DE102019128873A1 - 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 with thermoplastic packaging material (4) or the assembly of articles (2) wrapped with thermoplastic packaging material (4) is conveyed in a transport direction (TR) through a shrinking device (10). The article (2) wrapped with thermoplastic packaging material (4) or the assembly of articles (2) wrapped with thermoplastic packaging material (4) is exposed to shrinking medium (HL) from above and / or below, which has a first temperature (T1 ) having. 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 five 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.

State of the art

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.

description

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 a shrink tunnel and a housing surrounding the shrink tunnel with an entry area and an entry opening as well as an exit area and an exit opening for the articles or combinations of articles wrapped with the thermoplastic packaging material. Between the inlet opening and the outlet opening there extends at least one transport path for the articles wrapped with shrink material, on which these articles in the transport direction through the shrink tunnel to get promoted. 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 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 enveloped with thermoplastic packaging material or the enveloped assembly of articles is at least partially exposed to the side 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.

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 spray devices, in particular to the shaft walls of the shrinking device or to areas of the shaft walls of the shrinking device.

For the provision of shrinking medium, the shrinking device preferably comprises at least one fan for sucking in air from the interior of the shrinking device. A distribution device can be assigned to the fan, which divides the sucked air into at least two partial flows, a first partial flow being assigned to the first device and a second partial flow being 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, it can be in the case of the first heating device 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 fed back into the interior of the shrink tunnel as a shrinking medium, the shrinking medium in particular on the side surfaces of the with thermoplastic packaging material wrapped article is passed. 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 shrink medium for the lateral impact 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 air sucked out of the interior by the fan is introduced directly into the shaft walls.

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 shrinking device comprises a second heating device, which is the first device assigned. Here, the air sucked out by the fan is first brought to the second temperature by a heating device. Part of the air heated in this way is fed directly into the shaft walls. 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 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 exposed to shrinking medium at the first temperature from above and / or from below and then laterally exposed to shrinking 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 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, shrinking medium of the second, in particular lower, temperature is introduced laterally into the interior of the shrink tunnel, while in a third temperature zone, shrinking medium with a third temperature is introduced from above and / or below and from the side. In this arrangement, the first temperature zone and the second Temperature zone can be swapped. 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.

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

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.

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 each temperature sensors which determine the temperature of the shrinking medium which is applied to the articles or article combinations wrapped with the thermoplastic packaging material via the respective spraying device or shaft wall. 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 setpoint value, the heating of the sucked in air via the first heating device and / or the second heating device can be adapted 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 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, after leaving the shrink tunnel, a coolant, for example cooling air, is applied to the packaging units 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 forming 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 that also optimizes the shrinkage process serves, it can be provided that the different areas of the articles or combinations of articles enveloped 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.

Figure list

• 1 zeigt eine Schrumpfvorrichtung und einen Schrumpfungsprozess nach dem bekannten Stand der Technik.
• 2A bis 2D stellen das Schrumpfen eines thermoplastischen Verpackungsmaterials um die Artikel in verschiedenen Bereichen entlang der Transportstrecke innerhalb des Schrumpftunnels der Schrumpfvorrichtung gemäß 1 dar.
• 3 zeigt eine Schrumpfvorrichtung und einen Schrumpfungsprozess gemäß vorliegender Erfindung.
• 4A und 4B zeigen jeweils einen Teilbereich einer Schrumpfvorrichtung gemäß vorliegender Erfindung.
• 5 zeigt in schematischer Weise eine erste Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• 6 zeigt in schematischer Weise eine zweite Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• 7 zeigt in schematischer Weise eine dritte Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• 8 zeigt in schematischer Weise eine vierte Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• 9 zeigt eine Schrumpfvorrichtung analog zu 3 ohne umhüllte Artikelgruppe.
• 10 zeigt in schematischer Weise eine fünfte Ausführungsform einer Schrumpfvorrichtung mit unterschiedlich temperiertem Schrumpfmedium.
• 11A bis 11 D 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 forms are simplified and other forms are shown enlarged in relation to other elements for better illustration.

