Calibrated Hose for Pipe Repair

Abstract

The present invention provides a tensile strength of more than 2200 N according to DIN 53857 and an air permeability of 10 liters / (dm 2 x minutes), the overlapping ends of the fabric are sewn together with at least one stitch along the entire length of the hose. A plastic fabric is applied to the outside of the stitching, extending over the stitched area of ​​the hose, resulting in a substantially smooth exterior and improved structural stability. The invention also relates to the use of the fabric hose to seal defective pipes, a pipe rehabilitation kit including the fabric hose, and a method of rehabilitation and / or repairing pipes using the fabric hose or kit.

Description

[Technical Field]

[0001] The present invention provides a tensile strength of more than 2200 N according to DIN 53857 and an air permeability of 10 liters / (dm 2 x minutes), the overlapping ends of the fabric are sewn together with at least one stitch along the entire length of the hose. A plastic fabric is attached to the outside of the stitching, extending over the area of ​​the hose where the stitching was made. The invention also relates to the use of the fabric hose to seal a defective pipe, a pipe rehabilitation kit including the fabric hose, and a method of rehabilitation and / or repairing a pipe using the fabric hose or kit. [Background technology]

[0002] Rehabilitating or replacing underground water or sewer pipes is very expensive and time-consuming. If work has to be done on pipes laid under roads, it inevitably causes significant disruption to traffic above. Also, structures built above may make it impossible to reach the pipes from above. In this case, building new structures along alternative routes would be very expensive.

[0003] To repair defective or otherwise rehabilitated pipes, a method has been developed to prevent the need to replace the pipe by drawing a lining, such as a hose, over the defective pipe wall and sealing it. This results in a slight reduction in cross section, but this is within acceptable limits.

[0004] EP 3137804 B1 describes a lining for repairing partially damaged drinking water or wastewater pipes. The braided hose material used here lacks radial and axial strength and is therefore typically placed against the inner wall of the damaged pipe during installation, replicating any protrusions, for example. This can lead to the formation of new blockages or cavities during repair, which can lead to new leaks and blockages in the pipe.

[0005] In conventional wastewater pipe rehabilitation, a felt hose is inserted using the so-called inversion method. In this method, a slideway or film hose (pre-liner) is first pulled into the pipe to be rehabilitated as a so-called lost form, and then a felt hose (main liner) is pulled in as a carrier hose along with the calibration hose. However, due to their material properties (non-reinforced plastic film and felt fabric), neither the pre-liner nor the main liner can absorb radial or axial forces. The combination of the main liner and calibration hose has limited axial force absorption. Due to its material structure, conventional pre-liners are impermeable to air. All components are installed one by one using the inversion method. In this case, this installation is performed between maintenance manholes or between a maintenance manhole and a "dead" end (i.e., installation into an inaccessible pipe end, the so-called open-end method). After installation, the system is pressurized to approximately 0.8 bar and expanded. The synthetic resin contained in the main liner is then cured. This system also has the disadvantage that it replicates any imperfect contours of the pipe wall to be rehabilitated, resulting in the negative consequences mentioned above. The system is unable to absorb much axial force, so the irregular cross section of the old pipe is replicated. The felt hose conforms to the shape of the old pipe, including all its deformations.

[0006] Another known method, the so-called hybrid liner method, uses a hybrid liner, i.e., a felt hose reinforced with a glass fiber mat. This hybrid liner is pulled into a light- and air-impermeable reinforced film hose (pre-liner) and pulled into the defective pipe together with a calibration hose. The hybrid liner is supplied or impregnated with a synthetic resin in situ at the construction site. The assembly is pulled between the manholes and radially expanded using the calibration hose. The synthetic resin contained in the hybrid liner is then cured.

