Three-Layer Window Joint Sealing System for Moisture and Heat Regulation
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Solution Overview
Problem
Current materials for insulating and sealing joinery, such as windows and exterior doors, fail to effectively regulate heat and moisture flow while preventing uncontrolled air infiltration and biological degradation, leading to inefficiencies in energy and acoustic performance.
Innovation Solution
A three-layer system comprising a polyurethane foam-based insulation material in the middle area, a low vapor permeability sealing material on the interior, and a vapor-permeable sealing material on the exterior, with liquid foil-based front layers that harden to provide controlled diffusion resistance and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single material is used for both insulation and sealing, then the device complexity is reduced, but the ability to regulate heat and moisture flow is insufficient
Solution Approach 1:
The joint sealing system is divided into three distinct layers: an external sealing layer, an insulating layer, and an internal sealing layer. Each layer performs a specific function - the external layer provides weather sealing and vapor permeability, the insulating layer provides thermal insulation, and the internal layer provides vapor barrier and interior sealing. This segmentation allows each material to be optimized for its specific function, resolving the contradiction between system simplicity and moisture flow regulation capability.
Solution Approach 2:
The patent employs a composite material system where three different materials with complementary properties are combined in a layered structure. The external sealing material is vapor-permeable to allow moisture escape, the insulating material provides thermal resistance, and the internal sealing material provides vapor barrier properties. This composite approach enables the system to regulate heat and moisture flow effectively while maintaining structural integrity.
2Ease of manufacture
If conventional polyurethane foam is used for insulation, then ease of manufacture is improved, but uncontrolled air infiltration and biological degradation occur
Solution Approach 1:
The patent merges the functions of air sealing, moisture management, and thermal insulation into an integrated three-layer system. The external and internal sealing layers work together with the insulating layer to simultaneously prevent air infiltration while allowing controlled moisture vapor transmission. This combination maintains the ease of polyurethane foam application while eliminating its deficiencies in air infiltration control and biological resistance.
Solution Approach 2:
The sealing layers act as intermediaries between the insulating material and the external environment. The external sealing layer protects the polyurethane foam from UV radiation and biological degradation, while the internal sealing layer prevents moisture ingress from the interior. These intermediary layers enable the use of conventional polyurethane foam while protecting it from harmful factors.
3Reliability
If vapor barrier is applied on the exterior side, then moisture protection is improved, but condensation risk increases due to trapped moisture
Solution Approach 1:
Instead of placing the vapor barrier on the exterior side as in conventional systems, the patent inverts the arrangement by placing the vapor-permeable layer on the exterior and the vapor barrier (internal sealing layer) on the interior side. This inversion allows moisture vapor to escape from the insulating layer through the exterior permeable layer, preventing condensation while still providing moisture protection from the interior.
Solution Approach 2:
The patent applies different vapor permeability properties at different locations within the joint system. The external sealing layer has high vapor permeability to allow moisture escape to the exterior, while the internal sealing layer has low vapor permeability to prevent moisture ingress from the interior. This local differentiation of material properties optimizes moisture management and prevents condensation throughout the joint.
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 system enhances thermal and acoustic efficiency, prolongs the life of the joint, and simplifies the sealing process by regulating moisture and air flow, while being environmentally sustainable and compatible with various construction materials.
Implementation Method 1
an insulating material in the internal area of the joint... The insulating material consists of a single-component, moisture-cure flexible polymer foam
Implementation Method 2
a vapor-permeable sealing material in the external area of the joint... a low vapor permeability sealing material in the internal area of the joint... regulating the flow of heat and moisture
Implementation Method 3
a sealant in at least one front area of the joint edge... a single-component and moisture-cure sealant and can be injected before curing
Data Source
AI summary
A sealing system for joints of joinery construction elements, especially windows and exit doors, includes an insulating material, an internal sealing layer disposed over an interior surface of the insulating material and an external sealing layer disposed over an exterior surface of the insulating material. The internal sealing layer has a low vapor permeability with an equivalent diffusion resistance factor (Sd) equal to or greater than 30 m, and the external sealing layer has a vapor permeability greater than the vapor permeability of the internal sealing layer with an equivalent diffusion resistance factor (Sd) not greater than 2 m.