DE4242435A1 - Ribbed plastic flexible tube for waste gas extn. - Google Patents

Abstract

The tube comprises layer(s) of thin, heat and chemical resistant plastic, e.g., fluoropolymer, max. thickness 0.3mm and a further layer which may be a thin metal, pref. aluminium or copper. Layers are applied by helical winding on a core and are given a ribbed profile before an internal paper layer is stripped off and pulled back through the hollow core. The plastic tube and metal outer are set in a heating chamber. Prodn. appts. comprises a hollow winding core with a band stripping guide after the ribbing die. A band stripping device comprising driven rollers is at the rear end of the winding core. A heating chamber for setting the formed tube is followed by a haul off to maintain tube tension in the chamber.

Description

The invention relates to a method for producing a flexible tube in the form of a helical coil of tapes ten and grooved pipe, in which at least two layers of tape are offset wound against each other on a core to form a tube and then be grooved helically. The invention relates to white terhin on a device for performing the aforementioned Ver driving and a pipe that is made by this process.

There are two fundamentally different processes for making Pipes of the type mentioned are known. According to the one procedure bands of smooth and different material overlap and in individual band layers offset against each other on a core and by means of a groove nut rotating around this core grooved helically. The winding pitch or the winding angle  the bands on the one hand and the helical creasing of the one Pipe coiled strips are different in angle, so that strength and cohesion due to this measure alone the strips come about with the coiled and grooved tube, see above like a relatively cheap flexibility. Generally is the helical creasing is much narrower and less ren pitch angle. According to a fundamentally different procedure those in a groove device with a larger number behind on the other side of the grooved rollers, pre-grooved belts are produced and wound on a winding core to form a tube, the edges of the Bands are folded together. The preparation of the interlocking takes place on the grooving device, and he closes the folds follows after winding on the winding core. With such pipes the winding angle of the tapes corresponds to the pitch of the screw ben-shaped creasing. In the majority of the Ver If the tubes are manufactured, the strips are folded together recognizable.

The invention relates to a method of the first type and on pipes made afterwards. Have been known for a long time Methods, devices and pipes made therewith, in particular especially the best of several layers of tapes wound on top of each other hen, these tapes made of paper, plastic and thin metal fo lien can exist, depending on the application and requirements at the Use. To make such pipes more stable for their uses make, the individual also when winding on the winding core Tapes or tape layers glued together (DE-PS 10 29 218; DE-AS 11 30 681), these publications only state of the art are mentioned for example.

In the field of heating and water heating with gaseous or liquid fuels, especially for residential buildings the so-called "condensing technology" has been developed in recent years. The exhaust gases are used in specially designed boilers not only the rest of the sensible warmth, but also most of it deprived of latent heat and used for the heating system. Here the exhaust gases are cooled down to below the dew point, the entrained Water vapor condenses and releases heat. The exhaust gas temperatures can drop to below 40 ° Celsius. Thereby much higher degrees of utilization of the fuel used  reachable.

Because with low temperature boilers, especially with the so-called "Calorific value" boilers the temperature of the exhaust gases to below 100 ° Celsius is lowered, liquid condensates are formed, and not only Condensed water, but it also condenses originally in the Sulfur compound containing gaseous or liquid fuel in the form of sulfuric acid. The liquid condensates do not have to can only be derived, but by their appearance there is also Need the exhaust pipes at least on their inner surfaces form such that they are not, for example, of sulfuric acid to be attacked. Exhaust pipes made of steel or egg, which were common until now Senblech are therefore unsuitable. Exhaust pipes have also been removed Plastics used. However, not all plastics are suitable because it is required that the plastics are highly heat-resistant have speed, since it cannot always be ensured that the Ab gases have a temperature that does not exceed 100 ° Celsius. A further difficulty when using plastics for the exhaust gas Pipes is that these pipes are injection molded in a closed form or need to be extruded. That doesn't just require it large injection molding machines and molds, which are correspondingly expensive are, but certain wall thicknesses can not be below steps - for molding and injection molding reasons - and as a result, the consumption of the higher-quality suitable here Plastics much higher than this for the intended purpose would be necessary.

The invention also relates to a flexible exhaust pipe, ins especially in the form of a corrugated hose.

Known exhaust pipes of this type are made from a single material produced. However, the problem arises that the material in terms of flexibility must be chosen and there corrosion problems with metallic exhaust pipes due to the smoke gases and the occasional accumulation of condensate or problems when using polymers due to their Em sensitivity to mechanical damage.

According to the invention it is therefore proposed that the exhaust pipe be off a multi-layer material.  

Through these measures, the various can be chosen accordingly high corrosion resistance on the one hand and on the other hand, considerable protection of the exhaust pipe against damage achievements can be achieved while maintaining flexibility.

