DE102011001546B4 - Apparatus for producing tube bodies - Google Patents

Abstract

Apparatus for producing tube bodies for packaging tubes, comprising an elongate mandrel (3) extending in an axial direction, around which a substrate web can be formed to produce a tubular shape (4), several of which have a mandrel surface (16) Gas outlet openings (15) which can be pressurized with gas are provided to produce an air cushion between the mandrel (3) and the tube shape (4), and welding means (9) are provided for welding the tube shape (4), characterized in that temperature control means (14) for the defined heating and / or cooling of the compressed gas, in particular the compressed air, are provided.

Description

The invention relates to a device according to claim 1 for producing tube bodies for packaging tubes, comprising an elongated mandrel extending in an axial direction about which a substrate web for forming a tubular shape is deformable, wherein in the mandrel a plurality of gas outlet openings for producing an air cushion between the mandrel and the tube shape are provided. Furthermore, the invention relates to a method for producing tube bodies according to claim 16.

From the US 3,388,017 A a device for the production of tube tubes is known. The device comprises a mandrel for forming substrate, a welding device, and a cooling device with liquid coolant.

General is in the DE 41 21 427 C2 a device for producing tube bodies described. In this case, an endless substrate web, usually a laminate, in particular a plastic laminate, which depending on the application may comprise a metal foil or a metallization layer, formed around an elongated cylindrical mandrel, such that an overlap region between two longitudinal edges is formed, wherein the overlap region welded to the production of the tube shape with suitable welding means, in particular a high-frequency welding device and is transported further in the direction of the longitudinal extension of the mandrel. In the axial direction spaced from the welding device usually a cutting device is provided, with which the produced pipe string is cut to length in tube body desired axial extent. Usually, in known devices for producing tube bodies in the transport direction of the substrate web or the tube form behind the welding means, a cooling device is provided, along which slides the tube shape, and cools the welded seam produced by means of the welding means from radially outside. This creates a considerable space requirement for the overall device.

A major problem in the practice of the packaging tube manufacturing is the need for improvement roundness of the tubular body. When the longitudinal edge regions are welded, the material stresses that affect the roundness negatively affect the roundness.

From practice, it is known to provide on the mandrel at two 180 ° facing away from each other positions an air outlet hole with a diameter of several millimeters, wherein the two air outlet holes not directly on the cylinder surface, d. H. are not arranged on the curved mandrel surface, but on each of a lateral, flat flattening, which are located radially within the cylindrical envelope contour of the mandrel. Compressed air escapes from the air outlet holes, which is intended to reduce the friction in an area immediately adjacent to the two holes between the pipe form and the mandrel.

Depending on the choice of material of the substrate occurs in spite of the two air outlet holes to considerable friction between the pipe and the mandrel and possibly even abrasions, which on the one hand contamination of the tube inside with abrasion dust result and also make regular cleaning of the mandrel necessary. In addition, undesirable scratches can occur in the tube. This is due, inter alia, to the fact that the tubular shape is acted upon in the radial direction inwardly on the cylindrical mandrel surface by means of concave contoured rollers or belts and transported in the transport direction due to the frictional action between the rollers or the bands and the tubular shape.

The contamination of the pipe body with abrasion dust is particularly problematic in the production of tubes for the pharmaceutical industry, since on the one hand a high degree of purity is required and on the other hand materials with a high coefficient of friction are usually used.

Based on the aforementioned prior art, the present invention seeks to provide an apparatus and a method by which the roundness of the tube body is improved and preferably simultaneously reduces scratches in the tube and Abriebungserscheinungen, preferably avoided, to the contamination of the tube with Minimize dust and increase the maintenance and cleaning intervals of the mandrel. Preferably, the device should be able to produce a higher number of tube bodies per unit of time. In particular, the device should be suitable for producing tubes for the pharmaceutical industry. Preferably, the space requirement of the device should be minimized.

This object is achieved in a generic device for producing tube bodies for packaging tubes and the features of claim 1. With regard to the method we solved the problem with the features of claim 16.

Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention. To avoid repetition, device-disclosed features as according to the method disclosed apply and be claimable. Likewise, according to the method disclosed features should be considered as device disclosed and claimed claimable.

