WO2013131622A1

WO2013131622A1 - Use of a polymer material

Info

Publication number: WO2013131622A1
Application number: PCT/EP2013/000562
Authority: WO
Inventors: Guido Kania; Volker Liebel
Original assignee: Rehau Ag + Co
Priority date: 2012-03-06
Filing date: 2013-02-27
Publication date: 2013-09-12
Also published as: DE102012101854A1

Abstract

The present invention relates to the use of a polymer material, which is a non-cross-linked polyolefin and, in an internal pressure resistance test according to ISO 1167-1 and ISO 1167-2, has an internal pressure resistance which is on or above a reference curve in the temperature range from 10 to 110°C, corresponding to the following definition: Ig t = - 219 - (62,600.752 x Ig sigma) / T + 90,635.353 / T + 126.387 x Ig sigma, wherein t represents the time in h, T represents the temperature in K and sigma represents the hydrostatic tension in MPa, for producing at least one layer of a multilayer tube (1) or at least one layer of a multilayer moulded tubular part (1', 1", 1"') for a tube arrangement of a district heating network.

Description

Use of a polymer material

The invention relates to the use of a polymer material for producing a layer of a multilayer pipe or a layer of a multilayer pipe molding, a process for producing a multilayer pipe or a multilayer molding and the multilayer pipe or multilayer pipe molding produced by the method.

The provision of heating and heating for homes and buildings, which is carried out by means of so-called district heating networks, is a cheap and efficient technique for directing heat from the place of production to the individual consumers.

For this purpose, so-called district heating pipes are used, which are able to direct the flowing in the pipes heated fluid over very long distances to the consumers, without causing significant heat energy losses.

For this purpose, the pipes are thermally insulated.

For the actual media-carrying pipe from the state of the art known from crosslinked polyethylene (PE-X) or steel.

A very common technique to produce such district heating pipes is to produce a medium pipe, for example of PE-X with one or more foam layers of an expanded polymer material such as PE-X or polyethylene (PE) or polypropylene (PP), which form the insulation.

Such a prefabricated package of medium pipe and foam layers is then drawn into a prefabricated flexible corrugated pipe. To connect these district heating pipes with each other pipe fittings are required, as well as to produce, for example, branches and side connections. Such known from the prior art district heating pipes are expensive to produce, because of the many steps to be carried out error-prone and difficult to connect to each other, since in cross-linked polyethylene is only a limited weldability or steel is a considerable effort to produce a welded connection to operate.

This is where the invention, which has set itself the task, a suitable

Polymer material, which met the high demands that are placed on district heating pipes, select and provide for the production of a pipe or a pipe fitting for a pipe assembly of a district heating network. In addition, that should

Polymer material in a simple manner be welded, so as to be able to make connections.

The object is achieved in accordance with the invention and overcome the disadvantages known from the prior art by using a polymer material which is an uncrosslinked polyolefin and has an internal pressure resistance in an internal pressure test according to ISO 1167-1 and ISO 1167-2 is above a reference curve in the temperature range of 10 to 110 ° C, which satisfies the following definition: Ig t = - 219 - (62600.752 x Ig sigma) / T + 90635.353 / T + 126.387 x Ig sigma where t is for the time in hours (h), T is the temperature in Kelvin (K) and sigma for the hydrostatic stress in megapascals (MPa), to form therefrom at least one layer of a multilayer pipe or at least one layer of a multilayer pipe molding for a pipe system of a district heating network manufacture.

Where sigma, t and T are oriented towards the following areas:

- sigma (tension) is 1 MPa to 20 MPa,

- 1 (time) from 0.1 h to 1,000,000 h (about 100 years),

T from 0 ° C (273.15 K) to 110 ° C (383.15 K).

By the use according to the invention of a polymer material according to the definition described above, it is possible to provide a multilayer pipe or a multilayer pipe molding, each with at least one layer of said polymer material for a pipe arrangement of a district heating network. Such a tube or tubular molding can be produced in a simple manner, causes low production costs, is durable, withstands the prevailing pressures and temperatures of the medium conveyed in them over long periods of time, and can be connected to one another by welding techniques in a simple manner.

