EP1169404A1

EP1169404A1 - Method of sealing pipes and repair kit

Info

Publication number: EP1169404A1
Application number: EP00918804A
Authority: EP
Inventors: Klaus Tranelis; Hans-Rolf Dierdorf; Bernhard Grünewälder; Werner Haller; Bernhard SCHÖTTMER; Peter Deckers; Birgit Ness
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1999-03-19
Filing date: 2000-03-15
Publication date: 2002-01-09
Also published as: WO2000056831A1; DE10012443A1

Abstract

The invention relates to a method for reinforcing or sealing the walls of hollow bodies. According to said method the area of a hollow body which is to be reinforced or sealed is at least partly enveloped by at least one woven fabric which is permeable to a curing outer adhesive or by a non-woven of this type, after which the woven fabric or non-woven is impregnated with an adhesive. The invention also relates to a repair kit which can be used to reinforce or seal the walls of hollow bodies. Said kit comprises at least one woven fabric or non-woven permeable to a curing adhesive with which a hollow body can be at least partly enveloped, as well as at least one curing adhesive to which the woven fabric or non-woven is permeable.

Description

Pipeline sealing process and repair kit

The invention relates to a method for reinforcing or sealing hollow body walls, in which a hollow body in the area to be reinforced or sealed is at least partially enclosed with at least one fabric or nonwoven fabric that is permeable to a curable external adhesive, and the fabric or nonwoven fabric is then impregnated with an adhesive . Furthermore, the invention relates to a repair kit for use in the reinforcement or sealing of hollow body walls, comprising at least one fabric permeable to a curable adhesive or such a nonwoven fabric with which a hollow body can be at least partially enclosed, and at least one curable adhesive for which the fabric or the nonwoven is permeable.

Hollow bodies that can be filled or filled in the walls, for example in the case of pipelines or boilers made of metal or plastic, are frequently damaged in the course of the operating time due to external influences (for example weather, temperature fluctuations or chemicals). Such damaged areas generally result in at least a reduction in the operational safety of the hollow body concerned. However, if the damaged areas are continuous openings over the entire cross-section of a hollow body wall, filling material usually emerges from the hollow body immediately or in the case of filling. This effect occurs particularly drastically with hollow bodies under pressure, for example pressure boilers, gas or

Liquid pipes, on. In such cases, the means for immediate permanent repair of the hollow body are often not available, especially not if the damage occurs in households. As a consequence, there is usually long downtime of the affected hollow body with the associated inconvenience.

There was therefore a need for a simple method that would quickly restore the defective hollow body walls mentioned above to an operational state, at least temporarily.

WO 94/05945 relates to a method for reinforcing corroded pipes, in particular pipelines, or containers, which allows reinforcing, for example, corroded pipeline sections during operation. The document describes a method for repairing pressure points that extend in the direction of the pipe or container center. For this purpose, a filling material is first entered into the printing point so that the filling material completely fills the printing point. A tape with high tensile strength is then wrapped around the filled point, it being possible for an adhesive to be applied to the outside of the previous winding between each winding. The high tensile strength tape used consists of high tensile strength fibers which are embedded in a binder matrix. The document does not show that the tape used is permeable to the adhesive used. A disadvantage of this method is that it is obviously not suitable for use in the case of breakthroughs in the tube wall, but rather only reinforces the wall. In addition, handling matrix-reinforced, inflexible fabric tapes of the type described in the publication is complex and, for example, almost impossible in difficult-to-access places. US-A 4,756,337 relates to a kit for use in sealing low pressure gas pipes and a corresponding method. Here, a pressure-sensitive, adhesive-impermeable tape is first wound around the area to be sealed and then wrapped with a fabric soaked in adhesive.

US-A 4,681,986 relates to a kit for use in isolating exposed cable junctions and a corresponding method. The exposed connection point is first wrapped with an amorphous insulation material and then enclosed with a tissue soaked in adhesive.

A disadvantage of the latter methods known from the prior art is that they require several separate work steps using different sealing materials. In particular, handling is made more difficult by the fact that the sealing process must be successfully completed when the first layer of sealant is applied, since additional layers of fabric contribute little or nothing to the sealing success.

There was therefore a need for a method which allowed a hollow body wall to be brought into an operational state again at least temporarily with as few work steps and as few materials as possible. Furthermore, there was the task of making the process so simple that it can also be used by insufficiently trained people with the necessary care and observance of an attached instruction with sufficient prospect of success, for example in the home area. Furthermore, the task was to provide a kit that contains the components required to carry out the method, so that the person using the method has all the means necessary for successfully carrying out the method.

The objects are achieved by a method in which a hollow body in the area to be reinforced or sealed is at least partially enclosed with at least one fabric or such a nonwoven fabric that is permeable to a curable external adhesive and the fabric or the nonwoven fabric is subsequently impregnated with an adhesive, and also by means of a repair kit which contains at least one fabric or such a nonwoven fabric which is permeable to a curable adhesive and at least one curable adhesive for which the fabric or the nonwoven fabric is permeable.