In the present technical field of production of flexible, d. H. do not stare, tube bodies for packaging tubes is the particular problem that the flexible substrate web as a tube shape wraps around the mandrel by at least 360 °, as soon as the substrate web was formed into a tubular shape in which touch two longitudinal edge regions of the substrate web. "Tube shape" is understood to be the state in which the wrap angle is at least 360 ° - welding does not yet have to have taken place. This tube shape does not readily slide along the mandrel, but is normally subjected to force from radially outward to radially inward by means of appropriate means, inter alia, to generate sufficient stiction between the means and the tube shape which ensures that the tube shape is achieved by means of the Means in the axial direction, d. H. is transported in the direction of the longitudinal extension of the mandrel. Due to the fact that the flexible substrate web is subjected to a direct external force on the outside radially and is pressed radially inward, the friction conditions between the tubular form and the mandrel increase dramatically. This effect is further enhanced by the fact that the substrate web forms a tubular shape and usually the longitudinal edge regions of the tubular mold are subjected to force in opposite circumferential directions by means of the welding process in order to allow the welding process. By wrapping the rubbing effect is additionally increased.

The invention is based on the idea to provide (one or more) tempering, with which the temperature of the compressed gas and thus of the gas cushion between the tube shape and the mandrel can be selectively influenced. The temperature control means preferably comprise a heat exchanger. Most preferably, the temperature control is associated with a control mechanism to keep the predetermined or predeterminable temperature of the compressed gas at a certain temperature or in a certain temperature range.

It can be provided for cooling the compressed gas temperature control, in particular to dispense in this way in the art used, acting radially outward on the tube mold cooling means with which previously the weld was cooled. In a further development of the invention, it is provided to dispense with such additional, externally acting cooling devices.

It is very particularly preferred to form the temperature control means in order to heat a compressed gas volume flow fed to the gas outlet openings, in particular to a temperature at which it is ensured that material tensions are taken from the then preferably already welded tubular form. As a result, the roundness of the tube shape and ultimately of the suspended, in particular cylindrical tube body can be substantially improved.

For this purpose, the gas temperature should preferably be above 80 ° C, but should be below the melting point of the substrate material, in particular significantly. A preferred temperature range to which the compressed gas can be heated is between 80 ° C and 120 ° C. By the above-mentioned heating, material stresses resulting in particular from the welding process are reduced, thereby improving the roundness of the tubular body. For this purpose, heated air at the axial height of the welding means and / or the welding means can preferably exit downstream through corresponding gas outlet openings in the mandrel. Preferably, the tubular shape is heated over a large area, in particular fully, which can be ensured by the provision of a plurality of gas outlet openings. Additionally or alternatively, as mentioned above, temperature control for cooling compressed gas may be provided, for example, to achieve a rapid cooling of the weld area or the previously heated over a large area tube shape or for fixing a specially shaped tube shape.

It is particularly preferred if the mandrel has at least two, preferably mutually sealed axial sections (chambers), which in each case, in particular independently, be acted upon by a compressed gas volume flow, wherein the temperature of at least one of the gas volume flows is adjustable with temperature control, preferably such that in a first axial section (first chamber) heated air, preferably from a temperature range between 80 ° C and 120 ° C, can escape through gas outlet openings. Cooler gas can preferably escape through gas outlet openings provided in a second axial section (second chamber) of the mandrel, with the aim of causing cooling of the tubular shape, in particular a weld seam produced with the aid of the welding agent and / or the tubular shape which may have previously been heated in the first axial section over a large area. The cooling gas may, for example, be air at room temperature, or tempered air or another gas defined with the aid of appropriate tempering agents. Preferably, the second axial section is downstream of the first axial section in the transport direction of the tubular shape.

The development of the invention described above is not limited to two axial sections. Thus, more than two separately be supplied with compressed gas axial sections may be provided, wherein preferably at least one of the axial sections are associated with temperature control. The temperature preferably differs from at least two gas volume flows conducted to different axial sections.

It is particularly preferred to produce a gas cushion which is preferably circumferentially closed, as far as possible, between the substrate web which has been formed into a tube and the mandrel which has a comparatively large axial extent and preferably also a greater circumferential extent than the air cushion previously produced by two single air outlet holes. To pressurize the gas outlet openings with compressed gas, of course, a compressed gas source connected to the mandrel is provided. In contrast to the prior art preferably at least two, preferably substantially more than two axially spaced gas outlet openings are provided, which are also in contrast to the prior art directly in the curved mandrel surface and not radially offset inwardly as in the prior art Envelope contour of the spine. As a result, the spread or sliding action of the gas cushion according to the invention is substantially improved. In addition, the spread of the gas cushion is improved so that the temperature of the tube shape can be taken over this improved influence. In this case, a plurality of gas outlet openings, at least two gas outlet openings, are preferably understood to mean a number of gas outlet openings exceeding the number two.

The optimization of the gas cushion also leads to a lower dust contamination of the tube interior, smoother inner surfaces and the possibility also previously difficult or unusable, a comparatively large coefficient of friction exhibiting substrate material, especially for the pharmaceutical industry.

