Composite Rabbet Element for Airtight Window Sealing

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Solution Overview

Problem

Traditional rabbet elements for windows and doors face challenges in providing adequate insulation, mechanical stability, and airtightness while also absorbing static and dynamic impacts, leading to heat losses and condensation due to poor connections with concrete panels and insufficient fire resistance.

Innovation Solution

A composite rabbet element with screwable plates coated in fire-stable materials and a glass fibre net-reinforced mineral render, embedded in concrete walls using screw anchors or wood screws, ensuring mechanical stability, airtightness, and fire-proofing, with a λ-value comparable to mineral wool.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If cement-based chipboard is used to form the rabbet element, then the mechanical connection to concrete panels is improved, but the airtightness deteriorates due to poor connection and cracking

Engineering Contradiction:
Improvemechanical connection strengthVSAvoidairtightness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent employs a composite structure consisting of an insulation layer (mineral wool or similar) sandwiched between two plates (inner plate and outer plate). This composite construction combines the mechanical strength of the plates with the insulating and sealing properties of the insulation material, creating a system that simultaneously achieves strong mechanical connection and reliable airtightness. The insulation layer acts as a continuous sealing barrier that prevents air leakage while the plates provide structural integrity.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If insulation thickness is increased to reduce line loss, then the thermal insulation performance is improved, but the mechanical stability deteriorates due to deeper rabbets

Engineering Contradiction:
Improveheat lossVSAvoidmechanical stability
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The composite structure with rigid plates on both sides of the insulation layer provides mechanical reinforcement that allows for increased insulation thickness without compromising structural stability. The inner plate transfers loads to the concrete panel, while the outer plate provides a stable mounting surface for windows and doors, enabling the use of thicker insulation materials to reduce thermal bridging and line losses.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The rabbet element is segmented into distinct functional layers: the inner plate for structural connection, the insulation layer for thermal performance, and the outer plate for mechanical support and sealing. This segmentation allows each component to be optimized independently - the insulation thickness can be increased for better thermal performance while the plates maintain mechanical stability.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If chipboard is used for the rabbet element, then the ease of manufacture is improved, but the fire resistance deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfire resistance
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces combustible chipboard with a composite construction using non-combustible materials: mineral wool insulation and metal or fire-resistant plates. This composite structure maintains ease of manufacture through standardized components while providing superior fire resistance, as the insulation layer and plates are both fire-resistant materials that do not contribute to fire spread.

Inventive Principle:
Principle #40Composite materials

4Quantity of substance

If the rabbet element uses traditional construction methods, then the cost is reduced, but the airtightness and insulation performance deteriorate due to line losses

Engineering Contradiction:
Improvematerial costVSAvoidairtightness
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The composite rabbet element with continuous insulation layer and sealed joints provides superior airtightness compared to traditional discontinuous insulation methods. The system integrates the insulation material into the structural assembly, creating a continuous thermal and air barrier that eliminates thermal bridging and line losses, thereby improving energy performance while remaining cost-effective through reduced heat loss.

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 provides enhanced mechanical stability, airtightness, and fire-proofing, reducing heat losses and condensation by maintaining a λ-value equivalent to mineral wool, while supporting dynamic loads and wind pressures, thus meeting national and international building standards.

Implementation Method 1

said screwable plates being glued on the insulation layer

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

coated with a thin layer of a highly adhesive mineral render reinforced with a glass fibre net, which makes the rabbet element very fire-proof

Methodology Applied
Scientific EffectFire resistance: Refractory Material

Implementation Method 3

a rabbet element comprising an insulation layer... maintains a λ-value equivalent to mineral wool

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2224070B1Rabbet element, use hereof and method of mounting a rabbet element
Publication Date: 2019.10.09 HIBE
  • EP2224070B1 patent drawingFigure 1
  • EP2224070B1 patent drawingFigure 2
  • EP2224070B1 patent drawingFigure 3

AI summary

A rabbet element (1) for doors and windows, said rabbet element (1) comprising an insulation (2), where at least two sides of the insulation (2) have screwable plates (3) glued thereon. The invention also relates to a method of mounting the rabbet element (1) as well as use of the rabbet element. The said rabbet element (1) and the said method ensure complete airtightness between windows and doors and the facade plane, so that national and/or international requirements with respect to the airtightness of buildings may be observed. Also, line loss (heat loss in the edge zones) around windows and doors is prevented, thereby obviating the risk of draught, condensation and heat loss.