WO2011139219A1

WO2011139219A1 - Dust removing web guide

Info

Publication number: WO2011139219A1
Application number: PCT/SE2011/050546
Authority: WO
Inventors: Mats Martinsson; Jakob RINGSTRÖM; Jan Jakobsson; Mats Hedse
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 2010-05-05
Filing date: 2011-05-02
Publication date: 2011-11-10
Also published as: SE1000456A1; EP2566800A1; BR112012027319A2; AR081460A1; RU2012152083A; EP2566800B1; EP2566800A4

Abstract

The present invention relates to an apparatus for guiding a web of packaging material. The apparatus comprises a groove (111) extending along the direction of transport (A) of the web, in which groove (111) a longitudinal edge of the web is intended to run during advancement of the web, abutting a bottom of the groove (111). The apparatus differs from prior art devices in that it further includes suction orifices (115) distributed along the length of the groove (111) for applying a partial vacuum for the removal of air and dust from the groove (111) and its surroundings.

Description

DUST REMOVING WEB GUIDE

TECHNICAL FIELD

The present invention relates to an apparatus for guiding a web of packaging material and removing dust from the same from an edge thereof.

BACKGROUND

The background for the present invention is described in detail in a previous application by the same applicant WO2004/041697, which is considered to be more than sufficient for the skilled person to fully understand the background of the present invention, for which reason the background section of the present application is kept short.

The present invention relates to web guiding of a planar material web. In particular it relates to guiding of a web of packaging material used for packaging of food products.

Within the field of packaging food products, and in particular packaging such products under aseptic conditions use is often made of sterilized packaging containers, such as Tetra Brik Aseptic (registered trademark). Tetra Brik Aseptic, as well as similar packages, may be manufactured by forming and sealing a strip-rolled packaging material. The packaging material comprises a layer of fibrous material, such as paper, sandwiched between two or more layers of thermoplastic, such as polyethylene. The side of the packaging material to be contacted by product may also comprise a barrier material layer, such as an aluminium layer, which in turn is covered by a layer of thermoplastic material.

In a typical packaging process the packaging material is sterilized, whereafter the two longitudinal edges of the packaging material are joined such as to form a continuous tube. The tube of packaging material is filled with product, usually sterilized product, whereafter the tube is provided with transversal seals such as to form pillow-shaped packages that may be severed from the continuous tube and folded into individual packaging containers.

Instead of using a tube of packaging material the material web may be cut into blanks in a first step, whereafter the blanks are folded into packaging containers, with or without addition of opening devices or similar packaging portions. The present invention is particularly well-suited for the described type of packaging material, and also for situations where the packaging material is used for production of packages in which high level of sterilization is required (and where dust is explicitly undesired).

One conclusion drawn in the previous application is that the laminated sides of the packaging material generate limited amounts of dust when compared to the edges, where the fibrous paper core is exposed and larger amount of dust is generated. The dust generation is even more pronounced when the edge is subjected to mechanical wear, such as during web guiding. Thus, locating the dust removal in the web guide removes dust where it is generated, and is thus highly efficient.

Prior art solutions for removing dust from paper web also include innumerable variations of vacuum cleaners and compressed air systems, which are not as such interesting for the present invention, and more thoroughly described in the previously mentioned application.

The cited application discloses a web guide in accordance with Fig. 1, 2 and 3, to be described in the following. As shown in Fig. 1, the web guide 10 includes a groove 11 in which one longitudinal edge of the paper web is intended to run. The groove 11 extends throughout the entire web guide 10 and thus has open ends in the end pieces 10a, 10b of the guide apparatus 10. Seen from the end piece 10a (see Fig. 1), the groove 11 has a so-called keyhole configuration with an inner portion 1 la in the transverse direction A which is of larger cross section than an outer portion l ib. Outermost, the groove 11 has a conical portion 11c which forms a funnel which opens towards the paper web. The web guide 10 is of one piece construction from an easily processed material, such as some suitable form of plastic. The keyhole shape of the groove 11 is employed for securing a rule 12 which forms an abutment surface for the bypassing longitudinal edge the web. The rule 12 is made of a harder material such as, for example, a metal. The rule 12 is, for example, formed from a rod which has been provided with a planar surface 12b. In its ends, the rule 12 has been provided with bevels 12c, 12d in order to commence and terminate the contact with the longitudinal edge of the web in a gentle manner.