In this connection it can further be provided that the exhaust gas line is made up of several, preferably three, layers, preferably that the outer layer by a preferably easily deformable metal, for example made of aluminum, and the innermost layer made of a polymer plastic, for example PVDF, is formed.

This is due to the use of the polymer, on the one hand is accordingly flexible and on the other hand against the exhaust gases and any condensation is relatively insensitive, one high resistance of the exhaust pipe against the attack of the exhaust gases reached and on the other hand through the metallic outer layer very extensive protection against mechanical damage to the Exhaust pipe reached, resulting in a correspondingly long service life the exhaust pipe is ensured.

It is particularly advantageous if the middle layer is made of paper consists.

In this way, a secure bond between the outside and the inside layer guaranteed because the paper layer the different Thermal expansion of the two adjacent layers absorb easily men and at the same time as thermal insulation between the two serves other layers so that there is no excessive heating the metallic outer layer comes.

According to a further feature of the invention it can be provided that the individual layers are formed from wound foils, wherein preferably the films of the individual layers are glued together or are welded.

This results in a very simple construction of the exhaust gas tung.  

It can also be provided that the innermost layer consists of a con the material is resistant to moisture.

According to another feature of the invention it can be provided that the individual layers of overlapping wound film strips are formed.

In this way, the individual layers can be made to a high degree of stability.

The invention has set itself the task of a tube of the genus contemporary type, as well as a method and a device for its Manufacturing, creating that for the aforementioned purposes is particularly well suited. This tube is said to be highly flexible have high mechanical strength and high gas tightness be resistant to everyone up to its inner surface occurring aggressiveness through heat and chemicals, in particular their acids.

To solve this problem, a method is the first one Job mentioned type characterized in that the inner layer a thin, high-strength paper and the subsequent layer of egg up to a maximum of 0.3 mm thick tape made of a thermoplastic, however, there is heat-resistant plastic up to approx. 150 ° Celsius, the high Chemical resistance, especially acid resistance, where in the inner paper layer after the creasing process pulled off the hollow winding core and the plastic layer below is fixed in a heating chamber. After a particularly advantageous one The pipe is originally wound from three layers and grooved, an innermost layer of paper, which after the Creasing process is withdrawn, a middle layer of aluminum, after the fixing process in the heating chamber through the hollow wrap mandrel is pulled off, so that it is only wound from one position tes and grooved tube made of plastic.

The plastic tape overlapped on the winding core is in the groove nut helically with grooves. The guts ter consists of an outer and inner grooving tool, which itself rotates relative to the winding core. When creating the grooves and there with deformation of the tube wound from plastic tape  Friction between the groove nut and the plastic of the pipe. This friction creates heat. The temperature can rise in this way rise that they at least increase the thermoplastic melts or becomes doughy, causing further deformation becomes impossible. Cooling the outer part of the grooved nut The resulting frictional heat can easily be dissipated. The inner part of the grooved nut can, however, be used to drain the rei not be cooled. The use of a co-wound On the one hand, paper tape reduces the occurrence of friction and thus frictional heat and on the other hand the direct influence of the Frictional heat on the plastic. Because that with wrapped paper the inner layer is only a manufacturing aid, it will after Grooving process deducted and within the hollow mandrel guided. In the subordinate heating chamber, this will only be done Plastic existing, helically grooved pipe fixes the means it is heated so far that the overlapping edges of the wound tape, melting tightly and tightly together tie. The warming depends on the used one thermoplastic and its special melting create. To avoid each other when heating up lying flanks of the grooves of the tube by melting together connect, a corresponding one is placed on the pipe in the heating chamber Train exerted from the end of the tube, causing the coil to stretch Tube created to touch the groove flanks during heating prevention.

Another possibility is to use a also with coiled and grooved metal tape, which after the fixation process in the heating chamber through the hollow winding core withdrawn and thus separated from the tube. This in the heating Chamber still existing, innermost layer made of metal, especially from Aluminum has the additional advantage that due to the heat the metal expands while applying a corresponding pressure on the plastic layer, its creasing and especially the band overlaps. This additional pressure means that especially the fixation and welding of the tape overlaps favored.

According to another procedure, the tube can also be used with a third, outer layer of paper, which after the  Grooving process is subtracted, so that cooling of the outer Part of the creasing nut is not required.