[0007] After curing, the hybrid liner has significantly higher resistance than a simple felt hose due to the reinforcement of the integrated glass fiber mat, which has a high modulus and flexural strength. However, the rigidity of the integrated glass fiber mat means that the inversion method cannot be used. The hybrid liner can only be installed by pulling it into the pipe without twisting, and the limited flexibility of the glass fiber limits its bending range. Therefore, its installation is only possible between freely accessible maintenance manholes, which makes it more complicated and costly. The object of the present invention is to propose an assembly and a method that avoids or at least significantly reduces the disadvantages known in the prior art.

[0008] WO 2020 / 244883 A1 describes a system for rehabilitating pipes using a fabric layer placed on the inner wall of the pipe, a felt layer disposed underneath, and an inner fabric layer coated with a release agent, particularly silicone. In the system described in WO 2020 / 244883 A1, the fabric layer is formed from an integrally woven (integral woven) fabric hose, eliminating seams or welded seams that could be weak points in the hose. Unfortunately, one drawback of this system is that hoses available based on this technology lack sufficient tear resistance, meaning that the hose may break during pipe rehabilitation, potentially ruining the rehabilitation results. Another drawback is that the hoses are relatively expensive because they are manufactured using specialized machinery rather than large tubular fabrics. Summary of the Invention [Problem to be solved by the invention]

[0009] Against this background, there is a need for a pipe rehabilitation system that can be manufactured cost-effectively, yet has sufficient tear resistance and resilience to rehabilitate the pipe without defects, breaks, or holes. [Means for solving the problem]

[0010] The present invention meets this need. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a surface view showing the structure of a fabric hose. [Figure 2] This is a back view showing the structure of the fabric hose. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the research that forms the basis of the present invention, it was surprisingly discovered that a hose with sufficient stability can be manufactured from a fabric commonly referred to as "airbag fabric." This fabric has an air permeability of 10 liters / (dm 2 The fabric is characterized by a permeability of less than 2200 N / 5 cm (measured in accordance with DIN EN ISO 9237:1995, test pressure 500 Pa) and a maximum tensile strength of at least 2200 N / 5 cm. This means that the fabric is specifically designed to provide a specific air permeability and maximum tensile strength without the need for a coating. To manufacture a fabric hose from this fabric, the two ends of the fabric are joined with a seam. A plastic fabric is then applied to the seam. This fabric distributes the tension applied to the seam over a larger area of ​​the hose while covering the protruding part of the seam and protecting it from damage due to friction with other components of the repair system. This application procedure is particularly advantageous for "calibration hoses," which are used as the innermost component of a repair system and are removed from the pipe after the synthetic resin has hardened.

[0013] According to a first aspect of the present invention, the maximum tensile strength according to DIN 53857 is at least 2200 N / 5 cm and the air permeability is 10 liters / (dm 2 x minutes), the overlapping ends of the fabric are joined by at least one stitch along the entire length of the fabric hose, and a plastic fabric is attached to the outside of the stitching, covering the area of ​​the stitching of the hose.

[0014] To give the tubular structure particularly advantageous durability, it is suitable to have at least two seams connecting the overlapping ends of the fabric, with three seams proving to be the best compromise between processing effort and strength, and therefore this design is particularly preferred.

[0015] If the hose has several seams, they are preferably spaced far enough apart so that the stability of the fabric is not affected by the seams and the overlapping ends of the fabric do not overlap more than necessary, which would increase material costs. For these reasons, it is preferable to space the multiple seams 0.1 to 1 cm apart, more preferably 0.2 to 0.6 cm apart.

[0016] In the present invention, there are no restrictions on the material from which the fabric is made, as long as the maximum tension is at least 2200N / 5cm according to DIN 53857. The "5cm" specification indicates that the maximum tension is measured on a belt with a width of 5cm.

[0017] The requirement that the maximum tension be within a predetermined range can be met if this maximum tension is achieved in either the machine direction or the weft direction of the fabric, and in the hose of the present invention, this maximum tension is preferably achieved in the circumferential direction of the hose.

[0018] Commercially available materials from which fabrics having the required properties can be manufactured are, for example, polyamide and PET (polyethylene terephthalate) fabrics, which are preferred for manufacturing the hoses of the present invention. Particularly preferred are polyamide fabrics, especially polyamide 6, polyamide 6.6 and polyamide 4.6.

