DE102019119292A1 - A process for producing a multilayer film and a master roll of a multilayer film can be produced with such a process - Google Patents

Abstract

A method for producing a multilayer film (2) from two outer layers (4, 6) and one or more inner layers (8) lying between them, all layers lying on top of one another and being connected to one another via a lamination, in which the first outer layer (4) is separated from a first Unwinding roll (10) is fed to a lamination process, an inner layer (8) is fed from a second unwinding roll (12) to the lamination process, in the lamination process the first outer layer (4) with the inner layer (8) in a first gap (14) between a first cooling roller (16) and a first counterpressure roller (18) assigned to it are pressed against one another, a laminator (20) being arranged above the gap (14), from which a liquid laminating composition (22) is placed between the layers entering the gap (14) (4, 8) is introduced, this lamination process optionally with the film composite produced in each case in the previous lamination process and one further each of one white teren unwinding roller fed inner layer between further cooling rollers and these respectively assigned additional counterpressure rollers using further laminators is continued until the desired number of superimposed inner layers is reached, the lamination process with the film composite (24) resulting from the previous lamination processes and the second from a last unwinding roll (26) supplied outer layer (6) is continued in a last gap (28) between a last cooling roller (30) and a last counterpressure roller (32) assigned to it and with a laminator (34) arranged above the last gap (28) and the The resulting multilayer film (2) is rolled up to form a master roll (36), characterized in that at least one of the inner layers (8) is at least in two parts made up of two partial layers (8a, 8b) and these partial layers (8a, 8b) are inside the multilayer film (2 ) positioned next to each other form the inner layer (8), the at least two sub-layers (8a, 8b) of this inner layer (8) for the lamination process of two different unwinding rollers (12a, 12b) arranged parallel but offset to one another, a common gap (14) between a common cooling roller (16) and a common counterpressure roller assigned to it (18) are supplied.

Description

The invention relates to a method for producing a multilayer film from two outer layers and one or more inner layers lying between them, with all layers lying on top of one another and being connected to one another via a lamination. In the process, the first outer layer is fed to a lamination process from a first unwinding roll. An inner layer is fed to the laminating process by a second unwinding roll. In the lamination process, the first outer layer and the inner layer are pressed against one another in a first gap between a first cooling roller and a first counter-pressure roller assigned to it. A laminator is arranged above the gap, from which a liquid laminating composition is introduced between the layers entering the gap. This lamination process is optionally repeated with the film composite created in the previous lamination process and a further inner layer fed by a further unwinding roller between further cooling rollers and further counterpressure rollers assigned to them using further laminators until the desired number of superimposed inner layers is reached. The lamination process is continued with the film composite resulting from the previous lamination processes and the second outer layer fed by a last unwinding roll in a gap between a last cooling roller and a last counterpressure roller assigned to it and with a laminator arranged above the gap, and the resulting multilayer film is rolled up into a master roll .

Such lamination processes have been known and tested for many years. The material of the individual layers and the number of layers can be varied, as can the width of the multilayer film.

The invention is based on the object of providing a method of the type mentioned at the outset for producing a multilayer film which is more flexible in terms of individual requirements for the multilayer film that is produced. The invention is also based on the object of providing a master roll of a multilayer film that can be produced using such a method.

The invention is achieved by a method of the type mentioned at the outset, in which at least one of the inner layers is formed in at least two parts from two sub-layers and these sub-layers positioned next to one another within the multilayer films form the inner layer. The at least two sub-layers of this inner layer are fed to a common gap between a common cooling roller and a common counter-pressure roller assigned to it by two different unwinding rollers arranged parallel but offset for the lamination process. This configuration makes it possible for an inner layer to be present within a multilayer film in the layer structure, which consists of two sub-layers positioned next to one another within the layer, these sub-layers being able to differ from one another in terms of material, orientation and / or width. Furthermore, the distance between the sub-layers can be varied.

