WO2000053415A1

WO2000053415A1 - Wall structure, lining material and methods for manufacture thereof

Info

Publication number: WO2000053415A1
Application number: PCT/DK2000/000079
Authority: WO
Inventors: Finn Erik Jacobsen
Original assignee: KE Burgmann AS
Current assignee: EagleBurgmann KE AS
Priority date: 1999-03-05
Filing date: 2000-02-25
Publication date: 2000-09-14
Anticipated expiration: 2001-09-05
Also published as: DK199900318A; AU2794200A

Abstract

The invention relates to a wall structure comprising a first surface structure, said wall structure also consisting of a lining material comprising at least one flouroplastic foil melted together with a woven material, and onto which first surface structure of the wall structure the said lining material has been applied by means of a binding agent. The invention also relates to methods of manufacture of a wall structure and a lining material.

Description

Wall structure, lining material and methods for manufacture thereof

Background of the invention The invention relates to a wall structure as specified in the preamble of claim 1 , a lining material as specified in the preamble of claim 8 and a method for manufacture of a wall structure as specified in the preamble of claim 10 and a method for manufacture of a lining material as specified in the preamble of claim 1 1.

When using a storage tank or piping for chemicals and similar aggressive materials, it is important that the tank/piping is resistant against the material to be stored or transported therein in order to minimize problems of corrosion and thereby prolong the durability of the tank/piping. In this connection, various solutions with linings and coatings are known. However, they tend to crack fairly easily and are difficult to repair properly. If the tank/piping is to be used for another chemical, it is extremely difficult - if not impossible - to clean the tank/piping properly for residues of the former material.

Today, a similar problem is known from piping in flue gas channels which has been fitted with coatings whose purpose it is both to isolate and prevent the piping/wall of the tank from being affected by high temperatures causing damage to it.

A method is known from European patent application No. 0 026 309 A2 whose purpose it is to provide a bonding between a woven material and an underlying flouroplastic material of e.g. a PTFE plate. However, the technique described in the publication has the disadvantage that the woven material must be applied onto the PTFE material by heat transmission through the woven material which is the reason why the method involves the use of a special bonding mat whose discrete structure provides the possibility to make a discrete bonding line between the PTFE structure and the woven structure. The described method provides a somewhat weak bonding between the PTFE structure and the woven material, just as the quality of the bonding is extremely difficult to predict. Another significant problem with the above-mentioned lining material is that it has turned out that the presence of non- bonded pockets between the flouroplastic structure and the woven material results in a potential perforation of the outer flouroplastic structure which may quickly penetrate a large part of the lining material through these non-bonded pockets or channels. Naturally, this is particularly critical when the penetrating material consists of strong acids or similar chemicals that are actively contributing to breaking down the lining material by penetrating it and the underlying wall structure.

In addition, it should be noted that the above-mentioned technical solution - apart from the technical drawbacks - is expensive to manufacture.

This must be seen in the light of the fact that teflon material in its cured form is extremely difficult to join with anything. Thus, there has been a tendency to laminate teflon materials with e.g. a glass fibre fabric or to treat it with environmentally hazardous acids or the like with the purpose of creating a coating that can be joined with an underlying material by means of a binding agent.

Meanwhile, all these solutions are quite time-consuming and expensive, just as the processing of the flouroplastic material weakens its mechanical properties against e.g. wear and tear.

On the basis of this, the purpose of the invention is to provide a material and a method for lining of a surface in order to increase durability, including enhancement of resistance both thermally and chemically.

In addition, the purpose of the invention is also to provide a solution which is both simpler and less expensive than the known techniques. The invention

The invention relates to a wall structure comprising a first surface structure and at least one flouroplastic foil melted together with a woven material, said woven material being glued onto the first surface structure of the wall structure.

Despite the apparently somewhat fragile surface of the flouroplastic material, it has turned out that the above-mentioned wall structure is quite advantageous for a wide range of applications.

In connection with e.g. lining of piping or tanks it is apparent that the surface of the flouroplastic foil is relatively well protected as outside mechanical wear and tear is essentially limited to comprising liquids and/or air flows. Thus, the material has quite advantageous properties in relation to e.g. the inner lining of chemical installations where even small cracks in the flouroplastic foil are extremely critical.