[0019] In the present invention, there is no restriction on the fineness of the yarns used in the fabric, as long as the required strength can be achieved without using more material than necessary. The range of 200 to 700 dtex, especially 230 to 500 dtex, can be specified as an appropriate order of magnitude for the fineness of the warp and weft yarns. The basis weight (which depends to some extent on the fineness) of the fabric from which the fabric hose is made is 120 to 400 g / m 2 , especially 140 to 320 g / m 2 It is preferable to adjust the temperature to within the range of

[0020] When using the fabric hose described above in the pipe rehabilitation system, it is suitable to apply a coating to the outside of the fabric hose of the present invention to prevent adhesion of synthetic resins. A silicone coating is particularly suitable. The "outside" of the hose refers to the side to which the plastic fabric is attached.

[0021] As mentioned above, the fabric from which the textile hose of the present invention is made has a maximum tension according to DIN 53857 of at least 2200 N / 5 cm. More preferably, the maximum tension is at least 2500 N / 5 cm, in particular at least 2700 N / 5 cm, and / or at most 6000 N / 5 cm, in particular at most 5000 N / 5 cm, and even more preferably at most 4500 N / 5 cm. Further advantageous properties of the fabric are its tear propagation resistance and elongation at maximum tension. The elongation at maximum tension is preferably greater than 15% and / or at most 70%. More preferably, the elongation at maximum tension is at least 20%, in particular at least 25%, and / or at most 60%, in particular at most 50%. A tear propagation resistance in the range of 80 to 300 N, in particular 100 to 250 N, is considered suitable. The elongation at maximum tension and the tear propagation resistance are measured in accordance with DIN 53857 and DIN 53859, respectively. The version of the standard in force on the filing date shall apply to all standards specified in this specification. Furthermore, the fabric, i.e. the polymer from which the fabric is made, preferably has a melting point of at least 120°C, preferably at least 150°C.

[0022] The plastic fabric is suitably made from a material that is sufficiently resistant to the synthetic resins used in the pipe rehabilitation system and is as unreactive as possible with said resins. Suitable materials include, in particular, polyolefins, polysilicones, or polyurethanes. Suitable polyolefins are, for example, polyethylene or polypropylene. Polysilicones or polyurethanes are particularly suitable because they already have release agent properties or are particularly heat-resistant, so they are not damaged by the heat that occurs when the synthetic resin hardens.

[0023] The width of the plastic fabric should be such that it covers any existing seams in the hose and has some overhang to securely fasten both ends to the fabric hose. Preferably, the plastic fabric extends over the seams joining the ends of the hose by a width of 0.5 to 3 cm, preferably 1 to 2 cm.

[0024] The plastic fabric has a thickness that provides the required durability for the layer, and a preferred range of thickness can be specified as 0.1 to 1.5 mm, preferably 0.2 to 0.8 mm.

[0025] The plastic fabric can be attached to the outside of the fabric hose of the present invention with a bonding agent such as an adhesive, or can be attached directly to the outside, for example by softening the plastic fabric exterior, such as by melting it, and then placing it over the hose.

[0026] The fabric hose of the present invention is preferably of a diameter that fits conventionally installed pipes. The diameter of the fabric hose is preferably in the range of 5-30 cm, preferably 8-20 cm, since repair systems based on the above-described techniques can be used more reliably on smaller diameter pipes due to the greater curvature of the pipes.

[0027] In the present invention, there is no limitation on the stitching method for making a hose by sewing both ends of the fabric. In one embodiment, the stitches can be double lock stitches, chain stitches, or double chain stitches, and in this case, the stitches are preferably formed at a stitch density in the range of 1.5 to 6 stitches / cm, particularly 2.5 to 5 stitches / cm.

[0028] There are no restrictions on the thread material or sewing thread used to join the two ends of the overlapped fabrics, as long as the material itself is stable enough. However, it is particularly suitable if the thread material or sewing thread has a total fineness in the range of 1000 to 3000 dtex, preferably 1200 to 2500 dtex, and / or a maximum tension of more than 50 N, preferably 70 to 200 N.

