Polyurethane Adhesive Low Heat Combustion Insulation
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Solution Overview
Problem
Polyurethane adhesives used in insulation panels have high gross heat of combustion, limiting the thickness of adhesive layers and causing manufacturing challenges, such as high viscosity and inconsistent bonding, which is inadequate for meeting fire safety standards like Euroclass A2.
Innovation Solution
A two-part polyurethane adhesive system comprising an aromatic polyisocyanate component and a polyol component with a polyether polyol, aromatic polyester diol, and a particulate mineral filler, which reduces gross heat of combustion while maintaining adequate bond strength and processability, without the need for solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If castor oil-based polyurethane adhesive is used to achieve good adhesive properties, then bond strength is improved, but gross heat of combustion increases beyond fire safety limits
Solution Approach 1:
The patent changes the chemical composition parameters of the polyol component by replacing castor oil with a blend of polyether polyol and aromatic polyester diol. This parameter change reduces the gross heat of combustion from above 4.0 MJ/m2 to below 4.0 MJ/m2 while maintaining adhesive performance through careful selection of hydroxyl equivalent weights and viscosity ranges.
Solution Approach 2:
The patent creates a composite polyol system combining polyether polyol (providing low heat of combustion and low viscosity) with aromatic polyester diol (providing adhesive strength). This composite material approach allows the adhesive to meet both fire safety requirements and bonding performance requirements simultaneously.
2Manufacturing precision
If adhesive layer thickness is increased to improve bonding and ease of manufacture, then manufacturing precision and bond reliability are improved, but gross heat of combustion exceeds fire safety standards
Solution Approach 1:
The patent changes the intrinsic heat of combustion parameter of the adhesive material itself, allowing thicker adhesive layers to be applied while staying within the 4.0 MJ/m2 fire safety limit. The reduced heat of combustion per unit area enables increased adhesive thickness without exceeding regulatory limits.
3Ease of operation
If polyol component viscosity is reduced to improve processability and mixing consistency, then ease of operation is improved, but adhesive bond strength may be compromised
Solution Approach 1:
The patent changes the viscosity parameter of the polyol component to a specific range (50-500 cP at 25°C) that optimizes both processability and adhesive performance. This parameter change ensures the adhesive can be easily pumped and mixed while maintaining adequate bond strength.
Solution Approach 2:
The patent uses a composite polyol system where polyether polyol provides low viscosity for ease of processing, while aromatic polyester diol contributes to adhesive strength. The synergistic combination allows both low viscosity and high bond strength to be achieved simultaneously.
4Ease of operation
If larger filler particles are used to reduce adhesive viscosity, then ease of operation is improved, but manufacturing precision deteriorates due to settling and equipment clogging
Solution Approach 1:
The patent changes the viscosity parameter through chemical composition selection rather than filler particle size manipulation. By selecting polyols with appropriate molecular weight and hydroxyl functionality, the adhesive achieves optimal viscosity without relying on large filler particles that would cause settling and clogging issues.
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 adhesive system achieves a low gross heat of combustion, allowing for thicker adhesive layers, easier processing, and improved bonding between fibrous ceramic and facing layers, while meeting stringent fire safety standards.
Implementation Method 1
a two-part polyurethane adhesive system comprising A) a polyisocyanate component that includes an aromatic polyisocyanate and B) a polyol component including B-1) from 20 to 75% by weight, based on the combined weights of components B-1) and B-2), of a polyether polyol or polyether polyol mixture
Data Source
AI summary
A polyurethane adhesive having a low gross heat of combustion is used to assemble insulation panels such as mineral wool insulation panels. The polyurethane adhesive contains a polyisocyanate side and a polyol side. The polyol side includes a certain polyether ether polyol and an aromatic polyester diol. The mixture of these polyols provides excellent adhesion together with suitably low viscosities, even at high filler levels, and a cured adhesive that has a low gross heat of combustion.