In a preferred embodiment of the invention, the at least two sub-layers of at least one inner layer are each formed by an aluminum foil. Aluminum foils are sold by a large number of manufacturers in standard widths of up to around 1,300 mm. Larger widths are only offered by a few manufacturers. A width of more than 2,000 mm, for example, is only supplied by a single supplier in the desired quality, in the thickness of 6 to 15 µm required for aluminum foils.

By supplying an inner layer of two parallel but offset unwinding rolls, the films of which then form the inner layer positioned next to each other in partial layers within the multilayer film, multilayer films with an aluminum layer with standard aluminum foils can be produced in one pass in larger widths and rolled up to form master rolls. The parent rolls are then subsequently cut into narrower customer rolls. This leads to an expansion of the capacity of the production plant that works with the method according to the invention.

In a preferred embodiment of the method according to the invention, the at least two partial layers of aluminum foil each have a glossy and a matt surface. At least one of the sub-layers is introduced into the gap with one orientation, the glossy side touching the cooling roller or the counter-pressure roller, and at least one further sub-layer is introduced into the gap with the opposite orientation, the matte side touching the cooling roller or the counter-cooling roller.

The film composite emerging from the gap then has the two partial layers of aluminum foil with an outer side of the aluminum foil facing away from the film composite. This outside is thus glossy in the case of a partial layer and matt in the case of at least one other partial layer made of aluminum foil. This makes it possible to respond to individual customer requests. One customer would like to have the glossy surface of the first outer layer facing and another customer possibly facing the second outer layer. With the method according to the invention, both customer requirements can be met in a single production process, thereby saving time. The The parent roll is only then split up into two or more customer rolls, separating the two partial layers of aluminum foil and the layers above and below.

A master roll of a multilayer film according to the invention that can be produced using one of the aforementioned processes, in which at least one inner layer consists of at least two partial layers of aluminum foil with a glossy and a matt side, the aluminum foils with regard to the matt and the glossy side in the multilayer film has the same advantage are oppositely oriented.

Advantageously, at least two sub-layers immediately adjacent to one another are introduced into the gap at a defined distance from one another, so that they are also spaced from one another in the multilayer film formed. When separating a master roll with such a multilayer film produced according to the invention into at least two customer rolls, the multilayer film or the master roll is separated from one another by two parallel cuts across the master roll and thus along the multilayer film. The middle trim is disposed of. The aforementioned embodiment of the method according to the invention now leads to the fact that there is less of the at least one inner layer with the two sub-layers in the area of this central edge trim, since these sub-layers are at a defined distance from one another. The distance is particularly preferably smaller than the two parallel cuts to one another and thus than the width of the middle edge trim to be disposed of. Both customer roles then each have one of the sub-layers. The method thus means that less material in the form of part of the inner layer has to be disposed of unused. This is particularly relevant both economically and ecologically in the event that the two partial layers consist of aluminum foil. The middle trimmed edge then has less aluminum foil than if the entire inner layer had been formed continuously from a single aluminum foil in a conventional manner.

A master roll of a multilayer film according to the invention that can be produced using one of the aforementioned methods, in which at least one inner layer consists of at least two sub-layers positioned next to one another, these sub-layers being spaced apart at a defined distance, has the same advantage.

In an advantageous embodiment of the method, at least two sub-layers of at least one inner layer have different widths. This makes it possible to use the method to produce a master roll from the multilayer film, which can be separated into different widths of customer rolls and optionally consist of different inner layers and / or less inner layer has to be disposed of as waste in the area of the central edge section.

In a particularly preferred embodiment of the invention, the liquid lamination composition consists essentially of a thermoplastic, in particular of polyethylene or polypropylene. Essentially consisting of means that conventional additives can be added to the thermoplastic (s), but do not have to be added.

• 1 eine Prinzipskizze einer Vorrichtung, die mit dem erfindungsgemäßen Verfahren arbeitet in der Aufsicht und
• 2 die Prinzipskizze aus 1 in einer Darstellung von der Seite, zusätzlich den Verlauf der Lagen illustrierend.

