Flashless Window Sash Moulding with PTFE Pressure Absorbing Inserts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing moulding technologies for reaction injection moulding of window sashes and frames often result in flash formation due to manufacturing imperfections, leading to costly removal processes, material waste, and aesthetic issues, with previous solutions being unsuitable for single large products or requiring additional wear-prone pressure distribution components.
Innovation Solution
A mould device with pressure-absorbing inserts made of heat-deformable synthetic fluoropolymer, such as PTFE, that elastic deform to seal gaps between mould parts, reducing flash formation by absorbing pressure and regaining shape for repeated use, and can be easily replaced or adjusted for different materials and pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional rigid mould parts are used, then manufacturing precision is maintained, but flash formation occurs due to gaps from manufacturing imperfections
Solution Approach 1:
The mould device applies local quality by making only the parting line regions flexible through inserts or localized flexible sections, while the rest of the mould structure remains rigid. This allows gap sealing at critical interfaces without compromising overall mould precision and stability.
Solution Approach 2:
The invention uses flexible inserts, diaphragms, or thin film structures at the parting lines to accommodate manufacturing imperfections. These flexible elements can deform to seal gaps between mould parts, preventing flash formation while maintaining the rigidity of the main mould structure.
2Object-generated harmful factors
If flexible mould plates are used to compensate for tolerances, then flash formation is reduced, but device complexity increases
Solution Approach 1:
The mould device is segmented into rigid main structure and separate flexible components (inserts, diaphragms, or thin films). This segmentation allows the flexible parts to be independently designed, installed, and replaced without redesigning the entire mould, thus reducing overall device complexity.
Solution Approach 2:
Flexible inserts or diaphragms act as intermediary elements between the rigid mould parts. These intermediaries absorb the tolerance variations and sealing functions, simplifying the design by isolating the complexity to specific components rather than the entire mould structure.
3Manufacturing precision
If flash trimming processes are applied, then aesthetic quality is improved, but production time and labour costs increase
Solution Approach 1:
The flexible parting line structures perform the sealing action preliminarily during the moulding process itself, preventing flash formation before it occurs. This eliminates the need for subsequent flash trimming operations, thereby maintaining surface quality while preserving production time and productivity.
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 effectively reduces flash formation on window sashes and frames, enhancing durability and longevity of moulding devices while minimizing material waste and production costs, and ensuring a tight seal even under increased heat conditions.
Implementation Method 1
at least one of said mould parts has at least one recess adapted for receiving at least one pressure absorbing insert arranged externally to the mould cavity and adjacent to the parting line of said mould cavity, said insert having at least a proximal edge, which is closest to the moulding device parting line, and a distal edge, which is farthest away from the moulding device parting line, said insert thereby sealing said mould cavity along the parting line
Implementation Method 2
the thickness dimension of said pressure absorbing insert is smaller at a parting line distal edge than at a parting line proximal edge
Implementation Method 3
the at least one pressure absorbing insert comprises a heat-deformable synthetic fluoropolymer, such as polytetrafluoroethylene (PTFE)
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~3b
AI summary
The present invention relates to a mould device adapted for use in a reaction injection moulding machine, in particular for the moulding of flashless parts, and to a method of moulding flashless parts. In particular a mould device adapted for use in a reaction injection mould for production of window sashes or frames by injection of reaction injection mould-processable material is provided, comprising a first mould part, and a second mould part adapted for defining a mould cavity and a parting line with said first mould part, wherein at least one of said mould parts has at least one recess adapted for receiving at least one pressure absorbing insert arranged externally to the mould cavity and adjacent to the parting line of said mould cavity.