Hydrophilic-Coated Pipe Liner for Curing Shrinkage Gaps
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Solution Overview
Problem
Existing liners for underground conduits and pipelines shrink during curing, creating gaps between the liner and the host pipe, leading to increased leakage and structural instability due to shrinkage and porosity, which exacerbates deterioration and collapse risks.
Innovation Solution
A fabric tube liner with a hydrophilic outer coating that minimally shrinks during curing and expands to seal gaps upon contact with liquid, using additives like milled graphite and a hydrophilic material to prevent leakage and enhance structural support, combined with a compressible rubber for additional sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If polyester or vinyl ester resins are used to impregnate the liner, then the liner provides structural support and seals cracks, but the liner shrinks 7-10% during curing creating gaps between the liner and host pipe
Solution Approach 1:
The patent changes the chemical composition parameters of the resin system by using epoxy resins instead of polyester or vinyl ester resins. This parameter change eliminates the 7-10% shrinkage that occurs with traditional resins during curing, while maintaining the structural support and crack-sealing functions of the liner.
Solution Approach 2:
The patent employs a composite material system combining epoxy resin with specific fibrous materials (glass fiber, carbon fiber, or organic polymers). This composite structure provides the necessary structural strength and dimensional stability, preventing shrinkage-induced gaps while maintaining crack-sealing capability.
2Strength
If the liner shrinks during curing, then the resin cures to form a hard lining, but gaps are created between the liner and host pipe causing increased deterioration and leakage
Solution Approach 1:
By changing the resin chemistry from polyester/vinyl ester to epoxy-based systems, the patent eliminates shrinkage during curing. This parameter change ensures the liner maintains continuous contact with the host pipe interior, preventing gap formation that would lead to leakage and deterioration while still forming the required hard lining.
Solution Approach 2:
The patent converts the potential harm of shrinkage-induced gaps into a benefit by using epoxy resins that exhibit minimal to no shrinkage. This transforms the curing process from a harmful shrinkage event into a beneficial expansion-free curing that maintains liner-host pipe contact and prevents leakage pathways.
3Force
If radial pressure is applied to expand the liner against the host pipe, then the liner adheres to the pipe wall, but shrinkage creates unsupported gaps where the liner deteriorates quickly
Solution Approach 1:
The patent changes the resin shrinkage parameter from 7-10% (polyester/vinyl ester) to near-zero (epoxy resin). This eliminates the formation of unsupported gaps between the liner and host pipe, preventing the rapid deterioration that occurs in gap regions and thereby extending the liner's service life despite the application of radial pressure during installation.
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 solution effectively prevents leakage and structural instability by maintaining a watertight seal and minimizing shrinkage, ensuring the liner remains securely attached to the host pipe, reducing the risk of further deterioration and collapse.
Implementation Method 1
the liner is coated with a hydrophilic material, which expands upon contact with a liquid to create a watertight seal in any gaps between the liner and the host pipe
Data Source
AI summary
A fabric tube liner for underground conduits, passageways, and pipelines, wherein such liner shrinks minimally upon curing and wherein any gaps between the liner and the host pipe are sealed with a hydrophilic coating. The liner may be used in conjunction with the known processes of lining underground conduits, passageways, and pipelines by either the eversion process or a pull-in liner using a winch and cable. The liner may be impregnated with a resin or resin may be applied after the liner has been installed in the underground host pipe. Upon contact with liquid permeating from the environment or leaking from the interior of the host pipe, the outer coating of the liner will expand to create a seal at the leak and prevent further leakage