In this manner, it is possible to obtain a wall structure according to the invention to be used in chemical installations which will improve the durability of the installations significantly. As the foil is optimally joined together with the bonding mat, the risk of penetrable cracks in the flouroplastic foil will be significantly reduced and the immediate result of a potential perforation not cause a spread of decomposing acids within the lining material. This is due to the fact that there are no large pockets between the woven material and the flouroplastic foil as is the case with the known techniques.

In addition, it should be noted that the term "glued" specified in the characterizing part of claim 1 and should be broadly understood as any kind of bonding of the materials by means of one or more adhesives.

By, as specified in claim 2, letting at least one of the flouroplastic layers consist of PTFE foil, a particularly advantageous embodiment has been obtained. In particular, when using PTFE foil, a preferred combination of foil properties and price has been obtained

PTFE foils of this character are easy to work with and process In addition, they are also creating a minimum of waste which makes them environmentally friendly

By, as specified in claim 4, letting the woven material consist of a glass fibre fabric, sihcat fibre fabric, aramid fibre fabric or similar fibre fabrics, a preferred and cost- efficient embodiment of the invention has been obtained Together with the above- mentioned specified fibre, non-cured glass fibre, sihcat fibre, aramid fibre, carbon fibre or similar fabrics constitute a particularly advantageous and handy material which will maintain its advantageous properties in its cured version m relation to both the barrier properties and to the overall strength of the mateπal

By, as specified in claim 4, letting the first surface structure constitute the exterior surface of a ship wall, a particularly advantageous embodiment of the invention is obtained which is superior on so many levels when compared to the existing technique One of these advantages is that a ship wall with a coating of the above- mentioned type is provided with particularly advantageous surface properties in relation to the environment in which it is to be used The flouroplastic material will provide good barrier properties against water This means that corrosion and the like may be prevented without using chemical barriers such as environmentally hazardous paints etc More importantly, flouroplastic mateπals are an attractive alternative to more or less environmentally hazardous substrates whose purpose it is to combat e g the formation of algae on the outer side of the ship This is due to the fact that algae cannot attach to the smooth surface of the flouroplastic material

Yet another advantage of the smooth surface is that in relation to water flows, the surface is less exposed to friction This means that a hull completely or partly constituted by ship walls according to the embodiment of the lm ention will have reduced kinematics which may increase the speed of the ship in the water or reduce the required engine power By, as specified in claim 5, letting the first surface structure constitute the exterior surface of the wing of an aircraft, a wing structure is obtained with minimal friction in relation to air flows.

In a similar manner, problems with icing of the wings of aircrafts may be limited or completely avoided as the ice is not likely to stick to the surface of the wing due to minimal friction.

This is a great advantage in relation to the existing technology in this area as the latter includes the use of chemicals with the risk of polluting the surrounding environment.

By, as specified in claim 6, letting the first surface structure constitute the exterior surface of a wind turbine wing, power generated by a given wind turbine may be increased by means of relatively easy and inexpensive means since even small reductions in friction between the surface of the wind turbine wing and the air flows around it will provide the possibility of a significantly improved degree of efficiency.

Another property that makes the technology particularly advantageous in relation to a wind turbine wing is that a wing according to the invention excitates less noise which has been a core issue in connection with the development of wind turbine wings for years.

In relation to icing, the advantages applying to wings on aircrafts do also apply to wind turbine wings. The existing technology within the area includes the use of electrical heaters in the wings where energy for the heaters is taken from the energy produced by the wind turbine. The use of heaters naturally implies a certain reduction in the actual efficiency of the wind turbine whilst also making it more expensive to purchase and maintain. Common to all of the above-mentioned structures is that the requirements to a durable, reliable adhesion to the basic structure itself are quite extensive. This is partly based on the fact that the surface of these structures will be exposed to strong physical impact during use. Also, it is understood that cracks or a lack of bonding between the layers of the structure is not acceptable during use.

