HYDROGEN TUBE

Abstract

A tube and use of a tube for guiding hydrogen, preferably in a vehicle. The tube encloses a lumen and comprises several layers, wherein the layers of the tube includes at least two barrier layers. An inner barrier layer comprises a first plastic, and an outer barrier layer comprises a second plastic. The barrier layers are separated from each other by a separating layer, and the tube has a supporting layer enclosed by the inner barrier layer. The first plastic is a vinyl alcohol plastic, and the second plastic is a vinyl alcohol plastic.

Claims

1. A use of a tube for guiding hydrogen, in particular in a vehicle, wherein the tube encloses a lumen and comprises several layers, wherein the tube has least two barrier layers, wherein an inner barrier layer of the at least two barrier layers comprises a first plastic, wherein an outer barrier layer of the at least two barrier layers comprises a second plastic, wherein the first plastic is a vinyl alcohol plastic, wherein the barrier layers are separated from each other by a separating layer, wherein the tube has a supporting layer, wherein the supporting layer is enclosed by the inner barrier layer, wherein the second plastic is a vinyl alcohol plastic.

2. The use according to claim 1, wherein the separating layer comprises a plastic.

3. The use according to claim 1, wherein the supporting layer has a material that is softer than that of the inner barrier layer.

4. The use according to claim 1, wherein the first plastic and/or the second plastic is an ethylene vinyl alcohol copolymer (EVOH), a butenediol vinyl alcohol copolymer (BVOH) or a polyvinyl alcohol (PVOH).

5. The use according to claim 1, wherein the layer thickness of the inner barrier layer is smaller than or equal to the layer thickness of the outer barrier layer.

6. The use according to claim 1, wherein the added thickness of the layer thicknesses of the inner barrier layer and the outer barrier layer measures at least 0.1 mm.

7. The use according to claim 1, wherein the tube has a third barrier layer and a second separating layer, wherein the third barrier layer encloses the outer barrier layer, wherein the second separating layer is arranged between the outer barrier layer and the third barrier layer.

8. The use according to claim 1, wherein a boundary layer encloses the outer barrier layer or the third barrier layer, and preferably is formed of a plastic, further preferably a polyamide and in particular PA 6, PA 11, PA 12 and/or PA 612.

9. The use according to claim 1, wherein the tube has at least one bonding agent ply, wherein the boundary layer preferably comprises the bonding agent ply and a boundary ply, wherein the boundary ply preferably comprises a plastic, in particular a polyamide, for example PA 11, PA 12 and/or PA 612.

10. The use according to claim 1, wherein the supporting layer encloses a protective layer, wherein the protective layer forms the innermost layer of the tube, wherein the protective layer has a fluoropolymer, in particular ETFE.

11. The use according to claim 1, wherein the innermost layer, in particular the supporting layer or the protective layer, comprises an additive for increasing the conductivity.

12. The use according to claim 1, wherein the separating layer comprises a polyamide.

13. The use according to claim 12, wherein the separating layer comprises polyamide PA 6.

14. The use according to claim 1, wherein a boundary layer comprises a polyamide and in particular PA 6, PA 11, PA 12 and/or PA 612.

15. The use according to claim 14, wherein a boundary layer comprises polyamide PA 6, PA 11, PA 12 and/or PA 612.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present disclosure will be described below on three figures based upon three exemplary embodiments. Shown on

[0027] FIG. 1 is a cross section of a first tube according to the invention,

[0028] FIG. 2 is a cross section of a second tube according to the invention, and

[0029] FIG. 3 is a cross section of a third tube according to the invention.

DETAILED DESCRIPTION

[0030] FIG. 1 shows the cross section of a first exemplary embodiment of a tube 1. According to the latter, the tube 1 in this exemplary embodiment comprises a total of five layers (3, 4, 5, 6, 7), which enclose a lumen 2. From the inside out, the tube 1 in this exemplary embodiment comprises a supporting layer 3, an inner barrier layer 4, a separating layer 5, an outer barrier layer 6, as well as a boundary layer 7.

[0031] Involved in the case of the inner barrier layer 4 and outer barrier layer 6 are layers that each have a vinyl alcohol plastic. In this exemplary embodiment, both barrier layers have an EVOH, wherein it is preferred that the inner barrier layer 4 and/or the outer barrier layer 6 consist of an EVOH. The ethylene content of the vinyl alcohol plastic of the inner barrier layer 4 and/or the outer barrier layer 6 preferably comes to at most 35 mol. % and further preferably to at most 33 mol. %. According to a special embodiment, the ethylene content of the inner barrier layer 4 and/or the outer barrier layer 6 comes to 32 mol. %. It is preferred that the inner barrier layer 4 and/or the outer barrier layer 6 consist of the vinyl alcohol plastic. The inner barrier layer 4 and the outer barrier layer advantageously consist of the same material. In this exemplary embodiment, the layer thickness of the inner barrier layer 4 measures 0.12 mm, while the layer thickness of the outer barrier layer 6 can measure 0.15 mm, for example.