Preferably, the gas cushion is dimensioned so that the substrate converted to the tube shape completely, in particular up to the axial end of the mandrel slides on the air cushion, whereby friction and thus abrasion effects can be at least largely avoided.

It is particularly useful if the gas outlet openings, at least in part, not in flats, grooves, etc. d. H. are arranged within a, or set back to a, in particular cylindrical, envelope contour of the mandrel, but directly in the cylinder jacket surface of the mandrel, to allow a more uniform air cushion formation.

As will be explained in detail later, it is particularly preferred that the mandrel, at least in sections, d. H. at least in a surface portion to be provided with a porous material, preferably at least partially form of this, wherein in the case of providing porous material under the gas outlet openings, the pores of the porous, preferably foamed material are to be understood.

It has been found to be particularly advantageous if the mean pore size, i. H. in that the arithmetic mean of the pore size is selected from a value range between approximately 0.05 μm and 2 mm, preferably between 0.1 μm and 2 mm. In principle, different materials are suitable for the choice of material for forming the porous material or the porous material section, for example a metal foam, a ceramic foam or a plastic foam. The material should be chosen to meet the strength requirements.

Particularly preferably, the average diameter of the gas outlet openings is selected from a value range between 0.5 μm and 2 mm, preferably between 0.1 μm and 1 mm, preferably between 1 μm and 100 μm, even more preferably between 1 μm and 10 μm. This small diameter of the gas outlet openings can be ensured in particular if the gas outlet openings, as will be explained later, are formed by pores in a microporous and / or nanoporous material. In particular, when the gas outlet openings are formed, at least in part, by a nano-material structure, the mean pore diameter can be substantially lower and is preferably less than 1 μm.

It was recognized that it is advantageous for the formation of a significantly improved compared to the prior art air cushion to provide the largest possible number of gas outlet openings, in particular for compressed air in the mandrel, through which gas, in particular compressed air can flow from radially inward to radially outward , Very particular preference is given to providing at least ten, preferably at least 50, or at least 100, or at least 150, or more than 200, or more than 300, or more than 400, or more than 500, or preferably more than 1000 or several thousand, gas outlet openings. Gas outlet openings are preferably over an axial extent of at least 20%, preferably at least 30%, more preferably at least 50% of the total axial extent of the mandrel, in order to realize a good gas cushion over a long distance.

It is particularly expedient if at least ten, preferably at least 20, preferably at least 50, even more preferably at least 100, very preferably at least 150, or even more preferably at least 200 gas outlet openings or more than a thousand gas outlet openings arranged at different axial positions along the axial extension of the mandrel are.

Additionally or alternatively, it is preferred if at least ten, preferably at least 20, more preferably at least 50, even more preferably at least 100 or at least 500 or at least 1000 gas outlet openings are arranged at different circumferential positions thanks to the circumferential extent of the mandrel.

Particularly good air cushion properties are achieved if at least 5, preferably at least 10, preferably at least 15, more preferably at least 20, even more preferably at least 50, 100, 150, 200, 1000, 2000 or 5000 gas outlet openings per cm 2 of the mandrel surface in at least one surface section of the mandrel are provided.

It is particularly preferred if the welding means are welding agents which comprise at least one welding band received in a longitudinal groove of the mandrel and moving together with the substrate. Preferably, a welding region of the substrate is sandwiched between this so-called inner sweatband and a sweatband acting radially outward, wherein the heating takes place, for example, by means of a high-frequency source (HF source). If required, in addition to or as an alternative to an HF source arranged outside the mandrel, an additional HF source may be provided within the mandrel.

With regard to the formation of the gas outlet openings, there are different possibilities. According to a first variant, the gas outlet openings are introduced, for example, as discrete, preferably mechanically produced openings into a mandrel material, in particular into a sheet having a cylindrical envelope contour, for example by drilling, cutting, laser and / or punching. According to a second preferred variant, the gas outlet openings are formed as outwardly open pores in a, preferably metallic or ceramic, porous, in particular microporous material. This material can be, for example, sintered material or produced by thermal spraying material or a metal foam.

As stated above, it has proven to be particularly expedient if the gas outlet openings are formed, at least in part, by pores in a microporous material, in the case of the provision of microporous material, for example sintered material or a porous material produced by thermal spraying or foamed material. The pores of such a microporous material have compared to mechanically produced gas outlet openings much smaller cross-sections, so that a finely distributed air cushion can be generated. The mean pore diameter in the case of the microporous material is preferably from a value range between 0.05 μm and 2 mm, very particularly preferably between 0.1 μm and 1 mm, preferably between 1 μm and 500 μm, even more preferably between 0.1 μm and 100 μm.