If, for example, for stability reasons or other phy to improve the physical properties of the pipe is desired can also use an outer layer instead of the outer layer made of paper Metal, preferably aluminum or copper, and optionally one another layer of paper in ribbon form with coiled and grooved will. It is particularly advantageous that an outer, from Metal existing layer a surface with little reflection, for example, has a blackened surface. An outer The metal layer acts in the subsequent heat fixation in the Heating chamber in the same advantageous way as before standing with reference to the inner layer of metal. If the outer layer of metal has an outer surface with less Reflection on that heat is achieved in the heat chamber is much more effective. The heat chamber can ver be shortened, or the throughput speed due to the heat chamber can be increased.

According to the second method described at the beginning, pipes are also producible according to the invention. After that is a procedure for the manufacture introduce a flexible tube in the form of a helical grooved tube wound from tapes during winding are folded together at their edges, characterized by net that at least one band to form the inner tube from art material, the material thickness of which is at most 0.3 mm and the in a temperature range of at least -150 ° C to + 150 ° C tempe resistant to aging and highly chemicals, especially acid-resistant dig, together with a band of thin metal to form the Provide outer tube in a groove device with longitudinal grooves and intimately connected to each other, then a wrap device fed and wound helically into a tube are folded together with the edges of the tape.

This method has the advantage of causing the bands to flute easier to control and influence from the different materials is flowable, in particular the individual manufacturing steps, and the necessary devices, easier and clearer cher. Due to the folds of the edges of the wound into the tube  The tightness of tapes can be controlled particularly well, the pipe can also be a special Fe adapted to the purpose give stability with simple construction.

When performing this procedure, the two tapes can be made Plastic and metal separately fed to the grooving device and there united for common deformation or also already intimately connected to the groove device be performed.

As a thermoplastic, acid-resistant plastic for which the pipe, or the inner tube forming band are preferably fluorine thermoplastics used, in particular PTFE = polytetrafluoroethylene or PVDF = Polyvinylidene fluoride. The latter plastic has proven to be particularly advantageous in terms of its economy and proven its processability. It's not just special acid-resistant, but its permanent temperature resistance lies both at very low temperatures of around -150 ° C and sufficient up to at least + 150 ° C. That is enough for the majority of the Purposes. The other plastics mentioned have one still significantly expanded range of permanent temperature resistance speed.

Further special features of the process result from the spec Description.

A device according to the invention is characterized in that the winding core, designed as a hollow core, follows a tape take-off guide the grooved nut and a tape puller with each other standing, driven rollers or in the form of a take-up spool on has open end of the winding core, and one to the tape take-off subsequent heating chamber for the wound and grooved pipe and a downstream pipe extraction device to the keep it under tension.

The tape take-off and device ensures that First, the first layer of paper tape that has been coiled and grooved after the creasing process is pulled inwards so that it is out Plastic tape to release coiled tube for heat treatment however, before the creasing process against excessive exposure of  To protect frictional heat.

If a metal band is wrapped around the fixie as the inner layer Favor of plastic in the heat chamber is on close to the heat chamber also a tape take-off in Arranged inside the tube or the hollow core for pulling the Metal tape and a tape pull device on the open front End of the winding core.

Process for producing a flexible pipe in the form of a helically pre-grooved tube wound from tapes, the are folded at their edges during wrapping, characterized in that at least one band to form the Inner tube is made of plastic, the material thickness is highest 0.3 mm and that in a temperature range of at least -150 ° C to + 150 ° C temperature resistant and highly chemical resistant, is particularly acid-resistant, together with a tape made of thin Metal to form the outer tube in a groove device Provide longitudinal grooves and be intimately connected to each other, then fed to a winding device and screwed be wrapped in a tube with the edges of the tape folded at the.

According to this procedure, the two bands made of plastic and Metal separately fed to the grooving device and in this before direction united with each other and flatly connected with each other will.

The two bands can also be made of plastic and metal even intimately before the introduction into the grooving device be connected.

The Herge according to the above-described method and the device Posed tube has an innermost, possibly only winding position from a plastic band, the material thickness of which is at most 0.3 Is millimeters, the plastic in a temperature range Temperature-resistant and highly chemical from at least -150 ° C to + 150 ° C is kalienfest, in particular acid-proof.

The innermost layer of the tube consists of a plastic band  PVDF = polyvinylidene fluoride or from PTFE = polytetrafluoroethylene and the band or bands forming the outer layers (consist) of thin metal, preferably aluminum or stainless steel.

This outer layer increases the mechanical strength of the pipe improved, as well as the resistance to external influences Climate and temperature influences.

These plastics mentioned have the ge in the task mentioned properties, but they are relatively expensive. By using these plastics in combination with outside made of metal, it is possible to strip the innermost layers ge with a relatively very low strength because due to the special structure of the tube from several layers, the outer layers made of metal or especially aluminum, ins special the mechanical strength of the pipe, which is for practice on the other hand however, the flexibility of the tube is not affected in any way becomes.

