EP1988042B1 - Device and method for folding a web of material - Google Patents

Abstract

The method involves holding a material web (1) at a front section (7) in a running direction. Individual sections are aligned based on the front section of the material web in the running direction. Other sections are brought into a zig-zag form by two sets of knives, and the aligned sections are successively pushed together. The material web is directly guided before incremental folding of the material web by a web storage. An independent claim is also included for a device for folding a material web.

Description

The invention relates to a method for folding a material web, wherein sections of the material web are placed by opposing folding knife in a zigzag shape. The invention also relates to a device for folding a material web in a zigzag shape with an opposite, folding blade having folding device. The material web can be formed, in particular, from a carrier layer of paper, essentially flat packaging pieces laid on the carrier layer and a film cover layer, the cover layer being connected to the carrier layer around the packaging pieces. In order to make available a large number of packaging pieces arranged between the carrier layer and the covering layer for a user, the material web is laid in a zigzag form, wherein usually sections with one packing piece, for example a filter paper for laboratory analytical purposes, should be separable. When folding a damage to the layers of the web is to be avoided, since otherwise a protection of the packaging piece from contamination and contamination is no longer guaranteed.

A method and a device with the features described above are known from the document DE 10 2004 025 501 A1 known. In the known device, a material web, for example a textile fabric for an air filter, is supplied continuously and laid by rotational and translational movements of two arranged on opposite sides of the web folding blades in a zigzag shape and moved into a heated folding channel, wherein the folding edges are fixed by heat , The disadvantage is that the material web is exposed in the folding large mechanical and thermal loads. The processing of webs with a low strength is not possible. From the publication EP 0 934 225 B1 It is known to provide a material web initially in the passage of two embossing rollers mutually with transverse embossments that facilitate subsequent folding of the web into a zigzag shape by pushing together. By embossing the web is however heavily stressed; In a multilayer web, destruction of individual layers may occur.

Further prior art is known from US 2005/0257655 A1 known.

The invention has for its object to provide a method for folding a web, in which the web is exposed to a low load. In particular, a precise folding of a stiff, multi-layer material web is to be made possible.

Based on a method with the features described above, the object is achieved in that the material web is intermittently held on a front in the running direction section, several subsequent sections are brought by a first knife set and an opposite second knife set in a zigzag shape, wherein the aligned portions subsequently be pushed together. The first and the second set of blades are each formed from a plurality of folding blades, typically arranged at the same distance. Due to the cyclic movements of the folding knife of the first and the second set of knives always exactly reproducible folding of the sections is possible, whereby the load of the material web is limited. Since the sections are guided by the folding blades in the folding, also an exact folding of a stiff material web is made possible.

In the context of a preferred embodiment of the method according to the invention, it is provided that in a cycle a predetermined number of sections is placed in a zigzag shape, wherein the individual sections be aligned successively from the front in the running direction portion of the web. When setting up the fixed at one end of the front portion and aligning the subsequent sections further sections are drawn in the area between the first and the second set of blades according to the shortening of the web until finally forms the predetermined zigzag shape at the end of the clock then the number of knives equals the number of folded sections. Sharp bending and increased stress only occurs when a fold is formed between two sections. The position of the folds is precisely determined by the distance between two adjacent counteracting folding knives in the delivered state.

In order to allow the clockwise folding an adaptation to further, upstream process steps or to a continuous feeding of the material web, the material web can be guided over a web memory, which can be temporarily stored and then temporarily output a certain length of the material web.

For ease of folding, a web of material can be supplied, which is provided at the transition areas between their sections with perforations, weakenings, for example in the form of a groove, or fold lines. In the context of a preferred embodiment of the invention, the areas at which the sections adjoin one another are provided, prior to folding, with fold lines extending transversely to the web longitudinal direction, which are formed in such a way that the material web is prefolded alternately according to the later zigzag shape.

The control of the web run can in the context of the invention, for example, by printed on the web rapport marks or repeat punching take place, these are preferably detected optically, with a light barrier, a digital camera or the like. After folding, it is also possible to provide further processing, for example cutting to length and packaging of packages of the material web, each of which is formed from a plurality of sections.

The invention also provides a device for folding a material web in a zigzag form, which is particularly suitable for carrying out the method described above. The device has a folding device, wherein according to the invention it is provided that the folding device operates in cycles and has a holding knife for fixing a front section of the material web in the running direction, a first and an opposite second knife set and a slide for the cyclic output of the folded sections. The folding blades are typically arranged substantially perpendicular to the running direction of the material web at an equal distance and deliverable for aligning the sections perpendicular to the material web. In order to enable a fast and efficient processing of the material web, the knife sets each have a plurality of folding blades, but with increasing number of folding blades, the manufacturing costs and the control effort of the folding device increase. Depending on the application, the sets of knives, for example, each have between 3 and 12, preferably between 5 and 8 folding knife.