It is also possible to form the gas outlet openings the mandrel, at least partially form of porous metal foam, wherein the metal foam may be formed, for example, as aluminum foam. It is also possible to put the metal foam with ceramic material in order to increase the stability. It is also conceivable for the metal foam to form a type of support for further microporous and / or nanoporous material, whereby this further material, which then forms the mandrel surfaces, can be sintered or produced by thermal spraying or by foaming with propellant gas.

It is very particularly preferred if the pore size of the pores of the microporous material, in particular of the metal foam, decreases towards the surface of the mandrel.

In addition or as an alternative to microporous material, nanoporous material can be provided for forming the gas outlet openings, wherein it is particularly preferred for a previously mentioned microporous material to serve as a carrier for the nanoporous material then forming a type of coating. The molecular size of the nanomaterial used is preferably between 0.5 nm and 500 nm, very particularly preferably between 0.5 nm and 200 nm. The nanomaterial is preferably a metallic material, for example based on nickel, or zirconium oxide, or titanium oxide, or silica or alumina.

In principle, it is possible to form the porous, in particular the microporous and / or nanoporous, material in a self-supporting manner, ie to realize a sufficient thickness extent (radial extent) that no supporting structure is necessary in the interior. However, an embodiment in which the porous, in particular foamed material is applied to one is preferred Support structure. In this case, a small thickness extension of the porous, in particular microporous and / or nanoporous, material can be realized, preferably from a thickness extension region (radial extension region) between 0.5 mm and 10 mm, preferably between 1 mm and 5 mm. Preferably, a support structure for the porous material is formed so that care is taken for a uniform air distribution in the axial and / or circumferential direction in the interior of the mandrel.

Particularly useful is a variant in which at least one gas discharge channel is provided, with which the gas exiting through the gas outlet openings, in particular air, in particular in the axial direction, can be removed, preferably to avoid unwanted inflation of the welded tube shape. One possibility is to provide on the outer circumference of the mandrel at least one, preferably in the axial direction groove (Gasabführnut) in which the gas is transported away, d. H. can foam.

Preferably, a plurality of such grooves, in particular a plurality of circumferentially spaced grooves are provided. Additionally or alternatively to the provision of grooves in the mandrel outer surface, it is possible to provide in the mandrel at least one Luftabführöffnung, preferably several Luftabführöffnungen that lead to at least one Gasabführkanal inside the mandrel, so that the gas exiting through the gas outlet openings through these discharge openings in the Abführkanal can flow in the interior of the mandrel and there can be dissipated in the interior, preferably in the axial direction.

The invention also leads to a method for producing tube bodies, in particular involving a device according to the invention. The core of the method is to heat defined and shaped around the mandrel shaped tube shape to heat and it is particularly preferred to heat the tube shape such that this results in improved roundness - this requires the compressed gas volume flow, which is supplied to the gas outlet openings be heated in such a way that, in particular during the welding process resulting material stresses are reduced in the tube shape. For this purpose, it has proved to be particularly advantageous to heat the compressed gas volume flow by means of the temperature control to a temperature from a temperature range between about 80 ° C and 120 ° C. It is very particularly preferred if the heating downstream is followed by cooling of the tube shape, again via a (further) (cooler) gas volume flow. For this purpose, the mandrel, in particular in at least, two sequentially arranged axial sections may be divided, wherein through gas outlet openings in a first (front) axial portion heated air exits and in a further (second), arranged in the transport direction of the tube shape behind the first axial section axial section cooler air. It is also conceivable that the air temperature cascades over several sections in order not to abruptly deter the tube shape, but the temperature in several stages, d. H. quasi-continuous reduction. It is particularly preferred if, by providing a cooling gas cushion, it is possible to be obliged to provide additional cooling means acting on the pipe mold from the outside. This considerably reduces the space requirement of the device.

