Polymer Foam–Fiber Construction Element for Thermal and Vapor Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing thermally insulating construction elements do not effectively utilize bio-based materials for optimal thermal insulation and vapor resistance, leading to suboptimal performance in maintaining thermal integrity and moisture control.

Innovation Solution

A construction element design featuring a polymer foam layer topped with a lignocellulose or cellulose fiber layer, where the fiber layer provides enhanced thermal resistance and vapor impermeability, with ribs and beams for structural support and reduced thermal bridging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single layer of insulating material is used, then the construction element is simpler and cheaper to manufacture, but the thermal insulation performance and vapor resistance are insufficient

Engineering Contradiction:
Improvethermal insulation performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining two different insulating material layers: a first layer made of polymer foam (EPS, XPS, PU, or PI) and a second layer made of natural fibers (wood fiber, flax fiber, or hemp fiber). Each material contributes different properties - the polymer foam provides vapor impermeability and structural stability, while the natural fiber layer provides thermal insulation and breathability. This composite structure resolves the contradiction by achieving superior thermal insulation performance without requiring a single complex material, instead using a coordinated system of two simpler materials.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent segments the insulating material into two distinct layers with different functions. The first layer (polymer foam) is positioned to provide vapor resistance and structural support, while the second layer (natural fiber) provides thermal insulation. This segmentation allows each layer to be optimized for its specific function, resolving the contradiction between performance and complexity by dividing the system into manageable, functionally-specialized components.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the first layer of insulating material is placed above the second layer, then vapor impermeability is improved, but water vapor absorption increases

Engineering Contradiction:
Improvevapor impermeabilityVSAvoidwater vapor absorption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent inverts the conventional arrangement by placing the vapor-impermeable polymer foam layer at the bottom (first layer) and the breathable natural fiber layer at the top (second layer). This inversion ensures that the vapor barrier is positioned where it is most effective - at the warm side of the insulation - preventing water vapor from penetrating into the insulation from the interior. The breathable top layer then allows any moisture to evaporate outward, resolving the contradiction by strategically positioning materials to prevent both vapor ingress and moisture accumulation.

Inventive Principle:
Principle #13The other way round (Inversion)

3Adaptability or versatility

If bio-based materials are used to increase the proportion of natural materials, then ecological benefits are improved, but thermal insulation performance may be reduced

Engineering Contradiction:
Improveecological compatibilityVSAvoidthermal insulation performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses composite materials to combine the ecological benefits of bio-based natural fibers with the high thermal insulation performance of polymer foam. The natural fiber layer (wood fiber, flax fiber, or hemp fiber) provides sustainability and breathability, while the polymer foam layer provides superior thermal insulation and vapor resistance. The synergistic combination resolves the contradiction by allowing each material to contribute its strengths, achieving both ecological compatibility and high thermal insulation performance that neither material could achieve alone.

Inventive Principle:
Principle #40Composite materials

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 design achieves superior thermal insulation and vapor resistance, allowing the construction element to maintain lower attic temperatures and reduce moisture ingress, while utilizing a high percentage of bio-based materials for ecological benefits.

Implementation Method 1

a first layer of plate shaped insulating material (3) and a second layer of plate shaped insulating material (5)... The first layer of plate shaped insulating material comprises or consists of a board made of polymer foam

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The lignocellulose fibers or cellulose fibers of the second layer of plate shaped insulating material provide a higher thermal resistance for the construction element due to their high specific heat capacity

Methodology Applied
Scientific EffectHeat absorption and storage: Heat Sink

Implementation Method 3

the first layer of plate shaped insulating material is much more vapor impermeable than the second layer of plate shaped insulating material due to its polymer foam composition

Methodology Applied
Scientific EffectVapor impermeability: Permeation

Data Source

PatentEP4610447A1Construction element
Publication Date: 2025.09.03 UNILIN BVBA
  • EP4610447A1 patent drawingFigure 1~3
  • EP4610447A1 patent drawingFigure 4~5
  • EP4610447A1 patent drawing

AI summary

A construction element (1) comprises a first layer of plate shaped insulating material (3) and a second layer of plate shaped insulating material (5). The second layer of plate shaped insulating material is located above the first layer of plate shaped insulating material. The first layer of plate shaped insulating material comprises or consists of a board made of polymer foam. The second layer of plate shaped insulating material comprises or consists of a board made of lignocellulose fibers or cellulose fibers. The ratio of the thickness (D1) of the first layer of plate shaped insulating material to the thickness (D2) of the second layer of plate shaped insulating material is preferably between 2 and 0.5.