Fireproof Membrane Edge Protection for Tunnel Linings

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Solution Overview

Problem

Existing tunnel lining membranes made of plastic materials often fail to meet fire resistance requirements when exposed to flames perpendicular to their edge cross-sectional surfaces, unlike those exposed to flames on plane surfaces.

Innovation Solution

A thin plastic membrane with a thickness of 0.5 to 3 mm, featuring a reduced thickness edge and sides with fire protection enhancements such as fire-resistant tape, extruded strings, or uneven surfaces like fins and grooves, which provide comprehensive fire protection by preventing direct exposure to flames and improving adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a thin plastic membrane is used for tunnel lining, then ease of installation and cost are improved, but fire resistance when exposed to flames perpendicular to edge surfaces deteriorates

Engineering Contradiction:
Improveease of installationVSAvoidfire resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies different properties to different parts of the membrane: the main body remains thin plastic for ease of installation, while the edges receive fire protective treatments (fire-resistant coating, tape, or extruded material) to enhance fire resistance. This local differentiation resolves the contradiction between overall ease of manufacture and specific fire resistance requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a composite structure by combining thin plastic material with fire protective materials at the edges. The composite consists of the base plastic membrane plus fire-resistant layers (coating, tape, or extruded material), achieving both ease of installation and improved fire resistance through material combination.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the membrane thickness is reduced to 0.5-3 mm, then ease of installation and cost are improved, but structural strength and fire resistance deteriorate

Engineering Contradiction:
Improveease of installationVSAvoidstructural strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent maintains thin thickness (0.5-3 mm) for the main membrane body to ensure ease of installation, while locally reinforcing the edges with fire protective materials that also provide structural support. This localized reinforcement resolves the contradiction between overall thinness and edge strength requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fire protective materials are applied to the edges during the manufacturing process before installation. This preliminary action ensures that the edges are pre-reinforced with structural strength, allowing the thin membrane to be both easy to install and sufficiently strong where needed.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If fire protective materials are added to the membrane edges, then fire resistance is improved, but device complexity and manufacturing complexity increase

Engineering Contradiction:
Improvefire resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fire protective materials are applied to the edges during the manufacturing process rather than requiring separate post-installation steps. This preliminary action integrates fire protection into the production line, reducing overall complexity despite adding manufacturing steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the fire protection function with the edge structure itself. Instead of adding separate complex fire suppression systems, the fire protective materials are integrated directly into the edge construction, simplifying the overall device while maintaining fire resistance.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3109401B1Fireproof membrane and method for its fabrication
Publication Date: 2019.11.20 CHEETHAM JOHN OLDROYD
  • EP3109401B1 patent drawingFigure 1~3
  • EP3109401B1 patent drawingFigure 4~5
  • EP3109401B1 patent drawingFigure 6~7

AI summary

This publication relates to a method and a fire protective lining or membrane for improving fire resistance of a lining or membrane (10) of a plastic material to be used in association with supporting structures (22), such as for example buildings tunnel walls, wherein a surface of the supporting structure (22) is provided with a thin lining or membrane (10) fixed to the surface by means of bolts, and where the membrane or lining (10) is exposed to the possibilities of open flames or fire on the surface facing the tunnel cavity. A fire protection (15) is added to at least one end edge surface (12) of the lining or membrane (10), the added fire protection (15) being configured in such way that the edge (12) of the lining or membrane (10) is prevented from catching fire when exposed to open flames or a burning object.