Non-excavation repair pipeline and preparation method thereof

Abstract

The invention belongs to the technical field of trenchless repair of pipelines, and particularly relates to a trenchless repair pipeline and a preparation method thereof. The trenchless repair pipeline is composed of a lining pipe and an interface filling body distributed on the outer surface of the lining pipe. The interface filling body is composed of a plurality of sealed cavity bags and filling materials filled in the cavity bags. The material of the cavity bag is a degradable film, and the filling material comprises a moisture-curing polymer material. According to the trenchless repair pipeline, irregular gaps between the new pipeline and the old pipeline are filled in a self-adaptive mode by means of the characteristic that the moisture-cured polymer is cured / swelled when meeting water after the thin film is degraded, three-dimensional tight attachment and structural integrity are achieved, and the leakage risk is thoroughly eliminated.

Description

Technical Field

[0001] This invention belongs to the field of trenchless pipeline repair technology, specifically relating to a trenchless pipeline repair method and its preparation method. Background Technology

[0002] Urban underground pipe networks are the "lifeline" for the operation of modern cities, and their safe operation is directly related to the stable development of the social economy and the protection of people's livelihoods. However, with the acceleration of urbanization, the problem of aging pipe networks has become increasingly prominent. Urban pipe networks built in the early stages have generally entered their "advanced age," with a large number of pipes having been in service for more than 20-30 years and generally suffering from structural defects such as corrosion, damage, and leakage.

[0003] Trenchless repair technologies utilize existing pipeline routes for repair and replacement through minimal or no excavation, offering a significant advantage in terms of minimal impact on the urban environment. Ultraviolet in-situ curing (UV-CIPP) is one of the most widely used trenchless pipeline repair technologies. Its basic process involves inserting a resin-impregnated hose (often called a "liner") into the old pipeline to be repaired, inflating it to expand and adhere it to the inner wall of the old pipe, and then using ultraviolet light to cure the resin, forming a new pipe with high structural strength inside the old pipeline. However, this technology has a key drawback: during the inflation and bonding process, the resin-impregnated hose has limited deformation capacity. When the inner wall of the old pipeline has severe corrosion, local collapse, misaligned joints, or other irregular deformations, the outer surface of the cured new pipe (repair structural layer) is difficult to tightly and continuously adhere to these uneven inner walls of the old pipe. This results in gaps or cavities between the old and new pipes. The hazards of these gaps / cavities are: (1) Reduced structural integrity: The new pipe cannot effectively share the load of the old pipe, affecting the overall structural strength of the repaired pipe; (2) Formation of leakage channels: Groundwater or fluid inside the pipe may leak through the gaps, failing to achieve the desired repair effect; (3) Shortened service life: Sediment and sand easily accumulate in the gaps or hydraulic erosion may occur, which may affect the stability of the repaired pipe in the long term.

[0004] Therefore, there is an urgent need for a trenchless repair technology that can effectively and adaptively fill the irregular gaps between new and old pipelines to solve problems such as poor integrity, low repair quality, and short service life caused by the loose fit between the new and old pipeline interfaces. Summary of the Invention

[0005] The present invention aims to overcome the above-mentioned defects of the prior art and provide an interface adaptive trenchless repair pipeline and its preparation method. By setting a special "interface filler" on the outer surface of the repair structure layer, the filler can adaptively expand and fill the irregular gap between the old and new pipelines in response to the moisture in the environment for a period of time after the repair construction is completed, thereby achieving a tight, continuous and integral combination of the old and new pipelines, significantly improving the repair quality and pipeline service life.

[0006] Specifically, the present invention provides the following technical solutions: A trenchless repair pipe comprises an inner liner and an interface filler distributed on the outer surface of the inner liner; the interface filler comprises a plurality of sealed cavities and a filling material filling the cavity. The cavity bladder is made of a biodegradable film, and the filling material includes a moisture-curing polymer material.

[0007] Preferably, the biodegradable film is a polylactic acid film modified with polybutylene terephthalate (PET) or polyhydroxybutyrate (PHB) modified with polylactic acid. Studies have found that the cavity capsule made from the above-mentioned modified polylactic acid film has a tensile strength of over 20 MPa, which can, to a certain extent, prevent the film from breaking due to external forces during construction. Furthermore, after being buried in a natural soil environment at 25±2℃ for 6 months, its mass loss rate is not less than 30%, ensuring effective overflow of the internally moisturized and cured polymer material, making it particularly suitable for this invention.

