Reinforced Thermoplastic Pipe Barrier Structure Without Tie Layers

Solution Overview

Problem

The production of multilayer EVOH structures for reinforced thermoplastic pipes is complex and inefficient, requiring expensive equipment due to the need for tie layers to enhance bonding between EVOH and polyamide layers, which complicates the manufacturing process.

Innovation Solution

A permeation barrier layer comprising an external thermoplastic polymer layer, an intermediate EVOH copolymer layer, and an internal polyamide layer, where at least a portion of the intermediate layer is in contact with the external and internal layers, eliminating the need for tie layers and simplifying the structure to fewer than 5 layers, such as a 3-layer configuration with polyamide 6 as the primary polymer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If tie layers are added to enhance bonding between EVOH and polyamide layers, then adhesion between layers is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveadhesion between layersVSAvoidnumber of layers

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The invention removes the tie layers from the multilayer structure, extracting the unnecessary adhesive components while maintaining layer bonding through direct contact between EVOH and polyamide layers, thereby simplifying the structure from 5+ layers to 3 layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses composite material properties where the EVOH and polyamide layers are directly bonded through compatible surface properties and molecular interactions, eliminating the need for separate adhesive tie layers while maintaining structural integrity

Inventive Principle:

Principle #40Composite materials

2Strength

If tie layers are added to enhance bonding between EVOH and polyamide layers, then adhesion between layers is improved, but manufacturing cost increases

Engineering Contradiction:

Improveadhesion between layersVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The invention removes the tie layers from the multilayer structure, extracting the unnecessary adhesive components while maintaining layer bonding through direct contact between EVOH and polyamide layers, thereby simplifying the structure from 5+ layers to 3 layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention discards the redundant tie layer materials and processes, recovering manufacturing efficiency by reducing extrusion steps, material costs, and production time while maintaining adequate layer adhesion

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If multilayer structure with tie layers is used, then moisture protection of EVOH is improved, but productivity decreases due to complex production

Engineering Contradiction:

Improvemoisture protectionVSAvoidproduction efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The invention removes the tie layers from the multilayer structure, extracting the unnecessary adhesive components while maintaining layer bonding through direct contact between EVOH and polyamide layers, thereby simplifying the structure from 5+ layers to 3 layers

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the structural parameters by reducing the number of layers and eliminating adhesive components, while maintaining the moisture barrier function through optimized EVOH layer positioning and direct layer contact

Inventive Principle:

Principle #35Parameter changes

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 configuration reduces the complexity and cost of production while maintaining low permeability and moisture resistance, allowing for efficient transportation of oilfield fluids without the need for additional adhesive layers, thereby enhancing the structural integrity and operational efficiency of the pipes.

Implementation Method 1

EVOH provides a particular benefit in the transportation of hydrogen due to its low permeability relative to polymers. However, due to its hydrophilic nature and sensitivity to moisture, EVOH is not generally used individually as a low permeation barrier.

Methodology Applied

Scientific EffectPermeation barrier: Permeation

Implementation Method 2

EVOH can be used in a multilayer structure to reduce its exposure to moisture and prevent the increase in permeability of EVOH.

Methodology Applied

Scientific EffectPhysical barrier: Physical Containment

Data Source

PatentUS20240209965A1Reinforced thermoplastic pipes

Publication Date: 2024.06.27 POLYFLOW LLC

AI summary

There is provided a permeation barrier layer for a reinforced thermoplastic pipe for transportation of oilfield fluids. The permeation barrier layer comprises (i) an external layer comprising a first thermoplastic polymer, (ii) an intermediate layer comprising ethylene vinyl alcohol (EVOH) copolymers, and (iii) an internal layer comprising a polyamide. At least a portion of the intermediate layer is in contact with the external layer and/or the internal layer. There is also provided a reinforced thermoplastic pipe body comprising a permeation barrier layer and at least one reinforcement layer comprising fibres or wires. There is further provided a method for producing a permeation barrier layer for a reinforced thermoplastic pipe for transportation of oilfield fluids and a method for producing a reinforced thermoplastic pipe body.