The invention thus relates to a method for reinforcing or sealing hollow body walls, in which a hollow body in the area to be reinforced or sealed is at least partially enclosed in the area to be reinforced or sealed with at least one fabric or such nonwoven material that is permeable to a curable external adhesive, and then the fabric or nonwoven fabric is also enclosed is soaked in an adhesive.

The term "hollow body", as used in the context of the present text, refers, for example, to containers for holding, storing or treating liquids, gases or flowable solids and to pipelines for the transport of liquids, gases or flowable solids, the aforementioned Containers or pipes may be suitable for pressureless operation or for use under pressure. The hollow bodies can have any cross section, for example circular, oval or angular. In a preferred embodiment of the invention, the term refers "Hollow body" on the pipes and containers mentioned with at least approximately oval or circular cross-section.

In the context of the present text, an "area to be reinforced or sealed" is understood to mean an area in the wall of the hollow body which is so defective that safe operation of the hollow body can no longer be guaranteed or is impossible. Examples of areas to be reinforced or sealed are cracks, corrosion spots, dents, dents, faulty seals or solder joints and the like. The aforementioned defective areas can extend over larger areas of the wall or affect only a small part of the wall. A damaged point can extend, for example, in the longitudinal axis of the hollow body, provided that the hollow body has a defined longitudinal axis, or can affect the hollow body circumferentially.

In a preferred embodiment of the invention, the method according to the invention is applied to hollow bodies which have a diameter of not more than about 100 cm, for example about 50 cm or about 40 cm. In a further preferred embodiment of the invention, the method is applied to hollow bodies whose diameter is approximately 0.1 to approximately 30 cm, in particular approximately 0.5 to approximately 15 cm.

If the method according to the invention is applied to hollow bodies which are under pressure during their operation, the expected operating pressure should generally not exceed about 30 bar. Depending on the type and extent of the damaged area and the material of the hollow body, a lower upper limit may be appropriate. Damaged areas of greater extent, such as extensive corrosion or extensive cracks, the more than about a third of the circumference of the hollow body may require lower expected upper pressure limits. In general, the operating pressure to be expected in such cases should be less than approximately 20 bar, in particular approximately 16 bar or less.

The method according to the invention is fundamentally suitable for hollow bodies made from a wide variety of materials, it not being necessary for the hollow body to consist of only one material. The method according to the invention is particularly suitable, for example, for hollow bodies made of plastics, metal, concrete, porcelain (earthenware), ceramic or composite materials which comprise the materials mentioned and, if appropriate, further substances. Materials for which the process according to the invention is particularly suitable are, for example, polyvinyl chloride (PVC-U and -C), poly (acrylonitrile-butadiene-styrene) (ABS), copper, brass, steel, cast iron, lead, zinc, concrete, porcelain (Earthenware), AZ pipes or ceramics, or mixtures or composites of two or more of the materials mentioned.

In the context of the method according to the invention, the damaged area is first at least partially enclosed with at least a tissue or such a nonwoven fabric that is permeable to a curable outer adhesive, and the fabric or nonwoven fabric is then impregnated with the outer adhesive.

In the context of the present text, an “external adhesive” is understood to mean an adhesive which is applied from the outside after the fabric or the nonwoven has been applied.

The term "curable" means in the context of the present text that the adhesive either under ambient conditions, as in the Use of the method according to the invention usually prevails, cures automatically, or cures only as a result of an action to be carried out by the user (for example heating, moistening, irradiating or the like). Temperatures from approximately 5 ° C. to approximately 50 ° C. and atmospheric humidity values from approximately 10 to approximately 100% are considered to be the usual conditions when carrying out the process according to the invention.

External adhesives which are suitable within the scope of the method according to the invention are those adhesives which both have good adhesion to the surface of the hollow body and also ensure an adhesive bond with the fabric or nonwoven used. In addition, suitable adhesives have a pot life which, on the one hand, enables problem-free application to and penetration of the fabric or the nonwoven fabric, but on the other hand enables the quickest possible usability of such a reinforced or sealed area. Suitable adhesives have a pot life of less than about 15 minutes, in particular less than about 5 minutes, at about 20 ° C. Particularly suitable pot lives are about 0.5 to about 4 minutes, for example about 1 to about 3 minutes. At higher or lower application temperatures, for example, an external adhesive can be used, which ensures compliance with the pot life mentioned under the corresponding conditions. If the pot life depends on the air humidity, as can be the case, for example, with polyurethane systems, the values given here apply, for example, at about 20 to about 23 ° C. and about 50 to about 65% relative air humidity.

Suitable adhesives can be used both as one-component systems (1K) and in the form of two-component systems (2K). In the context of a preferred embodiment of the invention, a two-component adhesive is used.

Suitable types of adhesive are curable adhesives based on polyurethane, polyester, epoxy resin or (meth) acrylate or a mixture of two or more such adhesives. In a preferred embodiment of the invention, external adhesives which are suitable in the context of the present invention have no pressure-sensitive adhesive properties after curing, in particular after the pot life has ended.