The need for expensive plastic for such pipes is essential less than with previously known in other ways Pipes and this results in a significant economic advantage part of the use of the tubes according to the invention on wide Ge offer makes possible. In addition, the pipes according to the inven dung have a high flexibility, so that when laying in the In practice, only the connections to the exhaust pipe of the fireplace are to be established and if necessary also a connection to the outside end of the pipe in the form of a fitting or a rain cover or the like. Any connections with elbows, Elbows or the like are not required, so that Connection and installation on site only takes a little time demands and is accordingly economical. Furthermore leaves also due to the construction of the tube with outer metal layers a very good and tight welding of the innermost made of plastic Establish existing layer so that the required tightness is guaranteed for such pipes. Although the generic known pipes consisting of different layers in the various which layers already had different materials the material combination of the tube according to the invention so far unbe  known and not yet used. The aforementioned property However, the advantages and advantages of a tube according to the invention show that such a pipe in particular economically outstanding advantages offers, but the intended use is not on the mentioned case game is limited with low temperature firing. Also in the Refrigeration technology at extremely low temperatures is what makes such pipes stand out suitable because the plastics mentioned have a constant temperature have stability that from about -150 ° C to at least + 150 ° C enough.

When using a plastic from the PTFE group for the inner Most position of the tube, it is often sufficient and appropriate, only a single outermost layer of stainless steel in the form of a corresponding to use wound tape, as this gives the desired mechani strength can already be achieved.

The thickness of the plastic tape for the innermost layer can be less be as 0.3 mm. This will result in a very low consumption of the expensive Plastic achieved and thus a high level of economy.

The invention is described below using an exemplary embodiment With reference to the drawings explained in more detail. Show in the drawings

Figure 1 is a schematic side view, partially cut GE, a device according to the invention.

Fig. 2 is a schematic side view, partially cut away, of another manufacturing device according to the invention;

Figure 3 is a view, partly in section, of a tube according to the invention.

Fig. 4 is a cross section through a pipe wall as cut off from the Fig. 3;

Fig. 5 cross section through a tube of several layers;

Fig. 5a corresponding to Figure 5 in an improved version.

Fig. 6 view of a pipe section, produced with a device according to Fig. 2;

FIG. 7 partial cross section through a tube according to FIG. 6;

Fig. 8 greatly enlarged partial cross section in FIGS. 6 and 7.

The shown in Fig. 1 is a schematic representation of an on device for the manufacture of pipes according to the invention is shortened ben at several points by appropriate cutouts. The device consists of a winding core 1 around which a tape reel 2 is moved in a circular manner at the angle of incidence of the winding in order to wind the tape 3 from the reel 2 onto the winding core 1 in a helical manner.

The spool 2 is rotatably mounted on a shaft and provided with a guide and inhibiting device 4 to give the tape a certain tension when winding onto the winding core 1 and to prevent the tape 3 from uncoiling from the spool 2 can. The rotary shaft of the coil 2 is pivotally attached to a rotary arm 6 with a joint 5 . By means of the swivel joint 5 , the angle of attack of the spool 2 and thus the winding angle of the tape 3 relative to the winding core 1 can be set depending on the desired specifications. The swivel arm 6 is mounted around the winding core 1 or its storage 7 by means of corresponding roller bearings 8 and driven.

The bearing 7 or holder of the winding core 1 is, like this, designed as a hollow tube and provided with an opening 9 at the front end of the device. The arrangement is such that the winding core 1 with the most varied diameters is to be fitted on the bearing 7 in order to be able to produce tubes with different diameters. It is only a krei send driven tape reel 2 is shown. Of course, several such coils can be arranged if several layers of tapes are to be wound one above the other to form the tube, wherein these several layers can also consist of different materials. In general, devices of this type are designed such that, instead of a single rotary arm 6 for supporting the coil 2, a plurality of such rotary arms 6 are arranged in a spoke-like manner on a common bearing and offset at an angle from one another and carry the corresponding coils 2 , which of course each have their own pivot connections 5 on the rotating arms 6 are arranged to be able to adjust the winding angle.

The winding core 1 is surrounded by an area which serves to wind up the band or bands 3 by the groove nut 10 , which in turn is driven to rotate around the winding core 1 and consists of an inner part 11 and an outer part 12 . The inner part 11 forms, as it were, the end of the support tube 7 , which for this purpose is rotated synchronously with the drive of the outer part 12 via its own drive. Between the inner part 11 and the outer part 12 of the groove nut, the tube wound from strips 3 is passed on the winding core and see helically with grooves ver or the grooves are formed in the wall, the pitch angle of the grooves being formed by the groove nut are, usually different, compared to the slope angle of the helically wound tapes 3rd

Behind the winding nut 10 , the winding core is still continued with the section 1 a for guiding the grooved and flexible tube 13 , which then passes through a continuous heating chamber 14 . In the example shown here, this once-through heating chamber 14 is supplied with hot air via a fan 15 . Of course, radiant heaters or the like can also be arranged in the continuous heating chamber 14 for heating the continuous tube.