It is very particularly preferred if an air cushion of pressurized gas heated by means of corresponding temperature control means is produced at the axial height of the welding means and / or, which is particularly preferred, downstream of the welding means in order to reduce the stresses resulting from the welding operation.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. These show in:

1 a top view of an apparatus for the production of tube bodies in a schematic representation,

2 a top view of a mandrel with discretely introduced into a mandrel material gas outlet openings,

3 a, at least in sections, formed from a microporous material mandrel,

4 a sectional view of a formed of microporous material mandrel with a surrounding this tubular shape, which is subjected to force radially from the outside via a forming belt radially inward,

5 a cross-sectional view according to 4 , Here, concave shaped rollers are shown, with which the forming belt according to 4 is pressed inward in the radial direction on the tubular body, so as to effect a sufficient adhesive force between the forming belt and tubular body to transport with the tubular body together with the forming belt by means of the rotating rollers in the direction of the longitudinal extension of the mandrel,

6 a representation of alternative combined pressing and conveying means in the form of directly acting on the tubular body and the tubular body in the direction of the longitudinal extent of the mandrel entraining conveyor belts, the radial are arranged outside a flattened area of the mandrel,

7 an alternative sectional view of a mandrel with only partially shown longitudinal groove, in which a sweatband is arranged by welding means,

8th a cross-sectional view through the mandrel according to 7 in the height of the longitudinal groove, wherein radially outside the longitudinal groove an energy source, here an HF source for heating a welding area is arranged,

9 3 is a schematic sectional view of a mandrel which is subdivided into two axial sections and can be acted upon independently of one another by a respective gas volume flow, wherein the temperature of at least one of the gas volume flows, preferably regulated, is adjustable.

10 a schematic side view of a mandrel with a coating of gas outlet openings forming porous, preferably foamed material, wherein in the mandrel surface a plurality of evenly spaced circumferentially, designed as Gasabführnuten Gasabführkanäle are provided,

11 a highly schematic longitudinal sectional view of a possible Dornausführungsvariante, in which can escape through the pores of porous material gas via larger discharge openings radially inwardly into the mandrel and there in an inner Gasabführkanal in the axial direction, and

12 a cross-sectional view through a possible embodiment of a mandrel, in which a coating of a porous, in particular foamed material, for example with metal or ceramic is provided on a support structure, wherein the support structure a plurality of circumferentially juxtaposed and extending in the axial direction Zuführnuten for compressed gas which ensures an at least approximately uniform distribution of the gas flow. If necessary, the embodiment shown can be combined with a discharge opening for discharging gas inside the mandrel and / or provided with on the outer circumference Gasabführkanälen, for example in the form of Gasabführnuten.

In the figures, like elements and elements having the same function are denoted by the same reference numerals.

In 1 is a device in a plan view 1 for producing tube tubes for packaging tubes shown. With the section of the device shown is a flat, initially web-shaped, for example, single or multilayer, substrate 2 around a, here cylindrical, thorn 3 in a tube shape 4 shaped, one between two longitudinal edges 5 . 6 trained overlap area 7 which of two longitudinal edge regions of the substrate 2 is formed. In a region further downstream in the direction of transport R, the shaped tube is cut into tube tubes of the desired length (not shown).

The substrate 2 are associated with transport rollers, not shown, with which the substrate 2 in the direction of the thorn 3 is transported in the transport direction R. The forming takes place with the help of concave contoured rolls 8th (combined pressing and conveying equipment 19 ), which transforms the substrate from the flat sheet shape into the tube shape 4 reshape the thorn 3 eng closely and is transported along this in the transport direction R on to the aforementioned, not shown cutting device. The roles 8th can act as shown directly on the tube shape or at least one not shown for clarity reasons, for example in the 4 and 5 shown form band.

In transport direction R behind the rollers 8th there are welding agents 9 , For example, a high-frequency welding device, for welding the overlap region 7 More precisely, for welding the superimposed longitudinal edge regions of the substrate 2 or the pipe shape 4 , In the transport direction R behind it are pressing means 10 for solidifying or pressing with the help of the welding agent 9 generated weld 11 ,

In the transport direction behind the pressing means 10 are not shown in the prior art coolant for cooling the welding process hot weld, wherein the coolant is preferably omitted in development of the invention, since the cooling function can be taken over by later to be explained gas outlet openings exiting compressed gas.

To reduce the friction between the substrate 2 , more precisely, the tube shape 4 and the thorn 3 , is the thorn 3 with a variety of in 1 Not shown gas outlet openings provided by the radially inward to outward radially a gas, in particular compressed air can blow out to a, preferably uniform air cushion between the substrate 2 , more precisely, the tube shape 4 and the thorn 3 train. Different design variants of the gas outlet openings are given by way of example with reference to FIG 2 and 3 ,

Out 1 It can be seen that the mandrel compressed gas is supplied via a compressed gas line - this compressed gas exits to form a gas cushion from the located in the mandrel surface gas outlet opening. The compressed gas is from a compressed gas source 36 via temperature control agent 14 directed to the interior of the spine.

