EP0080195A2 - Tube formed by helically winding a continuous paper or cardboard strip or the like, and method for its manufacture - Google Patents

Abstract

1. Portative tubing of round cross section manufactured from a continuously helically wound web material having high restoring forces after elastic deformation such as paper, paperboard or the like, the wall or wall thickness of which tubing is defined essentially by at least one layer of flutes lying parallelly to each other and being aligned with their main extension in the longitudinal direction of the web and of the helices, as well as inner and outer covering layers for the flutes, neighbouring marginal areas of the web being connected to the covering layers in the area of the crests and hollows of the flutes, characterized in, that at least one of the covering layer forms, by way of a side strip (21, 22), an integral component of the undulated web material (23) of neighbouring winding sections, and that neighbouring marginal areas of the undulated web material overlap each other and are connected with each other.

Description

Field of the Invention

The invention relates to a tube strand made of a continuous, helically wound web of paper, cardboard or similar material, edge regions of the web overlapping one another and being firmly connected to one another to form the tube strand wall, and a method for producing a continuous web from a continuously running web made of paper, cardboard or similar material helically coiled tubing. The term "similar material" refers to materials that are suitable as substitute materials for paper or cardboard in terms of their nature, behavior and / or use, e.g. Plastic-laminated papers or cardboards, laminated papers or cardboards, textile plastic laminates or combinations of such materials, which are subject to restoring forces during the deformation, i.e. tend to return to their original shape.

State of the art

In the production of paper or cardboard tubes, which are used, for example, to produce shipping tubes, sleeves for household paper, spools, etc., it is known to wind a plurality of paper webs one above the other over a mandrel, the thickness of the wall of which is from the continuous tubing cut tubes, sleeves or coils from the number of paper web layers that are wound one above the other. The individual helical coils overlap each other len margin areas. This known method does not deform the paper webs. Such pipe strings are very stiff, ie they are not bendable, and their weight and paper consumption is relatively high due to the multiple winding.

Furthermore, it is known to produce continuous tubing strands from an aluminum foil web, which is also continuously wound in a helical shape after it has previously been formed into waves over its entire width. Such pipe strands are mainly used for the production of air conditioning and ventilation pipes and can be cut according to the desired length. Usual thicknesses of the aluminum foil are between 0.08 and 0.2 mm. As a result of the waves, the pipe strands or pipes are easily bendable. Due to the material properties of aluminum, the shafts are very dimensionally stable, i.e. their deformation is only possible when force is applied to them. A major disadvantage, however, is that they absorb only low tensile, tensile and compressive forces. In addition, aluminum is relatively expensive as a material for various applications.

Task

The invention has for its object to provide a pipe string of the type described above, which has a high strength with low weight, and at the same time to propose a method of the type also described above, with which such pipe strings can be produced in a cost-effective manner.

Solution and advantages

The object on which the invention is based is achieved in the case of a tubular string in that the web is formed over at least part of its width with a plurality of parallel shafts which are aligned with their main extent in the longitudinal direction of the web and the helical coil.

In the method, the object is achieved in that the web is deformed over at least part of its width to form waves extending in its longitudinal and downward directions and is joined to the pipe string wall with partial overlap and connection of its side edges.

The advantages which can be achieved with the invention consist in particular in the fact that a tube product of extraordinarily low weight with surprisingly high strength values for materials such as paper or similar materials is obtained, which is suitable as a substitute product for a very wide variety of purposes. Pipes of this type, the walls of which can be structured in the manner of corrugated cardboard, can be used both for packaging and as sleeves or load-bearing elements for coils, but they can also be used for insulation purposes as well as for the transport of gaseous or - with appropriate impregnation - more liquid Media into consideration. With the invention, therefore, a mass product of relatively high quality can be achieved for a wide variety of requirements in relation to the material costs, taking into account that paper materials obtained in recycling can be used for many purposes.

Developments of the invention

In order to achieve the strongest and most stable bond possible between adjacent web parts and at the same time to achieve the required dimensional stability with regard to the restoring forces of the material, various measures can be used individually or in combination with one another.