[0032] It is very preferred that the separating layer 5 have a plastic, which preferably involves a polyamide, and especially preferably PA 6. PA 6 adheres well to vinyl alcohol plastics, and in particular to ethylene vinyl alcohol copolymers, so that the separating layer 5 together with the two barrier layers 4, 6 forms a robust layered composite 4, 5, 6. In addition, polyamide or PA 6 is less brittle or tougher than the two barrier layers 4, 6 composed of EVOH, so that the separating layer stabilizes the layered composite 4, 5, 6 from this standpoint as well. The underlying idea of the invention becomes clear from the layered composite 4, 5, 6, since the layered composite 4, 5, 6 permits significantly better bending owing to the separating layer 5 than a continuous barrier layer, whose layer thickness corresponds to 0.27 mm, and hence to the added layer thicknesses of the inner barrier layer 4 and the outer barrier layer 6. The layer thickness of the separating layer 5 can measure 0.1 mm in this exemplary embodiment.

[0033] The protective layer 3 preferably comprises a plastic, and preferably consists of a plastic. In particular, the plastic of the supporting layer 3 can comprise a polyamide, preferably PA 6. A typical layer thickness of the supporting layer can be 0.08 mm. In this exemplary embodiment, the supporting layer 3 is the layer which borders the tube 1 to the inside, and hence toward the lumen 2, and consequently also comes into contact with the hydrogen. In this regard, the supporting layer protects the inner barrier layer 4 against washouts, for example. In particular, however, the supporting layer 3 supports the comparatively brittle inner barrier layer 4 on its interior side, so that the inner barrier layer 4 develops fewer cracks during the formation of bends. In addition, the supporting layer 3 protects the inner barrier layer 4 when the tube 1 is pushed onto a quick connector, and there experiences a press fit.

[0034] When it forms the innermost layer of the tube 1, the supporting layer 3 advantageously has an additive that increases the conductivity. For example, this additive can be conductive carbon black, which in any event makes the supporting layer 3 as the innermost layer so conductive as to avoid critical electrical charge values.

[0035] It is preferred that the tube 1 have a boundary layer 7, which forms the outermost layer of the tube 1 on FIG. 1. In this exemplary embodiment, the boundary layer 7 is arranged directly on the outer barrier layer 6. The boundary layer 7 advantageously consists of a plastic or a polyamide or PA 6. The layer thickness of the boundary layer 7 can come to 0.3 mm.

[0036] The exemplary embodiment shown on FIG. 2 is a tube 1, which is configured identically to the first exemplary embodiment with respect to layers 3 to 6. As opposed to the first exemplary embodiment, however, the boundary layer was given a two-ply design. The boundary layer 7 in the second exemplary embodiment according to FIG. 2 has a bonding agent ply 8 as well as a boundary ply 9. The boundary ply 9 in this exemplary embodiment preferably consists of a plastic, in particular a polyamide and especially preferably PA 11 or PA 12. Given the poorer adhesion of PA 11 or PA 12 on vinyl alcohol plastics, the bonding agent ply 8 is provided, which can have a polyolefin, in particular polypropylene or polyethylene, for example. However, the bonding agent ply can also comprise an adhesion-modified polyamide or a polyamide 6. In this exemplary embodiment, the layer thickness of the bonding agent ply 8 can measure 0.05 mm. For example, the layer thickness of the boundary ply 9 can come to 0.25 mm.

[0037] FIG. 3 shows a third exemplary embodiment of a tube 1 according to the invention, which differs from the exemplary embodiment on FIG. 2 primarily in that not the supporting layer 3, but rather a protective layer 10 inwardly adjacent thereto forms the innermost layer of the tube 1. For example, the protective layer 10 can have a polyamide or a fluoropolymer. The fluoropolymer preferably involves an ETFE. The layer thickness of the protective layer 10 can measure 0.15 mm. The protective layer 10 advantageously comprises an additive, so as to increase the conductivity of the protective layer 10. In particular, the additive can involve conductive carbon black.

REFERENCE LIST

[0038] 1 Tube [0039] 2 Lumens [0040] 3 Supporting layer [0041] 4 Inner barrier layer [0042] 5 Separating layer [0043] 6 Outer barrier layer [0044] 7 Boundary layer [0045] 8 Bonding agent ply of 7 [0046] 9 Boundary ply of 7 [0047] 10 Protective layer