Multilayer Polyurethane Insulation Board for Dimensional Stability

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Solution Overview

Problem

Existing external thermal insulation composite systems using closed cell polyurethane foams exhibit diminished dimensional stability, which is not adequately addressed by conventional materials like EPS.

Innovation Solution

A multilayer thermal insulation board comprising a closed cell polyurethane/polyisocyanurate foam layer with less than 20% open cell volume and an open cell polyurethane/polyisocyanurate foam layer with greater than 80% open cell volume is used, providing improved insulation and mitigating dimensional changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If closed cell polyurethane foam is used for thermal insulation, then insulation properties are improved, but dimensional stability deteriorates

Engineering Contradiction:
Improvethermal insulationVSAvoiddimensional stability
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent applies composite materials by combining closed cell polyurethane foam layers with open cell polyisocyanurate foam layers in a multilayer configuration. The closed cell layers provide superior thermal insulation with low thermal conductivity, while the open cell layers compensate for dimensional changes through their cellular structure, achieving both energy efficiency and dimensional stability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The insulation board is segmented into multiple functional layers: closed cell polyurethane layers for thermal insulation and open cell polyisocyanurate layers for dimensional stability. This segmentation allows each layer to perform its specific function optimally, with the closed cell layers minimizing heat transfer and the open cell layers accommodating thermal expansion and contraction

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If open cell polyurethane foam is used, then dimensional stability is improved, but insulation properties deteriorate

Engineering Contradiction:
Improvedimensional stabilityVSAvoidthermal insulation
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent creates a composite material system where open cell polyisocyanurate foam layers are combined with closed cell polyurethane layers. The open cell structure of the polyisocyanurate provides dimensional stability and flexibility, while the closed cell polyurethane provides the primary thermal insulation barrier, achieving a balance between both properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different regions of the insulation board have different cellular structures optimized for different functions. The closed cell polyurethane regions provide high insulation value where thermal performance is critical, while the open cell polyisocyanurate regions provide dimensional stability and flexibility, creating local quality variations that satisfy different performance requirements

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 combination enhances insulation properties while stabilizing dimensional changes, offering superior thermal performance and stability in external thermal insulation composite systems.

Implementation Method 1

The closed cell layer may provide insulation properties

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

the open cell layer of the multilayer thermal insulation board may help mitigate the effect of dimensional changes of the closed cell layer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3717243B1Polyurethane-based insulation board
Publication Date: 2025.11.26 DOW GLOBAL TECHNOLOGIES LLC
  • EP3717243B1 patent drawingFigure 1

AI summary

External thermal insulation composite systems described herein include a concrete or masonry wall and a multilayer thermal insulation board disposed on the concrete or masonry wall. The multilayer thermal insulation board includes at least one closed cell foam layer comprising polyurethane and polyisocyanurate having an open cell volume of less than 20% by volume according to ASTM D 6226 and at least one open cell foam layer comprising polyurethane and polyisocyanurate having an open cell volume of greater than 80% by volume according to ASTM D 6226.