to the article or the article assembly that is at least partially wrapped with thermoplastic packaging material is significantly reduced compared to known shrinking devices. In particular, the first partial flow HL1 is inflated from above over a large area of the upper hood 11, so that the shrinking medium of the first partial flow HL1 also flows into the interior of the shrinking device 10 at the lowest possible flow rate.

The Fig. 8 shows in a schematic manner a fourth embodiment of a shrinking device 10 with differently tempered shrinking medium, while the Fig. 9 shows schematically a fifth embodiment of a shrinking device 10 with shrinking medium at different temperatures. Here, two heating registers 14, 16 are used to control the temperature of the shrinking medium.

According to the in Fig. 8 The embodiment shown, the heating registers 14, 16 are connected in parallel. A first part of the air sucked in by the fan 12 from the interior of the shrinking device 10 is heated by a first heating register 14 to a first temperature T1 and sprayed onto the wrapped groups of items via the top hood 11 and from below via the bottom chamber 15.

A second part of the air sucked in by the fan 12 from the interior of the shrinking device 10 is heated to a second temperature T2 by a second heating register 16, the second temperature T2 preferably being lower than the first temperature T1. The hot air to which the second temperature T2 is applied HL is introduced into the shaft walls 7 of the shrinking device 10 and laterally sprayed onto the wrapped groups of articles.

According to the in Fig. 9 The embodiment shown here are two heating registers 14, 16 connected in series. The air sucked in by the fan 12 from the interior of the shrinking device 10 is heated to a temperature T2 by a first heating register 14.

A part of the hot air HL heated to temperature T2 is introduced into the shaft walls 7 of the shrinking device 10 and is sprayed laterally onto the wrapped groups of articles. The remaining part of the hot air HL heated to the temperature T2 is heated to an increased temperature T1 by a second heating register 16. The hot air HL to which the increased temperature T1 is applied is sprayed onto the enveloped groups of articles via the upper hood 11 from above and via the bottom chamber 15 from below.

The Fig. 10 shows a shrinking device 10 analogous to FIG Fig. 3 . The Fig. 11 shows a further embodiment of a shrinking device 10 analogous to FIG Fig. 3 without a wrapped article group, whereby the wrapped article group has not been shown for reasons of clarity. By means of a fan 12, air is sucked in from the interior space 8 of the shrink tunnel of the shrinking device 10, preferably via a suction panel (not shown). A distribution device 21 is assigned to the fan 12, which divides the sucked air into at least two partial flows.

At the in Fig. 10 In the illustrated embodiment, a first partial flow is assigned to a first device for feeding a shrinking medium HL subjected to a first temperature T1 to an upper spraying device, in particular to the upper hood 11, and / or for feeding to a lower spraying device, in particular the bottom chamber 15.

A second partial flow is assigned to a second device for supplying a shrinking medium HL to which a second temperature T2 is applied to the shaft walls 7. For example, it is provided that part of the air is fed directly back into the shaft walls 7 in order to be injected laterally into the interior space 8 via the shaft walls 7 and in particular in the direction of the wrapped group of articles.

Another part of the sucked in air is heated to a temperature T1 via a heating register 14 and injected into the interior 8 from above and below. For example, a first temperature sensor 18 is assigned to the bottom chamber 15. This determines the temperature of the hot air HL supplied from the heating register 14. The determined value is transmitted to a control device 17, which compares the determined value with the desired target value, in particular a temperature T1. If the comparison results in a deviation of the determined actual value from the setpoint value T1, then the control device 17 regulates the heating register 14. In addition, a temperature sensor (not shown) assigned to the upper hood 11 can be provided.

Furthermore, at least one second temperature sensor 19 can be assigned to the shaft walls 7, which sensor determines the temperature of the hot air HL fed into the shaft walls 7. If the determined value is below the desired target temperature value T2, a second heating register 16 is activated, which heats the air sucked in by the fan 12 to the desired temperature T2 before it is fed into the shaft walls 7.