In particular, such a pipe or pipe fitting resists the conditions under which a district heating network is operated. These include the permanent action of the fluid under temperature and pressure on the wall of polymer material, pressure peaks and fluctuations as well as temperature peaks and fluctuations. Likewise, the expansion behavior of the material has to be taken into account, which is decisively influenced by temperature and pressure. Finally, a durable material is needed because a district heating network should have a long life.

All this is ensured by the use of the polymer material described above.

It has been found in the context of the present invention to be advantageous if the polymer material is a polyethylene.

A polyethylene is a very easily processable polymer material that can be used in both

Extrusion as well as injection molding process is processed to produce pipes or pipe fittings.

A polyethylene is inert, durable and is not attacked by the conductive fluids when used in a district heating network, moreover, it is conveniently available. It has proved to be very advantageous in the context of the invention if the innermost, i. the lumen of the tube or pipe molding facing layer of the

Polymer material, as described above, is formed.

This innermost layer of the pipe or pipe molding comes into contact with the medium to be conductive.

In the context of the invention, it has furthermore proven to be advantageous if at least one barrier layer is arranged on the side facing away from the lumen or in the layer of polymer material. Such a barrier layer prevents or reduces to a very high degree the passage of substances from the environment into the lumen of the tube or out of the lumen of the tube into the environment.

It has proved to be particularly favorable when a barrier layer is used as the barrier layer, which prevents or limits the passage of water vapor and / or the passage of oxygen.

In the context of the invention can also be provided that a plurality of barrier layers are provided in a combination. In the context of the invention has further been found to be advantageous if a thermal barrier coating is disposed on the layer of polymer material or on the barrier layer. Such a thermal barrier coating may for example consist of a polymer foam material, wherein the polymer is a polypropylene foam, a polyurethane foam is a foam of crosslinked or uncrosslinked polyethylene or the like.

The polymeric material is physically or chemically foamed with a gas.

The polymer foam produced in this way can be open-celled or closed-celled.

Preference is given to a closed-cell polymer foam, since this has advantages in terms of its thermal insulation properties and a possible water absorption.

Likewise, the thermal barrier coating can be multi-layered. It is also multi-layered constructions which also include alternative insulating layer materials, such as e.g. Airgel, included, can be produced. As the material of the thermal barrier coating, it is preferred to choose one which shows no failure, no degradation or similar changes with respect to the temperature of the medium to be conducted. The thickness of the thermal barrier coating is chosen so that the desired thermal insulation effect occurs. In a preferred development of the present invention, provision is made for a diffusion barrier layer to be arranged on the side of the thermal barrier coating facing away from the lumen of the pipe or pipe fitting.

A diffusion barrier layer arranged there on the thermal barrier coating is suitable for protecting the thermal barrier coating from the ingress of substances from the environment. In addition, the diffusion barrier layer can also prevent substances from the thermal barrier coating from entering the environment.

In particular, it can also be provided that the diffusion barrier layer is designed so that gases from the polymer foam, which forms the thermal barrier coating, do not diffuse outwards into the environment, but remain in the thermal barrier coating and thereby maintain the effectiveness of the thermal barrier coating.

In the context of the present invention may also be advantageously provided that a protective layer is arranged, which forms the outermost layer of the pipe or pipe molding.

By providing a protective layer which forms the outermost layer of the pipe or pipe molding, a highly resistant pipe or pipe molding can be made, which ensures a high resistance to damage during storage, transport and installation of the pipes or pipe fittings.

In the context of a favorable development of the invention, the protective layer can be corrugated or smooth, furthermore it can be provided that the protective layer consists of a polyethylene (PE) or a polyethylene with increased resistance to tearing or a cross-linked polyethylene (PE-X) or similar resistant materials is made.

It may prove favorable in the present invention if at least one adhesion promoter layer is arranged between two of the abovementioned layers. An adhesive layer causes a particularly strong bond between two adjacent layers, so that an adhesive bond is formed. It is also included in the invention that adhesion promoter layers are formed between all adjoining layers.

