Elastic Polyurethane Foam Fire-Stop Seal for Building Joints
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Solution Overview
Problem
Current fireproof expansion joints deteriorate due to compression and decompression phenomena, are not adapted to building expansion movements, and require additional materials for installation, leading to reduced effectiveness and safety concerns.
Innovation Solution
A preformed elastic polyurethane foam caulking system with a high percentage of flame retardants, designed to compress for easy installation and adapt to building movements, eliminating the need for additional bonding materials and maintaining fire resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fibrous products (rock wool or glass wool) are used for fire-resistant joints, then fire resistance and thermal insulation are improved, but the joint deteriorates due to alternating compression and decompression, and personal protective equipment is required for installation
Solution Approach 1:
The patent changes the material parameters from fibrous products to a foam-based material with specific chemical composition (polyol, isocyanate, blowing agent, catalyst). This new material maintains fire resistance through its chemical formulation while achieving the desired mechanical stability to resist deterioration from alternating compression and decompression.
Solution Approach 2:
The invention uses a composite foam material combining multiple components (polyol with specific molecular mass and OH number, isocyanate, blowing agent, catalyst, and optional flame retardants) to achieve both fire resistance and mechanical stability simultaneously, eliminating the need for separate adhesive materials.
2Ease of operation
If conventional foam sealant is used, then ease of installation is improved, but fire resistance is compromised due to use of halogenated products
Solution Approach 1:
The patent modifies the chemical parameters of the foam material by selecting specific polyols (molecular mass 4000-7000 g/mol, OH number 20-40) and isocyanates with controlled NCO content (5-25%), combined with non-halogenated blowing agents. This achieves both ease of installation through foam properties and fire resistance by eliminating halogenated compounds.
3Temperature
If rock wool or glass wool beads are used, then thermal insulation is improved, but additional adhesive materials are required to prevent beads from falling out
Solution Approach 1:
The patent merges the functions of thermal insulation, structural integrity, and adhesion into a single foam material. The foam simultaneously provides thermal insulation through its cellular structure, maintains structural integrity through its elastic properties, and adheres to substrates without requiring separate adhesive materials.
Solution Approach 2:
The foam material serves multiple functions: thermal insulation, fire resistance, structural stability under compression/decompression, and self-adhesion. This multi-functional material eliminates the need for separate adhesive components required by fibrous bead systems.
4Reliability
If fibrous products are used for expansion joints, then fire resistance is improved, but adaptability to building expansion movements is reduced
Solution Approach 1:
The patent changes the material from rigid or brittle fibrous products to an elastic foam material with specific mechanical properties. The foam's cellular structure and polymer matrix provide elasticity and compressibility, enabling adaptation to building expansion and contraction movements while maintaining fire resistance through its chemical composition.
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 provides long-lasting thermal insulation and tightness, resists deformation, and maintains fire resistance, ensuring effective sealing and protection against hot gases and smoke for extended periods.
Implementation Method 1
The foam is obtained by a reaction between: at least one polyol with a molecular mass between 4000 and 7000 g/mol and an OH number between 20 and 40 (mg KOH/g)... and an isocyanate in the form of a prepolymer or quasi-prepolymer
Implementation Method 2
mixed with 0.3 to 1.5 wt% water as a blowing agent
Implementation Method 3
0.1 to 2 wt% an amine-type catalytic system
Implementation Method 4
said material comprises at least 50 wt% flame retardants
Implementation Method 5
A preformed elastic polyurethane foam caulking system with a high percentage of flame retardants, designed to compress for easy installation and adapt to building movements
Implementation Method 6
The solution provides long-lasting thermal insulation and tightness
Data Source
Figure 1a~2
Figure 3a~4
Figure 5a~5b
AI summary
The invention relates to a caulking or filling device having fire-break properties and made of an elastic material comprising a polyurethane foam. The foam is obtained by reacting at least one polyol having a molecular weight of 4000 to 7000 g/mol and an OH index of 20 to 40 (mg KOH/g), and an isocyanate in the form of a prepolymer or quasi-prepolymer comprising between 5 and 25% of free NCO functions. The elastic material comprises at least 50 wt % of flame-retarding agents. The invention also relates to the use of the device for making seals or fillings having fire-stopping characteristics.