• 1 shows a shrinking device and a shrinking process according to the known prior art.
• 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 1 represent.
• 3 Fig. 10 shows a shrinking device and a shrinking process according to the present invention.
• 4A and 4B each show a partial area of a shrinking device according to the present invention.
• 5 shows in a schematic manner a first embodiment of a shrinking device with differently tempered shrinking medium.
• 6th shows in a schematic way a second embodiment of a shrinking device with differently tempered shrinking medium.
• 7th shows in a schematic manner a third embodiment of a shrinking device with differently tempered shrinking medium.
• 8th shows in a schematic way a fourth embodiment of a shrinking device with differently tempered shrinking medium.
• 9 shows a shrink device analogous to FIG 3 without wrapped article group.
• 10 shows in a schematic manner a fifth embodiment of a shrinking device with differently tempered shrinking medium.
• 11A to 11 D 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.

1 shows a cross section of a shrink device 1 and schematically demonstrates a prior art shrinkage process. items 2 , in particular beverage containers, bottles 3 , Cans or the like are put together in article groups in a dividing module (not shown) and in a wrapping module (not shown) with a flat thermoplastic packaging material, in particular a cut of a shrink film 4th , enveloped. If in the following the term shrink film 4th is used, it is intended to encompass any suitable thermoplastic packaging material. The arrangements from articles 2 and shrink film 4th are also referred to as wrapped article groups 5 . The wrapped article groups 5 are in one transport direction on a transport route TS which in particular by a conveyor belt 6th is formed by the shrink tunnel of the shrink device 1 transported.

At least one heating means (not shown) is arranged in the shrink tunnel hot air HL generated as a shrinking medium. The hot air HL with a temperature T , for example with a temperature T = 180 degrees Celsius, is over the shaft walls 7th laterally in the direction of the wrapped article groups 5 in the interior 8th blown in the shrink tunnel. At the shaft walls 7th it is, for example, lateral spraying devices in the form of perforated hollow bodies. The shrinking device shown 1 shows a single-lane shrink tunnel with two side shaft walls 7th , each with the interior 8th of the shrink tunnel facing side surfaces of the shaft walls 7th as outflow surfaces 9 are trained. The two shaft walls 7th are also called outer shaft walls 7a designated.

In addition, it can be provided that part of the shrinking medium generated by the heating means is in the form of hot air HL from below onto the wrapped article groups 5 is blown. In particular, the conveyor belt 6th designed accordingly 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 4th to the articles 2 shrunk around. 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 2A to 2D represent the shrinking of the shrink film 4th around the bottles 3 the wrapped item group 5 in different areas along the transport route TS inside the shrink tunnel of the shrink device 1 according to 1 represent. 2A shows the situation in the beginning of the shrink tunnel 1 . The shrink film 4th was for example by means of a film wrapping device or a wrapping module (not shown) around the bottles 3 beaten around. In the shrink tunnel, the outflow surfaces 9 the shaft walls 7th Hot air HL the temperature T or another suitable shrink medium on the side of the wrapped article groups 5 bloated. The wider the wrapped article group 5 is transported in the transport direction through the shrink tunnel, the more the shrink film shrinks 4th around the bottles according to their properties 3 around. On the side surfaces with the foils that were initially freely overlapping protruding FÜ the so-called foil eyes are formed. In particular, the shrinking process begins at the protruding film that initially overlaps freely at the sides FÜ , which is identified by "S", and continues in the direction of the center of the film "M", which is particularly evident in 2D can be clearly seen. Initially, there is a small distance between the outflow surfaces 9 and the shrink film 4th (see. 2A) . The distance between the outflow surfaces 9 and the shrink film 4th is already in the middle area of the shrink tunnel due to the shrinking of the shrink film 4th enlarged to a medium distance (cf. 2 B and 2C ). Before the wrapped item group 5 the shrink tunnel of the shrink device 1 leaves (cf. 1 ), the shrink film lies 4th largely completely close to the outer surfaces of the bottles 3 whereby a maximum distance between the outflow surfaces 9 the shaft walls and the bottles 3 of the wrapped article groups 5 exists (compare 2D ).

3 shows a shrink device 10 and a shrinking process according to the present invention. It is provided here that the shrinking medium, in particular hot air HL , a first temperature T1 from above onto the wrapped item group 5 is applied and that continues, in particular at the same time, over the shaft walls 7th Shrink medium, especially hot air HL , a second temperature T2 from the sides on the wrapped article group 5 is applied. In particular, it is provided that between the first temperature T1 and the second temperature T2 there is a temperature difference of at least three degrees Celsius. 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 points out of the shaft walls 7th a second temperature T2 from around 160 to 180 degrees Celsius, while the shrinking medium fed in from above has a first temperature T1 having at least five degrees Celsius above the second temperature T2 lies. The first temperature is preferably T1 at least ten degrees Celsius above the second temperature T2 .