In the context of the invention, the folding knives of the first set of knives can be arranged on a common carrier and the folding knives of the second set of knives can be delivered linearly independently of one another, wherein typically the folding knives of the first set of knives can be delivered jointly via the carrier. With a very low load capacity of the material web and to achieve a particularly high accuracy, can also be provided in a particularly preferred embodiment, that both the folding knife the first and the second set of knives are individually deliverable. For less stringent requirements, for example, it may be sufficient if the folding blades of the first blade set on the common carrier and only groups of, for example, two folding blades of the second blade set are independently deliverable.

In particular in order to achieve high cycle rates of the folding device of typically more than 3 cycles per minute, preferably more than 5 cycles per minute, it can be provided that the carrier of the first set of knives, the folding knives of the second set of knives the holding knife and / or the slide hydraulically or are pneumatically driven. Such a drive allows particularly fast switching and delivery times, whereby a simple control by electronically controllable valves is possible and whereby a particularly simple and space-saving construction of the folding device is made possible.

In a preferred embodiment of the invention, the device is designed such that the folding device is a folding station upstream for folding and pre-folding of the material web. Particularly preferably, the upstream folding station on a support plate, extending in the web longitudinal direction web guide and two oppositely acting, arranged transversely to the web guide folding units, the folding units each having a clamping device with at least one jaw and a sword, with the fold areas of the web to form a loop in a gap of the clamping device are insertable, and wherein the jaw is movable to produce fold lines of the material web. The gap may for example be formed between the jaw and an associated stop surface of the carrier plate or between two jaws.

In the context of such an embodiment, the folding areas of the material web are moved out of the web plane in the folding station to form a loop and provided with a fold line. Since the jaw act laterally on the introduced into the gap of the clamping device loop during a closing movement, a strong strain and consequent damage to the material web can be prevented, whereby rigid, multi-layer webs can be prefolded by the arrangement of the fold line. To easily remove the fold areas after folding from the folding stations and to avoid excessive tension, the folding stations can have an ejection element, such as an ejector blade. Upon the opening of the at least one jaw, the ejector blade is then moved into the opening gap to push the folding area out of the clamping device.

In order to be able to compensate for a train and a temporary change in length during folding, a web memory is preferably arranged in front of and / or behind the folding station. For the propulsion of the material web, for example servo drives with a residual path optimization can be provided. As with the folding device, the moving parts of the folding station can be driven hydraulically or pneumatically. Depending on the type of material web, the described folding station can achieve clock rates for producing the fold line of more than 25 cycles per minute, preferably more than 40 cycles per minute.

In addition to the folding device and the optionally provided folding station, the entire device can also have a cutting blade for cutting material web packages.

Fig.1

eine Vorrichtung zum Falten einer Materialbahn in einer Übersichtsdarstellung,

Fig. 2a

die zugeführte Materialbahn im ungefalteten Zustand,

Fig. 2b

ein Paket mit in Zickzackform aufeinander gefalteten Abschnitten der Materialbahn,

Fig. 3

eine Falzstation zum Vorfalten der Materialbahn,

Fig. 4a

eine Falteinrichtung zum Ausrichten der Abschnitte der Materialbahn in einer perspektivischen Seitenansicht,

Fig. 4b

eine vereinfachte Seitenansicht einer alternativen Ausgestaltung der Falteinrichtung zum Ausrichten der Abschnitte der Materialbahn,

Fig. 5

die Anordnung gemäß Fig. 4a in einer perspektivischen Ansicht von unten.

The invention will be explained in the following with reference to a drawing showing only one exemplary embodiment. They show schematically:

Fig.1

a device for folding a material web in an overview,

Fig. 2a

the supplied material web in the unfolded state,

Fig. 2b

a package with zig-zag folded sections of the material web,

Fig. 3

a folding station for pre-folding the material web,

Fig. 4a

a folding device for aligning the sections of the material web in a perspective side view,

Fig. 4b

a simplified side view of an alternative embodiment of the folding device for aligning the sections of the material web,

Fig. 5

the arrangement according to Fig. 4a in a perspective view from below.

Fig. 1 shows a device for folding a material web 1 in a zigzag shape. The apparatus comprises a station 2 for generating lines of weakness, a folding station 3 for prefolding the material web 1, web stores 4 formed as register roll arrangements, roller feeds 5 for advancing the material web 1, a folding device 6 for aligning sections 7 of the material web 1, a separation station 8 Cutting to length packages 9, each having a plurality of sections 7 of the web 1 and a rotary table 10 for temporarily storing the packages 9 before packaging.