In 2 is a section of a thorn 3 for a device 1 according to 1 shown, with the spine 3 is shown cut in the upper area. The with the reference number 13 marked arrow direction 13 symbolizes the gas supply, here the compressed air supply inside the mandrel 3 , wherein the compressed air by tempering 14 promoted, which are formed in the embodiment shown as a water heater, compressed air can be alternatively promoted from heated compressed air tanks. The temperature control means designed as a heating medium 14 Heat the compressed air to a preferred temperature from 80 ° C to 120 ° C to reduce stress in the substrate material, thereby improving the roundness of the tube shape.

In the embodiment according to 2 are both a variety of gas outlet openings 15 arranged in an axial direction A coincident with the transport direction in succession, as well as in the circumferential direction next to each other, wherein the gas outlet openings 15 directly in the form of a cylinder surface curved surface of the mandrel 16 of the thorn 3 and not radially inwardly offset therefrom. The gas outlet openings 15 are formed of discrete, for example cylindrically contoured, in an outer tubular metal sheet 17 introduced, for example punched holes. Because the air radially inwardly through the trained as a hollow mandrel 3 is fed and then through the gas outlet opening 15 penetrates to the outside.

In the embodiment according to 3 the mandrel is at least partially made of a porous material 18 (For example, polished metal foam) formed, the plurality of micropores formed gas outlet openings 15 has, which are arranged both axially, as well as in the circumferential direction next to each other, so as to ensure the formation of an air cushion. Also in the embodiment according to 3 The compressed air is supplied by optional heating means 14 directed.

In 4 is an alternative view of a longitudinal sectional view of a mandrel 3 shown. This is hollow inside and pressurized gas, in particular compressed air can be acted upon, wherein the compressed gas through microporous mandrel material 18 migrates in the radial direction to the outside. Preferably, the microporous material is a metal foam, for example an aluminum foam, which is optionally provided with stabilizing additives. With the help of the compressed gas is between the from a substrate 2 formed pipe shape 4 and the thorn 3 formed an air cushion. The pipe shape 4 is in the transport direction R by means of combined pressing and conveying means 19 transported, in the embodiment shown, a forming belt 20 which extends radially inward against the tube shape 4 is pressed, thus a static friction between the forming belt 20 and the flexible tube shape 4 to produce, so that the pipe shape 4 from the forming belt 20 in the axial transport direction R is taken.

In the embodiment shown, the porous material 18 self-supporting, ie has no additional support structure. In an alternative embodiment, not shown, is the microporous material 18 applied to a support structure, which is formed for example by a cylindrical perforated plate.

Instead of the microporous material 18 can, at least in sections, a nanoporous material be provided. It is also conceivable to provide nanoporous material on microporous material so that the pore size of the mandrel material as a whole decreases from radially inward to radially outward.

In 5 is a cross-sectional view through 4 shown, with the in 4 for clarity, not shown concave rollers 8th are shown, the radially outward of the forming belt 20 the combined pressing and conveying equipment 19 kraftbeaufschlagen. To recognize further is the thorn 3 of microporous material in which a plurality, preferably several thousand gas outlet openings 15 (Here pores) are formed, can escape through the pressurized gas from radially inside to radially outside to between the tube shape 4 and the thorn 3 to form an air cushion.

6 shows in a cross-sectional view alternatively formed pressing and positive locking means 19 , These include in the embodiment shown two parallel conveyor belts 21 , which are driven and in turn due to the friction effect the tube shape 4 in the transport direction, ie in the plane of the drawing into it. The conveyor belts 21 are pressed inward in the radial direction to provide the necessary static friction. In addition to the two conveyor belts 21 is a support role 22 provided the pipe shape 4 in a lower area. The support roller 22 can also be designed as a drive roller.

7 shows a mandrel made of porous material 18 , wherein in the mandrel only partially shown longitudinal groove 23 is provided, in which a ( inner) sweatband 24 is arranged, which in operation radially inward on the tube shape, in particular in an overlap region 7 is applied, the tube shape of the inner sweatband 24 and another, not shown outer sweatband (see. 8th ) is then sandwiched and then subjected to welding energy, such as high frequency radiation.

8th shows a cross-sectional view through the mandrel 3 at the level of the longitudinal groove 23 with the (inner) sweatband arranged inside 24 , Parallel to this running with the tube shape inner sweatband 24 is an outer sweatband 25 provided, with the two sweatbands 24 . 25 the pipe shape 4 sandwiched in a welding area. Also marked is outside the outer sweatband 25 an RF source 26 the welding agent 9 ,

In 9 is another alternative embodiment of the spine 3 shown in a longitudinal sectional view. In this case, the mandrel is in two axial sections, namely a first axial section 27 and a second axial section 28 split, which are sealed against each other, so that each made of porous material 18 trained axial sections can be acted upon separately each with a pressure gas flow. The first gas volume flow for acting on the first axial section is denoted by the reference numeral 29 marked and shown only schematically as an arrow. The second gas volume flow is denoted by the reference numeral 30 and for example via a pipeline to the second axial section 28 , especially in the interior of the spine 3 guided.