It is preferably provided that the shrinking medium has the first temperature T1 the transport path at least in a central area between the two TS for the wrapped item group 5 limiting shaft walls 7th is inflated onto this from above, so that the shrinking process does not affect the protruding film FÜ begins, but in the central areas where the shrink film 4th above the article 2 the wrapped item group 5 rests. This ensures that the shrinking process takes place from the inside out, ie the shrink film 4th first shrinks in the middle area and attaches itself firmly to the article from above 2 on before the shrink wrap 4th 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 the shrinking medium, in particular hot air HL , a first temperature T1 from below onto the wrapped item group 5 is applied. This also makes the shrink film 4th below the article 2 shrunk inside out. Alternatively, the shrinking medium supplied from below can also have a third 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, different temperatures result in the interior 8th of the shrink tunnel of the shrink device 10 a mean process temperature or interior temperature that is between the first temperature T1 and the second temperature T2 lies.

According to one embodiment it can be provided that at least two temperature zones are formed within the shrink tunnel. The wrapped article groups are in a first temperature zone 5 from above and / or below with shrinking medium of a first temperature T1 and laterally with shrinking medium at a second, in particular lower, temperature T2 applied. The wrapped article groups are in a second temperature zone 5 before exiting the shrink tunnel, the shrinking medium of the same temperature is applied on all sides, ie there is no temperature difference between the shrinking medium fed in from above and / or below and the shrinking medium fed in from the side.

4A and 4B each show a partial area of a shrinking device according to the present invention, in particular FIG 4A an upper portion of a shrinking device 10 according to the present invention and 4B shows a lower portion.

In particular, in 4A the top hood 11 the shrink device 10 shown. There are three shaft walls on this 7th arranged so that within the shrink device shown 10 a two-lane processing of wrapped article groups (not shown) can take place. In particular, there are two outer shaft walls 7a and a middle inner shaft wall 7i on the top hood 11 arranged.

The inner shaft wall 7i has outflow surfaces with shrinking medium outlet openings on both parallel to the transport direction TR arranged side wall surfaces, so that shrink medium flows into the interior of the shrink tunnel on both sides and thus ensures that hot air or the like is applied to the side of the article. The well-known shaft walls 7th are walls with an inner cavity into which the shrinking medium is blown. The shaft walls point to this 7th in each case at least one air inlet opening, preferably arranged in the upper area, through which the shrinking medium enters the shaft wall from above 7th is blown in and then flows through the shrink medium outlet openings of the at least one outflow surface into the interior of the shrink tunnel.

The shrink device 10 includes a fan 12th , the air from the interior of the shrink tunnel laterally through an intake panel 13th sucks. A first part of that from the blower 12th sucked in air becomes a heating register 14th supplied and in this to a first temperature T1 warmed up. The one at a first temperature T1 warmed hot air HL is over the top hood 11 from above into the interior of the shrink tunnel and applied from above onto the wrapped article groups, in particular inflated. Furthermore, part of the temperature can be added to the first T1 heated hot air HL via the bottom chamber of the shrink device 10 be inflated from below onto the underside of the wrapped article groups.

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

In 4B is especially the transport route TS for the wrapped article groups to be recognized, which preferably by a conveyor belt 6th is formed, which is motorized by a suitable drive 20th is driven.

Furthermore, in the 4A and 4B two different temperature zones TZ1 and TZ2 shown. In the first temperature zone TZ1 , for example, according to 4A over about 70 percent of the transport route TS extends or which extends according to 4B over about 50 percent of the transport route TS extends, it is provided in particular that the wrapped article groups from above and / or below with shrinking medium of a first temperature T1 and laterally with shrinking medium at a second, in particular lower, temperature T2 be applied (compare 3 ). In contrast, in the second temperature zone TZ2 , for example, according to 4A over the last 30 percent or according to 4B over 50 percent of the transport route TS extends, provided be 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.