The simplest embodiment of a pipe according to the invention is wound with two layers of tape, that is, at least two rotating arms 6 are connected to a common drive. A spool 2 is rotatable on each of the two rotating arms and is adjustable in the winding angle. The coil 2 , which winds the inner layer on the winding core 1 , contains a tape 3 made of paper, while the coil 2 , which winds the overlying layer, a tape 3 made of plastic, namely from PVDF or PTFE on the winding core and over the paper layer already there wraps. These two screw-wound layers of tape form on the winding core 1 a smooth tube, which, following the winding pitch, the groove nut 10 is pushed to be provided with helical grooves there. In operation of the device, the feed of the wound smooth tube is carried out by means of the grooved nut, which grips the wall of the smooth tube in a form-fitting manner during the grooving process, helically groves it and thus transports it further.

At the end of section 1 a of the winding core, a support paper guide 16 is arranged. If the beginning of the wound and grooved tube with its feed movement projects beyond this end with the paper guide 16 , the inner band layer 17 of the wound and grooved tube, which consists of a paper band, is separated from the outer layer and over the paper guide 16 through the hollow Winding core 1 a and 1 or the mounting tube 7 arranged there is returned to the front end 9 of the mounting tube 7 . From the pipe mouth 9 , the paper tape 17 is evenly drawn off by a take-off device 18 , which consists of two driven counter-rotating rollers or rollers 19 . Since the paper tape 17 is wound helically in the tube, it is of course also subtracted to a certain extent, as shown in the drawing.

In the heating chamber 14 is therefore, according to the exemplary embodiment described here, only the wound from a layer of a plastic band and grooved tube inserted and fixed by the heat in the heating chamber 14 , that is, the overlapping edges of the plastic band are in the heating chamber 14 softened or melted so far that they bond tightly and tightly together, so that the heating chamber leaving send helically wound and flexible plastic tube is largely gas-tight.

With this heating and fixing of the tube made of plastic, there is a risk that flanks of the grooves lying against one another will also connect with one another and at least the flexibility of the tube is thereby impaired. In order to prevent this, the pipe is kept under tension in the heating chamber 14 in the simplest manner by means of a corresponding device (not shown) at the end of the heating chamber 14 , that is to say with a slight pull, so that flanks of grooves are prevented within the heating chamber lie together.

In practice, however, it has been shown to be particularly advantageous if, at least as the inner layer of the pipe wrapped in plastic, a layer of aluminum or copper tape is wound and of course also grooved. Under certain circumstances, this innermost layer of a metal strip can be the only "auxiliary" layer and it can be dispensed with on an innermost layer of paper, with the paper strip 17 being removed from the heating chamber 14 . A coiled and grooved innermost layer of metal tape causes, in the heating chamber 14 , due to its heating and subsequent expansion, to exert pressure on the outer or subsequent layer of plastic, so that a better and safer fixing or fusing together the superimposed plastic layers on the edges of the plastic band is effected. The inner layer of metal tape also effectively prevents, of course, that the flanks of the grooving of the plastic tube can not lie directly against each other and fuse or stick together in the heating channel. The use of an innermost layer of metal tape and the better thermal conductivity of the metal also ensure a uniform distribution of the heat and heating of the plastic. The coiled, co-grooved and co-conveyed by the heating duct 14 , which forms the innermost layer, is withdrawn inwardly from the finished plastic tube in the same way after leaving the heating duct, as previously described with regard to the paper band 17 . The metal strip is also first through the tube in the heating channel and then further through the hollow winding core and the holding tube 7 to the front end and there out of the mouth 9 , by means of the trigger device 18 , 19 , deducted.

When winding the tube, a further band 3 made of metal, preferably aluminum or copper, can also be wound onto the plastic band by a corresponding spool 2 , in order to then be grooved together with the other band layers in the groove nut 10 and thus formed into a flexible tube will. This outer layer made of metal has a positive effect in the heating chamber 14 in the same way as that previously described in connection with the inner layer made of metal strip. This effect can be further improved in that the metal strip of the outer layer is treated on its outer surface in such a way that this surface has a low heat flexion, for example the surface can be blackened. As a result, the heat absorption in the heating chamber is intensified, so that this heating chamber 14 can be shortened or the running speed through the heating chamber can be increased. This outer layer of metal is not removed from the tube after leaving the heating chamber, but rather serves to improve in particular the mechanical properties of the plastic tube, if this is desired for a wide variety of uses.