By, as specified in claim 7, letting the first surface structure constitute the interior of a container/tank or a pipe for a chemical installation, several user-specific advantages of the invention have been obtained as chemical tanks or piping are required to have unique properties in relation to the surface of the wall.

The invention also relates to a lining material for lining of a wall structure comprising a woven material and at least one flouroplastic material, wherein said woven material is coated on the one side with a flouroplastic foil, said flouroplastic material being melted together with the flouroplastic foil in such a manner that that said flouroplastic foil is joined together with the woven material.

The coated flouroplastic material is defined as a flouroplastic material that has been melted onto one side of the woven material prior carrying out the joining of the flouroplastic foil.

By coating the woven material on one side and subsequently carrying out a bonding of the flouroplastic foil and the coating, a significant part of the required melting heat is generated through the flouroplastic foil. Consequently, it is necessary to use a foil which has a small thickness which, in turn, results in the lining material in its uncured state being relatively flexible in relation to e.g. bending properties.

The combination of a woven material and a flouroplastic foil which is optimally and mutually bonded provides a unique and flexible material that may be shaped in almost any way to adapt to given structural forms. This means that e.g. existing structures may receive subsequent treatment in a relatively uncomplicated manner if a fitting or lining is required or desired after completion of that structure. An important advantage of a bonding material according to the invention must be seen in the light of the fact that within certain fields of application, the requirements to shape, secure bonding, smooth transitions between junctions/weldings etc. are quite extensive. One example of this is if the material is to be used for lining of ships, wings of aircrafts, wind turbine wings or similar exposed structures.

In that connection, it should be mentioned that a material according to the invention may provide a particularly advantageous low level of friction due to its very smooth surface properties between the lined structure and a flow medium such as air or water subjecting it to friction.

These surface properties may also be used to increase the degree of efficiency of the wind turbine wing or to e.g. reduce friction between a hull and the water.

Apart from that, it should be noted that a lining material according to the invention features only a small bonding between the outer surface, the flouroplastic foil, and the non-desired elements such as e.g. algae or similar biological materials. A lining material according to the invention is thus a quite interesting alternative to poisonous and environmentally hazardous algae-limiting types of paint.

Common to all of the fields of application mentioned above is that they all have extensive requirements to shape, secure bonding between the foil and the woven material, and finally to the potential of being able to establish a reasonable strong bonding between the woven material and the structure to be lined in practice.

By, as specified in claim 9, applying the coating of woven material with the flouroplastic material all over one side of the woven material, an advantageous embodiment of the invention has been obtained which combines the optimal bonding properties between the flouroplastic foil and the woven material, the flexibility of the entire lining material and the mutual bonding of the coating and the woven material in a positive manner. Thus, it has turned out that a woven material according to the invention is not particularly prone to local cracks and slips between the coating and the woven material during e.g. application on a wall structure.

The invention comprises another method of manufacture of a wall structure comprising a first surface structure and a lining material comprising at least one flouroplastic foil, said lining material comprising a woven material with a coating of flouroplastic material on the one side prior to melting it together with flouroplastic foil and subsequently fixing it onto the first surface surface by means of a binding agent.

Also, the invention relates to a method of manufacture of a lining material for lining of a wall structure comprising at least one flouroplastic foil, said lining material consisting of a woven material with a coating of flouroplastic material on the one side prior to melting it together with one or more flouroplastic foils.

Figure

The invention will be described in the following with reference to the drawing where

Fig. 1 shows the mounting of a laminate onto a surface according to the invention and a cross section of the laminate.

Detailed description

The invention consists of a foil laminate 4 comprising a fibre mat 1 such as glass fibre fabric, silicat fibre fabric, aramid fibre fabric, coal fibre fabric or similar fabrics placed on a layer of vinylester 5 on a non-coated surface 6. The surface 6 may e.g. be a wall of metal, glass fibre or a plastic material. On the opposite side of the vinylester 5, the fibre mat 1 is coated with a layer of flouroplastic coating 2 such as e.g. PTFE (teflon). In addition, the coating layer is provided with a foil 3 of a flour polymer material such as e.g. PTFE, PFA, FEP etc. The layer of flouroplastic coating 2 is "moulded" onto one of the surface structure of the fibre mat 1 creating a solid bonding between the layer of flouroplastic 2 and the underlying mat 1. A flouroplastic foil 3, in this case a PTFE foil, is subsequently laminated together with the layer of flouroplastic coating 2.