[0008] Preferably, the moisture-curing polymer material is a polyurethane prepolymer. Studies have found that polyurethane prepolymers can cure upon exposure to moisture, with a volume expansion rate of ≥100%, and their wet bond strength with concrete after curing is not less than 0.5 MPa, thus effectively filling and repairing the interface, making them particularly suitable for this invention.

[0009] Preferably, the hollow bladder is elongated and extends along the length of the inner liner tube, with several hollow bladders arranged in a strip on the outer surface of the inner liner tube. This structure avoids the wet-curing polymer from being entirely distributed at the bottom due to gravity during pipe repair, which would hinder full interface filling. It also prevents the complete loss of wet-curing polymer due to film rupture caused by local foreign objects during construction.

[0010] More preferably, the width (W) of each of the hollow bladders is 5% to 20% of the nominal diameter (D) of the inner liner tube.

[0011] Preferably, the filling material accounts for 40% to 80% of the total volume of the cavity inside the bladder.

[0012] The present invention also provides a method for preparing the above-mentioned trenchless repair pipeline, comprising the following steps: (1) The filling material is encapsulated into a long strip-shaped capsule without air inside using a biodegradable film; (2) Several long strip-shaped capsules are bonded to the outer surface of the inner liner tube with adhesive film, sealed, dried and stored for later use.

[0013] The beneficial effects of this invention are at least as follows: (1) The present invention provides a trenchless repair pipe, which uses an interface filler made of a biodegradable film-encapsulated moisture-curing polymer material on the outer surface of the inner liner pipe. By utilizing the property that the polymer cures / expands when it comes into contact with water after the film is degraded in the environment, it adaptively fills the irregular gaps between the new and old pipes, achieving three-dimensional tight fit and structural integrity, and completely eliminating the risk of leakage. (2) The present invention provides a trenchless repair pipe with the interface filler arranged in strips along the pipe diameter direction, which is compatible with existing construction technology, reduces the impact on the pipe diameter, and significantly improves the service life of the repaired pipe. (3) The present invention provides a trenchless repair pipe with a membrane that is completely degradable and pollution-free, which breaks through the core defects of poor interface bonding and low quality of traditional trenchless repair technology, and provides an efficient and green repair solution for highly corrosive / misaligned pipe networks. Attached Figure Description

[0014] Figure 1 This is a structural schematic diagram of trenchless pipeline repair provided in the embodiment; Figure 2 yes Figure 1 Enlarged view of a local area; where 1-inner liner tube, 21-hollow bladder, 22-filling material. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art, or in accordance with the product manual.

[0016] Example 1 like Figure 1-2 As shown, Embodiment 1 provides a trenchless repair pipe, which consists of an inner liner (1) with a diameter (D) of 600 mm and an interface filler distributed on the outer surface of the inner liner; the interface filler consists of a plurality of sealed cavity bladders (21) and a filling material (22) filling the cavity bladders. The hollow capsule is made of poly(butylene terephthalate)-modified polylactic acid film, manufactured by Dongguan Shuotai Industrial Co., Ltd., with a tensile strength of 28.8 MPa. After being buried in a natural soil environment at 25±2℃ for 6 months, its mass loss rate is 33.8%. The filling material is a moisture-curing polyurethane prepolymer grout, composed of polyurethane prepolymer with isocyanate-terminated groups in a mass ratio of 1:2 and filler (the filler is composed of fly ash and quartz sand in a mass ratio of 1:4). The isocyanate groups (-NCO) at the ends of the polyurethane prepolymer react with water molecules in a humid environment to form urea bonds, creating a three-dimensional cross-linked network to complete curing. After curing, the wet bond strength with concrete is 0.8 MPa, and the volume expansion rate is 220%. The hollow bladder is long and extends along the length of the inner liner tube. Several hollow bladders are arranged in strips on the outer surface of the inner liner tube. The width (W) of a single hollow bladder is 10% of the diameter (D) of the inner liner tube, i.e., 60 mm. The filling material accounts for 40% of the total volume of the cavity inside the hollow capsule.