5 shows in a schematic manner a first embodiment of a shrinking device 10 with shrinking medium at different temperatures, in particular analogous to 4A . The different temperatures are generated by the fact that part of the sucked in air is used as a shrinking medium at the second temperature T2 straight back into the shaft walls without re-heating 7th of the shrink tunnel of the shrink device 10 is blown. The other part of the sucked in air is passed through a heating register 14th to an elevated first temperature T1 heated and over the top hood 11 blown into the interior of the shrink tunnel from above. In addition, some of the hot air is used HL with the increased first temperature T1 a floor chamber 15th of the shrink tunnel. The floor chamber 15th is especially below the transport route TS arranged for the wrapped article groups and has an outflow surface on its upper side, so that over the bottom chamber 15th hot air HL the first temperature T1 can be sprayed onto the wrapped article groups from below.

6th shows in a schematic way a second embodiment of a shrinking device 10 with shrinking medium at different temperatures. Only the top hood is used here 11 further heated hot air HL with the higher first temperature T1 fed while both the shaft walls 7th as well as the floor chamber 15th with hot air HL the second, especially lower, temperature T2 are supplied. In particular, part of the interior space of the shrink tunnel is removed by the blower 12th sucked air directly back into the shaft walls 7th and in the bottom chamber 15th initiated.

7th shows a third embodiment of a shrinking device in a schematic manner 10 with shrinking medium at different temperatures and 8th shows in a schematic manner a fourth embodiment of a shrinking device 10 with shrinking medium at different temperatures. There are two heating registers in each case 14th , 16 used to control the temperature of the shrinking medium.

According to the in 7th The embodiment shown are the heating registers 14th , 16 connected in parallel. A first part of the by the blower 12th from the interior of the shrinking device 10 sucked in air is passed through a first heating register 14th to a first temperature T1 heated and over the top hood 11 from above as well as via the floor chamber 15th sprayed onto the wrapped article groups from below. A second part of the by the blower 12th from the interior of the shrinking device 10 sucked in air is passed through a second heating register 16 to a second temperature T2 heated, the second temperature T2 is preferably less than the first temperature T1 . The one with the second temperature T2 applied hot air HL is in the shaft walls 7th the shrink device 10 initiated and sprayed on the side of the wrapped article groups.

According to the in 8th The embodiment shown here are two heating registers 14th , 16 connected in series. The one by the blower 12th from the interior of the shrinking device 10 sucked in air is passed through a first heating register 14th on a temperature T2 heated. Part of the temperature T2 heat hot air HL is in the shaft walls 7th the shrink device 10 initiated and sprayed on the side of the wrapped article groups. The remaining part of the on temperature T2 heat hot air HL is through a second heating register 16 to an elevated temperature T1 heated. The one with the elevated temperature T1 applied hot air HL is over the top hood 11 from above as well as via the floor chamber 15th sprayed onto the wrapped article groups from below.

9 shows a shrink device analogous to FIG 3 , whereby for the sake of clarity the wrapped article group has not been shown. By means of a fan 12th becomes air from the interior 8th of the shrink tunnel of the shrink device 10 preferably sucked in via a suction panel (not shown). The blower 12th is a distribution facility 21 assigned, which divides the sucked air into at least two partial flows. A first substream is sent to a first device for supplying one with a first temperature T1 applied shrinking medium HL to an upper spray device, in particular to the upper hood 11 , and / or for feeding to a lower spray device, in particular the floor chamber 15th , assigned. A second substream is sent to a second device for supplying one with a second temperature T2 applied shrinking medium HL to the shaft walls 7th assigned. For example, it is provided that some of the air is returned directly to the shaft walls 7th is fed to via the shaft walls 7th laterally in the interior 8th and in particular to be injected in the direction of the wrapped group of articles. Another part of the air is drawn in via a heating register 14th on a temperature T1 warmed up and from above and below into the interior 8th sprayed. For example, the bottom chamber 15th a first temperature sensor 18th assigned. This determines the temperature from the heating register 14th supplied hot air HL . The determined value is sent to a control device 17th which communicates the determined value with the desired target value, in particular a temperature T1 , compares. If the comparison shows a deviation of the determined actual value from the target value T1 , then the control device regulates 17th the heating register 14th . In addition, the top hood 11 associated temperature sensor (not shown) may be provided.

Furthermore, the shaft walls 7th at least one second temperature sensor 19th assigned to the temperature of the in the shaft walls 7th fed in hot air HL determined. If the determined value is below the desired target temperature value T2 , then a second heating register 16 which is controlled by the blower 12th sucked air to the desired temperature T2 heated before they enter the shaft walls 7th is fed in.

