Composite Pipe Melt Temperature Control for Void Prevention
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Solution Overview
Problem
Existing composite pipes face issues such as variances in thickness, radial/hoop expansion, and longitudinal movement between material layers, leading to internal deformities, leakage, and premature wear during fluid/gas transport, as well as the formation of voids and annuli that can cause permeation and pipe failure.
Innovation Solution
A method of manufacturing a composite pipe with a coherent bond among material layers, utilizing melt temperature relationships and controlled cooling of the extruded pipe core to prevent expansion and contraction, ensuring a unitary mass with no voids or annuli, and using prepreg or similar materials for reinforcement to enhance chemical and pressure resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the extrusion process is used to form multi-layer pipe, then pipe manufacturing efficiency is improved, but variances in pipe thickness and radial/hoop expansion occur leading to internal deformities
Solution Approach 1:
The patent applies parameter changes by carefully controlling the melt temperatures of different material layers during extrusion. The intermediate layer has a melt temperature within 20°F of the inner layer, while the outer layer has a melt temperature within 40°F of the inner layer. This temperature parameter control prevents radial expansion and contraction, ensuring uniform pipe thickness and eliminating internal deformities while maintaining manufacturing efficiency.
2Reliability
If multiple material layers are joined together in composite pipe, then chemical and pressure resistance is improved, but longitudinal movement between layers causes abrasion and premature wear
Solution Approach 1:
The patent uses composite materials with specific melt temperature relationships to create a coherent multi-layer structure. The intermediate layer acts as a bonding interface with melt temperature within 20°F of the inner layer, ensuring strong adhesion. The outer layer has melt temperature within 40°F of the inner layer, creating a unified composite structure that prevents longitudinal movement between layers, eliminating abrasion and extending pipe service life while maintaining chemical and pressure resistance.
Solution Approach 2:
The patent applies local quality by assigning different melt temperature characteristics to different layers. The intermediate layer has a melt temperature specifically controlled within 20°F of the inner layer for optimal bonding, while the outer layer has a melt temperature within 40°F of the inner layer. This localized temperature differentiation ensures coherent bonding at each interface, preventing layer movement and abrasion while maintaining overall pipe integrity.
3Device complexity
If annuli and voids appear between pipe layers, then manufacturing complexity is reduced, but gas permeation occurs leading to pipe failure
Solution Approach 1:
The patent eliminates annuli and voids by controlling the melt temperature parameters of the material layers. The intermediate layer's melt temperature is within 20°F of the inner layer, and the outer layer's melt temperature is within 40°F of the inner layer. This parameter control ensures all layers are in a plastic state during extrusion, allowing them to bond coherently without forming voids or annuli, thereby preventing gas permeation and maintaining pipe integrity without increasing manufacturing complexity.
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 results in a composite pipe with improved resistance to deformation, leakage, and permeation, allowing for efficient transport of pressurized fluids/gases with reduced risk of premature failure and enabling cost-effective butt fusion in the field.
Implementation Method 1
the intermediate layer has a melt temperature within 20° F. of the melt temperature of the inner layer and the outer layer has a melt temperature within 40° F. of the melt temperature of the inner layer
Implementation Method 2
a cooling of the extruded pipe core during the subsequent wrapping of intermediate reinforcing layers
Data Source
AI summary
A composite pipe and method of manufacture comprises an inner core coated with a resinous material, a prepreg material helically wound about the inner core and an outer shell covering the wound prepreg materials. The materials are applied at preselected melt temperatures to assure coherence among the materials and preclusion of voids and/or annuli therebetween. The melt temperature of the inner core is greater than the melt temperature of the coating and prepeg layers such that the heating needed to cohere these materials has no deleterious effect on the integrity of the inner pipe core. A cooling of the inner pipe core during initial application of the tape layer of prepreg materials stabilizes the radial configuration of the pipe core during tape wrapping and thus the appearance of undesirable voids and/or annuli in the composite pipe mass.