Thus, in each case, a part of the two waves in relation to the width of the outside of the parts of the paper web which are adjacent to one another in the overlap area should and can contact each other in the flank area and be connected to one another there. In many applications, however, it can be even more advantageous if at least one of the shafts lies side by side in the overlapping area Parts of the web are in engagement with at least one shaft of the adjacent part of the web. It can be left open which part of the web width the waves occupy. However, the shafts can also be arranged over the entire web width, in which case at least the two outer shafts of adjacent web parts should overlap one another in order to fulfill the aforementioned purpose.

It is very advantageous if the web has an undulated side strip on at least one side of the waves, which covers at least part of the waves of the adjacent web part and is connected to the covered wave heads. This non-corrugated side strip not only serves as a smooth lamination of the shafts, but also acts as a load-bearing element with regard to their dimensional stability and prevents the shafts from being smoothed due to the restoring forces of the material. In this context, it is particularly advantageous to design or leave the web on both sides of the shafts with an undulating side strip, one of which overlaps or covers the underside of one adjacent web part and the other the top of the other adjacent web part. Thus, for a tubular string, as seen in cross-section, may have a completely smooth interior and exterior wall, while the intermediate Wandun sstärke ^g is formed by the corrugated material and thus constitutes the strength-determining part of the tube Stanges.

It should also be mentioned that, despite the overlapping, smooth web parts, the outer shafts should also advantageously mesh with one another in order to achieve sufficient "toothing" in the edge region.

The web is preferably at least in the area of the shafts with a material-stiffening application made of wax, a thin plastic film or the like. coated or soaked. These This measure is unavoidable in the case of pipe strands designed in accordance with the invention, in which no smooth lateral overlap areas are provided, but which are corrugated continuously over the entire web width, since otherwise the resetting forces of the material would immediately result in smoothing after leaving the devices producing the waves. The material stiffening order thus serves to maintain the shape. However, it can expediently also be used in those cases in which smooth side overlaps are provided, in particular when high demands are placed on the pipe string material. Such requirements can concern, for example, both the strength and the tightness, ie impermeability to gases and liquids.

Since the area of the inner wall is subjected to compression forces in a pipe string with a wall thickness of a few millimeters, according to the invention (principle of the accordion or the stovepipe knee; tensile and compressive forces in relation to the neutral fiber on the bending beam), the web can at least in the area of the Parts forming the inner wall of the tubing string, such as shafts and / or inner overlap, are provided with a knurling which extends essentially transversely to the longitudinal direction of the paper web. So the compression is better absorbed; they compensate for the opposing forces that occur in the outside area.

Furthermore, the pipe string wall can be formed from at least two superimposed, helically wound and provided with shafts running in the longitudinal direction of the helix. Such a double or even multilayer, i.e. The use of more than two layers is particularly advantageous if a thicker wall is required for reasons of strength or insulation.

In the manufacturing method described above, there are various preferred implementation options.

In view of the compression forces mentioned, the web can be pre-deformed at least over part of its width substantially transversely to its longitudinal direction, e.g. be knurled. This is done, for example, with finely corrugated roller rollers.

The shafts are preferably produced by pushing the web together transversely to its longitudinal extent, in a particularly preferred manner step by step, in order to keep the forces exerted on the material during the wave formation within manageable limits. The wave formation can take place gradually symmetrically, starting in the middle of the path, but it is also possible to make it asymmetrical, e.g. starting from one side.

In view of the restoring forces of the material, the web can immediately or at least in the area of the waves with a stiffening material such as wax, solidifying liquid plastic or the like after the wave formation. soaked, coated or provided in a similar manner.

In order to achieve a firm connection in the edge area of the adjacent web areas, the procedure is such that the web is at least partially provided with adhesive in these overlap areas before the helical winding, in particular on the heads of the overlapping or overlapping shafts, and glued. Such a connection is procedurally simple to manufacture and can be integrated into the overall sequence of the manufacturing process.

