Transparent Tape Sealing for Cured-in-Place Liner Seam Curing
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Solution Overview
Problem
The stitching process in cured-in-place resin-impregnated liners creates fluid leaks due to tiny holes and incomplete curing of the seam area, which can lead to structural instability and leakage, especially when using non-transparent tapes that block electromagnetic radiation used for curing.
Innovation Solution
A method involving a transparent tape that undergoes phase transitions with electromagnetic radiation, allowing it to be fixed to the liner without blocking curing radiation, ensuring the seam is fully cured and sealed, using a tape that is transparent to the curing wavelength to prevent delamination and achieve uniform curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-transparent tape is used to seal the stitched area of the liner, then fluid-tightness is improved, but curing of the seam area is blocked due to electromagnetic radiation absorption
Solution Approach 1:
The patent applies a transparent tape instead of a non-transparent one, allowing electromagnetic radiation to pass through and cure the resin in the stitched area while maintaining the sealing function. The transparency property enables simultaneous achievement of fluid-tightness and complete curing.
Solution Approach 2:
The transparent tape acts as an intermediary material that fulfills both functions: sealing the stitched area to prevent fluid leakage and allowing electromagnetic radiation to penetrate through to cure the resin. This mediator resolves the contradiction between blocking radiation for sealing and transmitting radiation for curing.
2Stability of the object's composition
If the stitched area is sealed before resin impregnation, then structural stability is improved, but resin penetration to the seam area is blocked
Solution Approach 1:
The tape is applied to the stitched area before resin impregnation to provide preliminary structural stability and prevent resin leakage during handling. The transparent nature ensures that resin can still penetrate to the seam area during subsequent impregnation processes.
Solution Approach 2:
The transparency of the tape allows resin to penetrate through to the stitched area during impregnation while still providing structural support, resolving the contradiction between early stabilization and resin access.
3Reliability
If a tape is applied to cover the stitched area, then fluid leakage is prevented, but delamination may occur due to differential curing
Solution Approach 1:
The transparent tape allows uniform curing of the resin both under and around the tape, eliminating differential curing stresses that cause delamination. This maintains strong bonding while preventing fluid leakage.
Solution Approach 2:
The patent changes the optical parameter (transparency) of the tape material to enable uniform electromagnetic radiation penetration, ensuring consistent resin curing throughout and preventing bond strength degradation from differential curing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method ensures the structural stability and fluid-tightness of the seam area, preventing leaks and structural damage by allowing complete penetration of curing radiation through the transparent tape, maintaining the same stability as the rest of the liner.
Implementation Method 1
The tape is at least transparent to electromagnetic radiation of the first wavelength or a first wavelength range
Implementation Method 2
The fibrous material of the liner is subsequently impregnated with a curable resin, such as styrene/polyester or styrene-free polyester, styrene/vinylester or styrene-free vinylester, vinylester urethane, furan, phenol, water glass, epoxy, methacrylate, isocyanate or the like. The resin should be curable by application of heat or electromagnetic radiation
Implementation Method 3
the fixation surface being capable of a first phase transition from solid to liquid state by irradiation of electromagnetic radiation of a first wavelength or a first wavelength range
Implementation Method 4
The fixation surface is substantially non-adhesive prior to the phase transitions of the fixation surface
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3C
AI summary
The present invention relates to a method of renovating a pipeline by using a cured-in-place resin-impregnated liner, which is sealed by a transparent tape for sealing the liner prior to resin impregnation. The method is carried out by providing a continuous web assembly including a fibrous web material defining a first surface and a fluid-impermeable coating of a first polymeric material defining an opposite second surface. The web assembly defines a first edge and an opposite second edge. The first and second edges are positioned adjacent each other to form a tubular liner and are joined and stitched together to establish a continuous stitched area bridging the first and second edges. Further, there is provided a flexible and fluid-impermeable tape of a second polymeric material compatible with the first polymeric material and having a fixation surface being capable of a first phase transition from solid to liquid state by electromagnetic radiation of a first wavelength range and of a second phase transition from liquid to solid state when allowed to cool. After the second phase transition, the tape is transparent to electromagnetic radiation of a second wavelength range. The tape is applied to the second surface, the fixation surface facing the second surface and covering the continuous stitched area. The tape is then irradiated with electromagnetic radiation of the first wavelength range for causing the first phase transition and permanently fixating the tape to the surface coating by causing the second phase transition. The liner is then impregnated with a resin being curable by irradiation of electromagnetic radiation of the second wavelength range, whereupon it is inverted into the pipeline by contacting the first surface constituting the outer surface of the liner after the inversion to the inner surface of the pipeline, and the second surface of the liner constituting its inner surface after the inversion is irradiated with electromagnetic radiation of the second wavelength range.