Of course, an outer layer of paper tape can first be wound onto the plastic layer, especially if there is a risk that the outer groove flanks will abut and fuse together in the heating chamber 14 . This outer layer of paper can be removed in a simple manner after leaving the heating chamber, but it can also remain on the tube, if this is desired for the purposes of the tube, it can also form an intermediate layer to which another layer of metal originally bound is wound, so that the tube then consists of an innermost layer made of plastic, an intermediate layer made of paper and an outermost layer made of metal tape, all layers being of course helically grooved in the groove nut 10 and resulting in a flexible tube. It is essential that the inner layer of the tube always consists of the plastic already described with high temperature and chemical resistance and has a high gas tightness.

The heating in the heating chamber 14 is advantageously carried out at a temperature of 230 ° C. When loading the heating chamber 14 with hot air, the heating chamber is in the preferred manufacturing and since with the passage speed of the tube about 12 meters long and the passage speed of the tube is about 1.2 to 1.3 meters per minute. With an arrangement of heat radiators in the heating chamber 14 , their length is about one meter, at the same throughput speed. The grooves created in the tube preferably have a depth of 3 to 3.5 millimeters at about six hundred grooves per meter.

In Fig. 2 another device is shown - for the production of pipes according to the invention. This device relates to the method mentioned at the beginning in the second place. This produces tubes that are wound from pre-grooved tapes on a core to form a tube, with the tape edges that overlap each other being folded together during the winding process.

The apparatus of FIG. 2 consists of two hintereinanderste Henden supply reels. A supply of metal strip is wound on the outer reel 101 , and a supply of plastic strip is wound on the reel 102 behind it in the production direction. The plastic is a fluorine compound. Both bands have essentially the same width, ie the plastic band can also be somewhat narrower than the metal band.

The direction of production corresponds to the arrow A. It can be seen that when the strips are simultaneously pulled off the reels 101 and 102, these overlap, the plastic strip - from the reel 102 - coming to rest under the metal strip.

The belts lying one above the other are fed to a grooving device 103 , which is shown here partly interrupted. This grooving device consists of a larger number of Walzenpaa ren, the rollers 104 and 105 , each forming a pair, are arranged one above the other, the roller 104 above the roller 105 and between them form the passage for the belt. The rollers 104 and 105 are driven by on their rotary shafts arranged gears 106 and 107 , each interlocking mutually, so that all rollers 104 and 105 of the entire Ril lenvorrichtung 103 are rotated in unison by a drive, not shown here.

The roller pairs 104 , 105 are provided on their lateral surfaces with interlocking grooves, beginning in the middle of the lateral surfaces starting, the number and depth of the grooves on the roller pairs in the production direction, that is to say from right to left, increase.

The band drawn through the groove device 103 is subsequently provided with grooves running in the longitudinal direction, so that the cross section has approximately the shape of a sine curve, as is shown in FIGS. 7 and 8. The edge regions are initially not covered by the shape, they remain flat and are angled up or down by separate roller pairs 108 at the end of the device 103 . The greater thickness of the band in the side view achieved by the deformation is illustrated by reference number 109 .

The pre-grooved belt 109 is fed to the tube winding device 112 after leaving the grooving device 103 .

The tube winding device 112 is expediently arranged at an angle to the groove device 103 which corresponds approximately to the angle at which the pre-grooved tape is wound helically to the tube. It consists of a mounting plate on which adjustable pressure rollers 114 are arranged. The winding core 113 rotates in the center of the mounting plate, on which the pressure rollers 114 with their adjustable mounting brackets are aligned. In the infeed direction in front of the winding core 113 , a tape guide 111 is arranged, which has two adjustable pairs of rollers 110 and can be adjusted at an angle relative to the winding core 113 , in order to feed the tape 109 into the width of the diameter of the winding core used and thus of the tube produced of the band 109 and the winding angle dependent thereon.

With helical winding of the tape 109 on the winding core 113 and thus forming the tube, the tape 109 is bent around the core by the first pressure rollers 114 at the inlet, from the white rollers 114 then the superimposed bends on the tape edges to firm and tight Fold 307 shaped and compressed.

The result is a pipe in accordance with the Figs. 6 to 8. In the view to Fig. 6, it is seen that a number to each limited in such a tube of grooves of a fold 307 and so on through the creases 306 receives the tube the desired Flexibility and rigidity - due to the folds 307 the tightness and also additional form rigidity.