Depending on the requirements of the end product, the waves can be formed over part of the web width in such a way that either a smooth side strip remains on one of the two sides of the web, which extends over or under the entire wave width of the adjacent web part, or that in each case to both One smooth side strip remains on each side of the web, in which case one of the side strips engages under its adjacent part of the web and the other Side stripes overlaps its neighboring web part. So you get either a single-layer or a double-layer smooth covering of the shafts. For a firm, shape-retaining connection, the shafts in the area of their heads and at appropriate and respectively suitable places on the smooth side strips are coated with adhesive such as glue and glued to the adjacent web parts overlapping them.

In the production of multi-layer pipe strands, the procedure is advantageously such that at least two webs are wound one above the other and connected to one another after the waves have been formed.

If the overall requirements so require, e.g. With regard to special insulation, tightness and / or strength requirements, the pipe string wall can advantageously be covered on its inside and / or outside with a smooth paper or film web.

Embodiments

• Fig. 1 einen Querschnitt durch einen Teil eines erfindungsgemäß ausgebildeten Rohrstranges,
• Fig. 2 verschiedene Stufen beim Ausbilden eines Rohrstranges nach Fig. 1,
• Fig. 3 in vergrößertem Maßstab einen Auschnitt III-III der Fig. 2,
• Fig. 4 eine Variante der Ausbildung nach Fig. 2,
• Fig. 5 in vergrößertem Maßstab einen Ausschnitt V-V der Fig. 4,
• Fig. 6 einen Querschnitt eines Teils eines gegenüber Fig. 1 abgewandelten Aufbaus eines Rohrstranges nach der Erfindung,
• Fig. 7 im Querschnitt einen Teil der Wandung des Rohrstranges der Fig. 6 während der Herstellung,
• Fig. 8 in vergrößertem Maßstab einen Ausschnitt VIII-VIII der Fig. 7,
• Fig. 9 eine weitere Ausführungsvariante des Rohrstranges nach Fig. 1 und 6 im Querschnitt,
• Fig. 10 einen Querschnitt durch einen Teil der Wandunq des Rohrstranges der Fig. 9 bei der Herstellung,
• Fig. 11 in vergrößertem Maßstab einen Ausschnitt XI-XI der Fig. 10,
• Fig. 12 eine andere Ausbildungsvariante eines Rohrstranges nach der Erfindung,
• Fig. 13 eine weitere Ausbildungsform eines Rohrstranges nach der Erfindung und
• Fig. 14 zwei Möglichkeiten bei der Vorbereitung einer Panierbahn zur Herstellung erfindungsgemäßer Rohrstränge.

Some embodiments of the invention are shown in the schematic drawing and are explained in more detail below. It shows

• 1 shows a cross section through part of a pipe string designed according to the invention,
• 2 different stages in the formation of a pipe string according to FIG. 1,
• 3 is an enlarged section III-III of FIG. 2,
• 4 shows a variant of the design according to FIG. 2,
• 5 shows a section VV of FIG. 4 on an enlarged scale,
• 6 shows a cross section of a part of a construction of a pipe string according to the invention which is modified compared to FIG. 1,
• 7 in cross section a part of the wall of the tubing of FIG. 6 during manufacture,
• 8 is an enlarged detail of a section VIII-VIII of FIG. 7,
• 9 shows a further embodiment variant of the pipe string according to FIGS. 1 and 6 in cross section,
• 10 shows a cross section through part of the wall of the pipe run of FIG. 9 during manufacture,
• 11 shows a section XI-XI of FIG. 10 on an enlarged scale,
• 12 shows another embodiment of a pipe string according to the invention,
• Fig. 13 shows another embodiment of a pipe string according to the invention and
• 14 shows two possibilities in the preparation of a breading track for the production of pipe strings according to the invention.

The illustrated exemplary embodiments all relate to the use of paper as a material web, although, as stated, other suitable materials which are equivalent or similar to paper in terms of their nature, their behavior and / or their possible uses are also suitable.

Fig. 1 shows a pipe string 10 produced according to the invention, each with a smooth inner and outer wall, which is produced by helically winding a continuous paper web 2, whereby adjacent paper web parts a, b, c, d, e ... arise.

