EP1317335A1

EP1317335A1 - Method for producing a composite tube

Info

Publication number: EP1317335A1
Application number: EP01976032A
Authority: EP
Inventors: Albrecht Hille
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-15
Filing date: 2001-09-13
Publication date: 2003-06-11
Also published as: DE10046140C1; AU2001295428A1; WO2002022347A1

Abstract

The invention relates to a method for producing a composite tube consisting of a long, extended inner tube (16) and a hardenable, resined fibrous layer, especially for use in duct sanitation work, a practically endless needle felt strip (7) being produced on the spot.

Description

V E R FA H R E N Z U R H E RST E L L U N G E I N ES V E R B U N D S C H LA U C H S

The invention relates to a method for producing a composite hose consisting of an elongated inner hose and a hardenable, resin-drenched fiber layer, which is used in particular for sewer renovation work. The composite hose drawn into the sewer to be renovated is inflated or expanded from the inside and then z. B. cured by means of UV light.

It is known to make the fiber layer from a needle felt, which is produced continuously as a practically endless belt by means of a needle machine. For better handling, the finished needle felt tape is usually picked in fixed lengths of up to about 150 m, stored in roll form and made available for the production of composite hoses.

A generic method for producing a composite hose is described, for example, in German Patent 38 19 657. There, a plastic-impregnated glass fiber felt mat is placed on a glass fiber woven or knitted web and connected to it. By merging the longitudinal edges, the resulting combination sheet is formed into a tube.

International patent 96/19693 further develops the method known from DE 38 19 657, on the one hand by using two glass cut fiber mats, between which a glass needle felt mat is arranged, and on the other hand by using a low-viscosity synthetic resin which is in the outer layer of the Composite hose is pre-gelled. Another generic method for producing a composite hose is shown in German Patent 43 39 756. Here, at least two resin-impregnated fiber tapes are unwound in the longitudinal direction on a tubular protective film and formed into a tube by connecting the longitudinal edges.

The German utility model 297 11 444 in turn represents a further development of the composite hose manufactured in accordance with DE 43 39 756, in that the longitudinal edges of the fiber slivers are provided with anchoring in order to avoid disadvantageous local thickening due to the overlap of the longitudinal edges. European patent 0 712 352 also represents an example of a generic method for producing a composite tube. Here, a fiber ribbon is formed on a foil tube on a foil tube to form a hardenable, resin-impregnated tube on a winding dome. Common to the known production processes is the use of the known needle felt mats fed in roll form, as is shown, for example, in each case in FIG. 1 of DE 43 39 756 and EP 0 712 352. In this type of production of composite hoses, inevitable bumps are created at the ends of the needle felt mats, which for many technological applications cannot be firmly connected to one another. On the one hand, the length of the composite hoses is limited by the length of the needle felt mats supplied, on the other hand, considerable waste is created when using shorter composite hoses.

Through the use of the known needle felt rolls, the known manufacturing processes are also associated with a large outlay on equipment. The systems have to be adjusted very precisely, are prone to malfunction and can only produce the composite hoses at low speed. The manufacturing process often has to be interrupted to change the rolls from which the fiber mats run. On the one hand, these are used up relatively quickly, but on the other hand, they cannot be enlarged arbitrarily, since they should be exchangeable by hand. It is therefore an object of the present invention, while avoiding the features known from the prior art, to provide a method for producing a composite hose which is simple, inexpensive, less prone to failure and quick.

This object is achieved with a generic method which comprises the following method steps:

- Continuous production of a practically endless, elongated needle felt tape of approximately twice the width of the inner tube by means of a first needle machine; - Continuous feeding and placing of the inner tube on the practically endless needle felt belt;

- Continuous folding of the outer edges of the needle felt tape around the inner tube;

- Continuous needling of the outer edges of the needle felt tape to form a needle felt tube using a second needle machine. The needle felt hose produced on site in this way has practically no discernible fluctuations in thickness, shoulders, abutting edges or the like on the circumference or in the longitudinal direction. Discontinuities. With the method described, it is therefore possible to produce a composite hose practically endlessly. The production length here is not limited by the relatively short fiber webs as in the prior art, but only by the roll with the relatively long inner tube - lengths of up to 1000 m are customary. This means that even shorter pieces of hose can be produced with practically no waste if required.

Advantageous embodiments of the invention are the subject of the dependent claims.

It is preferred if longitudinal fibers are incorporated into the needle felt tape. This measure considerably increases the tensile strength of the composite hose in the longitudinal direction, which is necessary for pulling the composite hose into the sewer to be renovated.

In order not to weaken the longitudinal fibers unnecessarily by the subsequent needling, it is preferred if they are worked in running between the needles of the first and second needling machines. If it is necessary to meet the respective specific requirements, additional nonwoven layers can be added above and / or below the needle felt tape before the inner tube is put on.