FIG. 7 shows a section through the wall of the tube according to FIG. 6, both the groove 306 and the fold 307 can be seen. The fold 307 can be shaped and folded in various known ways.

FIG. 8 shows a further enlargement of this cross section of the tube wall. The tube wall consists of an inner wall C made of plastic or an inner tube made of plastic and an outer wall A made of metal or an outer tube. The two walls A and C are expediently intimately connected to one another over a large area. In the area of the fold 307 , a heat effect that occurs during or after the final manufacture of the fold results in a softening of the plastic and thus a particularly good seal.

The tape used in the process from the plastics mentioned has a maximum thickness of 0.3 millimeters. It becomes essential consumed less plastic material for such a tube than in the manufacture of a comparable pipe by spraying, whereby a wall thickness of less than 0.8 millimeters is not feasible.

In Fig. 3 is a portion of a tube 213 according to the invention, as it is generated with the device described above, Darge presents, with part of the wall broken away to show the cross-section. It can be seen that it is a helically grooved tube, which has a high flexibility. The winding of the tape, that is, the line that shows the tape edge of the helically wound tape is not shown in this drawing so as not to impair the clarity. However, the tape winding usually takes place with a larger pitch angle than the creasing, so that a not inconsiderable mechanical strength of the tube is achieved by cutting the grooves with the tape edge at an angle. Depending on the application, an overlap of the edges of each wound tape is of course provided. This overlap can extend for certain purposes up to the band half, so that the tube wall wound from a band, due to the half overlap of the adjacent turns, practically consists of two band thicknesses.

FIG. 4 shows the enlarged detail of the section through the tube wall according to FIG. 3. It can be seen that the flanks of the grooves run at a very acute angle to one another, so that it can be seen that with a slight pressure in the axial direction of the tube, the flanks of the individual grooves can be touched, in particular in the vicinity of the rounding transitions. The pipe wall shown here consists of three layers, namely an inner layer C, which is made of plastic, a middle layer B, which can consist of paper or metal, and an outer layer A, which can also consist of paper or metal. Of course, it is also possible to add further outer layers, depending on the purpose and requirements that are placed on the pipe. It is essential, however, that the tube according to the inven tion can consist of a single layer of plastic, which is highly heat and chemical resistant, and that this layer of plastic always forms the innermost layer in multi-layer pipes.

The tube according to the invention according to FIG. 3 has screw-shaped grooves with a small pitch angle. The tapes with a larger pitch angle that make up the wall of the pipe are not shown here, so as not to disturb the clarity.

The wall of the tube 213 itself, which is shown in cross section in FIG. 4, has an approximately sinusoidal shape, the flanks of the individual grooves partially running in a straight line and being set at an acute angle to one another. With a special shape, however, they can also run parallel to one another. From the formation of these grooves, the particularly good flexibility of such tubes is achieved in a known manner.

In particular, the wall consists of an inner layer C from the mentioned plastic, i.e. made of PVDF or PTFE, in a thickness of maximum 0.3 mm. The following middle layer B persists this embodiment of aluminum foil, and the fol outer layer A also consists of aluminum foil. These three Layers are made of strips with the same pitch, but offset against each other each other, wound up and then grooved so that the result pipe has achieved high strength and very good flexibility. At The inner layer of plastic is the overlap of art fabric tape that arise during winding, tightly ver  welds, so that the resulting tube in addition to its high mechani strength and flexibility also for those mentioned at the beginning has the required gas tightness.

The wall of the exhaust pipe 301 in FIG. 5 has three layers be built. The outer layer 303 is made of a metal, for example aluminum, stainless steel or copper, and protects against mechanical damage.

The middle layer 304 consists of optionally impregnated paper and the innermost layer 305 consists of a polymer, for example PVDF.

The innermost and outermost layers 305 and 303 are glued to the middle layer 304 and connected to one another in this way.

Claims (17)