This paper web 2, the width of which can be chosen as desired and which is based on the one hand on the existing starting materials and on the other hand on the dimensions of the mechanical devices for processing the paper web, is provided with waves 3 at least over part of its width in a device suitable for this purpose, the height of which essentially determines the thickness of the raw strand wall. The shafts 3 are expediently produced by pushing the paper web together, at least the corrugated paper web part then remaining until the paper web is joined, in order to avoid regression due to the restoring forces of the paper.

The construction of the tubing string 10 goes in detail from Fi ^g. 2 and 3. There are four adjacent web parts a, b, c, d of FIG. 1, of which only one is shown completely, while the other three parts are recognizable. The paper web is formed over a part of its width with waves 3, six in the example shown, by gradually pushing them together. This corrugation area is designated 23, its width in Fi ^g. 2 recognizable. On both sides of the shafts 3 there is an undulating, ie smooth, side strip 21 and 22 respectively. The width of these side strips can also be seen in FIG. 2. In the present example, both side strips 21 and 22 are selected to have the same width, but they can also have different widths. The total width of the paper web is thus composed of the two side strips 21 and 22 and the wave area 23 after the waves 3 have been attached and is likewise indicated in FIG. 2. With regard to the subsequent helical winding, the configuration of the shaft region 23 is to be selected such that one of the side strips, in the present case the right side strip 21, above, and the other side strip, in the example shown, the side strip 22 comes to lie below. It is thereby achieved that the two side strips 21 and 22 overlap or underlap the respectively adjacent paper web part and cover the undulating region 23 thereof. By applying adhesive to the outside of the heads or feet (extremes) of the shafts 3 and the inside or outside of the corresponding places (ie at a distance from the shaft division) of the overlapping side strips and applying appropriate pressure, the side strips 21 and 22 with the shafts 3 glued so that the shaft areas 23 are dimensionally stabilized in this way and a regression of the waves due to the restoring forces of the paper is not possible.

From the example shown in Fig. 3 in an enlarged scale detail III-III of Fig. 2, the position of the individual layers and _T ei-- le in the finished tubing become more apparent. In total there are here four adjacent portions of the track portions a, b, c, d of the web 2 seen, wherein each reference numeral digits of a paper web portion of the corresponding letter of the respective _P is a-pierbahnteils respectively assigned.

A wave area 23d is closed on the right by a wave area 23d and on the left by a wave area 23b by nestling the last wave in each case. In this area of contact or nestling of the flanks, gluing should advantageously also take place. The wave region 23c is completely covered on one side by the top side strip 21b of the left adjacent paper web part b and on the other side by the bottom side strip 22d of the right adjacent paper web part d. As a result of the selected width of the side edge strips 21 and 22, which is greater than the width of the wave region 23, the side strip 21b covering the wave region 23c is still partially covered by the next side strip 21a of the paper web part a to the left of it, while in turn covering the it overlaps the right side strip 21c adjacent to it. Bonding also takes place in these overlapping areas. The same applies to the below side strip 22 so that the side strip 22d covers the side strip 22c to the left thereof.

2 and 3, the pitch of the helical coil is indicated. A substantial part of the paper web width thus serves to cover the shaft area 23, so that in this embodiment there is a closed, smooth inner and outer wall. The inner wall is determined by the side strips 21 at the top, the outer wall by the side strips 22 at the bottom.

The embodiment of FIGS. 4 and 5 essentially has the same structure as the example of FIGS. 2 and 3, in particular with regard to the side strips 21 and 22 covering the wave regions 23; the only difference is that in Fig. 4 and 5 the waves of adjacent paper web parts partially interlock, namely here a pair of waves 3b, c. This results in an even firmer and more durable possibility of connecting adjacent paper web parts a, b, c, d.