In order to cause the longitudinal edge of the web to run against the abutment surface 12b of the rule 12, the guide apparatus 10 is provided with two clamping wheels 13a, 13b which rotate freely and which between them clamp the web. The abutment surface 12b of the rule 12 extends in the same direction as the running direction A of the web and the wheels 13 a, 13b are obliquely inclined a few degrees a so that they draw the web outwards somewhat towards the guide apparatus 10 (see Fig. 2) in the transverse direction B of the web.

At that portion 10c which the paper web first passes in the guide apparatus 10, the walls l id and 1 le of the groove display a first extent in the transverse direction B. At one portion lOd which the web last passes in the guide apparatus, the walls l id, l ie display a second extent in the transverse direction B which is greater than the above mentioned first extent.

The first portion 10c of the guide apparatus in the transport direction A has a groove 11 which only displays the circular cross section 1 1a and the straight walls 1 lb out towards the web, while the second portion lOd has a groove 11 which also displays the funnel-shaped portion 11c open towards the web.

At this funnel-shaped portion 11c with extra long groove walls l id, l ie, the guide apparatus is further provided with an aperture 14 to which a partial vacuum (not shown) is extended to be connected. This source of partial vacuum may be a standard vacuum cleaner which delivers a vacuum of the order of magnitude of 10-20%, i.e. 0,1-0,2 bars partial vacuum.

This aperture 14 is, via a channel in the guide apparatus, in communication with an aperture 15 which discharges in the bottom of the groove 11 in the centre of the above mentioned portion lOd with long groove walls l id, l ie.

In order further to amplify the funnel configuration of the walls l ie, 1 Id of the groove 11, the funnel-shaped walls l ie, l id have been provided with a bore 16 which extends directly down to the aperture 15 in the bottom of the groove 11.

The rule 12 is designed so that it extends into the portion lOd displaying long groove walls l id, l ie and terminates by a bevel 12d immediately before the aperture 15 in the bottom of the groove 11. By such means, the dust which is released when the contact is discontinued between the abutment surface 12b of the rule 12 and the web edge will be directly sucked in via the aperture 15. Since the bottom 1 la of the groove 11 retains its form along the running direction A of the web, a communication will be formed after the termination of the rule 12 in the bottom 1 la of the groove 11 between the upper and the lower side of the web.

When a web passes the guide apparatus, its edge will be guided by the abutment surface 12b of the rule 12 by the intermediary of a gentle connection 12c and released by the intermediary of a gentle termination 12d. The dust, such as particles of plastic, paper or the like, will be sucked into the aperture 15 to a connected source of partial vacuum.

Though having major advantages as compared to other systems, there are still improvements to be made. The present invention aims at providing such improved web guide enabling efficient dust removal with limited air mass flow, while providing additional beneficial features. SUMMARY OF THE INVENTION

For the purposes of achieving one or several of the improvements mentioned above, the present invention provides an apparatus for guiding a web of packaging material, comprising a groove extending along the direction of transport of the web, in which groove a longitudinal edge of the web is intended to run during advancement of the web, abutting a bottom of the groove. The web-guiding apparatus is characterized in that the groove further includes suction orifices distributed along the length of the groove for applying a partial vacuum via a tubing for the removal of air and dust from the groove and its surroundings.

The advantages following from the inventive characteristics are disclosed in the following detailed description. In the detailed description several characteristics may be combined in a single embodiment, which should not be construed as that the different characteristics have to be used in combination - only that it is possible to do so.

In one or more embodiments the suction orifices may be arranged in two series on either side of a longitudinal axis of symmetry of the groove, and in one or more related embodiments the series may be arranged symmetrically on either side of said longitudinal axis.

The groove may in one or several embodiments be V-shaped and arranged to receive the web at the tip of the V-shape.

In one or more embodiments the V-shaped groove is provided in an assembly comprising a cylinder sector, thus creating a manifold in the shape of a cylinder with a V- shaped cut in the longitudinal direction, and a portion of the tubing. The resulting assembly is insertable in a circular through hole of the apparatus.