At the in Fig. 11 In the illustrated embodiment, a first partial flow HL1 is assigned to a first device for supplying a shrinking medium to which a first temperature T1 is applied to an upper spray device, in particular to the upper hood 11. A second partial flow HL2 is assigned to a second device for supplying a shrinking medium HL to which a second temperature T2 is applied to the shaft walls 7 and for supplying the lower spraying device, in particular the bottom chamber 15. In particular, it is provided that the second partial flow HL2 of the air is fed directly back into the shaft walls 7 and the bottom chamber 15, to be injected laterally and from below into the interior 8 and in particular in the direction of the wrapped group of articles. The first partial flow HL1 of the sucked in air is heated to a temperature T1 via a heating register 14 and injected into the interior 8 from above.

For example, a first temperature sensor 18 is assigned to the bottom chamber 15. This determines the temperature of the second partial flow HL2 in hot air. The determined value is transmitted to a control device 17, which compares the determined value with the desired target value, in particular a temperature T2. If the comparison results in a deviation of the determined actual value from the setpoint value T2, then the control device 17 regulates the heating register 14 in order to increase the temperature of the first partial flow HL1, which enters the interior 8 of the shrinking device 10 from above via the upper hood (not shown) is introduced and thus to increase the temperature of the process air in the interior 8 of the shrinking device 10. In addition, a temperature sensor 25 assigned to the upper hood (not shown) can be provided.

Furthermore, at least one second temperature sensor 19 can be assigned to the shaft walls 7, which sensor determines the temperature of the second partial flow HL2 fed into the shaft walls 7. If the determined value is below the desired target temperature value T2, a second heating register 16 can be activated, if necessary, which heats the air sucked in by the fan 12 to the desired temperature T2 before it is fed into the shaft walls 7. Alternatively, the heating register 14 can again be regulated and the first partial flow HL1 can be heated further.

The Fig. 12 shows a further embodiment of a shrinking device 10 with differently tempered shrinking medium in a schematic manner. Here, air is sucked in from the interior of the shrinking device 10 via a first fan 12-1, heated to a first temperature T1 by means of a heating register 14 and fed to the top hood 11 and the bottom chamber 15 and to act on the wrapped groups of items from above or below used.

Furthermore, air is sucked in from the interior of the shrinking device 10 via a second fan 12-2 and fed to the shaft walls 7, where it is used to act on the wrapped groups of articles from the side. If necessary, the air from the second fan 12-2 is passed through a second heating register 16 and heated to a second temperature T2, which is in particular lower than the first temperature T1, before the air sucked in by the second fan 12-2 is fed to the shaft walls 7 becomes. This can in particular analogously to the embodiments of FIG Figures 10 and 11 are regulated by sensors.

The Figures 13A through 13D show the shrinkage process at different points in time, in particular the shrinkage behavior of the shrink film 4 around the articles 2 of the article group 5 is shown. Figure 13A shows a first state when the article group 5 wrapped with shrink film 4 enters the shrink device 10, Figure 13B shows a subsequent second state in which the shrinking process has already started. Figure 13C shows another later point in time at which the shrinking process has already progressed and Figure 13D shows a point in time shortly before or when leaving the shrinking device 10, at which the shrinking process is complete.

When the article group 5 wrapped with shrink film 4 enters the shrink device 10, the shrink film 4 protrudes laterally over the article 2 beyond ( Figure 13A ). With increasing energy supply in the form of shrink agent, the Shrink film 4 together, the shrinkage taking place in particular from the center of the film outwards in the direction of the edge of the film. The shrink film 4 attaches itself more and more to the article 2 ( Figures 13B and 13C ) until it finally rests firmly against the outer circumferential surfaces of the article 2 at least in some areas and thus securely holds the article 2 together.

The embodiments, examples and variants of the preceding paragraphs, the claims or the following description and the figures, including their different views or respective individual features, can be used independently of one another or in any combination. Features that are described in connection with an embodiment are applicable to all embodiments, provided that the features are not incompatible.