1. A method for producing a flexible tube in the form of a helically wound from ribbons and grooved tube in which at least two layers of tape are offset against one another and wound onto a core ( 1 ) to form a tube ( 13 ) and then helically grooved, as characterized by that the inner layer of a thin, high-strength paper and the subsequent layer of a maximum of 0.3 mm thick tape made of a thermoplastic, but up to about 150 ° C heat-resistant plastic, which has high chemical resistance, especially acid resistance, whereby the inner paper layer is then pulled off after the creasing process by the hollow winding core ( 1 ) and the plastic tube ( 13 ) is subsequently fixed in a heating chamber ( 14 ). 2. The method according to claim 1, characterized in that the tube is originally wound and grooved from three layers, namely an innermost layer of paper, which is removed after the grooving process, a middle layer of aluminum, which after the fixing process in the heating chamber ( 14 ) is pulled off through the hollow winding core ( 1 ), so that a plastic tube which is wound and grooved from only one layer is obtained. 3. The method according to claim 1, characterized in that in the heating chamber ( 14 ) by a corresponding train from the tube end, an expansion of the wound tube ( 13 ) it follows to prevent contact of the groove flanks during heating. 4. The method according to any one of the preceding claims, characterized characterized in that a wound outer layer of Pa pier is also removed after the scoring process. 5. The method according to any one of the preceding claims, characterized characterized in that another before the creasing process outer layer made of metal, preferably aluminum or copper and, if necessary, another layer of paper opened up in a ribbon shape be wrapped. 6. The method according to the preceding claim, characterized ge indicates that this is also wound as an outer layer te aluminum tape an outer surface with a ge wrestle reflection, preferably a blackened surface having. 7. The method according to any one of the preceding claims, characterized in that in the heating chamber ( 14 ) by means of warm air, preferably by means of radiant heaters, a temperature of 230 ° C is maintained. 8. The method according to any one of the preceding claims, characterized in that the grooves produced in the tube ( 13 ) have a depth of approximately 3 to 3.5 mm and there are approximately 600 grooves per meter. 9. Device for producing a from tapes ( 3 ) on a core ( 1 ) and then in a Rillenmut ter ( 10 ) helically grooved tube ( 13 ), at least one tape layer made of a thermoplastic, but up to 150 ° C heat-resistant and Highly chemical-resistant, in particular special acid-resistant plastic, with winding devices ( 2 ) for the different tape layers, characterized in that a winding core ( 1 , 1 a), designed as a hollow core, a tape take-off guide ( 17 ) after the groove nut ( 11 , 12 ) and having a band pull-off device with driven against each other stationary rollers (19) or in the form of a take-up reel at the open end of the winding core (1), as well as to the band pull-off guide (17) on closing passby heating chamber (14) for the wound and grooved tube (13) and a downstream pipe take-off device to keep it under tension. 10. The device according to claim 9, characterized in that with a sequential arrangement of tape winding devices ( 2 ) for paper, aluminum and plastic and, if necessary. Further subsequent to the continuous heating chamber ( 14 ), a tape draw guide ( 17 ) inside the tube ( 13 ) or the hollow core ( 1 a) is arranged for pulling the aluminum strip, and a strip pulling device ( 18 ) in the manner described above at the open front end ( 9 ) of the winding core ( 1 ) for the aluminum strip. 11. A process for producing a flexible tube in the form of a tube wound from pre-grooved strips, which are folded together at their edges during winding, characterized in that at least one strip ( 102 ) for forming the inner tube consists of plastic, the material thickness of which is 0 , 3 mm and which is temperature-resistant and highly chemical-resistant, in particular acid-resistant, in a temperature range of at least -150 ° C to + 150 ° C, together with a band ( 101 ) made of thin metal to form the outer tube in a groove device ( 103 ) provided with longitudinal grooves and intimately connected to each other, then fed to a winding device ( 112 ) and wound helically to form a tube with interlocking of the band edges. 12. The method according to claim 11, characterized in that the two bands made of plastic and metal are fed separately to the grooving device ( 103 ) and combined in this device and connected to one another in a flat manner. 13. The method according to claim 11, characterized in that the two bands made of plastic and metal are connected to each other flat in nig before introduction into the groove device ( 103 ). 14. The method according to claim 1 or 11, characterized in that the plastic film made of PVDF, PTFE or another Plastic with comparable heat and chemical properties exists. 15. Helically wound from pre-grooved strips, flexible tube, characterized in that it consists of an inner tube ( 305 , C) made of plastic, the material thickness of which is at most 0.3 mm and which is in a temperature range of at least -150 ° C to +150 ° C is temperature-resistant and highly chemical-resistant, in particular special acid-resistant, and further consists of at least one outer tube ( 303 , A) made of thin metal, both tubes being wound from pre-grooved tape in a helical manner with folds ( 307 ) of the tape edges and being intimately connected to one another. 16. helically wound from ribbons and grooved flexible tube, characterized in that the innermost, if necessary. Only winding layer ( 305 , C) of the tube ( 213 , 301 ) consists of a plastic strip, the material thickness of which is at most 0.3 mm, the plastic in a temperature range of at least -150 ° C to + 150 ° C, it is temperature-resistant and highly chemical-resistant, especially acid-resistant. 17. helically wound from strips and grooved flexible pipe, characterized by the use as an exhaust pipe and in that the outer layer ( 303 ) made of metal, for. As aluminum or stainless steel, and the inner layer ( 305 ) from a plastic of the group of fluorine compounds, preferably PVDF, is formed.