Suitable adhesives are those which can be prepared in the usual way from polyols and isocyanates. Particularly suitable are, for example, polyurethane adhesives which have prepolymers carrying NCO groups, as can be obtained by reacting suitable polyols with corresponding polyfunctional isocyanates. The polyols commonly used in the field of polyurethane adhesives can be used as polyols for producing such prepolymers. In particular, these are polyester polyols or polyether polyols or mixtures thereof. Suitable polyester polyols generally have a molecular weight (M _n ) of approximately 200 to approximately 50,000 and are generally obtained by reacting linear diols with dicarboxylic acids. If necessary, proportions of higher-functionality components may still be present in the reaction mixture in such a reaction. Suitable linear diols are, for example, the alkanediols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexanediol or their higher homologs and isomers, and mixtures of two or more of the compounds mentioned. Suitable dicarboxylic acids are the alkanedicarboxylic acids with 2 to about 40 C atoms, their higher homologues and isomers, and mixtures of two or more thereof. The aromatic dicarboxylic acids, for example the isomeric terephthalic acids, are also suitable. For the production of corresponding polyols the compounds mentioned are reacted with one another in such a way that molecules are formed which carry an average of more than one OH group, in particular about 1.5 to about 2.5. The polyols are then reacted with polyisocyanates, so that polyurethane prepolymers with at least one free isocyanate group result. Corresponding polyurethane systems can be formulated as 1K or 2K systems, with 2K systems usually having a high molecular weight polyol component and a component carrying isocyanate groups. In a preferred embodiment of the present invention, a polyurethane prepolymer based on MDI (4,4 ^'- diphenylmethane diisocyanate) is used as 1 K system and a polyether or polyester polyol, or a mixture of two or more of said polyols used. In a further preferred embodiment of the invention, a first component containing a polyether or polyester polyol or a mixture of two or more of the polyols mentioned and a second component containing an at least difunctional isocyanate are used as the two-component system.

Commercially available polyurethane adhesives suitable for the purposes of the present invention are, for example, Sista D 325 (1-component system) and Makroplast UK (2-component system) (both: Henkel, Düsseldorf).

Surprisingly, it was found that a special 2-component PU system consisting of a special polyol component and a special isocyanate component leads to excellent results. The isocyanate component based on a mixture of MDI and a polyisocyanate based on HDI should have an NCO value between 20.0 and 28.0, better between 21.0 and 26.0 and in a specially selected formulation between 22.5 and 24.5 wt .-% and preferably be unfilled. The polyol component is at least from a mixture of a branched polyalcohol with ether and ester groups and a polyetheraminopolyol. The OH number of the unfilled polyol mixture should be between 315 and 450, better between 340 and 410 and preferably between 355 and 390. The polyol component preferably also remains unfilled. Catalysis is not absolutely necessary; however, a small amount of catalyst is advantageous. The volume mixing ratio between the polyol component and isocyanate component can vary within a wide range. For better handling, a volume mixing ratio of 1: 1 should be aimed for. The crosslinking of both components should be approximately stoichiometric, with an NCO / OH ratio between 1, 20: 1, 00 to 0.80: 1, 00, better between 1, 10: 1, 00 to 0.90: 1, 00, but should preferably be set between 1.05: 1.00 to 1.00: 0.95.

The polyol component contains (in% by weight)

1. 62 to 73, preferably 70 to 65, of polyether / ester polyol,

2. 38 to 27, preferably 30 to 35, of polyetheraminopolyol,

3. 0.0 to 0.05, preferably 0.01 to 0.02 of catalyst and

4. 0.0 to 0.5, preferably 0.1 to 0.25, defoamer. The polyisocyanate component contains (in% by weight)

A) 15 to 45, preferably 25 to 35 in MDI and

B) 85 to 55, preferably 75 to 65, HDI-based polyisocyanate.

The coating should also have a consistency in the mixed state, which on the one hand allows amounts of 50 to 75 g, depending on the tube diameter, to be absorbed per defect and on the other hand soaks the bandage well without the coating flowing away from the application site. The viscosity in the mixed state, measured according to Brookfield at 23 ° C, should therefore be around 5,000 mPas. The quick hardening of the system is achieved through the special selection of the components and through a high quantity coating. A heat build-up forms, which allows the coating to harden quickly.

This 2K system based on polyurethane for the temporary repair of pressure and unpressurized pipelines is characterized above all by the fact that with a long processing time of at least 5 minutes, the coating cures, preferably in conjunction with the described method, after just one step Hour at 23 ° C is so high that a pipeline system repaired with it can withstand an operating pressure of 16 bar for at least 1,000 hours. If there is no pressure loss due to leakage, the test is passed.

In addition, the system is so flexible that changes in length on the pipes remain unaffected by the coating. The hardness of the cured coating therefore does not exceed the dimensionless value of 77, measured according to Shore D at 23 ° C.