In one or several embodiments the bottom of the groove slopes away from the web in a downstream region and in a downstream direction, in order to provide a smooth release of the abutment between the groove and the longitudinal edge of the web, and in another embodiment the bottom of the groove slopes away from the web in an upstream region and in an upstream direction, in order to provide a smooth initiation of the abutment between the groove and the longitudinal edge of the web.

Apart from possible slopes at its end, the bottom of the groove may in one or several embodiments follow a rectilinear path from an upstream region or a downstream region.

A suction opening may be arranged along the axis of symmetry of the groove, at a downstream half of the apparatus, for instance in said downstream region where, in use, the abutment of the longitudinal edge of a web has ceased. In an apparatus of one embodiment an underpressure of about 1-5 kPa, preferably 1-2 kPa, may be used for achieving an adequate effect.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detail hereinbelow, with reference to the accompanying, schematic Drawings which, for purposes of exemplification, show the currently preferred embodiments of the present invention according to both of its aspects. In the accompanying Drawings:

Fig. 1 shows a web guide apparatus in accordance with prior art.

Fig. 2 shows the apparatus illustrated in Fig. 1 seen straight from above, where the paper web is intended to run parallel with the plane of the Drawing, from below and upwards on the Drawing sheet.

Fig. 3 shows the apparatus illustrated in Figs. 1 and 2 seen straight in the transverse direction of the web.

Fig. 4 is a perspective view of a web guide in accordance with a first embodiment of the present invention.

Fig. 5 is a longitudinal section in perspective of the web guide of Fig. 4.

Fig. 6 is a transversal section of the web guide of Fig. 4.

Fig. 7 is a perspective view of a suction assembly according to one embodiment of the invention.

DETAILED DESCRIPTION OF ONE PREFERRED EMBODIMENT

A description of a first embodiment of the present invention will be given with reference to Figs. 4-6. Reference is also made to Figs. 1-3 since similar reference numerals are used for similar components. Also, after understanding the apparatus of Figs. 1, 2 and 3 the apparatus of Fig. 4 is readily understood, since a similar construction is used.

Starting with Fig. 4, a web of packaging material (not shown) is arranged to run in the direction indicated by arrow A, having one longitudinal edge arranged in the slot 120 and abutting onto the bottom of a V-shaped groove 111. A pair of clamping wheels or guide wheels 113a, 113b are arranged to clamp the web of packaging material and bias it towards the bottom of the V-shaped groove 111. In order to fulfil this purpose the plane in which the guide wheels 113, a, b rotate is inclined relative to a plane including the arrow A, which is described in general and in detail in the cited application, which description is applicable for the present application too. The slot 120 is of essentially constant width, but for the upstream end and the downstream end thereof, where its width increases, which is shown in Figs. 4 and 5.

The groove 111 extends along the entire apparatus 110 and the bottom thereof, at the interior tip of the V-shape, provides an abutment surface for the longitudinal edge of the web. In Fig.5 it is shown how a series of suction orifices 115 are arranged on one leg of the V- shape, and a similar series is arranged on the opposing leg of the V-shape. This arrangement will provide a symmetrical suction power, and prevent the web of material from leaning in one direction or the other. The V-shape 111 itself will constitute a well-defined guide for said longitudinal edge. In the illustrated example the V-shaped groove is accomplished by arranging a groove assembly 121 in a cylindrical bore 122 extending in the longitudinal direction, which is shown in Fig. 6, into which the slot 120 debouches. The assembly 121 (see also Fig. 7) comprises a cylinder sector combined with the V-shaped groove 111 forming a delimitation thereof, and may be slid into the cylindrical bore 122. In this context it should be noted that a tubing 114 providing the partial vacuum may form part of the assembly 121 and is consequently provided in a readily manner as well. This configuration simplifies manufacture and maintenance of the guide apparatus, since one of the major operational parts may be manufactured separately and simply slid into position in a circular bore of the apparatus. A locking bolt 128 (see Fig. 5) is used to lock the assembly 121 into position. This may be a convenient way of manufacturing an apparatus fulfilling the inventive purpose. The interior of the assembly 121 will constitute a plenum common for the suction orifices 115, and by applying an underpressure in to this plenum, via the tubing 114 the suction orifices 115 will be operational and start fulfilling their function.