The method according to the invention is discussed in more detail below with the aid of principle sketches. Show it:

• 1 a schematic diagram of a device that works with the method according to the invention in plan view and
• 2 the schematic diagram 1 in a representation from the side, additionally illustrating the course of the layers.

In the following, elements of the invention that have the same effect are provided with a uniform reference number, insofar as this makes sense. The features described below can also be the subject of the invention individually or in other combinations.

1 shows a schematic diagram of a device for illustrating the method according to the invention in plan view and FIG 2 shows this schematic diagram in side view.

In the method for producing a multilayer film 2 from two outer layers 4th , 6th and one or more intermediate inner layers 8th are all layers 4th , 6th , 8th on top of each other and are connected to one another via a lamination. The first outer layer 4th becomes of a first unwind role 10 fed to a lamination process. An inner layer 8th becomes of a second unwind role 12 fed to the lamination process. In the lamination process, the first outer layer 4th with the inner layer 8th within a first gap 14th between a first chill roll 16 and one of these associated first counter-pressure roller 18th pressed together. Above the gap 14th is a laminator 20th arranged from which a liquid lamination composition 22nd between the layers entering the gap 4th , 8th is introduced.

In the principle drawing there is only one inner layer 8th intended. If further inner layers are desired, the above-mentioned lamination process can optionally be continued with the respective film composite produced in the previous lamination process and a further inner layer returned by a further unwinding roller between further cooling rollers and further counterpressure rollers assigned to them, using further laminators, until the desired number superimposed inner layers is reached.

The lamination process is then carried out with the film composite created from the previous lamination process 24 and the second from a final unwind role 26th supplied outer layer 6th in a final crack 28 between a last chill roll 30th and a last counterpressure roller associated with this 32 as well as one above the last gap 28 arranged laminator 34 continued.

In the principle drawings are the first gap 14th between the first chill roll 16 and the first back pressure roller 18th and the last crack 28 between the last chill roll 30th and the last counterpressure roller assigned to it 32 each made wider than is the case in practice, so that the positioning of the counter-pressure rollers in the plan view 1 can be seen. In practice, the distance between the cooling roller and the counter-pressure roller corresponds approximately to the thickness of the foils introduced into the gap and of the laminating composition applied.

The resulting multilayer film 2 becomes a mother role 36 rolled up. A mother role 36 is a rolled-up multilayer film 2 which is later split into two or more customer rolls of the desired width.

At least one of the inner layers 8th is at least in two parts from two sub-layers 8a , 8b educated. These sub-locations 8a , 8b form within the multilayer film 2 the inner layer is positioned next to each other 8th . There are at least two sub-layers 8a , 8b this inner layer 8th for the lamination process of two different unwinding rolls arranged parallel but offset 12a , 12b a common gap 14th between a common chill roll 16 and a common counterpressure roller assigned to it 18th fed.

The at least two sub-layers 8a , 8b consist in the exemplary embodiment of aluminum foil and each have a glossy surface 38 and a relatively matte surface 40 . One of the sub-locations 8a becomes the shiny side with one orientation 38 the chill roll 16 or the counter pressure roller 18th touching in the gap 14th introduced and the further sub-layer 8b with the opposite orientation, the matte side is the chill roll 16 or the counter pressure roller 18th touching in the gap 14th introduced.

In the exemplary embodiment, the two sub-layers directly adjacent to one another are used 8a , 8b introduced into the gap at a defined distance A from one another, so that they are also in the multilayer film formed 2 are spaced from each other. The defined distance A is in the principle drawing by the distance A of the parallel but offset from one another arranged unwinding rollers 12a , 12b illustrated, which also in the case of a parallel displacement of the two rollers such that the axes of rotation of the two unwinding rollers 12a , 12b coincide with each other, still exist identically.