Even if “schematic” representations and views are generally spoken of in connection with the figures, this in no way means that the representations of the figures and their description are of subordinate importance with regard to the disclosure of the invention. The person skilled in the art is quite able to derive enough information from the schematically and abstractly drawn representations that facilitate his understanding of the invention without having to rely on the drawn and possibly not exactly to scale proportions of the articles and / or parts of the device or other drawn elements would be impaired in its understanding in any way. The figures enable the person skilled in the art as a reader to derive a better understanding of the inventive ideas formulated in the claims and in the general part of the description of general and / or more abstractly formulated ideas on the basis of the more specifically explained implementations of the method according to the invention and the more specifically explained functionality of the device according to the invention.

The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or changes can be made to the invention without departing from the scope of protection of the claims below.

List of reference symbols

1

Shrinking device

2

items

3

bottle

4th

Shrink film

5

wrapped article group

6th

Conveyor belt

7th

Shaft wall

7a

outer shaft wall

7i

inner shaft wall

8th

inner space

9

Outflow area

10

Shrinking device

11

Top hood

12th

fan

13th

Suction panel

14th

(first) heating register

15th

Floor chamber

16

second heating register

17th

Control device

18th

first temperature sensor

19th

second temperature sensor

20th

drive

21

Distribution device

25th

Temperature sensor

FÜ

Film overhang

HL

hot air

HL1

first partial flow

HL2

second partial flow

M.

Foil center

S.

Start shrinking process

T

temperature

T1

first temperature

T2

second (lower) temperature

TS

Transport route

TR

Transport direction

TZ1

first temperature zone

TZ2

second temperature zone

Claims (14)