[0029] A further feature of the present invention relates to the use of the fabric hose as described above as a calibration hose for sealing a defective pipe, which is used to press a composite of an outer hose and a felt layer impregnated with a synthetic resin mixture, inserted against the inner wall of the defective pipe, which can be conveniently done by filling the fabric hose with a gas, in particular air.

[0030] The outer hose in such applications is suitably made of an impermeable material, such as a plastic, but may also be made of a fabric, or the outer hose may be made of an impermeable fabric hose, in which fabric is combined with an impermeable material.

[0031] A further feature of the present invention relates to a kit for pipe, particularly sewer pipe rehabilitation, comprising a fabric hose A corresponding to the above-mentioned fabric hose, and a hose B having an outer fabric layer and an inner layer, the outer fabric layer being preferably water-impermeable and the inner layer comprising a felt layer impregnated with a synthetic resin mixture, the outer diameter of fabric hose A being the same as the inner diameter of hose B so as to abut against the inner layer of hose B when fabric hose A is completely filled with gas. In other words, when fabric hose A is filled with gas, the felt layer is pressed against the outer fabric layer, so that the outer diameter of fabric hose A is slightly smaller than the inner diameter of hose B.

[0032] In the above two aspects, the outer hose is preferably made of polyurethane or contains polyurethane, and forms a continuous layer with a fabric embedded therein as needed. Alternatively or additionally, the outer hose may have a basis weight of 170 to 500 g / m 2 , preferably 200 to 300 g / m 2 Let's say.

[0033] The fibrous material forming the felt layer is suitably any material commonly used in conventional pipe repair systems as identified above as prior art. The fibres of the fibrous material may be made of organic materials, such as thermoplastic polymers, in particular polyesters, or inorganic materials, such as glass. In a preferred embodiment, the fibrous material of the felt layer is based on glass fibres, in particular glass fibre felt. In another preferred embodiment, the fibrous material is polyester-based, preferably with a weight of 400-800 g / m. 2 , especially 500-700g / m 2 Regardless of the material from which the felt layer is formed, the pore volume of the felt layer is preferably in the range of 85 to 97%, and particularly preferably in the range of 90 to 95%.

[0034] If the curable system of the present invention comprises a fiber composite layer based on plastic fibers, in particular polyester fibers, this fiber composite layer may be covered with a polyurethane layer, which is arranged on the side of the fiber composite layer opposite the outer plastic layer. Hose systems of this type are commercially available, for example, from Browo Systems under the trademark "Brawoliner®".

[0035] Synthetic resins are usually curable materials, the hardening of which can be initiated preferably by the introduction of heat, steam or light. In order to introduce the synthetic resin into the interstices of the felt, it is convenient if the synthetic resin has a low enough viscosity to be able to impregnate the fibrous material (this viscosity can also be achieved by adding a solvent or by impregnation at elevated temperatures). Particularly suitable synthetic resins in this context are, for example, polyester resins (UP resins), vinyl ester resins (VE resins) and epoxy resins. Most preferred are two-component epoxy resins comprising a first component primarily composed of epoxy components, including diglycidyl ethers of bisphenol A, bisphenol F, or a mixture of bisphenols A and F, and oligomers of these bisphenols with glycerol, and a second component containing a diamine, preferably comprising at least one of aminoethylpiperazine, condensates of polypropylene glycol and aminopropanol (1-aminopropan-2-ol and / or 1-aminopropan-3-ol), 2-methylpentane-1,5-diamine, isophoronediamine, 2,4,6-tris(dimethylaminomethyl)phenol, trimethylhexane-1,6-diamine, 3,6-diazaoctane-1,8-diamine, and m-phenylenebis(methylamine), or formed from these compounds. Commercially available two-component epoxy resins that can be used as synthetic resins in the context of the present invention are, for example, the resin systems sold by Bodus GmbH under the names EP 50 and EP 80.

