Intumescent Fireproofing Strip for 120-Minute Joint Isolation

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Solution Overview

Problem

Existing fireproofing strips are complex to produce and do not effectively meet specific fire resistance criteria, such as maintaining isolation for up to 120 minutes, particularly in building joints.

Innovation Solution

A fireproofing strip made from reticulated PU soft foam impregnated with a binder, expandable graphite, and a phosphorus-containing compound, such as ammonium polyphosphate, which expands at specific temperatures to create a carbon-containing insulating layer, enhancing fire resistance and simplifying production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional PUR sealing strips with special impregnation are used, then fire resistance is improved, but production complexity increases

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

Solution Approach 1:

The patent uses reticulated foam material with a porous structure that allows impregnating agents to penetrate deeply and uniformly throughout the material. This porous structure enables efficient fireproofing impregnation while simplifying the production process through direct saturation of the foam matrix.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention combines reticulated foam material with fireproofing impregnating agents containing expandable graphite and phosphorus compounds to create a composite fireproofing strip. This composite structure integrates the mechanical properties of foam with the fire-resistant properties of the impregnating agents, achieving both fire resistance and production simplicity.

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If fire resistance duration is increased to meet 120 minutes criteria, then fire protection is improved, but material complexity increases

Engineering Contradiction:
Improvefire resistance durationVSAvoidmaterial complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The patent incorporates expandable graphite that undergoes phase transition when exposed to fire temperatures. The graphite expands dramatically, forming an insulating char layer that provides extended fire resistance. This phase transition mechanism delivers long-duration fire protection through a relatively simple material composition.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The impregnating agent contains phosphorus compounds that, when exposed to fire, promote charring and form protective carbon layers. The harmful heat and oxygen that would normally accelerate combustion are converted into beneficial char formation that protects the underlying material, extending fire resistance duration.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 strip provides high fire resistance, smoke-tightness, and simplified production, with improved insulation and fireproofing properties, including a high degree of smoke-tightness and simplified installation due to its low delayed resilience.

Implementation Method 1

It is known that expandable graphite has the characteristic of expanding when heated. This effect is used here for fireproofing purposes. Furthermore, due to this expansion of the expandable graphite a high pressure is generated

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the foam material support is penetrated completely by the impregnating agent

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

a carbon-containing insulating substance is produced which shields the foundation structure against the heat source

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3455329B1Fireproofing strip
Publication Date: 2025.09.10 TREMCO CPG GERMANY GMBH
  • EP3455329B1 patent drawingFigure 1

AI summary

Fireproofing device (1), in particular a fireproofing strip (1), with an elongate support (2), which is produced from a foam material, a non-woven fabric and/or a fibrous body and is provided with an impregnating agent. According to the invention this impregnating agent contains as components at least one liquid medium and a binder for binding solid components of the impregnating agent to the foam material and expandable graphite.