It is very particularly preferred if the two gas volume flows 29 . 30 have a mutually different temperature, wherein it is even more preferable if the arranged in the transport direction R before the second axial section first axial section 27 with a first, higher temperature having gas, in particular pressure medium, is acted upon as the second gas volume flow to produce two differently tempered air cushion, wherein with the first air cushion radially outside the first axial section, the tube shape 4 is heated, preferably to a temperature from a temperature range between about 80 ° C and about 120 ° C, so as to take stresses from the material, with the second, axially adjacent air cushion preferably the tube shape 4 is cooled. The temperature control of the first gas volume flow takes place with the aid of unillustrated, for example, a heat exchanger comprehensive temperature control.

In 10 is a section of a thorn 3 shown from the outside. It can be seen that the convex curved mandrel surface 16 from a porous material 18 , in particular a metal foam, a ceramic foam or a plastic foam, for example a polyurethane foam is formed. In the surface are a plurality, preferably uniformly circumferentially spaced Gasabführkanäle 31 provided in the form of axial grooves (Gasabführnuten). Through these gas discharge channels 31 This can be done by the gas outlet openings designed as pores 15 escaping compressed gas flow in the radial direction, whereby an unwanted inflating the tube shape is avoided.

11 shows in a highly schematic view of an alternative embodiment of a mandrel 3 in longitudinal section view. To recognize is an outer coating 32 from a porous material 16 ,

This porous coating 32 with its gas outlet openings formed by the pores is supported by a support structure 33 in which a plurality of circumferentially spaced Gaszuführkanäle 34 are provided, which distribute the inflowing compressed gas evenly. Inside the thorn 3 is a gas discharge channel 31 realized with an area between tube shape and mandrel surface 16 via at least one radially extending discharge opening 35 is connected, via the excess pressure gas inside in the Gasabführkanal 31 and can flow axially in this.

In 12 is shown schematically a cross-sectional view of an alternative mandrel embodiment variant. To recognize is a coating 32 made of porous material, which forms the gas outlet openings in the form of pores. The coating 32 may be single-layered, for example, made of microporous or nanoporous material or multi-layered, for example, in which applied or provided on a microporous inner layer, a nanoporous outer layer. In the embodiment shown, the total thickness of the coating is 32 2 mm. The coating 32 is carried by a support structure 33 comprising a plurality of gas supply channels formed as longitudinal grooves 34 which ensure a uniform air distribution. If necessary, the inner area, ie the area within the support structure 33 be used as Gasabführkanal in which air via at least one discharge opening from the mandrel surface 16 is supplied.

LIST OF REFERENCE NUMBERS

1

contraption

2

substratum

3

mandrel

4

tube shape

5

longitudinal edges

6

longitudinal edges

7

overlap area

8th

roll

9

welding means

10

pressing means

11

Weld

13

arrow

14

temperature control

15

Gas outlet openings

16

mandrel surface

17

metal sheet

18

porous material

19

Combined pressing and conveying means

20

forming belt

21

conveyor belts

22

supporting role

23

longitudinal groove

24

(inner) sweatband

25

(outer) sweatband

26

RF source

27

first axial section

28

second axial section

29

first gas volume flow

30

second gas volume flow

31

gas discharge channel

32

coating

33

support structure

34

gas supply

35

discharge opening

36

Compressed gas source

A

axially

R

transport direction

Claims (18)