[0036] The synthetic resin may further contain other components and additives to control properties, including, but not limited to, catalysts, heat and / or light stabilizers, thixotropic agents, plasticizers, solvents, mineral and organic fillers, blowing agents, dyes, and pigments.

[0037] A further aspect of the present invention relates to a method for the rehabilitation of pipes, in particular sewer pipes, preferably using the kit described above, comprising the steps of: a) forming an inner liner S1 in the pipe, the inner liner S1 having a fabric layer S11 in contact with the inner wall of the pipe and preferably impermeable to water, and an inner layer comprising a felt hose S12 and a synthetic resin mixture; b) inserting a fabric hose S2, which is the fabric hose coated with a release agent that does not adhere to the synthetic resin mixture, preferably silicone, inside the inner liner S1; c) sealing the fabric hose S2 in an essentially airtight manner; d) expanding the fabric hose S2; e) permanently compressing the fabric hose S2 and the inner liner S1 radially against a pipe; f) curing the curable synthetic resin mixture; g) removing the fabric hose S2 from inside the inner liner S1; Includes.

[0038] The fabric layer S11 may be formed as a fabric-reinforced hose, i.e., a hose having a continuous matrix with fabric embedded therein. Alternatively, the fabric layer may be replaced by a continuous matrix without fabric (i.e., a slideway or film hose). In this case, the hose may be made in one piece (without joining the ends). The fabric layer may be made as a one-piece woven fabric or, as described above for the hose of the present invention, may be suitably made with seams, especially in combination with a plastic woven fabric.

[0039] If fabric S11 or a corresponding layer not consisting of fabric is introduced, in a second step, this layer can be introduced into the pipe separately from the felt hose, and the felt hose S12 can be introduced into the pipe together with the plastic mixture separately from layer S11, or layers S11 and S12 can be introduced into the pipe as a composite (loosely bonded or bonded only with uncured synthetic resin). In this case, it is particularly advantageous to attach felt layer S12 and layer S11 to each other before inserting them into the pipe so that when the composite is inserted inverted into the pipe, the felt layer becomes the outer layer and the order of the layers is reversed. In this case, applying synthetic resin to the felt layer and allowing it to soak in at the construction site largely prevents the synthetic resin from contaminating other components. This method can also be used for pipes that are only accessible from one side during installation (open-end method).

[0040] The pipes that are rehabilitated and sealed as part of the above process are preferably sewer or waste pipes.

[0041] An apparatus capable of carrying out the method of the present invention is described, for example, in WO 2022 / 171622 A1, the relevant disclosure of which is incorporated herein by reference.

[0042] In an advantageous embodiment of the method of the present invention, the inside of the fabric hose S12 is exposed to heat, steam, or light during steps f) and g). If the second fabric hose is hermetically sealed, a heat, steam, or light source located inside the hose can advantageously assist in the curing of the synthetic resin mixture.

[0043] In a further advantageous embodiment of the method of the present invention, in step e) the textile hose is inflated to a pressure of 4 bar so that the first hose is tightly pressed against the pipe, in particular the wastewater pipe. This step results in a very tight, almost perfect pipe lining. At this stage of the method, the textile hose is already under pressure such that groundwater or the like cannot enter the lining from the outside until the synthetic resin has hardened.

[0044] The structure of the fabric hose of the present invention is shown in Figures 1 (front) and 2 (back). "Front" refers to the surface of the hose that can contact the felt layer; in the hose shown, the surface of this layer is silicone-treated. The hose is 20 cm wide when flattened and made of airbag fabric, with the ends of the fabric overlapping and joined with three stitches to form the hose. A piece of polyurethane approximately 4 cm wide is attached to the front of the hose, covering the seam, so that the seam is centered and the polyurethane piece protrudes approximately 1.5 cm beyond the seam in the width direction. The stitches are spaced approximately 3 mm apart.