The unfolded material web 1 is in the Fig. 2a and consists of a carrier layer 11, placed on the carrier layer 11 filter papers 12 and a cover layer 13 of a polyethylene film, which is connected to the filter papers 12 around with the carrier layer 11 made of paper. The material web 1 is to be folded between the individual filter papers 12, so that sections 7 can be separated, each with a filter paper 12b. In the illustrated embodiment, the carrier layer 11 has a thickness of about 80 microns and the polyethylene film of the cover layer 13 has a thickness of about 50 microns. The width of the material web 1 is 80 mm and the length of the sections to be folded 7 75 mm. Since the cover layer 13 is sealed to the carrier layer 11 between the filter papers 12, the material web 1 is comparatively stiff in these areas and thus difficult to fold. The filter papers 12 may be determined, for example, for laboratory analytical purposes, which is why in the folding process, the carrier layer 11 and the cover layer 13 may not be damaged, otherwise contamination may occur and a sterility of the filter papers 12 is no longer guaranteed. To control the web run to be folded sections 7 are each provided with repeat punching 14, which are optically detected. Fig. 2b shows a package 9 of several zig-zag folded sections 7 of the web 1, which can be supplied, for example in a dispenser to a user.

The material web 1 first passes through the station 2 to produce a line of weakness. The weakening line can be formed, for example, in the manner of a perforation, but the carrier layer 11 and / or the cover layer 13 are only partially scored or scored and not cut, as is usual in a perforation. The material web 1 is then guided over a first roll feed 5 and a first web store 4 for pre-folding in a folding station 3. The folding station 3 has a carrier plate 16, a running in the web longitudinal direction web guide 17 and two oppositely acting, arranged transversely to the web guide 17 folding units 18. The staggered in the web longitudinal direction folding units 18 each comprise a clamping device 19 with a jaw 20 and a sword 21, with a folded portion 22 of the web 1 to form a loop in a formed between the jaw 20 and a stop surface 24 of the support plate 16 gap 25 inserted are, wherein the clamping jaw 20 is then supplied to generate fold lines of the material web 1 by a closing action of the clamping device 19 in the direction of the loop formed. The propulsion of the material web 1 and the mutual generation of fold lines in the fold areas 22 takes place cyclically with a clock rate of up to 40 cycles per minute or more. Since the fold regions 22 are moved out of the web plane to produce the fold lines to form a loop, a length compensation is required which is made possible by the upstream web store 4. The swords 21 and the column 25 are arranged perpendicular to the running direction of the material web 1. Since in the folding, the clamping jaw 20 of the clamping device 19 acts laterally on the inserted from the blade 21 web 1, only relatively low loads on the material web 1, so that the carrier layer 11 and the cover layer 13 are not severed in the formation of the fold line. In order to avoid a large tensile load during further transport of the material web 1, an ejector blade 26 is provided as an ejection element 26, which pushes out the folding region 22 of the material web 1 from the opening gap 25 after opening the clamping device.

The mutually prefolded material web 1 is guided via a further roller feed 5 as a drive unit and a further web memory 4 to a cyclically operating folding device 6. The folding device 6 has a holding knife 27 for fixing a front section 7 of the material web in the running direction, a first and an opposite second knife set 28a, 28b and a slide 29 for the cyclic output the folded portions 7 on. The folding blades 30a, 30b are arranged perpendicular to the direction of movement of the material web 1 at an equal distance. The folding blades 30a of the first blade set 28a are fastened to a common carrier 31, wherein the folding blades 30b of the second blade set 28b are independently linearly deliverable. The carrier 31 of the first blade set 28a, the folding blade 30b of the second blade set 28b, the retaining blade 27 and the slider 29 are hydraulically or pneumatically driven, the associated drive units in Fig. 5 can be seen.

The folding of the material web 1 is preferably carried out by successively aligning the sections 7 in the folding device 6 starting from the front section 7 of the material web in the running direction. Fig. 4a shows the already aligned by linear feed movements of the folding blades 31a, 31 b sections 7 before they are pushed together after a retraction of the folding blades 31a, 31b of the slider 29 and output after a retraction of the holding knife 27. To compensate for the clock between the folding station 3 and the folding device 6, the second web memory 4 can temporarily store a corresponding length of the material web 1 and deliver it at short notice. In order to enable an accurate web guide, the roller feeds 5 can be equipped with an optical device for detecting the repeat punching 14 of the material web 1, wherein the roller feeds 5 are preferably designed as servo drives with a residual path optimization.