10 shows a fifth embodiment of a shrinking device in a schematic manner 10 with shrinking medium at different temperatures. Here, air is drawn from the interior of the shrinking device via a first fan 12-1 10 sucked in by means of a heating register 14th to a first temperature T1 heated and the top hood 11 as well as the floor chamber 15th fed and used to act on the wrapped article groups from above or below. Furthermore, air is released from the interior of the shrinking device via a second fan 12-2 10 sucked in and the shaft walls 7th fed, where it is used to act on the wrapped article groups from the side. If necessary, the air from the second fan 12-2 is passed through a second heating register 16 out and at a second temperature T2 heated, which is in particular lower than the first temperature T1 before that from the second fan 12-2 sucked in air the shaft walls 7th is fed. This can in particular analogously to the embodiment of FIG 9 are regulated by sensors.

11A to 11D show the shrinkage process at different points in time, in particular the shrinkage behavior of the shrink film 4th to the articles 2 the article group 5 shown. 11A shows a first state when the shrink film is running in 4th wrapped article group 5 into the shrinking device 10 , 11B shows a subsequent second state in which the shrinking process has already started. 11C shows another later point in time at which the shrinking process has already progressed and 11 D shows a point in time shortly before or when leaving the shrinking device 10 at which the shrinking process is complete.

When running in the with shrink film 4th wrapped article group 5 into the shrinking device 10 the shrink film stands 4th sideways over the article 2 beyond ( 11A) . With increasing energy supply in the form of shrinking agent, the shrink film pulls itself 4th 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 4th lays more and more to the articles 2 at ( 11B and 11C ), until they are finally at least partially fixed to the outer surface of the article 2 and the article 2 thus holds together securely.

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 should be 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

FÜ

Film overhang

HL

hot air

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

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19920057 A1 [0004]
• US 2010/0059036 A1 [0005]

Claims (15)

