Pipe Liner Resin Composition for Long-Pot-Life Wet Installation
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Solution Overview
Problem
Epoxy resin compositions have limited storage stability and short pot life due to rapid reactivity of nitrogen-containing hardeners, leading to premature curing and handling challenges, especially when applied in wet conditions, which limits their usage in applications requiring extended storage and installation periods.
Innovation Solution
A blended resin composition combining cyclic anhydrides, bisphenol A, and bisphenol F resins with a proprietary activator component that delays curing indefinitely until a specific threshold of heat is applied, allowing for extended shelf life up to six months and enabling adhesion to wet surfaces, thereby facilitating the use of a fully wetted liner in pipe lining applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If nitrogen-containing hardeners are used to cure epoxy resins, then the curing reaction proceeds rapidly, but the storage stability deteriorates and pot life shortens due to reactivity even at room temperature
Solution Approach 1:
The patent divides the curing system into separate components: the epoxy resin containing nitrogen-containing base and the acid anhydride curing agent are kept separate during storage and only mixed immediately before application. This segmentation prevents premature reaction while allowing rapid curing when combined, resolving the contradiction between fast curing and storage stability.
2Stability of the object's composition
If two-component epoxy systems are formulated separately, then storage stability is improved, but the application process becomes more complex and time-consuming
Solution Approach 1:
The patent combines the nitrogen-containing base with the epoxy resin in a single component formulation, eliminating the need for separate hardener containers and mixing equipment. The acid anhydride is applied separately but the overall system is simplified compared to traditional two-component epoxy systems, reducing application complexity while maintaining storage stability.
3Duration of action of moving object
If epoxy resin is mixed with hardener in advance, then the curing process can begin, but the working time is limited and application becomes tedious and expensive
Solution Approach 1:
The patent prepares the epoxy resin component in advance with the nitrogen-containing base already incorporated, so that when the acid anhydride is added at the application site, the curing reaction begins immediately. This preliminary preparation allows for extended pot life while maintaining efficient application, as the resin is ready to cure as soon as the anhydride contact occurs.
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 provides a long pot life and extended storage stability, allowing for the transportation and installation of wetted liners without premature curing, ensuring reliable adhesion and curing on wet surfaces, and extending the shelf life of the resin composition, reducing the risk of exothermic reactions and spontaneous combustion.
Implementation Method 1
After the two parts are mixed together, they begin a curing process that is typically triggered by exposure to heat, humidity or a ultra-violet light source, whereby the mixed material quickly begins to solidify.
Implementation Method 2
the curing process that is typically triggered by exposure to heat, humidity or a ultra-violet light source
Data Source
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AI summary
A resin composition and method for installing a pipe liner that allows the liner to be fully wet out with a resin and activator and stored for a period of up to six months prior to installation and curing. A method of lining a pipe with a delayed curing resin composition is also provided that includes fully wetting out a liner with a blended two part epoxy composition such that the liner can be transported in a wet out fashion, placed in a pipe to be lined and repositioned as needed without concern for the resin composition to begin curing.