In this manner, a flexible composite foil with a teflon coating 3 on the one side and a "uncured" glass fibre mat or another fibre mat 1 consisting of e.g. an aramid (kevlar), sicilat, carbon fibre on the other side is obtained. Thus, this foil may be placed on a surface in the same way that an ordinary glass fibre mat may be placed on a surface. According to the invention, the foil is only 1 or 2 mm thick and is extremely flexible which makes it easy to work with. This means that the product is easy and inexpensive to produce while also being easy to apply onto a surface.

When compared with known techniques, a lining with a composite foil according to the invention is superior by:

• Improved adhesion properties

• An increase in mechanical strength

• Improved absorption of thermal expansions • A double barrier in such a manner that there is no direct diffusion opening,

• Excellent chemical resistance properties

• Great thermal resistance as teflon may tolerate temperatures from to 250 C° to 370 C° which represents a significant improvement in relation to known linings; and • Significantly increased durability following from the above-mentioned improvements.

In addition, the foil may be used to repair conventional linings that have cracks and cannot be fixed to a satisfactory degree on the basis of the existing technique.

According to the invention, subsequent treatment of the inside of a tank/piping section may be carried out in the following manner: • Sandblasting of the surface of the steel wall

• Coating with a base coat

• Application of two layers of glass fibre mats saturated with vinylester, phenol, epoxy or the like, and then • Placing the teflon-coated foil with glass fibre fabrics mechanically onto the glass mats.

It has been recognized by the invention that the surface properties to be obtained with teflon-coated foils according to the invention may also be used for other purposes than tanks/piping, incl. various purposes involving ships, aircrafts, wind turbines and flat rooftops.

Apart from that, the invention will be usable in areas exposed to aggressive media of organic character which are desired to be protected against erosion or mechanical wear and tear. A further area of use could be when components/surfaces are desired to be protected against aggressive precipitants and strain by certain media.

Claims

Patent Claims

1. A wall structure comprising a first surface structure (6) characterized by the wall structure also comprising at least one flouroplastic foil (3) melted together with a woven material (1), said woven material (1) being glued onto the first surface structure (6) of a wall structure.

2. A wall structure according to claim I characterized by at least one of the layers of flouroplastic comprising a PTFE foil.

3. A wall structure according to claim l or2characterized by the woven material (1) being comprised by glass fibre fabric, aramid fabric, coal fibre fabric or the like.

4. A wall structure according to claims l to3characterized by the first surface structure constituting the exterior surface of a ship wall.

5. A wall structure according to claims l to3characterized by the first surface structure constituting the exterior surface of a wing of an aircraft.

6. A wall structure according to claims l to3characterized by the first surface structure constituting the exterior surface of a wind turbine wing.

7. A wall structure according to claims l to3characterized by the first surface structure constituting the interior of a container/tank or piping in a chemical installation.

8. A lining material for lining of wall structures (6) comprising a woven material (1) and at least one flouroplastic foil (3) c h a r a c t e r i z e d b y the woven material (1) being coated on one side with a flouroplastic material (2), said flouroplastic material (2) being melted together with the flouroplastic foil (3) in such a manner that the flouroplastic foil (3) is applied together with the woven material (1).

9. A lining material according to claim δcharacterized by the coating of the woven material (1) and the flouroplastic material (2) being applied over substantially one entire side of the woven material.

10. A method of manufacture of a wall structure comprising a first surface structure and a lining material comprising at least one flouroplastic foil characterized by the lining material consisting of a woven material onto which a coating of flouroplastic material is applied on one side prior to one or more flouroplastic foils being melted and subsequently fixed onto the first surface structure by means of a binding agent.

11. A method of manufacture of a lining material for lining of a wall structure comprising at least one flouroplastic foil characterized by the lining material comprising a woven material onto which a coating of flouroplastic material is added onto one side prior to one or more flouroplastic foils being melted onto it.