Pipe Liner Hot-Melt Bonding for UV-Cured Sewer Rehabilitation
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Solution Overview
Problem
Existing pipe liners lack effective bonding between the inner film and the resin-impregnated fiber tapes, necessitating the removal of the inner hose, which is not necessary with the present invention.
Innovation Solution
A thermally activatable hot-melt adhesive material with adhesion-promoting properties is used, tailored to the curing conditions, ensuring the inner film bonds firmly to the curable or cured carrier material during resin curing, eliminating the need for inner hose removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If functional groups on the inner film surface are used to react with fiber tubes, then bonding between inner film and resin-impregnated fiber material is improved, but the bonding is still insufficient and inner film removal is required
Solution Approach 1:
The patent changes the bonding mechanism from chemical reaction (functional groups) to thermal bonding (melting point and flow behavior). The thermally activatable hot-melt adhesive material is designed with specific melting point and flow characteristics that enable it to melt during resin curing and form strong bonds with both the inner film and resin-impregnated fiber material, achieving reliable bonding without film removal.
Solution Approach 2:
The patent introduces a composite structure where the inner film is combined with a thermally activatable hot-melt adhesive material layer. This composite approach allows the adhesive material to serve as an intermediate bonding layer that thermally bonds to both the inner film and the resin-impregnated fiber material, achieving superior bonding strength compared to using functional groups alone.
2Reliability
If inner film removal is performed to achieve adequate bonding, then bonding reliability is improved, but process complexity and time are increased
Solution Approach 1:
The thermally activatable hot-melt adhesive material is pre-applied to the inner film surface before resin installation. During the resin curing process, the exothermic heat automatically activates the adhesive material, which melts and bonds the inner film to the resin-impregnated fiber material. This preliminary preparation eliminates the need for subsequent inner film removal operations.
Solution Approach 2:
The resin curing process itself provides the heat necessary to activate the bonding mechanism. The exothermic heat generated during resin curing automatically melts the thermally activatable hot-melt adhesive material, enabling self-bonding without requiring external heating equipment or manual intervention for film removal.
3Reliability
If thermally activatable hot-melt adhesive material is used, then inner film bonding is improved and removal is eliminated, but material complexity is increased
Solution Approach 1:
The patent selects thermally activatable hot-melt adhesive materials with specific melting points and flow behaviors optimized for the resin curing temperature range. By carefully controlling these thermal parameters, the adhesive material achieves optimal bonding performance while maintaining compatibility with the resin curing process, balancing material complexity with bonding reliability.
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 inner film remains in the rehabilitated sewer pipe after installation, achieving improved adhesion, strength, and sealing properties, suitable for pressurized pipeline systems.
Implementation Method 1
at least one layer of a thermally activatable hot-melt adhesive material with adhesion-promoting properties, namely between the inner pipe film and a reinforcing layer
Implementation Method 2
an outer film facing the channel wall and an inner film facing the medium to be transported, with at least one reinforcing layer made of at least one fiber tube impregnated with a photochemically curable resin
Implementation Method 3
the temperature increases or temperatures occurring during the curing of the resin
Data Source
Figure 1A~1C
Figure 1D~1E
Figure 1F~2
AI summary
The present invention relates to a multi-layer pipe liner which has at least one layer of a thermally activatable hot-melt adhesive material with adhesion-promoting properties, namely between the inner pipe film and a reinforcing layer which contains a reinforcing material with a reaction material which can be cured under UV/light radiation, so that the inner pipe film bonds inseparably with the reinforcing layer during the curing process and forms a unit with the outer film on the channel wall.