BENT AND MULTILAYER PIPE

Abstract

A pipe (1) comprises at least one first layer (3) and one second layer (2), wherein the first layer (3) has a first plastic K1, wherein the first plastic K1 has a conversion temperature T.sub.UK1. The second layer (2) comprises a second plastic K2, wherein the second plastic K2 has a conversion temperature T.sub.UK2. The first layer (3) has an aggregate Z, wherein aggregate Z is not a polymer or copolymer. Aggregate Z is preferably a solid, wherein the solid is a semiconductor or nonconductor Aggregate Z facilitates the dielectric heating of the pipe.

Claims

1. A pipe comprising: at least one first layer and one second layer, wherein the first layer has a first plastic K1, wherein the first plastic K1 has a conversion temperature T.sub.UK1, wherein the second layer (2) comprises a second plastic K2, wherein the second plastic K2 has a conversion temperature T.sub.UK2, wherein the first layer (3) has an aggregate Z, wherein aggregate Z is not a polymer or copolymer, wherein an imaginary portion of a relative permittivity standardized by the electric field constant is allocated to the first plastic K1, and referred to as absorption factor A.sub.K1, wherein an imaginary portion of a relative permittivity standardized by the electric field constant is allocated to the second plastic K2, and referred to as absorption factor A.sub.K2, wherein an imaginary portion of a relative permittivity standardized by the electric field constant is allocated to aggregate Z, and referred to as absorption factor A.sub.Z, wherein an absorption factor A.sub.S1 is allocated to the first layer and an absorption factor A.sub.S2 is allocated to the second layer, wherein absorption factors A.sub.K1 and A.sub.Z at least codetermine the absorption factor A.sub.S1 of the first layer via their mixing ratio in the first layer, wherein the absorption factor A.sub.K2 of the second plastic K2 at least codetermines absorption factor A.sub.S2 of the second layer; wherein absorption factor A.sub.Z is larger than absorption factor A.sub.K1; and wherein aggregate Z is a solid, wherein the solid is a semiconductor or non-conductor.

2. The pipe according to claim 1, wherein the electrical conductivity of the pipe in a longitudinal direction of the pipe is less than 10.sup.8.

3. The pipe according to claim 1, wherein absorption factor A.sub.Z is larger than absorption factor A.sub.S2 or A.sub.K2.

4. The pipe according to claim 1, wherein absorption factor A.sub.K2 is larger than A.sub.K1.

5. The pipe according claim 1, wherein the plastic K1 of the first layer comprises a polymer, which is selected from one of the polymer classes aromatic polyamide (PA), aliphatic PA, partially aromatic PA, polyester (PES), polyetherketone (PEK), ethylene-vinyl alcohol copolymer (EVOH), fluoropolymer (FP), polyvinylidene chloride (PVDC), polyphenylene sulfide (PPS), polyurethane (PU), thermoplastic elastomer (TPE), polyolefin (PO), wherein the plastic K2 of the second layer (2) comprises a polymer selected from another of the mentioned polymer classes.

6. The pipe according to claim 1, wherein the pipe has a further layer or further layers made out of plastic, wherein the further layer or the further layers has or have aggregate Z.

7. The pipe according to claim 1, wherein the first plastic K1 and the second plastic K1 are thermoplastic, wherein the first conversion temperature T.sub.UK1 divided by the second conversion temperature T.sub.UK2 defines a conversion temperature ratio UV, wherein A.sub.K1 divided by A.sub.K2 defines an absorption ratio AV.sub.K, wherein the conversion temperature ratio UV divided by the absorption ratio AV.sub.K defines a primary ratio HV.sub.K, so that ${\mathrm{HV}}_K=\frac{\mathrm{UV}}{{\mathrm{AV}}_K}=\frac{T_{\mathrm{UK}1}}{A_{K1}}.Math.\frac{A_{K2}}{T_{\mathrm{UK}2}}$ applies, wherein a difference factor UF.sub.K is determined from the primary ratio HV.sub.K according to ${\mathrm{UF}}_K=\begin{array}{cc}{\mathrm{HV}}_K,& {\mathrm{HV}}_K>1\\ 1/{\mathrm{HV}}_K,& {\mathrm{HV}}_K<1\end{array}$ wherein A.sub.S1 divided by A.sub.S2 defines an absorption ratio AV.sub.S, wherein the conversion temperature ratio UV divided by the absorption ratio AV.sub.S defines a primary ratio HV.sub.S, so that ${\mathrm{HV}}_S=\frac{\mathrm{UV}}{{\mathrm{AV}}_S}=\frac{T_{\mathrm{UK}1}}{A_{S1}}.Math.\frac{A_{S2}}{T_{\mathrm{UK}2}}$ applies, wherein a difference factor UF.sub.S is determined from the primary ratio HV.sub.S according to ${\mathrm{UF}}_S=\begin{array}{cc}{\mathrm{HV}}_S,& {\mathrm{HV}}_S>1\\ 1/{\mathrm{HV}}_S,& {\mathrm{HV}}_S<1\end{array}$ wherein the inequality U
UF.sub.S<UF.sub.K is satisfied.