Method for shrinking a thermoplastic packaging material (4) onto an article (2) or onto an assembly of articles (2), wherein the article (2) wrapped with thermoplastic packaging material (4) or the assembly of articles wrapped with thermoplastic packaging material (4) (2) is conveyed over a transport path (TS) in a transport direction (TR) through a shrinking device (10), - wherein the article (2) enveloped with thermoplastic packaging material (4) or the compilation is at least partially exposed to shrinking medium (HL) from above, which has a first temperature (T1), and - wherein the article (2) wrapped with thermoplastic packaging material (4) or the compilation is at least partially exposed to the side with shrinking medium (HL) which has a second temperature (T2), wherein there is a temperature difference of at least three degrees Celsius between the first temperature (T1) and the second temperature (T2). Method according to claim 1, wherein the first temperature (T1) is higher than the second temperature (T2), in particular wherein the value of the first temperature (T1) is at least five degrees Celsius above the value of the second temperature (T2), in particular wherein the The value of the first temperature (T1) is at least ten degrees Celsius above the value of the second temperature (T2), preferably wherein the value of the first temperature (T1) is more than 190 degrees Celsius and the value of the second temperature (T2) at is around 180 degrees Celsius. Method according to claim 1 or 2, wherein the article (2) wrapped with thermoplastic packaging material (4) or the assembly simultaneously from above with shrinking medium (HL) of the first temperature (T1) and laterally with shrinking medium (HL) of the second temperature (T2) is acted upon, or the article (2) wrapped with thermoplastic packaging material (4) or the assembly first from above with shrinking medium (HL) of the first Temperature (T1) is applied and then laterally with shrinking medium (HL) of the second temperature (T2) is applied, or
wherein the article (2) wrapped in thermoplastic packaging material (4) or the compilation is first exposed to the side with shrinking medium (HL) at the second temperature (T2) and then from above with shrinking medium (HL) at the first temperature (T1) Method according to claim 1 or 2, wherein the method is carried out in a shrinking device (10) with at least two temperature zones formed one after the other in the transport direction (TR), - wherein in a first temperature zone (TZ1) the with thermoplastic packaging material (4) wrapped article (2) or the compilation at the same time from above and / or from below with shrinking medium (HL) of the first temperature (T1) and laterally and / or from below with shrinking medium (HL) of the second temperature (T2) is applied and wherein in a second temperature zone (TZ2) the article (2) wrapped with thermoplastic packaging material (4) or the assembly from above and / or below as well as from the side with shrinking medium (HL ) a third temperature is applied, or - wherein in a first temperature zone (TZ1) the article (2) wrapped with thermoplastic packaging material (4) or the assembly is acted upon from above and / or from below with shrinking medium (HL) of the first temperature (T1), the thermoplastic packaging material (4) wrapped articles (2) or the assembly in a second temperature zone is acted upon laterally and / or from below with shrinking medium (HL) of the second temperature (T2) and wherein in a third temperature zone the article (4) wrapped with thermoplastic packaging material (4) 2) or the compilation is acted upon from above and / or from below as well as from the side with shrinking medium (HL) of a third temperature. Method according to one of the preceding claims, wherein warm or hot air (HL) is sucked in from an interior (8) of the shrinking device (10) and divided into at least one first partial flow (HL1) and at least one second partial flow (HL2), whereby the shrinking device ( 10) comprises at least two shaft walls (7) a lower spraying device (15) and an upper spraying device (11),
wherein the first partial flow (HL1) is brought to the increased first temperature (T1) by means of a heating device (14) and is introduced into the interior (8) of the shrinking device (10) from above and / or below, and
wherein the second partial flow (HL2) is introduced into the shaft walls (7) and / or the lower spray device (15) of the shrinking device, the second partial flow (HL2) introduced into the shaft walls laterally and / or from below onto the thermoplastic packaging material (4 ) wrapped article (2) or the compilation is blown, or
wherein the first partial flow (HL1) is brought to the increased first temperature (T1) by means of a first heating device (14) and is introduced into the interior (8) of the shrinking device (10) from above and / or below, and wherein the second partial flow ( HL2) is brought to the second temperature (T2) by means of a second heating device (16) and is introduced into the shaft walls (7) and / or the lower spray device (15) of the shrinking device, the value of the second temperature (T2) increasing by at least three Degrees Celsius differs from the value of the first temperature (T1),
and wherein the second partial flow (HL2) introduced into the shaft walls is sprayed laterally and / or from below onto the article (2) enveloped with thermoplastic packaging material (4) or onto the assembly of articles (2) enveloped with thermoplastic packaging material (4), or
wherein the first partial flow (HL1) is heated by a heating device (14), and
wherein the article (2) wrapped in thermoplastic packaging material (4) or the assembly is at least partially exposed to the heated first partial flow (HL1) from above,
wherein the second partial flow (HL2) is fed directly to the shaft walls (7) and to the at least one lower spray device (15) of the shrinking device (10). Method according to one of Claims 1 to 5, wherein warm or hot air (HL) is sucked in from an interior (8) of the shrinking device (10),
