Polyamide Window Profile With Short Fibres for Weldable Corner Strength
Solution Overview
Problem
Existing window and door hollow chamber profiles face challenges in achieving high mechanical stability both longitudinally and transversely, while maintaining good thermal insulation and weldability, particularly in forming corner connections with sufficient strength without additional reinforcement displacement.
Innovation Solution
A window or door hollow chamber profile with a core profile made of polyamide material and short reinforcing fibres (0.1 mm to 12 mm) is used, combined with a compatible sheath profile, allowing for high mechanical stability and weldability with high corner strength without additional effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If continuous fibre reinforcement is used to achieve high mechanical stability in the longitudinal direction, then the modulus of elasticity increases to up to 70,000 N/mm2, but the weldability deteriorates and additional displacement of reinforced regions is required to achieve sufficient corner strength
Solution Approach 1:
The patent changes the fibre length parameter from continuous to short fibres (0.1-12mm), which fundamentally alters the material's behavior during welding. Short fibres do not interfere with the welding process as continuously long fibres do, enabling standard welding procedures to produce sufficient corner strength without additional displacement operations.
Solution Approach 2:
The patent uses a composite material structure combining polyamide matrix with short fibre reinforcement. This composite approach provides the necessary mechanical strength while maintaining weldability, as the short fibres are distributed throughout the matrix and do not create continuous paths that would interfere with welding heat transfer or structural integrity at joints.
2Strength
If high fibre content (more than 20% by weight) is used to achieve high mechanical stability, then the modulus of elasticity increases, but the corner strength of welded connections deteriorates without additional displacement effort
Solution Approach 1:
The patent optimizes the fibre length parameter to short fibres (0.1-12mm) which allows maintaining high fibre content (up to 50% by weight) while preserving weldability. The short fibre length ensures that even at high concentrations, the fibres do not create continuous reinforcement paths that would prevent proper welding heat transfer or structural bonding at corners.
3Strength
If metal reinforcement profile is inserted to improve mechanical stability, then the stability increases, but the thermal insulation properties significantly deteriorate
Solution Approach 1:
The patent replaces the traditional metal reinforcement profile with a polyamide-based composite material containing short fibres. This substitution eliminates the thermal bridge effect of metal reinforcement while maintaining the necessary mechanical strength through the fibre-reinforced plastic matrix, thereby preserving thermal insulation properties.
Solution Approach 2:
The patent employs a composite material system (polyamide matrix with short fibre reinforcement) that combines the mechanical strength previously achievable only with metal reinforcement while maintaining the thermal insulation properties of plastic materials, effectively replacing metal with a composite alternative.
4Strength
If short glass fibres with high content are used to achieve high mechanical stability, then the modulus of elasticity increases, but the weldability deteriorates with low corner strength
Solution Approach 1:
The patent precisely controls the fibre length parameter (0.1-12mm) and fibre content parameter (up to 50% by weight) to optimize the balance between mechanical strength and weldability. This parameter optimization ensures that the short fibres provide sufficient reinforcement while remaining short enough not to interfere with welding processes, achieving both high corner strength and good weldability.
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 profile achieves high mechanical stability in both longitudinal and transverse directions, with excellent weldability and corner strength, ensuring secure attachment of fittings and effective thermal insulation.
Implementation Method 1
a core profile comprising a plastic matrix formed of thermoplastic material and reinforcing fibres contained in the plastic matrix
Implementation Method 2
a corner connection which has been obtained by welding at least partially mitred portions of a window or door hollow chamber profile
Data Source
AI summary
The present invention relates to a window or door hollow chamber profile (1), comprising (a) a core profile (30) comprising a plastic matrix formed of thermoplastic material and reinforcing fibres contained in the plastic matrix; and (b) a sheath profile (40) at least partially sheathing the core profile (30) and made of a thermoplastic material compatible with the plastic material of the core profile (30), wherein the window or door hollow chamber profile (1) is distinguished in accordance with the invention in that the thermoplastic material of the core profile (30) is a polyamide material and the reinforcing fibres are short fibres with an average fibre length in the range from 0.1 mm to 12 mm. In addition, the present invention also relates to a corner connection that has been obtained by welding at least partially mitred portions of a window or door hollow chamber profile (1) of this kind.