Thin Metal Frame Member with Foam Core Insulation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional window and door frames, including those made from PVC and wooden cores with polyurethane shells, fail to meet stringent modern building insulation standards and are costly to produce, with issues related to material usage and internal tensions.

Innovation Solution

A method involving roll-forming thin metal sheets into frame shells, injecting a foaming material like isocyanate and polyol that expands within a calibration tube to set, providing a core with enhanced insulation and structural strength, reducing material usage and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If traditional wooden frame structures are used, then aesthetic appeal is achieved, but robustness and insulating properties are insufficient

Engineering Contradiction:
ImproverobustnessVSAvoidinsulating properties
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent employs a composite structure combining thin metal sheets (aluminum or stainless steel) with rigid foam core material. The metal provides structural strength and robustness, while the foam core delivers superior thermal insulation. This composite approach resolves the contradiction by integrating materials with complementary properties, achieving both mechanical strength and insulating performance that neither material could provide alone.

Inventive Principle:
Principle #40Composite materials

2Force

If PVC is used for window frames, then robustness is improved, but insulating properties and environmental friendliness deteriorate

Engineering Contradiction:
ImproverobustnessVSAvoidinsulating properties
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent replaces PVC with a composite of metal and foam materials. The metal shell provides the necessary robustness and structural integrity, while the foam core delivers superior thermal insulation compared to PVC. Additionally, this composite structure offers environmental advantages by eliminating PVC, addressing both the insulating property deficiency and environmental concerns.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If metal sheet thickness is reduced to 0.25 mm or less, then material usage and costs are reduced, but structural strength deteriorates

Engineering Contradiction:
Improvematerial usageVSAvoidstructural strength
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The patent uses thin metal sheets (0.25 mm or less) in combination with a rigid foam core to achieve the desired structural strength. The foam core acts as a structural reinforcement, compensating for the reduced thickness of the metal shell. This allows significant material reduction while maintaining or even improving overall structural performance through the synergistic effect of the composite structure.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different material properties to different parts of the frame structure. The thin metal shell provides local strength and durability where needed, while the foam core provides distributed structural support and insulation throughout the frame volume. This local differentiation of material functions enables the use of thinner metal while maintaining overall structural integrity.

Inventive Principle:
Principle #3Local quality

4Reliability

If foam material is injected into the frame shell, then insulating properties are improved, but internal tensions and shape deformation occur

Engineering Contradiction:
Improveinsulating propertiesVSAvoidinternal tensions
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent performs preliminary shaping of the metal frame shell through roll-forming before foam injection. This pre-formed shell acts as a constraint that guides the foam expansion and prevents unwanted shape deformation. The metal shell is prepared in advance to the correct geometry, ensuring that when foam is injected and expands, it fills the cavity uniformly without causing internal tensions or distorting the frame shape.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses thin metal sheets that have sufficient flexibility to be roll-formed into the desired frame profile, yet maintain enough rigidity to constrain foam expansion. The thin metal shell acts as a flexible formwork during foam injection, allowing the foam to expand and set while simultaneously preventing deformation and controlling internal tensions.

Inventive Principle:
Principle #30Flexible shells and thin films

5Strength

If complex production processes with multiple materials are used, then structural strength is improved, but manufacturing costs and complexity increase

Engineering Contradiction:
Improvestructural strengthVSAvoidproduction complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent uses a simple two-material composite structure (metal shell + foam core) that provides adequate structural strength for window and door frames. This simplified composite approach eliminates the need for complex multi-layer structures or additional reinforcement elements, reducing manufacturing complexity while maintaining necessary structural performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent combines multiple functions into a single integrated structure. The metal shell simultaneously provides structural strength, durability, and shape definition, while the foam core provides insulation and structural reinforcement. This merging of functions into a simple two-component system eliminates the need for separate insulation panels, reinforcement ribs, or decorative covers, significantly simplifying the production process.

Inventive Principle:
Principle #5Merging (Combining)

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 method results in frame members with insulation properties approximately 4-5 times better than wood, maintaining structural integrity and reducing internal tensions, while being more cost-effective and environmentally friendly.

Implementation Method 1

introducing a foaming material into the frame shell... a core of a foam material may be provided. The core may assume the shape of the profile

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 2

The composition may comprise isocyanate and polyol, which upon reaction with each other creates a foam which expands within the profile

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP3621779B1A method for making a frame member, a frame member, a frame structure and use of a frame member
Publication Date: 2021.03.03 VKR HOLDING AS
  • EP3621779B1 patent drawingFigure 1~2b
  • EP3621779B1 patent drawingFigure 3~4b
  • EP3621779B1 patent drawingFigure 5~6

AI summary

The present invention relates to a method of producing a frame member for a window or a door, the method comprising the steps of providing a sheet of metal, rollforming the sheet of metal into a frame shell having a predetermined profile, introducing a foaming material into the frame shell, and arranging the frame shell in a calibration tube until the foam material has set. The sheet of metal has a thickness of 0.25 mm or less. The present invention further relates to a frame member, a frame structure and use of such frame member.