In addition, the coating has high heat and boiling water resistance. In order to be able to measure the heat and water resistance of the coating as far as possible under harsh conditions, test standards from the wood industry have been used, since the test specimens bonded from beech wood swell and shrink considerably. Due to the high load on repaired pipelines, it therefore makes sense if the coating, used as an adhesive, achieves a value of> 6.0 N / mm ² , measured according to the adhesive standard DIN EN 204, stress group D4. The heat resistance, measured according to WATT 91, has values of> 9.0 N / mm ² (measured at 80 ° C). The heat resistance is This is important because pressurized water systems are operated at temperatures of 60 ° C and pressureless systems have to withstand even higher temperatures of up to 90 ° C.

Furthermore, the coating on the commercially available piping has sufficient adhesive properties. Different pipe materials are used in industry and household. As a rule, these are made of bondable plastics or metals such as PVC-U, PVC-C, ABS, galvanized or chromed metals, brass, VA steel or copper. In rare cases, lead pipes are also used. Pipelines made of the above-mentioned materials must therefore be tested in order to be as practical as possible. In order to simulate leaks such as stress cracks, holes or the like, a test was prepared. If leakage occurs in the area of the molded parts, such as on the fitting, T-piece or socket, which is very often the case, the usual repair systems, such as the fitting of clamps, are unusable. Therefore, in order to simulate the leakage in this area, a hole with a diameter of 3 mm was drilled in connection points in DN 40 plastic pipes and a hole with a diameter of 2 mm on ¹ inch metal pipes. The simulated defect must then be sanded down and cleaned with a solvent. The 2-component coating is then applied to the pipe from a 2-chamber double cartridge with a static mixer attached and spread with a brush. A 5 cm wide, 2.5 m long polyester tape, which is wrapped around the pipe together with the coating, serves as reinforcement and coating fixation.

Other notable features are:

- No storage stability problems even at temperatures of 40 ° C and longer storage times, because the reaction mechanism of Polyurethanes, polyaddition, generally behave better than those systems that result in polymerization.

- The coating system can be used universally on a wide variety of materials, since polyurethanes bring good to very good adhesion properties when the raw material components are carefully selected.

- The coating based on the 2-component PU system has compared to many other systems, e.g. based on polyester, polystyrene or PMMA further advantages in terms of odor emission.

- The raw material costs are usually cheaper.

Suitable adhesives for polyester are the adhesives conventionally produced from polyols and polycarboxylic acids. In a preferred embodiment of the invention, polyester adhesives are used which are based on butanediol-1, 4 or pentaerythritol, or a mixture thereof, and adipic acid or phthalic acid, isophthalic acid or terephthalic acid, or a mixture of two or more thereof.

Suitable epoxy resin adhesives are the adhesives which can be prepared in the usual way from polyols and epoxides. Epoxy resin adhesives which have bisphenol-A as the epoxy component and are cured with amines or polymercaptans are particularly suitable. Corresponding systems are known to the person skilled in the art. Suitable adhesives are available, for example, under the name Metallon E (from Henkel, Düsseldorf).

Suitable (meth) acrylate adhesives are the adhesives which can be prepared in the customary manner using acrylic acid and its esters or from methacrylic acid and its esters. The adhesives have at least one compound that can be subjected to a radical polymerization reaction. Particularly suitable in this regard are adhesives made from alkyl acrylates, cycloalkyl acrylates, alkyl methacrylates, cycloalkyl methacrylates, alkoxy acrylates, alkoxymethacrylates, alkylene diacrylates or alkylene dimethacrylates. Suitable monomers are, for example, methyl methacrylate, lauryl methacrylate, 2-

Ethylhexyl methacrylate, ethyl methacrylate, n-butyl methacrylate,

Isobutyl methacrylate or tert-butyl methacrylate, or mixtures of two or more thereof. In a preferred embodiment of the invention, the monomers used are methyl methacrylate, tetrahydrofurfuryl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, hydroxyethyl methacrylate or hydroxypropyl methacrylate or mixtures of two or more thereof. The proportion of said monomers in the adhesive to be used according to the invention is generally about 1 to about 90% by weight, for example about 10 to about 80% by weight or about 15 to about 60% by weight.

In the context of a preferred embodiment of the invention, two-component methacrylate adhesives or polyurethane adhesives are used.

The adhesives mentioned are generally used individually, but if appropriate a mixture of two or more of the adhesives or types of adhesives mentioned can also be used.

In order to ensure sufficient penetration of the fabric or nonwoven, the viscosity of the outer adhesive should not exceed a value of approximately 10,000 mPas (Brookfield, RVT, 23 ° C, spindle 4). In a preferred embodiment of the invention, the outer adhesive has a viscosity of about 500 to about 7,000, in particular about 1,500 to about 5,000 mPas (Brookfield, RVT, 23 ° C., spindle 4). If necessary, an inner adhesive can be applied to the area to be reinforced or sealed before the area to be reinforced or sealed by the fabric or the nonwoven fabric. The inner adhesive may be necessary, for example, if particularly good adhesion of the fabric or the nonwoven fabric to the surface of the hollow body is desired, or if the fabric or nonwoven fabric is to be fixed first on the surface of the hollow body, for example to prevent the fabric from slipping or to prevent the nonwoven. Frequently, the application of an internal adhesive can even improve the sealing success, ie the life of the seal can be extended if necessary, or there is an improved tolerance of the sealed damaged area for increased pressure load.