Reference numerals

2

Multilayer film

4th

first outer layer

6th

second outer layer

8th

Inner layer

8a

Part location

8b

Part location

10

first unwind roll

12

second supply roll

12a

parallel but offset unwinding roll

12b

parallel but offset unwinding roll

14th

first gap

16

first cooling roller

18th

first counter-pressure roller

20th

Laminator

22nd

liquid lamination composition

24

resulting film composite

26th

last unfolding role

28

last gap

30th

last chill roll

32

last counter-pressure roller

34

Laminator

36

Mother role

38

shiny surface of the aluminum foil

40

matt surface of the aluminum foil

A.

defined distance

Claims (8)

Method for producing a multilayer film (2) from two outer layers (4, 6) and one or several inner layers (8) lying in between, whereby all layers lie on top of one another and are connected to one another via a lamination, in which the first outer layer (4) is fed to a lamination process from a first unwinding roller (10), an inner layer (8) from a second unwinding roller ( 12) is fed to the lamination process, in the lamination process the first outer layer (4) and the inner layer (8) are pressed against one another in a first gap (14) between a first cooling roller (16) and a first counter-pressure roller (18) assigned to it, above A laminator (20) is arranged in the gap (14), from which a liquid lamination composition (22) is introduced between the layers (4, 8) entering the gap (14), this lamination process optionally with the film composite produced in the previous lamination process and in each case a further inner layer fed by in each case a further unwinding roller between further cooling rollers and these respectively associated further counterpressure rollers is continued using further laminators until the desired number of superimposed inner layers is reached, the lamination process with the film composite (24) created from the previous lamination processes and the second outer layer (6) fed from a last unwinding roller (26) in one last gap (28) between a last cooling roller (30) and a last counterpressure roller (32) assigned to it and with a laminator (34) arranged above the last gap (28) and the resulting multilayer film (2) becomes a master roll (36 ) is rolled up, characterized in that at least one of the inner layers (8) is formed at least in two parts from two partial layers (8a, 8b) and these partial layers (8a, 8b) positioned next to one another within the multilayer film (2) form the inner layer (8), wherein the at least two partial layers (8a, 8b) of this inner layer (8) for the lamination process of two ve r different unwinding rollers (12a, 12b) arranged parallel to one another but offset are fed to a common gap (14) between a common cooling roller (16) and a common counterpressure roller (18) assigned to it. Procedure according to Claim 1 , characterized in that the at least two partial layers (8a, 8b) of at least one inner layer (8) are each formed by an aluminum foil. Procedure according to Claim 2 , characterized in that the at least two partial layers (8a, 8b) made of aluminum foil each have a glossy (38) and a matt surface (40) and at least one of the partial layers (8a) with an orientation, the glossy side (38), the cooling roller ( 16) or the counter-pressure roller (18) is inserted into the gap (14) in a touching manner and at least one further partial layer (8b) with an opposite orientation, the matt side (40) touching the cooling roller (16) or the counter-pressure roller (18) into the gap (14) is introduced. Method according to one of the preceding claims, characterized in that at least two partial layers (8a, 8b) directly adjacent to one another are introduced into the gap (14) at a defined distance (A) from one another, so that they are also present in the multilayer film (2) formed. are spaced from each other. Method according to one of the preceding claims, characterized in that at least two partial layers (8a, 8b) of at least one inner layer (8) have different widths. Method according to one of the preceding claims, characterized in that the liquid lamination composition (22) consists essentially of a thermoplastic, in particular of polyethylene or polypropylene. Master roll (36) of a multilayer film (2) producible with a method according to one of the preceding claims, in which at least one inner layer (8) consists of at least two partial layers (8a, 8b) positioned next to one another, characterized in that at least two partial layers ( 8a, 8b) are spaced apart from one another at a defined distance (A). Master roll (36) of a multilayer film (2) can be produced using a method according to one of the preceding claims, in which at least one inner layer (8) consists of at least two partial layers (8a, 8b) made of aluminum foil with a glossy (38) and a matt surface (40 ), characterized in that the aluminum foils are oriented in opposite directions with respect to the matt and the glossy side in the multilayer film (2).

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