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 in one transport direction (TR) through a shrinking device (10), wherein the article (2) wrapped with thermoplastic packaging material (4) or the compilation is acted upon at least partially from above and / or from below with shrinking medium (HL) 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). Procedure according to Claim 1 , wherein the first temperature (T1) is higher than the second temperature (T2). Procedure according to Claim 1 or 2 , the article (2) wrapped in thermoplastic packaging material (4) or the assembly being acted upon simultaneously from above and / or from below with shrinking medium (HL) of the first temperature (T1) and laterally with shrinking medium (HL) of the second temperature (T2) becomes. Procedure according to Claim 1 or 2 whereby the article (2) wrapped in thermoplastic packaging material (4) or the assembly is first exposed to shrinking medium (HL) at the first temperature (T1) from above and / or from below and then laterally with shrinking medium (HL) at the second temperature ( T2) is applied or the article (2) wrapped in thermoplastic packaging material (4) or the assembly is first exposed to the side with shrinking medium (HL) at the second temperature (T2) and then from above and / or below with shrinking medium (HL) the first temperature (T1) is applied. Procedure according to Claim 1 or 2 , the method being carried out in a shrinking device (10) with at least two temperature zones formed one after the other in the transport direction (TR), with the article (2) wrapped with thermoplastic packaging material (4) or the assembly from above in a first temperature zone (TZ1) and / or from below with shrinking medium (HL) of the first temperature (T1) is applied laterally with shrinking medium (HL) of the second temperature (T2) and wherein in a second temperature zone (TZ2) the article (2 ) or the compilation from above and / or from below as well as from the side with shrinking medium (HL) of a third temperature is applied or wherein in a first temperature zone (TZ1) the article (2) wrapped with thermoplastic packaging material (4) or the compilation from above and / or is acted upon from below with shrinking medium (HL) of the first temperature (T1), with the thermoplastic em packaging material (4) wrapped article (2) or the assembly in a second temperature zone is acted upon laterally with shrinking medium (HL) of the second temperature (T2) and wherein in a third temperature zone the article (2) or wrapped with thermoplastic packaging material (4) 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 Claims 1 to 5 , 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 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 wherein the value of the second temperature (T2) is approximately 180 degrees Celsius. 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), a first part of the sucked air being raised to the increased first temperature (T1) by means of a heating device (14) brought and introduced from above and / or below into the interior (8) of the shrinking device (10) and wherein a second part of the sucked air is introduced into the shaft walls (7) of the shrinking device, the hot air (HL) introduced into the shaft walls laterally on the thermoplastic packaging material (4) wrapped article (2) or the compilation is sprayed or with a first part of the sucked air by means of a first heating device (14) brought to the increased first temperature (T1) and from above and / or below is introduced into the interior (8) of the shrinking device (10) and wherein a second part of the sucked in air by means of a second heating the device (16) is brought to the second temperature (T2) and introduced into the shaft walls (7) of the shrinking device, wherein the value of the second temperature (T2) differs by at least three degrees Celsius from the value of the first temperature (T1), and the hot air (HL) introduced into the shaft walls laterally onto the article (4) wrapped with thermoplastic packaging material (4). 2) or the assembly of articles (2) wrapped in thermoplastic packaging material (4) is sprayed on. Method according to one of the Claims 1 to 6th , wherein warm or hot air (HL) is sucked in from an interior (8) of the shrinking device (10), the sucked air being brought to the second temperature (T2) by means of a heating device and part of the air heated to the second temperature as the shrinking medium (HL) is introduced into the shaft walls (7) of the shrinking device, another part of the air heated to the second temperature as the shrinking medium (HL) being brought to the first temperature (T1) by means of a further heating device and into the interior from above and / or below (8) the shrinking device (10) is introduced. 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 setpoint value is determined, in particular wherein at least one heating device for shrinking medium (HL) is activated. Shrinking device (10) for shrinking a thermoplastic packaging material (4) onto an article (2) or onto an assembly of articles (2), the shrinking device (10) having at least one transport path (TS) with an input area and an output area for the article ( 2) or the assembly of articles (2), the article (2) or assembly of articles (2) being conveyed in a transport direction (TR), the transport route (TS) being limited on both sides by shaft walls (7), with the shaft walls (7) each have an outflow surface (9) directed towards the transport path (TS) with a plurality of outflow openings for shrinking medium (HL) directed towards the article (2) or the assembly of articles (2), the shrinking medium (HL) flows through the outflow openings into an interior space (8) of the shrinking device (10) in the direction of the transport path (TS), the shrinking device (10) at least ns a first device for supplying a shrink medium (HL) to which a first temperature (T1) is applied to an upper spray device (11) and / or for supplying a shrink medium (HL) to which a first temperature (T1) is applied to a lower spray device (15) ), 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 Shrink device (10) for performing a method according to one of the Claims 1 to 9 . Shrink device (10) after Claim 10 , wherein the shrinking device (10) comprises at least one fan (12) for sucking in air from the interior (8) of the shrinking device (10), wherein the at least one fan (12) is assigned a distribution device (21) which the sucked in air divided into at least two substreams, wherein a first substream can be assigned to the first device and wherein a second substream can be assigned to the second device. Shrink device (10) after 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 comprises a second heating device (14). Shrink device (10) after Claim 10 or 11 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. Shrink device (10) according to one of the Claims 10 to 13th , the shrinking device (10) having a control device (17) and at least one sensor assigned to the upper spraying device (11) and / or at least one sensor (18) assigned to the lower spraying device (15) and / or at least one assigned to the shaft walls (7) Sensor (19), and wherein the first device and / or the second device can be regulated and / or controlled on the basis of data determined by sensors. Shrink device (10) according to one of the Claims 10 to 14th , the shrink device (10) comprises at least two areas formed one after the other in the transport direction (TR) with different temperature zones, with shrinking medium (HL) of the first temperature (T1) via the upper spraying device (11) and / or via the lower spraying device within a first temperature zone (TZ1) (15) is introduced into the interior (8) of the shrinking device (10) and wherein, within the first temperature zone (TZ1), shrinking medium (HL) of the second temperature (T2) via the shaft walls (7) into the interior (8) of the shrinking device ( 10) is introduced and where, within a second temperature zone, shrinking medium (HL) of a third temperature via an upper spraying device (11) and / or via a lower spraying device (15) and via shaft walls (7) into the interior (8) of the shrinking device (10) ) is introduced or where within a first temperature zone (TZ1) shrinking medium (HL) of the first temperature (T1) via the upper spray device (1 1) and / or is introduced into the interior (8) of the shrinking device (10) via the lower spraying device (15) and within a second temperature zone shrinking medium (HL) of the second temperature (T2) via the shaft walls (7) into the interior (8) the shrinking device (10) is introduced and wherein, within a third temperature zone, shrinking medium (HL) at a third temperature via an upper spraying device (11) and / or via a lower spraying device (15) and via shaft walls (7) into the interior space ( 8) the shrinking device (10) is introduced.

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