The adhesives already mentioned above are suitable as the internal adhesive. However, it is also possible to use an adhesive that has permanent adhesive properties as the internal adhesive. The inner adhesive can, for example, also have a higher viscosity than the outer adhesive. A suitable upper limit for the viscosity of the outer adhesive is, for example, about 20,000 mPas. In a preferred embodiment of the invention, however, identical adhesives, i.e. curing adhesives, are used as the inner and outer adhesive.

In the context of the method according to the invention, all fabrics which have sufficient permeability for a curable external adhesive are suitable as fabrics.

All nonwovens that have sufficient permeability for a curable external adhesive are equally suitable as nonwovens. In the context of the present invention, the term “fabric” also includes structures which represent a mixed form of fabric and nonwoven, for example composites which have at least one fabric layer and at least one nonwoven layer or other mixed forms in which, for example, fabric surfaces and nonwoven surfaces alternate.

The term "permeability" refers to the ability of the fabric or nonwoven fabric to allow adhesive to pass through the fabric mesh or the spaces in the nonwoven fabric, so that the adhesive is completely penetrated into the fabric or nonwoven fabric. The permeability of a fabric or a nonwoven depends on the fabric or the nonwoven itself and on the adhesive used, in particular on the viscosity of the adhesive. In general, there is sufficient permeability in the sense of the invention if the adhesive penetrates at least one fabric layer or nonwoven fabric layer during its pot life, ie before it has fully hardened.

The term "fabric" includes fabrics which are made from natural fibers, synthetic fibers, metal fibers or glass fibers or mixtures of two or more of the fibers mentioned (mixed fabrics). Suitable materials are, for example, cotton, linen, sisal, hemp, flax, polyethylene, polytetrafluoroethylene, polyester, polyurethane, steel or glass fibers. Suitable blended fabrics have, for example, a combination of natural fibers and plastic fibers, in particular cotton fibers and polyester fibers. The proportion of natural fibers can be approximately 1 to approximately 99% by weight, the proportion of plastic fibers approximately 99 to approximately 1% by weight. The term "nonwoven fabric ¹ includes nonwovens made of synthetic and natural fibers, which can be obtained by general methods of manufacture known to the person skilled in the art, for example random nonwovens or spunlaced nonwovens.

In a preferred embodiment of the invention, a fabric is used which consists of polyester threads. In a further preferred embodiment, a fabric is used which consists of approximately 40 to approximately 80% by weight of cotton threads and approximately 20 to approximately 60% by weight of polyester threads.

In a further preferred embodiment of the invention, fabrics are used which have one or more of the following properties:

- plain weave 1: 1 or

- body bond - heat resistance:> 120 ° C,

- chain: Nm 34/2; 50 to 150 warp threads

- weft: Nm 28/1; 2 to 8 * 2 per cm,

- Mesh size warp / weft: about 100 to about 600 microns.

The fabrics or nonwovens which can be used in the context of the present invention can have a wide variety of dimensions, depending on the intended use, for example square, circular or oval. In a preferred embodiment of the invention, however, band-shaped fabrics or nonwovens are used, the length of which exceeds the width many times over. Particularly suitable are woven or nonwoven tapes which have a width of approximately 5 to 500 mm and a length of approximately 10 to 500 cm. In a preferred embodiment, woven or nonwoven tapes are used which have a width of about 40 to about 80 mm and a length of about 200 to about 300 cm.

The fabrics or nonwovens can optionally be mechanically or chemically pretreated, i.e. the fabric or nonwoven surface can, for example, be roughened or treated with adhesion promoters. The fabrics or nonwovens can optionally be heat-set or dyed in one or more colors. If necessary, the fabric or the nonwoven fabric can already be equipped with a pressure sensitive adhesive, but it should be ensured that the fabric or the nonwoven fabric can still be penetrated by the external adhesive in order to achieve an optimal sealing effect.

In a preferred embodiment of the method according to the invention, the damaged spot to be sealed or reinforced is first cleaned of adhering, coarse soiling in a first cleaning step and the surface is roughened. This first cleaning step is necessary when the area to be reinforced or sealed or the area to be covered with fabric or nonwoven has coarse dirt or is particularly smooth or both. The first cleaning step can be carried out using a wide variety of means which are generally known. A suitable means for carrying out the first cleaning step is, for example, a wire brush, which both removes coarse dirt and ensures that the surface is roughened at the damaged area. A further roughening can optionally be carried out using abrasives. In a further preferred embodiment of the invention, not only the immediate vicinity of the damaged area is roughened, but also surface parts going beyond it, preferably the entire circumference, which is to be wrapped with fabric or fleece. The area around the damaged area, preferably the entire area to be enclosed by the fabric or fleece, can then be chemically cleaned, in particular degreased and, if appropriate, freed from further organic residues, provided such contaminants are present. As a rule, all common solvents are suitable for this. In a preferred embodiment of the invention, however, a cleaning agent containing aliphatic alcohol or a mixture of two or more aliphatic alcohols, for example ethanol, propanol or isopropanol, is used for cleaning. In a preferred embodiment of the invention, the chemical cleaning step is always carried out.

