Expandable Graphite Surface Layer for Polyurethane Foam Flame Retardancy

Solution Overview

Problem

Existing flexible foams, particularly polyurethane and latex foams, face challenges in achieving improved flame retardant properties without compromising their static and dynamic fatigue properties, feel, and stiffness.

Innovation Solution

A flexible foam composition is developed that includes a polyurethane or latex foam body with an expandable graphite layer applied on at least one surface or partially within the foam body, enhancing flame retardant properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high loadings of flame retardants are used throughout the foam, then flame retardant properties are improved, but static and dynamic fatigue properties, feel, and stiffness deteriorate

Engineering Contradiction:

Improveflame retardant propertiesVSAvoidstatic and dynamic fatigue properties

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The flame retardant function is segmented from the bulk foam structure and concentrated in a surface layer. The expandable graphite is applied as a distinct layer on the foam surface rather than being distributed throughout the entire foam matrix, creating a functional segmentation that isolates the flame retardant benefit from the structural foam body.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flame retardant property is localized to the surface region where it is most needed for fire protection. The expandable graphite layer provides concentrated flame retardancy at the surface without requiring high loadings throughout the entire foam volume, thus maintaining the bulk foam's mechanical properties.

Inventive Principle:

Principle #3Local quality

2Reliability

If high loadings of flame retardants are used throughout the foam, then flame retardant properties are improved, but feel and stiffness deteriorate

Engineering Contradiction:

Improveflame retardant propertiesVSAvoidfeel and stiffness

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The flame retardant function is segmented from the bulk foam structure and concentrated in a surface layer. The expandable graphite is applied as a distinct layer on the foam surface rather than being distributed throughout the entire foam matrix, creating a functional segmentation that isolates the flame retardant benefit from the structural foam body.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flame retardant property is localized to the surface region where it is most needed for fire protection. The expandable graphite layer provides concentrated flame retardancy at the surface without requiring high loadings throughout the entire foam volume, thus maintaining the bulk foam's mechanical properties.

Inventive Principle:

Principle #3Local 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

The use of an expandable graphite layer significantly improves the flame retardant properties of flexible foams, allowing them to pass burn tests while maintaining desirable foam characteristics.

Implementation Method 1

an expandable graphite layer on at least one of the surfaces or at least partially within the flexible foam body adjacent the surface

Methodology Applied

Scientific EffectExpandable graphite expansion: Thermal Expansion

Data Source

PatentUS12240958B2Expandable graphite flame retardant layer for polyurethane and latex foam

Publication Date: 2025.03.04 L & P PROPERTY MANAGEMENT CO

AI summary

A flexible foam composition includes a flexible foam body having a surface, which flexible foam is polyurethane and/or latex flexible foam, and an expandable graphite layer on the surface or within the foam surface adjacent to the surface. The flexible foam composition with the expandable graphite layer imparts improved flame retardant properties to the composition.