Pipe Liner Sealing Without Eversion to Enable Longer Production
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Solution Overview
Problem
Existing methods for manufacturing pipe liners with a barrier coating on the inner surface are limited by the need for eversion, which restricts pipe liner length due to space and friction constraints, leading to increased installation costs and wastage.
Innovation Solution
A method of manufacturing pipe liners with a barrier-coated inner surface involves providing a sheet of fabric with a barrier coating, forming a fabric sleeve by bringing together opposing side edges, and using a strip of carrier material with a liquid sealant to join the edges, eliminating the need for eversion and allowing longer pipe liner production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pipe liners are manufactured with barrier coating on the inner surface using conventional methods, then the barrier coating can protect the inner surface, but the pipe liner length is restricted due to eversion space and friction constraints
Solution Approach 1:
The patent inverts the conventional manufacturing approach by forming the longitudinal seam first on the flat sheet, then inverting the entire assembly so that the barrier-coated surface ends up on the inner surface of the cylindrical pipe liner. This eliminates the need for post-manufacturing eversion of the completed liner, thereby removing the length restrictions associated with eversion space and friction constraints.
Solution Approach 2:
The patent performs the seam formation operation before the inversion step, rather than after. By joining the longitudinal edges of the flat sheet first (while still accessible and flat), and only then inverting the formed cylinder, the process avoids the difficulty of sewing or welding curved surfaces. This preliminary action enables longer liners to be manufactured without the friction and space limitations that would occur if inversion were performed after seam formation.
2Ease of operation
If pipe liners are manufactured in shorter sections to accommodate eversion constraints, then installation becomes more manageable, but installation costs increase and wastage occurs
Solution Approach 1:
By inverting the barrier-coated surface to the inner surface during manufacturing rather than requiring eversion of the installed liner, the patent enables production of longer pipe liners that can be installed as single pieces. This eliminates the need to join multiple sections together, reducing both installation complexity and material wastage from overlapping joints and trimming.
3Shape
If conventional seam joining methods are used on curved surfaces, then the pipe liner can be formed, but manufacturing precision and seam quality deteriorate
Solution Approach 1:
The patent performs the seam joining operation on the flat sheet before forming the cylindrical shape. This preliminary action allows the use of conventional flat-surface joining methods (sewing, welding, or adhesive bonding) which provide superior precision and quality compared to attempting to join curved surfaces. The cylindrical form is then achieved by inverting the already-seamed tube, maintaining both shape and seam quality.
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
This method enables the production of longer pipe liners without the need for eversion, reducing installation costs and wastage, and providing greater flexibility in pipe repair applications.
Implementation Method 1
joining together the two opposing side edges of the sheet of fabric with the strip of carrier material and the liquid sealant to form the longitudinal seam
Data Source
AI summary
The present invention provides a method and apparatus of manufacturing a pipe liner for lining the inside of a pipe, for example a water or sewerage pipe requiring repair. The pipe liner is mainly formed of a fabric sleeve, or a plurality of fabric sleeves, and comprises a fluid-proof barrier coating on the inside surface of the pipe liner. The method involves arranging a strip of carrier material comprising a liquid sealant inside the fabric sleeve of the pipe liner and in registration with two opposing side edges of the sheet of fabric, facing an inner barrier coating of the fabric sleeve. The method can advantageously provide such a pipe liner with an inner barrier coating without everting the pipe liner after manufacture. The present invention may provide for avoiding internal cross-welding of pipe liners and a method for testing the integrity of the barrier coating of pipe liners.