In a next step, the first adhesive can be applied if necessary. The application is preferably made to the full extent of the fabric or nonwoven.

Then, provided that the preceding steps have been carried out, otherwise as the first step, the area to be sealed or reinforced is at least partially enclosed with at least one fabric or nonwoven fabric that is permeable to a curable external adhesive. If the hollow body to be reinforced or sealed is a hollow body designed for unpressurized operation (for example a drain pipe), then it may be sufficient to cover only the damaged area with one or more layers of fabric or nonwoven fabric. In a preferred embodiment of the invention, however, the hollow body is comprehensively enclosed with the fabric or nonwoven in the area of the point to be reinforced or sealed. In a preferred embodiment of the invention, the point to be reinforced or sealed is enclosed in a spiral shape with a plurality of fabric or nonwoven layers. The number of layers of fabric or nonwoven depends on the type and Scope of the position to be strengthened or sealed. If the extent of the damaged area exceeds the width of the fabric or nonwoven fabric, several fabric or nonwoven fabric layers can be wrapped side by side, so that individual fabric or nonwoven fabric layers show partial overlap.

In a preferred embodiment of the invention, at least about two fabric or nonwoven layers are applied.

The outer adhesive can already be applied to each individual fabric or nonwoven layer or to several fabric or nonwoven layers during the application of the fabric or nonwoven. In this way, particularly with adhesives with a short pot life and when using dense fabrics with a small mesh size or dense nonwovens, particularly good penetration of the fabric or nonwoven with adhesive can be achieved. However, it is also possible to apply the adhesive only after the hollow body has been completely enclosed, so that the fabric or the nonwoven is impregnated with the adhesive from the outside.

In a preferred embodiment of the invention, the outer adhesive is already applied during the application of the fabric or nonwoven.

After the area to be reinforced or sealed is completely covered with fabric or nonwoven fabric in a sufficient number of layers and the fabric or nonwoven fabric is completely penetrated by the external adhesive, suitable measures for curing the adhesive can be taken, if this is necessary depending on the type of adhesive to be hit. Suitable measures can be, for example, moistening, irradiating or heating the soaked in adhesive Fabric or nonwoven, for example with a hot air blower. In the latter case, however, it should be ensured that the maximum permissible temperature with which adhesive and fabric or nonwoven can be loaded is not exceeded. Generally, the temperature should not exceed about 60 to about 80 ° C.

This results in the following general processing: Before starting work, the pipes must be depressurized. Appropriate measures must be taken to prevent the medium from leaking during work or until commissioning.

Metallic pipelines must first be cleaned and roughened from coarse contaminants such as hemp, sealing pastes, sealing tapes, rust, paint, etc. with a steel brush or emery cloth on both sides at a distance of 1.5 times the bandwidth. This area is then degreased with Tangit KS cleaning cloths from Henkel.

For plastic lines made of PVC-U, PVC-C and ABS, cleaning with Tangit KS cleaning cloths is sufficient.

The cartridge gun is opened, the double cartridge is inserted and the gun is locked again.

The cap on the tip of the cartridge is then removed and the static mixer is attached. The cartridge gun is now ready for use.

The adhesive components are now, by pressing the

Trigger lever, pressed into the static mixer, mixed and in one

Partially applied to the pipe surface and evenly distributed with a brush around the pipe circumference at least in bandwidth. The tape is then placed flush with the fitting in the adhesive bed and wrapped evenly in six layers around the pipe. Make sure that the tape is completely saturated with adhesive. It has proven to be expedient to press the adhesive through the fabric with the brush, since this simultaneously pre-models the tape. The adhesive is then applied on the fitting side, distributed and the tape is wound over the point to be sealed in the manner described.

Six tape layers must be applied on the fitting side as well as over the point to be sealed. Finally, the tape is wound over the tube side again. After bandaging, the band is adjusted by hand (use gloves!) To match the connecting element.

If only a crack or hole seal is to be made on the smooth piece of pipe, then, after the appropriate pipe preparation, it is sufficient to apply adhesive in a bandwidth to the left and right of the damaged area. The tape is then wrapped around the pipe 6-10 times in this area. Make sure that the tape is evenly saturated with adhesive.

The adhesive should be applied a little wider than the tape in order to ensure that the tape connects to the substrate even in the edge area of the tape.

When the system is depressurized, the repaired system can be put back into operation after only 15 minutes, at a pressure load of up to 6 bar after 30 minutes and at a pressure load of up to 16 bar after 60 minutes at 23 + 2 ° C. In a preferred embodiment of the invention, an adhesive which is self-curing, ie which cures without any further external influence, is used as the external adhesive.

The implementation of the method according to the invention is facilitated in particular when the required components are accessible as a kit, completely and in a coordinated form.

The present invention accordingly also relates to a repair kit for use in the reinforcement or sealing of hollow body walls, comprising at least one fabric permeable to a curable adhesive or such a nonwoven fabric with which a hollow body can be at least partially enclosed, and at least one curable adhesive for which the fabric or the nonwoven fabric is permeable to.

