Inverted Filament Winder Method for Pipeline Rehabilitation

Abstract

A pipe lining apparatus and methodology having a UV-curable, resin-impregnated reinforcement filament that is helically wound onto the inner surface of a tubular first lining layer disposed within a pipe by an inverted filament winding apparatus, the apparatus having a UV light to initiate curing of the filament as it is applied to the lining layer so as to bond the filament to the lining layer and rigidify the filament. A rigid second layer is then applied onto the filament winding layer and the first lining layer.

Claims

1. A method of helically winding a continuous reinforcement filament on the interior of a tubular member comprising the steps of: providing a continuous reinforcement filament comprising a UV-curable resin in an uncured state; applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member; and exposing said continuous reinforcement filament to UV light as it is applied to said inner wall of said tubular member to at least partially cure said UV-curable resin.

2. The method of claim 1, further comprising the step of subsequently exposing said continuous reinforcement filament to additional UV light to fully cure said UV-curable resin.

3. The method of claim 1, wherein said continuous reinforcement filament further comprises a heat-curable resin; and further comprising exposing said continuous reinforcement filament to a heat source to fully cure said heat-curable resin.

4. The method of claim 1, further comprising the step of forming said tubular member by applying an elastomeric coating to the inner wall of a pipe.

5. The method of claim 2, further comprising the step of forming said tubular member by applying an elastomeric coating to the inner wall of a pipe.

6. The method of claim 3, further comprising the step of forming said tubular member by applying an elastomeric coating to the inner wall of a pipe.

7. The method of claim 1, further comprising the step of applying a coating which cures to form a rigid member onto said continuous reinforcement filament and said tubular member after said continuous reinforcement filament has been applied and exposed to said UV-light.

8. The method of claim 2, further comprising the step of applying a coating which cures to form a rigid member onto said continuous reinforcement filament and said tubular member after said continuous reinforcement filament has been exposed to said additional UV light.

9. The method of claim 3, further comprising the step of applying a coating which cures to form a rigid member onto said continuous reinforcement filament and said tubular member after said continuous reinforcement filament has been applied, whereby the curing of said rigid coating supplies said heat to fully cure said heat-curable resin.

10. The method of claim 4, further comprising the step of applying a coating which cures to form a rigid member onto said continuous reinforcement filament and said tubular member after said continuous reinforcement filament has been applied and exposed to said UV-light.

11. The method of claim 1, further comprising the step of repeating one or more times said steps of providing a continuous reinforcement filament comprising a UV-curable resin in an uncured state; applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member; and exposing said continuous reinforcement filament to UV light as it is applied to said inner wall of said tubular member to at least partially cure said UV-curable resin; such that said continuous reinforcement filament is applied multiple times on said inner wall of said tubular member.

12. The method of claim 11, wherein said repeating step comprises at least once applying said continuous reinforcement filament in an opposite helical pattern on the inner wall of said tubular member.

13. The method of claim 1, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

14. The method of claim 13, wherein said inverted filament winder comprises a spool, whereby said step of providing a continuous reinforcement filament comprising a UV-curable resin in an uncured state comprises disposing said continuous reinforcement filament comprising said UV-curable resin in an uncured state on said spool.

15. The method of claim 2, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

16. The method of claim 3, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

17. The method of claim 4, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

18. The method of claim 7, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

19. The method of claim 8, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

20. The method of claim 9, further comprising the step of providing an inverted filament winder comprising a rotating applicator arm and a UV light positioned on said rotating applicator arm, whereby said step of applying said continuous reinforcement filament in a helical pattern on the inner wall of a tubular member is accomplished by passing said continuous reinforcement filament comprising a UV-curable resin in an uncured state through said rotating applicator arm to expose said continuous reinforcement filament to said UV light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a flow chart illustrating an embodiment of the method of forming a multi-layer pipe liner comprising wound filament reinforcement.

[0013] FIG. 2 is a flow illustrating a second embodiment of the method of forming a multi-layer pipe liner comprising wound filament reinforcement, wherein plural layers of wound filament reinforcement are applied.

[0014] FIG. 3 is a partially exposed, partially cross-sectional view of a multi-layer pipe liner in place within a pipe.

[0015] FIG. 4 is an illustration of an embodiment of the spool and applicator arm of the inverted filament winder apparatus, the spool being loaded with prepreg filament.

[0016] FIG. 5 is an illustration similar to FIG. 4 of an unloaded spool.

[0017] FIG. 6 is a cross-sectional end view of the spool and applicator arm of FIG. 4, taken along line 6-6.

[0018] FIG. 7 is a partial cross-sectional view of the spool and applicator arm of FIG. 4.

[0019] FIG. 8 is an end view of an embodiment of the inverted filament winder apparatus.