Fig. 6 shows a pipe string 11 which has a smooth inner wall and a corrugated outer contour. Details of this tubing string 11 can be seen in the detailed representation of FIGS. 7 and 8. As can be seen, only one side strip 21 lying at the top is provided in this embodiment, while the wave region 23 is formed up to the other edge of the paper web 2. Interlocking in the edge area is only provided for one shaft, as can be seen in particular from FIG. 8. The inner wall of the pipe string 10 is determined by the side strips 21a, 21b, 21c, which in part overlap twice. The outer contour results from the waves 23b, 23c, 23d. In this embodiment, gluing can therefore only take place in the area of the inner wall and the overlapping wave areas. Such pipe strands can be used when certain deformations of the outer contour can be accepted or may even be intended.

9 shows a pipe string 12 with a smooth outer wall and a corrugated inner wall structure. As can be seen from the detailed representations of FIGS. 10 and 11, there is a practically only 180 rotated arrangement compared to the embodiment of FIGS. 7 and 8, wherein instead of the side strips 21 shown there above, undulating side strips 22 underneath here undulate the wave areas 23 cover and wear on the outside.

This embodiment is, for example, in such cases advantageous applicatio ^g s in which a deformation of the internal structure is desirable to be able to compensate for example for bottle packaging or tube sheets to some variations in diameter of the coated parts.

Fig. 12 shows an embodiment in which a tubing string 13 is made of double-layer paper web material. Such multilayer pipe strands have a very high strength of their walls and are accordingly highly pressure-resistant and secured against bending.

a 14 FIG. 13 shows an embodiment% of the tubular string without smooth side strips, ie with corrugations formed over the entire width of the paper web. The waves of adjacent paper web parts ^g mesh with one another in a more or less large number, depending on the intended use, and thus form the interlocking connection. Since in such exclusively corrugated webs it is imperative to reset the waves due to the nature of the material, the paper web must in any case be provided with a material application which ensures dimensional stability.

14 shows a preparation stage for the paper web, here designated with its total width 2, in two variants. This preparation takes place before the generation of the wave profiles and consists in that the paper web 2 is knurled over part of its width or over the entire width. Such curling consists in a very tight gathering of the paper in order to be able to compensate for the differences in the forces occurring on the inner wall and outer wall during the later winding into helical coils. Such curling creates target compression points. They are required in the area of the inner parts of the paper web in the finished tubing string, since the highest compression forces occur here, while tensile forces can be absorbed in the outer area to the extent of the tensile strength of the paper material used, but without the paper being subject to stretching. Rather, if the tensile strength is exceeded, tearing occurs immediately. This is counteracted by the knurling, namely that a higher compression wheel can be achieved inside, force ratios as a result of which the diameter differences can thus be reasonably compensated for. In the upper part there is shown only a partial curling 41 which extends over the width of the inner side strip 21 and the width of the later wave region 23. The width of the side strip 22 lying on the outside in the finished pipe string is influenced only slightly.

However, it is also possible to design the curling as a curl 42 covering the entire paper web width 2, since a desired compression in the area of the outer side strip 22 has hardly any disadvantages. The choice between the knurls 41 and 42 essentially depends on the tools available.

The principle of wave profile formation is also indicated in FIG. 14. The paper web 2 is pushed together transversely to its longitudinal direction, that is to say in the direction of the arrows A, so that waves running in the longitudinal direction of the paper web arise in the region 23. Since the paper web runs lengthways through the machine, the waves can only be generated in stages, i.e. it is not possible to generate all the waves taking up the wave width 23 at the same time, but this must be done in succession in order to be able to control the pull-in forces in a reasonable manner.

The wave profile is formed using tools designed according to the waveform, e.g. in the form of rollers that carry such a profile on their circumference. However, these profiling tools do not form the subject of the present application and therefore do not need to be explained in more detail here. An example of such tools can be found in BE-PS 748 937, although they are used there to deform aluminum in the manufacture of corrugated aluminum tubes.