wherein the sucked air is brought to the second temperature (T2) by means of a heating device and part of the air heated to the second temperature is introduced as a shrinking medium (HL) into the shaft walls (7) of the shrinking device
another part of the air heated to the second temperature as a shrinking medium (HL) being brought to the first temperature (T1) by means of a further heating device and being introduced into the interior (8) of the shrinking device (10) from above and / or below. Method according to one of the preceding claims, wherein an actual value of the supplied shrinking medium (HL) is measured in an upper and / or a lower area and / or in a lateral area and
wherein the at least one measured actual value is compared with a target value,
wherein the first device and / or the second device is activated when a deviation between the actual value and the target value is determined, in particular wherein at least one heating device for shrinking medium (HL) is activated. Method according to one of Claims 1 to 7, a first volume of the first partial flow (HL1) being greater than a second volume of the second partial flow (HL2). Method according to one of Claims 1 to 8, the air being extracted from areas behind the outer shaft walls (7a), which areas are assigned to the side surfaces of the outer shaft walls (7a) not facing the transport path (TS), and / or
wherein the air of the first partial flow (HL1) is introduced over a large area from above into the interior (8) of the shrinking device (10), in particular wherein the air of the first partial flow (HL1) with a low flow velocity from above into the interior (8 ) flows into the shrinking device (10). Shrinking device (10) for shrinking a thermoplastic packaging material (4) onto an article (2) or onto an assembly of articles (2),
wherein the shrinking device (10) comprises an interior (8) with at least one transport path (TS) with an entrance area and an exit area for the article (2) or the assembly of articles (2), the article (2) or assembly of articles (2) are funded in one transport direction (TR),
wherein the transport path (TS) is limited on both sides by shaft walls (7), the shaft walls (7) each having an outflow surface (9) directed towards the transport path (TS) with a plurality of articles (2) or the combination of articles (2 ) has directed outflow openings for a shrinking medium (HL) formed by warm air, the shrinking medium (HL) flowing through the outflow openings into an interior (8) of the shrinking device (10) in the direction of the transport path (TS),
wherein the shrinking device (10) comprises at least one first device for feeding a shrinking medium (HL) to which a first temperature (T1) is applied to an upper spray device (11), and
wherein the shrinking device (10) comprises at least one second device for supplying a shrinking medium (HL) to which a second temperature (T2) is applied to the shaft walls (7) or to areas of the shaft walls (7) of the shrinking device (10),
in particular a shrinking device (10) for carrying out a method according to one of claims 1 to 9. The shrinking device (10) according to claim 10, wherein the shrinking device (10) comprises at least one suction device (12) for sucking in air from the interior (8) of the shrinking device (10), the at least one fan (12) having a distribution device (21) which divides the sucked-in air into at least two partial flows, a first partial flow (HL1) being assignable to the first device and a second partial flow (HL2) being assignable to the second device. Shrinking device (10) according to claim 10 or 11, wherein the at least one first device is a first heating device (14) or comprises a first heating device (14) and / or wherein the at least one second device is a second heating device (14) or a second Heating device (14) comprises, or
wherein the shrinking device (10) comprises a first heating device, which is assigned to the first device and the second device, and wherein the shrinking device (10) comprises a second heating device, which is assigned to the first device. Shrinking device (10) according to one of Claims 10 to 12, the shrinking device (10) having a control device (17) and at least one sensor (18) assigned to the upper spraying device (11) and / or at least one sensor (18) assigned to the lower spraying device (15) and / or comprises at least one sensor (19) assigned to the shaft walls (7), and wherein the first device and / or the second device can be regulated and / or controlled on the basis of data determined by sensors. Shrinking device (10) according to one of Claims 10 to 13, the shrinking device (10) comprising at least two areas formed one after the other in the transport direction (TR) with different temperature zones,
wherein within a first temperature zone (TZ1) shrinking medium (HL) of the first temperature (T1) is introduced into the interior (8) of the shrinking device (10) via the upper spraying device (11) and / or via the lower spraying device (15) and wherein within the first temperature zone (TZ1), shrinking medium (HL) of the second temperature (T2) is introduced into the interior (8) of the shrinking device (10) via the shaft walls (7) and / or via the lower spray device (15) and within a second temperature zone, shrinking medium (HL) at a third temperature is introduced into the interior (8) of the shrinking device (10) via an upper spraying device (11) and / or via a lower spraying device (15) and via shaft walls (7), or
wherein within a first temperature zone (TZ1) shrinking medium (HL) of the first temperature (T1) is introduced into the interior (8) of the shrinking device (10) via the upper spraying device (11) and / or via the lower spraying device (15) and wherein within a second temperature zone, shrinking medium (HL) of the second temperature (T2) is introduced into the interior (8) of the shrinking device (10) via the shaft walls (7) and / or via the lower spray device (15) and with shrinking medium within a third temperature zone (HL) of a third temperature is introduced into the interior (8) of the shrinking device (10) via an upper spraying device (11) and / or via a lower spraying device (15) and via shaft walls (7).

Images