DETAILED DESCRIPTION OF THE INVENTION

[0020] With reference to the figures, which are meant to be non-limiting as to the scope of the invention and which are not to scale, the inventive methodology and an apparatus are described in various embodiments. The term filament as used herein shall mean an elongated member such as a string, wire, thread, cloth strip, bundle of fibers, such as carbon fiber or fiberglass for example, or similar members, and the terms impregnated or prepreg as used herein shall mean that a filament is coated or infused with a curable resin.

[0021] The method comprises, in a first embodiment shown in FIG. 1, the steps of applying 100 a first liner 11 to the inside of a pipe 20, advancing 101 an inverted filament winder through the pipe 20, expelling 102 UV-curable resin-impregnated filament reinforcement 14 through a rotating applicator arm 32 onto the interior of the first liner layer 11 while exposing the filament 14 to UV light to partially cure and adhere the filament 14 to the first liner layer 11, (optionally) exposing 103 the adhered filament 14 to additional UV light to further cure the filament 14, and applying 104 a second liner layer 12 onto the first liner layer 11 and the wound filament reinforcement 14.

[0022] The method, in a second embodiment shown in FIG. 2, comprises the steps of applying 110 the first liner 11 to the inside of the pipe 20, advancing 111 the inverted filament winder through the pipe 20, expelling 112 UV-curable resin-impregnated filament reinforcement 14 through the rotating applicator arm 32 onto the interior of the first liner layer 11 while exposing the filament 14 to UV light to partially cure and adhere the filament 14 to the first liner layer 11, applying 113 one or more additional layers of UV-curable resin-impregnated filament reinforcement 14 through the rotating applicator arm 32 onto the interior of the first liner layer 11 while exposing to UV light to partially cure and adhere filament 14 to the first liner layer 11, (optionally) exposing 114 the adhered filament 14 to additional UV light to further cure the filament 14, and applying 115 the second liner layer 12 onto the first liner layer 11 and the wound filament reinforcement 14.

[0023] Furthermore, it is also to be understood that the method may consist of utilizing the inverted filament winding apparatus to deposit the UV-curable resin impregnated filament 14 in helical fashion onto the interior surface of any tubular member with simultaneous curing of the resin.

[0024] In a non-limiting representative embodiment, the method produces a multi-layer or laminate pipe liner 200 with filament winder reinforcement 14 disposed or embedded between two liner layers 11/12. As a representative and non-limiting example, the liner 200 may comprise a first or outer tubular layer 11 composed of a low modulus, high elongation, flexible, elastomeric material disposed within and bonded to a pipe 20, a second or inner tubular layer 12 disposed within and bonded to the first layer 11 and which is composed of a rigid, durable, thermoset polymeric material, and one or more wound resin-impregnated (prepreg) filaments 14 possessing high-strength (>4500 MPa), high modulus (>200 GPa), low elongation (<2%) that is sandwiched between the first and second layers 11/12.

[0025] Before starting the pipe lining process for in-situ pipes 20 being repaired or lined, the pipe 20 should be cleaned using conventional methods, such as blasting and pigging, etc. The pipe 20 is then lined internally, preferably by spray application, with a polymeric material to form the first or elastomeric liner layer 11. The first liner layer 11 is most preferably approximately 1-12 mm in thickness upon curing, with the optimal thickness being determined by pipe diameter. The first layer 11 mechanically bonds to the inner surface of the pipe or conduit 20, which may be composed of metal, polymer or concrete.

[0026] The prepreg filament winding 14 is then applied to the interior of the first layer 11 using an inverted filament winding apparatus 30, as illustrated in FIGS. 4-8. The apparatus 30 is inverted in the sense that the filament 14 is wound onto the interior of a tubular member as opposed to being wound externally onto the exterior of a cylindrical or tubular member. The filament winding apparatus 30 comprises a carriage or frame 38 that is typically provided with wheels 39 such that the winding apparatus 30 may be pulled, pushed or powered through the pipe 20. The winding apparatus 30 further comprises a spool 31 which retains the uncured prepreg filament 14, the spool 31 preferably oriented with its axis of rotation parallel to the axis of travel of the winding apparatus 30 through the pipe 20 in order to prevent imparting torsional stresses on the filament 14 as it is unwound from the spool 31.

[0027] In one embodiment the filament 14 is impregnated with the UV-curable resin, or a hybrid resin comprising a UV-curable resin component and a heat curable resin component (such that exothermic heat resulting from the curing of the rigid layer 12 performs the final curing of the resin-impregnated filament 14 after the initial curing by exposure to UV light), prior to disposition of the prepreg filament 14 on the spool 31. Alternatively, the apparatus 30 may be constructed such that the resin is coated or infused on or into the filament 14 within the apparatus 30 prior to delivery of the filament 14 through the applicator arm 32.