Claims

1. The maximum tension conforming to DIN 53857 is at least 2200 N / 5 cm, and the air permeability is 10 liters / (dm²). ２ A cloth hose made of fabric that is less than × minutes, A cloth hose characterized in that the overlapping ends of the fabric are joined by at least one seam along the entire length of the hose, and a plastic fabric extending over the area of ​​the seam of the hose is attached to the outside of the seam.

2. The fabric hose according to claim 1, wherein the overlapping ends of the fabric are sewn together with at least two, preferably three, seams, and the seams are spaced 0.1 to 1 cm apart from each other, more preferably 0.2 to 0.6 cm apart.

3. The cloth hose according to claim 1, wherein the fabric is a polyamide fabric or a PET fabric, preferably based on fibers made of polyamide 6, polyamide 6.6, polyamide 4.6, or polyethylene terephthalate.

4. The fabric has weft and warp threads, the weft and warp threads having a fineness in the range of 200 to 700 dtex, particularly 230 to 500 dtex, and / or a basis weight of 120 to 400 g / m ２ , especially 140-300 g / m ２ A cloth hose according to claim 1, which is within the range of the specified range.

5. The cloth hose according to claim 1, wherein the hose is modified on the outside with an adhesion-inhibiting coating, preferably a silicone coating.

6. The cloth hose according to claim 1, wherein the plastic fabric is made of a polyolefin, polysilicone, or polyurethane plastic, and / or the plastic fabric extends over the seam connecting both ends of the hose, with a width of 0.5 to 3 cm, preferably 1 to 2 cm.

7. The cloth hose according to claim 1, wherein the diameter of the hose is 5 to 30 cm, preferably 8 to 20 cm.

8. The fabric hose according to claim 1, wherein the stitch is a double lock stitch or a double chain stitch, preferably a double chain stitch, and more preferably a stitch density in the range of 1.5 to 6 stitches / cm, and more preferably 2.5 to 5 stitches / cm.

9. The cloth hose according to claim 1, wherein the seams are formed with sewing thread having a total fineness of 1000 to 3000 dtex, preferably 1200 to 2500 dtex, and / or a maximum tension of more than 50 N, preferably 70 to 200 N.

10. The use of a cloth hose according to any one of claims 1 to 6 as a calibration hose for sealing a faulty pipe, The calibration hose is a cloth hose used to press a composite of an outer hose and a felt layer impregnated with a synthetic resin mixture, which is inserted in contact with the inner wall of the faulty pipe.

11. A pipe rehabilitation kit comprising a cloth hose (A) according to any one of claims 1 to 9, and a hose B having an outer fabric layer and an inner layer, The outer fabric layer is preferably impermeable to water. The inner layer comprises a felt layer and a synthetic resin mixture. A pipe rehabilitation kit in which the outer diameter of the cloth hose (A) matches the inner diameter of the hose (B) such that when the cloth hose (A) is completely filled with gas, it comes into contact with the inner layer of the hose (B).

12. The pipe rehabilitation kit according to claim 8, wherein the synthetic resin mixture is curable, and preferably curing can be initiated by the introduction of heat, steam, or light.

13. A method for rehabilitating pipes, particularly sewer pipes, preferably using the kit described in claim 11, a) A step of forming an inner liner (S1) inside the pipe, having a fabric layer that contacts the inner wall of the pipe and is preferably impermeable to water, and an inner layer containing a felt hose and a synthetic resin mixture, b) Inserting a cloth hose (S2) according to any one of claims 1 to 9, which is coated with a release agent that does not adhere to the synthetic resin mixture, preferably silicone, into the inside of the inner liner (S1); c) A step of sealing the cloth hose (S2) in an essentially airtight state, d) A step of inflating the cloth hose (S2), e) A step of permanently pressing the cloth hose (S2) and the inner liner (S1) radially against the pipe, f) A step of curing the curable synthetic resin mixture, g) A method for rehabilitating a pipe, comprising the step of removing a cloth hose (S2) from the inside of the inner liner (S1).

14. The method according to claim 13, wherein the inside of the cloth hose (S2) is exposed to heat, steam, light, or microwaves during steps f) and g).

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