The entire guide apparatus is slidably arranged on rods (not shown) passing through the openings 124, which facilitates continuous movement along the B-direction (i.e. in the cross direction of the guided web). By tightening locking bolts 126 it is possible to lock the guide apparatus into place on the rods.

It is apparent from Figs. 4 and 5 that the bottom of the groove 111 slopes away from the longitudinal edge of the web in a downstream region 11 ID and in a downstream direction. This slope is arranged to provide a smooth release of the abutment between the groove and the longitudinal edge of the web.

In the same drawings it is shown how the bottom of the groove 111 may slope away from the web in an upstream region 111U and in an upstream direction, in order to provide a smooth initiation of the abutment between the groove and the longitudinal edge of the web. Between these sloping regions the bottom of the V-shaped groove may be essentially rectilinear.

During the engagement with the V-shaped groove, dust and debris may be generated from the longitudinal edge of the web material, in accordance with what is described in the background section of the present description. A portion of the dust and debris generated may be caught between the longitudinal edge of the web and the bottom of the V-shaped groove, in which case it will not be released until the longitudinal edge terminates engagement with said groove 111. For this reason at least one additional suction opening (not shown) may be arranged in a location along the longitudinal axis of the groove 111 (e.g. in the bottom thereof). It may e.g. be arranged in the downstream region 11 ID to free the longitudinal edge from dust and debris as it terminates engagement with the bottom of the V-shaped groove 111. This suction opening may be in fluid communication with the same plenum as the other suction orifices 115, yet it may also have an underpressure supply of its own.

It will readily be perceived by a person skilled in the art that a number of

modifications of the embodiments of the present invention described herein are conceivable without departing from the scope of the invention as this is defined in the appended Claims.

In addition, it is also possible to use the described apparatus without guide wheels, in which event it may not execute any specific guiding in the transverse direction but use is made of the favourable shape in order to effectively remove dust by suction.

Claims

1. An apparatus for guiding a web of packaging material, comprising a groove (111) extending along the direction of transport (A) of the web, in which groove (111) a longitudinal edge of the web is intended to run during advancement of the web, abutting a bottom of the groove (111) characterised in that the groove (111) further includes suction orifices (115) distributed along the length of the groove (111) for applying a partial vacuum via a tubing (114) for the removal of air and dust from the groove (111) and its surroundings.

2. The apparatus of claim 1, wherein the suction orifices are arranged in two series on either side of a longitudinal axis of symmetry of the groove (111).

3. The apparatus of claim 2, wherein the series are arranged symmetrically on either side of said longitudinal axis.

4. The apparatus of any preceding claim, wherein the groove (111) is V-shaped and arranged to receive the web at the tip of the V-shape.

5. The apparatus of claim 4, wherein the V-shaped groove is combined into an assembly (121) with a cylinder sector, thus creating a manifold in the shape of a cylinder with a V-shaped cut in the longitudinal direction, and a portion of the tubing (114) in one end thereof, said assembly being insertable in a circular through hole of the apparatus.

6. The apparatus of any preceding claim, wherein the bottom of the groove (111) slopes away from a guided web in a downstream region and in a downstream direction, in order to provide a smooth release of the abutment between the groove and the longitudinal edge of the web.

7. The apparatus of any preceding claim, wherein the bottom of the groove (111) slopes away from the web in an upstream region and in an upstream direction, in order to provide a smooth initiation of the abutment between the groove and the longitudinal edge of the web.

8. The apparatus of any preceding claim , wherein the bottom of the groove extends along a rectilinear path from an upstream region or a downstream region.

9. The apparatus of any preceding claim, further comprising a suction opening arranged along the axis of symmetry of the groove (111), at a downstream half of the apparatus.

10. The apparatus of claim 9 and 6, wherein the suction opening is arranged in said downstream region where, in use, the abutment of the longitudinal edge of a web has ceased.

11. The apparatus of any preceding claim, utilizing an underpressure of about 1-5 kPa, preferably 1-2 kPa.