According to a further preferred embodiment, alternatively or cumulatively, a nonwoven layer can also be supplied before the needle felt tape is produced. This then forms in particular a carrier layer for the fibers fed to the first needle machine. Depending on the application, an outer hose z. B. be arranged from foil.

The impregnation of the fiber layer z. B. with a suitable resin can be done at any suitable point within the process, in particular immediately before arranging the outer tube.

It is particularly preferred if the impregnation is carried out using a vacuum with the simultaneous introduction of mechanical energy. The viscosity of the thixotropic resin is temporarily reduced by the latter.

The invention is explained below on the basis of a preferred exemplary embodiment and with reference to the attached drawing figures, which show the following:

Fig. 1 shows schematically a device for performing an embodiment of the method according to the invention in side view; and

Fig. 2 shows the device of Fig. 1 in supervision.

A needle machine is shown in FIG. 1 at reference number 1. The basic technology for the production of needle felts by means of needle machines is known and need not be described here. The first needling machine 1 is fed by a cutting device 2 tangled fibers 3. If necessary, the tangled fibers 3 can also be aligned in certain preferred directions by an additionally provided guide plate, not shown here, a vibrating device or the like, before they are fed to the first needle machine 1. The tangled fibers 3 land on a conveyor belt 4, which feeds the tangled fibers 3 to the first needle machine 1.

In the embodiment shown, the supply of a fleece 5 to the first needling machine 1 is also provided. This has the advantage that the expenditure on equipment for feeding the tangled fibers 3 can be reduced, since these land on the fleece 5 as a carrier layer and can thus be easily fed to the first needle machine 1. Furthermore, the first needling machine 1 is fed with longitudinal fibers 6 in order to achieve a higher tensile strength in the longitudinal direction of the finished composite hose. These longitudinal fibers 6 are preferably arranged in such a way that they are not unnecessarily weakened by needling by means of the first needling machine 1 and also by subsequent needling by means of the second needling machine 1 1 (see below).

At the end of the first needle machine 1, the needle felt 7 runs out. In the embodiment shown here, a further fleece layer 8 or 9 is fed to this needle felt belt 7 both from above and from below. To support the layers, a conveyor belt 15 is also provided in this section. Above the tape formed from the nonwoven layer 9, needle felt tape 7 and nonwoven layer 8, the inner tube 16 is now placed on by a roller 10. As can be seen in FIG. 2, the flat inner tube 16 has approximately half the width of the needle felt band 7.

In a next processing step, the outer edges of the needle felt belt 7 (together with the fleece layers 8 and 9) are folded around the inner tube 16 and brought together above a shoe 12 of the second needle machine 11. There they are needled. The fleece and felt layer is then still impregnated with the resin in an impregnation device 13 using vacuum and, if appropriate, with the introduction of mechanical energy, and rolled up on a roller 14 for further processing.

REFERENCE NUMBER

First needle machine

cutting

random fibers

conveyor belt

fleece

longitudinal fibers

Nadelfilzband

nonwoven layer

roller

Second needle machine

shoe

Tränkeinrichtung

Roller with finished composite hose

conveyor belt

inner tube

Claims

PAT EN TA NSPRÜ CHE

1. A method for producing a composite tube consisting of an elongated inner tube and a hardenable, resin-drenched fiber layer, in particular for use in sewer rehabilitation, comprising the following process steps: 16) by means of a first needle machine (1);

- Continuous feeding and placing of the inner tube (16) on the practically endless needle felt belt (7); - Continuous folding of the outer edges of the needle felt tape (7) around the inner tube (16);

- Continuous needling of the outer edges of the needle felt tape (7) to a needle felt tube using a second needle machine (1 1).

2. The method according to claim 1, characterized in that in the needle felt tape (7) longitudinal fibers (6) are continuously incorporated.

3. The method according to claim 2, characterized in that the longitudinal fibers (6) are incorporated substantially between the needles of the first and second needle machine (1; 1 1).

4. The method according to any one of the preceding claims, characterized in that additional non-woven layers (8; 9) are continuously fed before placing the inner tube (16) above and / or below the needle felt belt (7).

5. The method according to any one of the preceding claims, characterized in that before the manufacture of the needle felt tape (7) a nonwoven layer (5) is fed continuously.

6. The method according to any one of the preceding claims, characterized in that an outer tube is arranged around the needle felt tube (5, 6, 7, 8, 9, 16).

7. The method according to any one of the preceding claims, characterized in that the impregnation of the fiber layer takes place at any suitable point within the process sequence, in particular immediately before the outer tube is arranged.

8. The method according to claim 7, characterized in that the impregnation takes place by the action of vacuum and / or mechanical energy.