Construction element, in particular door leaf

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Solution Overview

Problem

Existing door leaf components face challenges in achieving visually appealing and cost-effective attachment of profile elements to frame elements with folds, particularly in wood materials, due to issues with hot-melt adhesives leading to visible joints and inadequate water resistance.

Innovation Solution

A door leaf component with a frame element made of wood, featuring a profile element with a functional layer comprising copolyamide, which has optimal melt viscosity and crystalline density, allowing for adhesive-free attachment and forming chemical bonds for enhanced adhesion and moisture resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If hot-melt adhesives are used to attach profile elements to frame elements, then attachment is achieved, but visible joints are created that do not look visually appealing

Engineering Contradiction:
Improveattachment processVSAvoidvisual appearance
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The adhesive is extracted from the final visible structure by being applied in folds that are hidden within the profile element's geometry, removing the harmful visual joint while preserving the attachment function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The adhesive is nested within the folds of the profile element, where it is concealed inside the structural geometry, achieving both attachment and visual concealment

Inventive Principle:
Principle #7Nested doll (Nesting)

2Area of stationary object

If profile elements are attached to narrow surfaces of frame elements with folds, then coverage is achieved, but attachment and fixing become extremely demanding and expensive

Engineering Contradiction:
Improvecoverage areaVSAvoidattachment process
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The profile element is designed with dynamic folds that can be formed and adjusted to match the complex geometry of the frame element's narrow surfaces, enabling coverage of irregular areas through flexible forming rather than rigid attachment

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The fold dimensions (width and depth) are varied as parameters to adapt the profile element to different narrow surface geometries, simplifying the attachment process by using formability rather than complex fixing mechanisms

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If profile elements with hot-melt adhesives are used on wood frame elements, then attachment is achieved, but optimal fixation and required water resistance cannot be achieved

Engineering Contradiction:
Improveattachment processVSAvoidwater resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The mechanical/thermal attachment system (hot-melt adhesive) is replaced with a chemical bonding system where the copolyamide functional layer forms chemical bonds with the wood, achieving both attachment and water resistance through molecular-level adhesion

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

A composite structure is created with the copolyamide functional layer bonded to the wood frame element, combining the properties of both materials to achieve optimal fixation and water resistance that neither material could provide 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 solution enables economical and cost-effective production of door leaves with optimal adhesive strength, peel strength, and moisture resistance, ensuring secure attachment without visible parting lines and improved water resistance.

Implementation Method 1

the profile element is materially bonded to at least one fold via the functional layer

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

the material of the functional layer of the profile element has such an optimum melt viscosity according to ISO 2884

Methodology Applied
Scientific EffectMelt viscosity: Viscometer

Implementation Method 3

the required water resistance cannot be achieved

Methodology Applied
Scientific EffectMoisture resistance: Hydrophobe

Data Source

PatentEP3663499B1Construction element, in particular door leaf
Publication Date: 2022.04.20 REHAU AG & CO
  • EP3663499B1 patent drawingFigure 1
  • EP3663499B1 patent drawingFigure 2
  • EP3663499B1 patent drawingFigure 3

AI summary

The invention relates to a building component, in particular a door leaf, comprising at least one frame element, wherein at least one frame element has at least one rebate, and at least one profile element, comprising at least one decorative layer and at least one functional layer, wherein the functional layer comprises at least partially a polyamide, preferably a copolyamide, which is characterized in that the frame element consists at least partially of wood, in particular real wood, comprising cellulose, hemicellulose and lignin, that the profile element is materially bonded to at least one rebate via the functional layer, and that the material of the functional layer of the profile element has a melt viscosity of about 50 mPas to 100 Pas (Pascal seconds), preferably of about 500 mPas to 50 Pas, at 200 °C according to ISO 2884.