Composite Roofing Membrane with Char Barrier for Fire Resistance

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Solution Overview

Problem

Existing single-ply roofing membranes lack a char barrier in wood decking flat roof structures during fire events, and current non-charring fire-resistant materials do not adequately enhance fire-resistant performance.

Innovation Solution

A composite roofing membrane is created using a thermoplastic polymer sandwiched between a first scrim and a second scrim, with a fire-resistant fleece containing FR rayon and char scaffold fibers, forming a char barrier for structural support and flame resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional single-ply roofing membrane is used, then the membrane provides basic roofing coverage, but it lacks adequate fire resistance and char barrier formation during fire events

Engineering Contradiction:
Improvefire resistanceVSAvoidmembrane structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining a thermoplastic polymer membrane with a fire-resistant fleece layer containing FR rayon and char scaffold fibers. This composite structure creates a synergistic effect where the thermoplastic membrane provides waterproofing while the fleece layer forms a protective char barrier during fire events, thereby improving fire resistance without requiring a completely new membrane system

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The fire-resistant fleece layer is nested within the composite membrane structure, positioned between the thermoplastic polymer layers. This nested configuration allows the fire-resistant materials to be integrated into the existing membrane system, providing enhanced fire protection while maintaining the overall membrane architecture and avoiding significant structural complexity increases

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If additional non-charring FR materials are added to enhance fire resistance, then fire-resistant performance improves, but the membrane structure becomes more complex

Engineering Contradiction:
Improvefire-resistant performanceVSAvoidmembrane composition
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by concentrating fire-resistant materials specifically in the fleece layer that contacts the roof deck, rather than distributing fire-resistant additives throughout the entire membrane. This localized approach enhances fire-resistant performance at the critical interface with the wood decking while keeping the rest of the membrane structure relatively simple and cost-effective

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 composite membrane effectively withstands flame spread and meets or exceeds industry FR testing protocols, providing enhanced fire resistance and structural integrity to the roof deck.

Implementation Method 1

designed to form a 'char barrier' with some structural support. This resultant reinforced char is designed to withstand flame spread to the roof deck once the thermoplastic membrane has melted and/or burned away.

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

a fire-resistant fleece containing FR rayon and char scaffold fibers, forming a char barrier for structural support and flame resistance

Methodology Applied
Scientific EffectChar formation: Pyrolysis

Data Source

PatentEP3483353B1Fire resistant composite roofing membrane
Publication Date: 2021.07.07 MILLIKEN & CO
  • EP3483353B1 patent drawingFigure 1

AI summary

A composite roofing membrane containing a single ply roofing membrane containing a first membrane, a scrim, and a second membrane. The first side of the first membrane forms the upper surface of the composite roofing membrane and contains a thermoplastic polymer. The scrim has a machine and cross-machine direction and contains a yarn or fiber selected from the group consisting of polyester and glass, and a tensile strength in the machine direction is at least about 100 N/cm2. The second membrane contains a thermoplastic polymer. The composite roofing membrane also contains a fire resistant fleece containing a plurality of FR rayon staple fibers and a plurality of char scaffold fibers selected from the group consisting of partially oxidized acrylonitrile and silica staple fibers.