[0028] The winding apparatus 30 further comprises an applicator arm 32 extending radially outward beyond the circumference of the spool 31, the applicator arm 32 being powered for rotational movement about a centrally located axis parallel to the axis of travel of the winding apparatus 30 through the pipe 20. A follower arm 34 and follower roller 35 extend generally laterally from the end of the applicator arm 32, such that as the filament 14 is expelled through the aperture 36 at the end of the applicator arm 32, the follower roller 35 passes over the filament 14 to press it against the inner surface of the first liner layer 11 for better adhesion. The applicator arm 32 is structured to include an extension/retraction mechanism 33, i.e., a structure that allows for the lengthening and shortening of the applicator arm 32 in the radial direction, the extension/retraction mechanism 33 preferably being automatically responsive to changes in the interior diameter of the interior pipe wall 20 or any other inner surface, such as a mechanism comprising the telescoping structure and spring assembly shown in FIG. 6, a gas cylinder, equivalent mechanical constructs, or the like. This allows the follower roller 35 and the applicator aim 32 to adapt to imperfections in the interior pipe wall 20 and/or in the inner surface of the first liner layer 11 by moving radially inward or outward as needed. Powered feed rollers 37 are disposed within the applicator arm 32 to pull the filament 14 from the spool 31 and deliver it through the applicator arm aperture 36.

[0029] A UV light 40 is positioned on, at or adjacent the end of the applicator arm 32 such that the prepreg filament winding 14 is exposed to UV light as it is expelled from the applicator arm 32 and is pressed onto the first liner layer 11 by the follower roller 35. This exposure initiates curing or partially cures the UV-curable resin present in the filament 14, producing a tacky or temporarily adhesive surface that adheres and bonds the filament winding 14 to the first liner layer 11. With this methodology, apparatus and composition, the pre-cured filament 14 being deposited remains in a pliable, easily-handled state, as opposed to the stiff wire reinforcement required in earlier systems, the stiffness of the wire being necessary to maintain it in the expanded helical configuration. In one embodiment, an annular ring of UV lights 41 are positioned on the apparatus 30 such that additional curing of the filaments 14 now affixed to the inner wall of the first layer 11 occurs as needed. In another embodiment, the resin utilized for the filaments 14 is a hybrid resin comprising a UV-curable resin component and a heat curable resin component, such that final curing of the filaments 14 occurs by shadow curing when the second layer 12 is applied, the heat from the exothermic curing reaction of the second layer 12 providing the heat to cure the heat-curable resin and rigidify the wound filament 14.

[0030] The filament 14 is spirally or helically wound onto the first layer 11. The pitch and spacing of the wound filament 14 is determined by the advancement speed of the filament winder apparatus 30 and the rotational speed of the applicator arm 32, such that the method may produce a tightly spaced spiral or a more open spiral. In addition, multiple passes may be made through the pipe 20, or multiple filament winder apparatuses 30 may be utilized to deliver a plurality of helical windings 14. The additional windings 14 may be deposited between or cross over the first winding 14.

[0031] Since it is required to wind the filament 14 inside the host pipe 20 during the application process, the filament 14 is preferably retained on a spool 31 and stored in the apparatus 30. In this way, the filament 14 can be unwound directly from the rotatable spool 31 and adhered onto the elastomeric first liner 11 following linear and rotational motion of applicator arm 32 to create the helical filament shape. Alternatively, the filament 14 may be stored on a spool external to the pipe 20 and delivered to the applicator arm 32, in which case the winding direction of the filament 14 must be kept alternating in the application process, i.e., the filament 14 will be wound in one direction for a certain amount of rotations, then it will be wound in the opposite rotating direction but move in the same lining direction. The alternating winding motions can also avoid the filament 14 from winding and accumulating on the winding apparatus 30. The pitch distance (typically 0.5-16) of the wound filament 14 and the size/diameter (typically 0.02-0.50) of the filament 14 will usually depend on the host pipe 20 diameter and the internal working pressurebased on the thickness of the liner 200 vs. the surface area of the unreinforced liner 200 that can resist the stress between the reinforcement filament 14 pitches at the given pressure.

[0032] A preferred curing time for the filament winding 14 is in the range of 0.1 to 3 seconds depending on the pipe size and the speed of the rehabilitation lining process. After the helically wound filament 14 is sufficiently cured, the rigid lining material layer 12 is then sprayed on top of the elastomeric layer 11 and the filament winding 14. The second layer 12 preferably has a snap cure rate of approximately 3 to 300 seconds and a final or full cure rate or 1 hour to 24 hours and is applied at a thickness of approximately 3 to 100 mm, dependent on the host pipe size.

[0033] The application of elastomeric layer 11, filament winding 14 and rigid layer 12 can be finished in the same lining pass with an apparatus comprising the necessary functionalities or in separate passes by separate apparatuses, but the winding of filament 14 must be finished before the rigid lining application in the same pass. The rigid layer 12 is applied in the same lining pass right after the reinforcement fiber is at least substantially fixed and cured on the elastomeric layer 11.

[0034] It is understood that equivalents and substitutions to some of the elements and steps disclosed above may be obvious to those of skill in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.