Fig. 4b shows an alternative embodiment of the folding device 6, in which both the folding blade 30a of the first blade set 28a and the folding blade 30b of the second blade set 28b are individually deliverable. The alignment of the sections 7 of the material web 1 takes place starting from the front section 7 in the direction of travel in that alternately individual folding blades 30a, 30b of the first and second knife set 28a, 28b are delivered. The fact that all folding blades 28a, 28b are deliverable individually, the load on the material web 1 is reduced to a minimum, so that even very sensitive, constructed of different layers webs of material 1 can be processed.

Twelve sections 7 of the material web 1 are aligned in one stroke of the folding device 6, wherein the first blade set 28a and the second blade set 28b each have six folding blades 30a, 30b.

According to the invention, the material web 1 can be folded precisely at the stiff regions between the individual filter papers 12, without the carrier layer 11 or the cover layer 13 being damaged. With the described device, for example, packets 9 with 108 sections 7 can be generated in a time of about 90 seconds.

Claims (15)

1. A method for folding a material web (1), wherein sections (7) of the material web (1) are laid in a zigzag shape by opposing folding knives (30a, 30b) and wherein the aligned sections (7) are subsequently pushed together, characterised in that the material web (1) is held firmly at a front section (7) in the running direction in a cyclic manner, wherein in one cycle a plurality of sections (7) are brought into zigzag shape by a first knife set (28a) and an opposite second knife set (28b) and wherein the individual sections (7) are successively aligned starting from the front section (7) of the material web (1) in the running direction.
2. The method according to claim 1, characterised in that the material web (1) is guided through a web storage device (4) directly before the cyclic folding.
3. The method according to claim 1 or 2, characterised in that the regions at which the sections (7) adjoin one another are provided with folding lines running transversely to the material web (1) prior to folding, wherein the folding lines are formed in such a manner that the material web (1) is alternately pre-folded in a first and an opposite second direction to facilitate the subsequent folding.
4. The method according to any one of claims 1 to 3, characterised in that the web run is controlled by reference to pattern repeat marks or pattern repeat stampings (14) of the material web (1).
5. The method according to any one of claims 1 to 4, characterised in that after folding packets (9) having sections (7) folded over one another are cut to length from the material web (1).
6. An apparatus for folding a material web (1) in a zigzag shape comprising a cyclically operating folding device (6) which comprises a holding knife (27) for fixing a front section (7) of a material web (1) in the running direction and comprising a slider (29) for the cyclic output of the folded sections (7), characterised in that the folding device (6) comprises a first and an opposite second knife set (28a, 28b), wherein the first and the second knife set (28a, 28b) each comprise a plurality of folding knives (30a, 30b) which can be delivered substantially perpendicularly and individually to the material web (1) and guide the sections (7) of the material web (1).
7. The apparatus according to claim 6, characterised in that the folding knives (30a) of the first knife set (28a) are disposed on a common support (31) and that the folding knives (30b) of the second knife set (28b) can be delivered linearly independently of one another.
8. The apparatus according to claim 6, characterised in that the folding knives (30a) of the first knife set (28a) and the folding knives (30b) of the second knife set (28b) can be delivered linearly independently of one another.
9. The apparatus according to claim 7 or 8, characterised in that the support (31) of the first knife set (28a) or the individual folding knives (30a) of the first knife set (28a), the folding knives (30b) of the second knife set (28b), the holding knife (27) and/or the slider (29) are hydraulically or pneumatically driven.
10. The apparatus according to any one of claims 6 to 9, characterised in that the first and the second knife set (28a, 28b) each have between 3 and 10, preferably between 5 and 8 folding knives (30a, 30b).
11. The apparatus according to any one of claims 6 to 10, characterised in that the clock rate of the folding device (6) is greater than 3 cycles per minute, preferably greater than 5 cycles per minute.
12. The apparatus according to any one of claims 6 to 11, characterised in that a folding station (3) for folding and pre-folding the material web (1) is mounted upstream of the folding device (6).
13. The apparatus according to claim 12, characterised in that the folding station (3) comprises a support plate (16), a web guide (17) running in the longitudinal direction of the web and two oppositely acting folding units (18) disposed transversely to the web guide (17), wherein the folding units (18) each comprise a clamping device (19) with at least one clamping jaw (20) and a sword (21), by which means fold regions (22) of the material web (1) can be inserted into a gap (25) of the clamping device (19), and wherein the clamping jaw (20) is movable for producing folding lines of the material web (1).
14. The apparatus according to any one of claims 6 to 13, characterised in that at least one web storage device (4) and at least one propulsion unit are provided.
15. The apparatus according to any one of claims 6 to 14, characterised in that a separating station (8) is provided for cutting to length packets (9) of the material web (1).

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