The fabric or the nonwoven and the adhesive mentioned correspond to the fabrics, nonwovens and adhesives as have already been described above in the context of the present text.

In a preferred embodiment, the repair kit contains at least one curable adhesive, which is used, for example, as an outer or inner adhesive or, if both adhesives are identical, as the only adhesive, in at least one cartridge. The cartridge is designed in the usual way and usually has a nozzle for attaching an extrusion nozzle. If the adhesive is a 2-component adhesive, then a 2-chamber double cartridge is used as the cartridge. In a further preferred embodiment, the repair kit according to the invention also contains at least one of the following components:

Gloves, one or more extrusion nozzles, if necessary with

Static mixer,

Cartridge holder with extrusion device, for example a cartridge gun,

Brush,

Cleaning supplies.

All common plastic gloves are suitable as gloves, provided they are inert to the adhesives used.

The kit according to the invention optionally has one or more extrusion dies. If the adhesive to be used is a two-component adhesive, an extrusion nozzle is advantageously used which has a static mixer connected to the extrusion nozzle in order to mix the adhesive components. The use of a static mixer is particularly recommended, particularly because of the simple and uniform mixing and thus also the penetration of the textile tape.

In a further preferred embodiment of the invention, a cartridge is used to store the adhesive which is under pressure in order to enable the ingredients to be extruded automatically. This can be made possible, for example, by a cylinder filled with pressurized gas, which, after operating a corresponding trigger device, sets an extrusion piston in motion in the cartridge. The implementation of the method according to the invention with a repair kit according to the invention will now be explained by way of example for a pressurized, leaky pipeline with leakage. The leak is located directly at a connection point (fitting) The repair kit contains a 2-component adhesive in a 2-chamber double cartridge with a protective cap, a cartridge gun, fabric tape, gloves, cleaning agents and a brush.

First the line pressure is turned off. The area to be sealed is then cleaned thoroughly at a distance of 1.5 times the bandwidth to the left and right of the leak. For plastic lines, intensive cleaning with the included cleaning agent is sufficient. Metal lines must be cleaned with a steel brush to remove coarse dirt (hemp, paste, rust, paint, etc.) and roughened (sanded). After that, if necessary, a fine cleaning is carried out with the enclosed cleaning agent.

The double cartridge with the 2-component adhesive is then inserted into the gun and locked. Any existing cartridge protection cap is removed from the cartridge and an extrusion nozzle with a static mixer is screwed on. The adhesive is first applied to the pipe, spread evenly over the circumference of the pipe with at least the bandwidth using the brush supplied. The tape is placed directly on the fitting and the pipe is wrapped. In order to evenly soak the tape with glue, glue is applied again after each winding layer and spread with the enclosed brush. For example, approximately 6 layers of tape should be applied in this step. The adhesive is then applied to the leaky fitting and the tape is wound over the fitting (at least one band). The tape should also be soaked here (method of operation as already described), the number of layers can also here for example 6. The rest of the tape is wrapped again on the tube and soaked in adhesive. Thereafter, the tape can, if necessary, for example using the enclosed glove, be adapted to the shape of the part to be sealed by manual molding, for example by turning it in the tape direction.

The pot life of the adhesive based on polyacrylates is, for example, about 2 to about 3 minutes at 20 to 25 ° C. With a pressure load of up to about 6 bar, a minimum hardening time of about half an hour at over 6 bar of about one hour must be observed (measurement analogous to DIN 16970 on PVC-U pipes). When using a PU adhesive, it takes approx. 1 hour to cure until a pressure load of 16 bar is reached.

Examples:

I. raw material

Sovermol 1080, a branched polyalcohol with ether and ester groups from Henkel KGaA,

Voranol RA 800, a highly reactive, amine-based polyether polyol from Dow Chemical,

Perenol E8, a solvent mixture with silicone from Henkel KGaA,

Fomrez UL 24, a dimethyltin mercaptide from Witco GmbH, Desmodur VK 5, a polyisocyanate based on diphenylmethane diisocyanate from Bayer,

Desmodur DA, a polyisocyanate based on hexamethylene diisocyanate from Bayer.

II. Production process of the coating:

1. Polyol component

The individual components are placed in an evacuable laboratory dissolver at room temperature and heated to 70 ° C. with stirring at a stirring speed of 350 rpm. A vacuum of 15 mbar is then applied for 1 hour at the same stirring speed and temperature. The mixture is complete as soon as the water content, measured according to Karl Fischer, is below 0.05%.

2. Isocyanate component

The individual components are placed in an evacuable laboratory dissolver at room temperature and mixed with stirring at a stirring speed of 350 rpm for 15 minutes under a vacuum of 15 mbar. 3. Equipment

PC laboratory dissolver type LDV 1 from FA. PC Laborsystem GmbH,

CH - 4312 Mägden,

PVC pipes according to DIN 8062, manufacturers such as WKT, Wavin,

Metal pipes, usual qualities available in specialist shops,

Polyester tape, usual qualities available in specialist shops,

2 chamber cartridges and static mixer, usual qualities available from specialist dealers.