[0017] The specific steps of the above-mentioned trenchless repair pipeline preparation method are as follows: (1) After determining the production requirements, the moisture-curing polyurethane prepolymer grouting material is encapsulated and molded into a continuous long strip capsule with a width (W) of 60 mm, a filling amount of 40%, and no air inside by using polybutylene terephthalate-adipate modified polylactic acid film. (2) Use a high-strength adhesive film to bond the capsule to the outer surface of the inner liner tube, seal and dry it for later use.

[0018] In application, the aforementioned trenchless repair pipe is first dragged into the old pipe to be repaired, inflated to expand it and adhere it to the inner wall of the old pipe, and then cured by ultraviolet light to complete the pipe repair. Subsequently, during long-term use, the poly(butylene terephthalate)-modified polylactic acid film degrades, and the internal moisture-curing polyurethane grout overflows, cures and expands, effectively filling the gaps or cavities between the new and old pipes.

[0019] Example 2 like Figure 1-2 As shown, Embodiment 2 provides a trenchless repair pipe, which consists of an inner liner (1) with a diameter (D) of 1200 mm and an interface filler distributed on the outer surface of the inner liner; the interface filler consists of a plurality of sealed cavity bladders (21) and a filling material (22) filled inside the cavity bladders. The hollow capsule is made of polyhydroxybutyrate-modified polylactic acid film, manufactured by Dongguan Shuotai Industrial Co., Ltd., with a tensile strength of 23.2 MPa. After being buried in a natural soil environment at 25±2℃ for 6 months, its mass loss rate is 51.4%. The filling material is a moisture-curing polyurethane prepolymer grout, and its composition and formula are the same as those in Example 1. The hollow bladder is elongated and extends along the length of the inner liner tube. Several hollow bladders are arranged in strips on the outer surface of the inner liner tube. The width (W) of a single hollow bladder is 8% of the diameter (D) of the inner liner tube, i.e., 96 mm. The filling material accounts for 60% of the total volume of the cavity inside the hollow capsule.

[0020] The specific steps of the above-mentioned trenchless repair pipeline preparation method are as follows: (1) After determining the production requirements, the moisture-curing polyurethane prepolymer grouting material is encapsulated and molded into a continuous long strip capsule with a width (W) of 96 mm, a filling amount of 60%, and no air inside by using polyhydroxybutyrate modified polylactic acid film. (2) Use a high-strength adhesive film to bond the capsule to the outer surface of the inner liner tube, seal and dry it for later use.

[0021] In application, the aforementioned trenchless repair pipe is first dragged into the old pipe to be repaired, inflated to expand it and fit against the inner wall of the old pipe, and then cured by ultraviolet light to complete the pipe repair. Subsequently, during long-term use, the polyhydroxybutyrate-modified polylactic acid film degrades, and the internal moisture-curing polyurethane grout overflows, cures and expands, effectively filling the gaps or cavities between the new and old pipes.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A trenchless pipeline repair method, characterized in that, It consists of an inner liner tube and an interface filler distributed on the outer surface of the inner liner tube; the interface filler consists of a plurality of sealed cavities and a filling material filling the cavity. The cavity bladder is made of a biodegradable film, and the filling material includes a moisture-curing polymer material.

2. The trenchless pipeline repair method according to claim 1, characterized in that, The biodegradable film is a polylactic acid film modified with polybutylene terephthalate (PET) or a polyhydroxybutyrate (PHB) modified with polylactic acid.

3. A trenchless pipeline repair method according to claim 1 or 2, characterized in that, The moisture-curing polymer material is a polyurethane prepolymer.

4. A trenchless pipeline repair method according to claim 1 or 2, characterized in that, The hollow bladder is elongated and extends along the length of the inner liner tube, with several hollow bladders arranged in a strip on the outer surface of the inner liner tube.

5. The trenchless pipeline repair method according to claim 4, characterized in that, The width of each cavity bladder is 5% to 20% of the diameter of the inner liner tube.

6. A trenchless pipeline repair method according to claim 1 or 2, characterized in that, The filling material accounts for 40% to 80% of the total volume of the cavity inside the bladder.

7. The method for preparing trenchless repair pipelines according to any one of claims 1-6, characterized in that, Includes the following steps: (1) The filling material is encapsulated into a long strip-shaped capsule without air inside using a biodegradable film; (2) Several long strip-shaped capsules are bonded to the outer surface of the inner liner tube with adhesive film, sealed, dried and stored for later use.

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