Claims (22)

1. From a continuous, helically wound web made of paper, cardboard or similar material with high restoring force after elastic shaping, a tubular section of round cross-section, edge regions of the web overlap and are firmly connected to one another, characterized in that the web (2) has at least one Part of its width is formed with a plurality of shafts (3) lying parallel to one another and aligned with their main extent in the longitudinal direction of the track and the helical coil, which are provided with stabilizing means for compensating the restoring forces and, due to their shaft height, essentially the diameter of the inner and Determine the outer wall, and that the web is prepared at least in the area of the inner pipe string for absorbing compression forces caused by the pipe rounding. 2. Pipe string according to claim 1, characterized in that in each case a part of the two outer shafts (3) of the parts of the web (2) which are adjacent to one another in the overlap region, touches in the flank region and is connected to one another there. 3. Pipe string according to claim 1, characterized in that there is in each case at least one of the shafts (3) in the overlap region of adjacent parts (a, b, c, d) of the web (2) in engagement with at least one shaft of the adjacent part of the web . 4. Pipe string according to claim 1 or 3, characterized in that the shafts (3) over the entire Web width are arranged and at least the two outer waves of adjacent web parts overlap one another. 5. Pipe string according to one of claims 1 to 3, characterized in that the web (2) has at least on one side of the shafts (3) an undulating side strip (21, 22) which covers at least part of the waves of the adjacent web part and is connected to the shaft heads. 6. Pipe string according to claim 2, 3 or 5, characterized in that the web (2) on both sides of the shafts (3) is formed with an undulated side strip (21 and 22), one of which (21) the inside of an adjacent one Web part and the other (22) over-covers or covers the outside of the other adjacent web part. 7. Pipe string according to one of claims 1 to 6, characterized in that the web (2) od.dql at least in the region of the shafts (3) with a material-stiffening application made of wax, a thin plastic film. is coated or soaked. 8. Pipe string according to one of claims 1 to 7, characterized in that the web (2) at least in the region of the parts forming the pipe string inner wall such as waves and / or internal overlap with a substantially transverse to the web longitudinal direction Rädeluna (41, 42) is provided. 9. Pipe string according to one of claims 1 to 8, characterized in that the Rohrstrangwandunq is formed from at least two superimposed, helically wound and provided with in the longitudinal direction of the helical shafts provided tracks. 10. A method for producing a continuous, from a continuously running web of paper, cardboard or similar material helically coiled Rohrstranaes, characterized in that the web is deformed at least over part of its width to extend in its longitudinal and downward direction and partially overlap and connect their side edges to the tubing wall. 11. The method according to claim 10, characterized in that the web is pre-deformed at least over part of its width substantially transversely to its longitudinal direction, e.g. is knurled. 12. The method according to claim 10 or 11, characterized in that the waves are formed by pushing together the web transverse to its longitudinal extent. 13. The method according to claim 12, characterized in that the wave formation takes place in stages. 14. The method according to claim 13, characterized in that the wave formation is gradually symmetrical, starting in the middle of the web. 15. The method according to claim 13, characterized in that the wave formation takes place asymmetrically. 16. The method according to any one of claims 10 to 15, characterized in that the web or the like at least in the region of the shafts with a stiffening material such as wax, solidifying liquid plastic. is soaked, coated or provided in a similar manner. 17. The method according to any one of claims 10 to 16, characterized in that the web is at least partially provided with adhesive and glued in the overlap areas before the helical winding. 18. The method according to any one of claims 10 to 17, characterized in that the waves are formed over part of the width of the web such that a smooth side strip remains on one of the two sides of the web, which over the entire wave width of the respectively adjacent web part - or reaches under. 19. The method according to any one of claims 10 to 17, characterized in that the waves are formed over a part of the width of the web such that a smooth side strip remains on both sides of the web, one of the side strips engaging under its adjacent web part and the other side strips overlaps its adjacent part of the web. 20. The method according to claim 18 or 19, characterized in that the waves are covered in the region of their heads with adhesive and glued to the overlapping adjacent web strips. 21. The method according to any one of claims 10 to 20, characterized in that at least two webs are wound one above the other and connected to each other after the formation of the waves. 22. The method according to any one of claims 10 to 21, characterized in that the pipe string wall is covered on its inside and / or outside with a smooth paper or film web.

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