8. The pipe according to claim 1, wherein the pipe has one additional layer or several additional layers made out of plastic, wherein the additional layer or the additional layers comprise an aggregate Y with a weight portion G.sub.Y, wherein aggregate Y is a non-conducting or semiconducting solid.

9. The pipe according to claim 1, wherein the first layer or the layers with a semiconducting or non-conducting solid comprise(s) more than 50% of the weight of the pipe.

10. The pipe according to claim 7, wherein the difference factor UF.sub.S assumes a value of at most 5, and further preferentially of at most 2.

11. The pipe according to claim 1, wherein aggregate Z and/or aggregate Y is crystalline, and preferably a metal oxide.

12. The pipe according to claim 1, wherein aggregate Z and/or aggregate Y is in powder form, wherein the average particle diameter of aggregate Z and/or of aggregate Y measures at most 100 m.

13. The pipe according to claim 1, wherein one of the layers, is a barrier layer, wherein the material of the barrier layer has a plastic, which is selected from the group ethylene-vinyl alcohol copolymer, fluoropolymer, polyphthalamide, polyolefin, polyvinylidene chloride, thermoplastic elastomer.

14. The pipe according to claim 1, wherein the pipe has at least one bending point.

15. A fluid line comprising a pipe, wherein the pipe is designed according to claim 1, wherein the fluid line has a respective line connector at the ends of the pipe, wherein at least one of the line connectors can be reversibly connected with a counterpart.

16. The pipe according to claim 1, wherein the electrical conductivity of the pipe in a longitudinal direction of the pipe is less than 10.sup.9 S/m.

17. The pipe according to claim 1, wherein the first layer or the layers with a semiconducting or non-conducting solid comprises more than 90% of the weight of the pipe.

18. The pipe according to claim 1, wherein the pipe has at least two bending points.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The present disclosure will be explained in more detail below based on a drawing, which only represents an exemplary embodiment. Shown schematically on:

[0072] FIG. 1 is a cross section through a pipe according to the disclosure;

[0073] FIG. 2 is a side view of a fluid line according to the disclosure, comprising the pipe on FIG. 1, and further having two line connectors;

[0074] FIG. 3 is a front view of a retainer respectively arranged in the two line connectors.

DETAILED DESCRIPTION

[0075] According to FIG. 1, the inventive pipe 1 has three layers 2, 3, 4, wherein the middle layer 2 is a barrier layer and comprises EVOH. The outer layer 3 as well as the inner layer 4 each have a polyamide 6, wherein the polyamide 6 of the inner layer 4 is identical to the polyamide 6 of the outer layer 3. The polyamide 6 can have an absorption factor of 0.1, while the middle layer 2 made of EVOH has an absorption factor of 0.6 in this exemplary embodiment. The outer layer 3 made of polyamide 6 can be understood as the first layer with a first plastic K1, while the middle layer 2 is construed below as the second layer with a second plastic K2. The inner layer 4 in this exemplary embodiment can be understood as an other layer, which likewise has the first plastic K1.

[0076] As a consequence, absorption factor AK1 comes to a value of 0.1, while absorption factor AK2 measures 0.6. Both plastics K1 (PA6) and K2 (EVOH) are thermoplastic, so that their conversion point corresponds to their melting point minus 20 C. The conversion temperature TUK1 of polyamide 6 in this exemplary embodiment thus measures 200 K (=200 C.-20 C.), while the conversion temperature TUK2 of EVOH in this exemplary embodiment can measure 163 K (=183 C.-20 C.). Because the absorption factor is six times higher and the melting point is lower, dielectric heating brings the EVOH (second layer 2) to a temperature at which the EVOH can be readily bent much faster. However, the two polyamide layers (the first layer 3 and the other layer 4) are not yet sufficiently heated at the same point in time, so that they cannot be readily bent yet. If the pipe is further heated until the two polyamide layers also allow a satisfactory bending, the middle layer is heated so strongly that it literally burns, and loses its good barrier properties almost completely. In the present exemplary embodiment, the primary ratio HVK is calculated as follows:

[00006]${\mathrm{HV}}_K=\frac{\mathrm{UV}}{{\mathrm{AV}}_K}=\frac{T_{\mathrm{UK}1}}{T_{\mathrm{UK}2}}.Math.\frac{A_{K2}}{A_{K1}}=\frac{200}{163}.Math.\frac{0.6}{0.1}=7.3$

[0077] wherein HVK>1, so that the difference factor UFK likewise measures 7.3.

[0078] According to the disclosure, an aggregate Z in the form of powdered zirconium oxide (also known as zirconia) is mixed in with the first layer 3 and the other layer 4. This aggregate Z is a metal oxide, is present in a crystalline form, and can have an absorption factor AZ with the value of 2. As a consequence, aggregate Z has an absorption factor that is larger by about a factor of 20 than that of polyamide 6, and larger by a factor of 3 than that of EVOH. The weight portion GZ of aggregate Z in the two polyamide layers can measure 10% or 0.1. As a consequence, the absorption factor AS1 of the first layer 3 and absorption factor ASW of the other layer 4 is calculated as follows:

A.sub.S1=A.sub.SW=G.sub.K1.Math.A.sub.K1+G.sub.Z.Math.A.sub.Z=0.9.Math.0.1+0.1.Math.2=0.29

[0079] so that absorption factor AS1 and ASW was nearly tripled by mixing in aggregate Z. By contrast, absorption factor AS1 remains constant, and is thus identical to AK2. Therefore, the following value results for the primary ratio HVS:

[00007]${\mathrm{HV}}_S=\frac{\mathrm{UV}}{{\mathrm{AV}}_S}=\frac{T_{\mathrm{UK}1}}{T_{\mathrm{UK}2}}.Math.\frac{A_{S2}}{A_{S1}}=\frac{200}{163}.Math.\frac{0.6}{0.29}=2.5={\mathrm{UF}}_S$

[0080] As a result, difference factor UFS is smaller than difference factor UFK, so that inequality U is satisfied for the first layer 3. This also applies equally for the other layer 4, which consists of the same material as the first layer 3, and can consequently stem from the same polymer melt source.

[0081] FIG. 2 shows the pipe 1 on FIG. 1 as a constituent of a complete fluid line 5. Apart from the pipe 1 with bending points 11, the fluid line 5 in this exemplary embodiment also comprises two line connectors 6, which each are arranged at one end of the pipe 1. The line connectors 6 in this exemplary embodiment are designed as female line connectors 6, and capable of receiving male counterparts 7. Shown on the right side of FIG. 2 is such a male counterpart 7, which on its part can be connected to a pipe (as denoted), or even to other components (pumps, tanks, etc.). The counterpart in this exemplary embodiment comprises a connector shaft 9 as well as a circumferential collar 10.

[0082] For purposes of connection with the counterpart 7, the line connectors 6 each have a coupling body 8 with a female design, for example which is fastened to the pipe 1 via a frictional or substance-to-substance connection. For example, the substance-to-substance connection can be designed as a laser weld seam. For example, a frictional connection can be established via circumferential ribs of the coupling body 8, onto which the end of the pipe 1 is pushed. The coupling body 8 receives the connector shaft 9 of the counterpart 7, and its interior preferentially has an O-ring (not shown here) for sealing purposes.

[0083] The line connector and the accompanying counterpart 7 can advantageously be reversibly connected with each other, which ideally is achieved via a latched connection. For this purpose, a retainer 12 is pushed into the coupling body 8, wherein the retainer 12 preferably has a U-shaped design, see FIG. 3. The retainer 12 has a head section 14 as the U-base, as well as two arms 13 as the U-legs. The arms 13 can be elastically spread apart via the circumferential collar 10 of the counterpart 7, so that after passing the circumferential collar 10, the two arms 13 assume their original position once more, and latch the counterpart 7 back into the coupling body 8 again. The two arms 13 can be spread apart by pressing on the head section 14 and correspondingly configuring the coupling body 8, for example, so that the counterpart 7 can thereupon be pulled out of the coupling body 8.