4. Composition (in parts by weight)

III. Test method

1. Test standards

- DIN EN 204 Positioning sequence No. 5, assessment of adhesives for non-load-bearing components for connecting wood and wood-based materials,

- DIN EN 205 wood adhesives for non-load-bearing applications (test specimen production),

- Shore D hardness measurement according to DIN 53505, - Brookfield RTV ISO 2555 viscosity measurement,

- The pressure load was carried out on plastic pipes made of PVC-U analogous to DIN 16970

2. Other test methods:

- Storage stability test

Both the polyol component and the isocyanate component are stored over a period of 3 months at an elevated temperature of 40 ° C. The coating is considered to be stable in storage if the initial viscosity of the mixed adhesive system increases by less than twice.

- Pot life or processing time

When repairing the pipeline, the maximum processing time at 23 ° C and a relative humidity of 50% must be determined. The time is considered to be exceeded when the coating can no longer be spread with the brush.

IV. Results

after 2 h V. Determination of the absorption behavior of textile tapes

(Fabric or nonwoven) versus adhesives)

Test materials:

Test plate: material PVC-U

Board width at least 150 mm

Plate length 300 mm

Board thickness> 4 mm

Fabric tape: tape length 400 mm tape width> 60 mm

Tension weights 2 x 80 gr. Including clamp

Squeegee: film width 40 mm film thickness 0.7 mm

Execution:

The fabric tape to be tested is cut to a length of 400 mm. At the two ends of the cut, the tension weights are fastened with a clamp so that the fabric tape after insertion into the

Adhesive board hangs freely at least 20 mm on the side.

The squeegee is applied to the test plate over the entire length of the plate

Glue film 0.7 mm thick and 40 mm wide pulled out.

Immediately after the adhesive is applied, the fabric tape is level in the

Adhesive board inserted and the plate placed horizontally (without bending) on two support beams so that the tension weights hang freely.

The fabric tape must protrude at least 10 mm on both sides of the extended adhesive film.

The residence time of the fabric tape in the adhesive is max. 1 minutes at

20 + 2 ° C. The point in time at which a complete soaking of the fabric band has taken place is determined.

After one minute, the tension weights are removed and the absorption capacity is assessed.

Rating:

The impregnation ideally corresponds to the film width (without a

Blurring of the edge areas) and the film length of the applied

Adhesive.

When a complete soak is reached within the max.

The duration of the test is to be determined.

If this condition is not reached within the specified test time, the degree of impregnation in area percent must be determined. It must also be determined to what extent the edge areas (blurring of the edges) correspond to the applied adhesive film.

Annotation:

The result of the absorption capacity is essentially determined by the fabric base (cotton, polyester, glass fiber fabric, etc.), the fabric structure (warp, weft, etc.) and the viscosity or structure of the adhesive.

Claims

claims

1. A method for reinforcing or sealing hollow body walls, in which a hollow body in the area to be reinforced or sealed is at least partially enclosed with at least one fabric or such a nonwoven fabric that is permeable to a hardenable external adhesive, and the fabric or the nonwoven fabric is then impregnated with an adhesive .

2. The method according to claim 1, characterized in that an inner adhesive is applied to the area to be reinforced or sealed before the area to be reinforced or sealed by the fabric or the nonwoven.

3. The method according to claim 2, characterized in that the inner and outer adhesive are identical.

4. The method according to any one of claims 1 to 3, characterized in that the point to be reinforced or sealed is enclosed in a spiral shape with a plurality of fabric or nonwoven layers.

5. The method according to any one of claims 1 to 4, characterized in that a curable adhesive based on polyurethane, polyester, epoxy or (meth) acrylate or a mixture of two or more such adhesives is used as the outer and inner adhesive.

6. The method according to any one of claims 1 to 5, characterized in that the outer adhesive or the inner adhesive or both immediately before application a viscosity of 1500 to 5000 mPas (Brookfield RVT, 23 ° C, spindle 4, <10 U / min).

7. Repair kit for use in the reinforcement or sealing of hollow body walls, comprising at least one fabric or such a non-woven material that is permeable to a hardenable adhesive, with which a hollow body can be at least partially enclosed, and at least one hardenable adhesive for which the fabric or the non-woven fabric is permeable.

8. Repair kit according to claim 7, characterized in that the fabric has one or more of the following properties:

- Plain weave: 1: 1 or

- body attachment,

- heat resistance:> 120 ° C,

- chain: Nm 34/2; 50 to 150 warp threads

- weft: Nm 28/1; 2 to 8 ^* 2 per cm.

- Mesh size warp / weft: 100 to 600 μm.

9. Repair kit according to claim 7 or 8, characterized in that it contains at least one curable adhesive in a cartridge.

0. Repair kit according to one of claims 7 to 9, characterized in that the adhesive consists of a polyol and a polyisocyanate component which

1. 62 to 73% by weight of polyether / ester polyol,

2. 38 to 27% by weight of polyetheraminopolyol and

A) 15 to 45 wt .-% of MDI and

B) 85 to 55 wt .-% of polyisocyanate based on HDI.