The object to provide a method for producing a multilayer pipe or multilayer pipe molding, learns their solution in claim. 7

According to the invention, a method for producing a multilayer pipe or multilayer molding for a pipe arrangement of a district heating network is provided for this purpose. wherein at least one layer of the multilayer pipe or the multilayer molded part of a polymer material which is an uncrosslinked polyolefin and has an internal pressure resistance in an internal pressure test according to ISO 1 167-1 and ISO 1167-2, on or above a reference curve in the temperature range of 10 to 110 ° C, which corresponds to the following definition:

Ig t = - 219 - (62600.752 x Ig sigma) / T + 90635.353 / T + 126.387 x Ig sigma where t is the time in hours (h), T is the temperature in Kelvin (K) and sigma for the hydrostatic stress is expressed in megapascals (MPa).

The following areas are oriented to sigma, t and T:

- sigma (tension) is 1 MPa to 20 MPa,

- 1 (time) from 0.1 h to 1,000,000 h (about 100 years),

- T from 0 ° C (273, 15 K) to 110 ° C (383, 15 K).

Such a method for producing a multilayer pipe or multilayer pipe molding may be selected as an extrusion process or as an injection molding process or as a blowing process or as an in-line fabrication process or as a combined process from the above.

With the aid of the method, a multilayer pipe or a multilayer pipe molding according to the above description can be produced in a favorable manner.

In the context of the invention, it has proved to be very advantageous if the method is carried out such that at least one barrier layer is arranged on or in the layer of polymer material.

Arranging a barrier layer on or in the layer of polymer material can be realized in a simple manner in an extrusion process or coextrusion process or in an injection molding process.

Furthermore, it has turned out to be advantageous if, as part of the method, a thermal barrier coating is arranged and a diffusion barrier layer is arranged on the side of the thermal barrier coating facing away from the lumen of the pipe or pipe fitting. By a corresponding method, in which in addition to the production of at least one layer of the multilayer pipe or the multilayer molded part of the

Polymer material according to the above description also a heat-insulating layer and on the side facing away from the lumen of the tube or pipe molding side of the thermal insulation layer a diffusion barrier layer is particularly advantageous and favorable.

In this way, a pipe or pipe fitting with the described complex structure of its wall in a simple manufacturing process, for example a

Coextrusion or multi-component injection molding process without great effort, accessible in high reproducibility and with an outstanding quality level.

In the context of the present invention, the object of providing a multilayer pipe or multilayer pipe molding is solved by claim 10. The problem is solved by the method described above, a multilayer pipe or multilayer pipe molding is accessible in a simple manner.

In the above context of the invention, a multi-layer tubular shaped part is understood as meaning, for example, a pipe bend, a branch pipe, a T-piece, a sleeve or an electric welding sleeve, without this enumeration being conclusive.

An electric welding sleeve is particularly suitable for connecting pipes with each other or pipes and pipe fittings or pipe fittings with each other.

It is understood in the context of the present invention that an electric welding sleeve can be formed so that they can accommodate a pipe, two pipes, three pipes or four pipes and connect with each other or with one or more pipe fittings.

A pipeline consisting of pipes or pipe parts according to the present invention is particularly advantageous when the connection between the pipes or pipe fittings is made by butt welding.

Other important features and advantages of the invention will become apparent from the dependent claims, from the Fig. And from the accompanying figure description. It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are shown in the figures and will be explained in more detail in the following description, wherein like reference numerals refer to identical or functionally identical components. The invention will be explained by the attached figures as follows.

This shows:

1 shows a longitudinal section through a tube along the axis;

2 shows a longitudinal section through a pipe bend along the axis.

3 shows a longitudinal section through a T-piece along the axis. Fig. 4 is a longitudinal section through an electric welding sleeve along the axis.

In Fig. 1, a tube 1 is shown in a longitudinal sectional view along the axis.

The multilayer pipe 1 has a lumen 7 bounded by a layer 2 made of polymer material.

Fixedly connected to the layer 2 of polymer material is an adjacent barrier layer 3. On the side facing away from the lumen 7 of the tube 1 side of the barrier layer 3, a thermal barrier coating 4 is arranged. The thermal barrier coating 4 is preferably made of a foamed polymeric material.

The thermal barrier coating 4 has a diffusion barrier layer 5 on its side facing away from the lumen 7 of the tube 1. As the outermost layer of the tube 1, a protective layer 6 is disposed adjacent to the diffusion barrier layer 5.

All these layers are firmly connected. FIG. 2 shows a longitudinal section through a pipe bend 1 'along its axis.