Apparatus for producing tube bodies for packaging tubes, comprising an elongate mandrel extending in an axial direction (US Pat. 3 ) around which a substrate web for producing a tubular shape ( 4 ) is deformable, in which a mandrel surface ( 16 ) having thorn ( 3 ) a plurality of pressurizable gas acted upon gas outlet openings ( 15 ) for generating an air cushion between the mandrel ( 3 ) and the tube shape ( 4 ), and wherein welding means ( 9 ) for welding the tubular shape ( 4 ) are provided, characterized in that tempering ( 14 ) are provided for the defined heating and / or cooling of the compressed gas, in particular the compressed air. Apparatus according to claim 1, characterized in that more than two of the gas outlet openings ( 15 ) in the preferably convexly curved mandrel surface ( 16 ) are provided, of which at least two, preferably more than two gas outlet openings, ( 15 ) at different axial positions along the axial extension of the mandrel ( 3 ) are provided. Device according to one of claims 1 or 2, characterized in that the mandrel ( 3 ) a gas outlet openings ( 15 ) having first axial section ( 27 ), which with a via the temperature control ( 14 ) adjustable first-volume gas volume flow ( 29 ) is acted upon and a second axial section ( 28 ), which with a second, optionally via temperature control adjustable, second, preferably different from the first temperature, having temperature gas stream ( 30 ) is act bar. Device according to one of the preceding claims, characterized in that the acted upon by heated compressed gas gas outlet openings ( 15 ) at the axial height of the welding means ( 9 ) and / or in the transport direction of the tubular shape ( 4 ) the welding agents ( 9 ) are subordinate. Device according to one of the preceding claims, characterized in that in the mandrel ( 3 ) at least 10, preferably at least 50, 100, 150, 200, 300, 400, 500, 1000, 2000 or at least 5000 gas outlet openings ( 15 ) are provided. Device according to one of the preceding claims, characterized in that at least 10, 20, 50, 100, 150, 200, 500, 1000, 2000 or at least 5000 gas outlet openings ( 15 ) at different axial positions along the axial extension of the mandrel ( 3 ) are arranged. Device according to one of the preceding claims, characterized in that at least 10, 20, 50, 100, 500, 1000 or at least 2000 gas outlet openings ( 15 ) at different circumferential positions along the circumferential extent of the mandrel ( 3 ) are arranged. Device according to one of the preceding claims, characterized in that in at least one surface section at least 5, 10, 15, 20, 30, 50 or at least 100 gas outlet openings ( 15 ) per cm ^{2 of the} mandrel surface are provided. Device according to one of the preceding claims, characterized in that at least a part of the gas outlet openings ( 15 ), preferably most of the gas outlet openings ( 15 ), preferably all gas outlet openings ( 15 ) in a cylindrical surface of the mandrel ( 3 ) are provided. Device according to one of the preceding claims, characterized in that in the mandrel ( 3 ) a longitudinal groove is arranged, in which a sweatband, preferably as HF Welding device trained welding agent is added. Device according to one of the preceding claims, characterized in that the gas outlet openings ( 15 ) are introduced as discrete openings in a mandrel material, in particular a sheet, preferably by drilling, cutting, lasering and / or punching. Device according to one of the preceding claims, characterized in that the curved mandrel surface, at least in sections, of the gas outlet openings in the form of porous pores, in particular microporous and / or nanoporous material is formed. Device according to claim 12, characterized in that the porous material ( 18 ) comprises or is a sintered material, or a material produced by thermal spraying, or a metal foam, or a plastic foam, in particular a polyurethane foam, or a ceramic foam. Device according to one of claims 12 or 13, characterized in that the average pore size is selected from a value range between 0.05 .mu.m and 2.0 mm, preferably between 0.1 .mu.m and 1.0 mm. Device according to one of the preceding claims, characterized in that the tube shape ( 4 ) by means of radially adjacent to the mandrel ( 3 ), combined pressing and conveying means ( 19 radially inwardly toward a circumferentially curved mandrel surface (FIG. 16 ) of the spine ( 3 ) and due to a friction effect between the means and the tube shape ( 4 ) in the direction of the longitudinal direction of the mandrel ( 3 ) is transportable. Method for producing tube bodies for packaging tubes, in particular using a device according to one of the preceding claims, wherein a substrate web ( 2 ) to a tube shape ( 4 ) around a thorn ( 3 ) is formed and welded, and wherein between Dorn ( 3 ) and tube shape ( 4 ) by means of a compressed gas, a gas cushion is generated, characterized in that the compressed gas is heated defined and / or cooled. A method according to claim 16, characterized in that a gas outlet openings ( 15 ) having the first axial section ( 27 ) of the spine ( 3 ) with heated compressed gas, in particular with a temperature from a temperature range between 80 ° C and 120 ° C, for heating the tubular shape ( 4 ) and a second, gas outlet openings ( 15 ) having axial portion ( 28 ) is supplied with compressed gas for cooling the tubular shape, which, preferably at least 10 ° C, more preferably at least 20 ° C, more preferably at least 30 ° C or 40 ° C, is cooler than that of the first axial section ( 27 ) supplied compressed gas, wherein the temperature of the compressed gas of the second axial section is preferably selected from a temperature range between 10 ° C and 75 ° C. Method according to one of claims 16 or 17, characterized in that the gas temperature by means of the temperature control ( 14 ) is set to a temperature, in particular from a temperature range between 80 ° C and 120 ° C, preferably regulated, is set, at which material stresses reduce the tube shape.

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