Selectively Permeable Multilayer Structure for Corrosion Protection

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Solution Overview

Problem

Current protective covers for large objects during transportation and storage are inadequate as they fail to prevent moisture buildup, leading to corrosion and mold growth due to non-selective permeability and lack of hermetic sealing, and existing permeable materials do not offer a cost-effective solution with the required mechanical properties and flexibility.

Innovation Solution

A selectively permeable multilayer structure composed of ethylene acid copolymers, organic acids, and ethylene-containing polymers, with specific neutralization and blending processes to create a membrane that allows water vapor permeation while blocking liquids, providing high adhesion and mechanical strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high barrier films are used for wrapping large objects, then moisture impermeability is improved, but moisture buildup and corrosion risk increase due to lack of vapor transmission

Engineering Contradiction:
Improvemoisture impermeabilityVSAvoidcorrosion and mold growth
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the permeability parameters of the protective film by incorporating a specific polymer composition with controlled crystallinity and pore structure. The film transitions from complete impermeability to selective permeability, allowing water vapor transmission while blocking liquid water, thus preventing moisture buildup without compromising protection.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite material system consisting of multiple polymer layers with different properties. The structure includes an outer layer for liquid barrier, an inner layer for vapor transmission, and adhesive layers for bonding, creating a multi-functional protective film that simultaneously provides moisture blocking and vapor permeability.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If permeable materials are used to prevent moisture buildup, then corrosion prevention is improved, but mechanical strength and flexibility may be compromised

Engineering Contradiction:
Improvecorrosion preventionVSAvoidmechanical strength and flexibility
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent employs a composite film structure where each layer is optimized for its specific function. The outer barrier layer provides mechanical strength and liquid protection, while the inner permeable layer provides vapor transmission. The adhesive layers ensure proper bonding and maintain structural integrity, thus achieving both corrosion prevention and mechanical performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent develops a thin film structure that maintains flexibility while providing protective functions. The film can be conformally applied to various shapes and sizes of equipment, maintaining flexibility for easy installation while the polymer composition provides the necessary mechanical strength and selective permeability for corrosion protection.

Inventive Principle:
Principle #30Flexible shells and thin films

3Reliability

If hermetic sealing is implemented for large objects, then protection against external moisture is improved, but condensation buildup occurs due to trapped moisture

Engineering Contradiction:
Improveprotection against external moistureVSAvoidcondensation buildup
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the sealing parameters from complete hermetic sealing to controlled permeable sealing. The film allows water vapor to pass through while blocking liquid water, creating a dynamic sealing mechanism that prevents external moisture ingress while enabling internal moisture vapor escape, thus preventing condensation buildup.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces water vapor as an intermediary substance that can pass through the film. The selective permeable membrane acts as a mediator that allows vapor transmission while blocking liquid water, creating a pathway for moisture management without compromising the protective barrier function.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents moisture buildup, reducing corrosion and mold growth while maintaining mechanical integrity and flexibility, offering a cost-effective protective cover for large objects.

Implementation Method 1

A need exists for a material that can be a flexible, solid material with membrane characteristics that facilitate the transport of water vapor, for example, from equipment inside a cover to the atmosphere and block entry of liquids such as water, oil or corrosive fluids.

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentUS8420176B2Method for preparing a selectively permeable protective structure
Publication Date: 2013.04.16 DOW GLOBAL TECHNOLOGIES LLC

AI summary

A method for preparing a multilayer package comprising a substrate and a composition having a moisture vapor permeation value of at least 200 g-mil/m2/24h and barrier to liquid water. The method comprises melt blending an organic acid-modified ionomer with an ethylene-containing copolymer and a copolymer comprising a dicarboxylic acid derivative as a comonomer to provide a composition and applying the composition to the substrate in a molten condition and allowing the composition to cool and solidify.