The pipe bend V is a pipe molding which allows a connection of not shown here pipes 1, 1 with a certain angle, in the present case about 90 °. The lumen 7 of the pipe bend 1 'is bounded by a multilayer wall, wherein the structure is analogous, as described above under Fig. 1.

All reference numerals correspond to each other.

Fig. 3 shows a T-piece 1 "in a longitudinal sectional view along the axis.

With a T-piece 1 ", it is possible to pipe 1, 1 or pipe fittings 1 ', 1", 1 "' to each other.

The lumen 7 of the T-piece 1 "is bounded by a multilayer wall whose structure is already known in principle from the description of FIG. 1.

The reference numerals correspond to each other.

In Fig. 4, an electric welding sleeve 1 "'is reproduced, which is shown in a longitudinal sectional view along the axis.

An electric welding sleeve 1 "'is suitable to connect pipes 1, 1 or pipe fittings 1', 1", 1 "', wherein the welding process is initiated by applying an electrical voltage, whereby in the interior of the electric welding sleeve" by a heating wire

Polymer material is melted, which produces the welded joint.

The lumen 7 of the electric welding sleeve 1 "'is in this case limited by a multilayer wall whose structure has already been explained in the description of FIG.

The reference numerals correspond to each other.

- Claims - LIST OF REFERENCE NUMBERS

1 tube

r pipe bend

1 "tee

Electro socket

2 layer of polymer material

3 barrier layer

4 thermal barrier coating

5 diffusion barrier layer

6 protective layer

7 lumens of pipe or pipe fitting

8 heating wires

Claims

claims

1. Use of a polymer material which is an uncrosslinked polyolefin and in an internal pressure test according to ISO 1167-1 and ISO 1167-2 has an internal compressive strength which is on or above a reference curve in the temperature range of 10 to

110 ° C, which corresponds to the following definition:

Ig t = - 219 - (62600.752 x Ig sigma) / T + 90635.353 / T + 126.387 x Ig sigma where t is the time in h, T is the temperature in K and sigma is the hydrostatic stress in MPa for producing at least one layer (2) of a multilayer pipe (1) or at least one layer (2) of a multilayer pipe molding (1 ', 1 ", 1"') for a pipe system of a district heating network.

2. Use of a polymer material according to claim 1, wherein the polymer material is a polyethylene.

3. Use of a polymer material according to claim 1 or 2, wherein on or in the layer (2) of polymer material at least one barrier layer (3) is arranged.

4. Use of a polymer material according to one of the preceding claims, wherein on the layer (2) of polymer material or on the barrier layer (3) a thermal barrier coating (4) is arranged.

5. Use of a polymer material according to claim 4, wherein on the side facing away from the lumen (7) of the tube or pipe molding side of the thermal barrier coating (4) a diffusion barrier layer (5) is arranged.

6. Use of a polymer material according to any one of the preceding claims, wherein a protective layer (6) which forms the outermost layer of the tube (1) or pipe molding (1 \ 1 ", 1" ') is arranged.

7. A method for producing a multilayer pipe (1) or multilayer pipe molding (1 ', 1 ", 1"') for a pipe arrangement of a district heating network, wherein min. at least one layer (2) of the multilayer pipe (1) or of the multilayer pipe molding (1 \ 1 ", 1"') of a polymer material which is an uncrosslinked polyolefin and an internal pressure test according to ISO 1167-1 and ISO 1167-2 Internal compressive strength, which is on or above a reference curve in the temperature range of 10 to 110 ° C, which corresponds to the following definition:

Ig t = - 219 - (62600.752 x Ig sigma) / T + 90635.353 / T + 126.387 x Ig sigma where t is the time in h, T is the temperature in K and sigma is the hydrostatic stress in MPa , is shaped.

8. The method of claim 8, wherein on or in the layer (2) of polymer material at least one barrier layer (3) is arranged.

9. The method of claim 7 or 8, wherein a thermal barrier coating disposed on the lumen (7) of the tube (1) or pipe molding (1 ', 1 ", 1"') side facing away from the thermal barrier coating (4) a diffusion barrier layer (5 ) is arranged.

10. Multilayer pipe (1) or multilayer pipe molding (1 ', 1 ", 1"'), in particular a pipe bend, a pipe branch, a T-piece, a sleeve or an electric welding sleeve, produced by the method according to any one of claims 7 to 9.