Vacuum Infusion Channel Inversion for Composite Dry Spots
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Solution Overview
Problem
The challenge in vacuum-assisted resin transfer moulding (VARTM) is the occurrence of dry spots and air pockets in fibre composite mouldings due to incomplete impregnation of fibre materials with resin, which is difficult to resolve through conventional vacuum and pressure control, especially in large moulds where manual intervention is time-consuming and risky.
Innovation Solution
Periodically reversing the function of inlet and vacuum channels by connecting them to either the polymer source or vacuum source during the mould filling process, allowing for a flexible and powerful local vacuum to draw resin into dry spots and prevent air ingress, using semi-permeable membranes and oblong hollow profile bodies with flap valve functionality to enhance resin distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional vacuum and pressure control is used to fill the mould cavity, then the filling process is simple to control, but dry spots and air pockets occur due to incomplete impregnation of fibre materials with resin
Solution Approach 1:
The patent applies inversion by periodically reversing the function of inlet and vacuum channels. Channels that normally serve as inlet channels are temporarily converted to vacuum channels, and vice versa. This allows resin to be drawn back towards inlet channels to eliminate dry spots, and air pockets to be evacuated through what were previously inlet channels, thereby achieving complete impregnation without adding complex control systems
Solution Approach 2:
The patent implements periodic action by cycling the functions of inlet and vacuum channels during the mould filling process. The control system periodically switches which channels receive resin and which channels evacuate air, creating a dynamic filling pattern that ensures complete resin distribution throughout the fibre material while maintaining simple channel infrastructure
2Reliability
If manual intervention is used to repair dry spots in large moulds, then dry spots can be addressed, but the process is time-consuming and risks deformation of fibre material and vacuum bag perforation
Solution Approach 1:
The patent applies preliminary action by proactively eliminating dry spots during the automated mould filling process itself, rather than waiting for manual inspection and repair. The periodic reversal of channel functions continuously monitors and corrects resin distribution issues as they occur, ensuring complete impregnation before the mould is closed and cured, thereby eliminating the need for time-consuming manual repair operations
Solution Approach 2:
The system implements self-service by automatically detecting and correcting dry spots through periodic channel function reversal without requiring manual intervention. The control system autonomously manages resin distribution by switching channel functions, and the process self-corrects any incomplete impregnation areas, eliminating the need for external repair operations that consume time and risk damage
3Adaptability or versatility
If vacuum channels and inlet channels have fixed functions, then the system is simple to operate, but flexible resin distribution and air management cannot be achieved
Solution Approach 1:
The patent applies universality by designing channels that can perform multiple functions - each channel can alternatively serve as either a vacuum channel or an inlet channel depending on the process stage. This multi-functionality is achieved through a control system that switches the connection of each channel between the vacuum source and resin source, providing flexible resin distribution and air management capabilities while maintaining a relatively simple physical channel structure
Solution Approach 2:
The patent implements dynamics by making the channel functions changeable during the mould filling process. The control system dynamically assigns different roles to different channels at different times, allowing the system to adapt resin distribution patterns and air evacuation paths according to the filling progress and detected dry spot locations, thereby achieving versatility without requiring complex permanent channel configurations
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
This approach ensures complete and efficient filling of the mould cavity, reduces the risk of dry spots, and maintains structural integrity by allowing for effective resin distribution and air management, even in the presence of leaks or deformations.
Implementation Method 1
a vacuum is generated in the mould cavity hereby drawing in the polymer
Implementation Method 2
a vacuum is generated in the mould cavity hereby drawing in the polymer. Often a minor positive pressure is generated at the inlet side
Implementation Method 3
using semi-permeable membranes and oblong hollow profile bodies with flap valve functionality to enhance resin distribution
Data Source
AI summary
Apparatus and method of producing fiber composite moldings by means of vacuum infusion applying a mold with a mold cavity, a plurality of inlet channels (3, 21, 22) communicating with the mold cavity and a polymer source (7) with liquid polymer, a plurality of vacuum channels (2) communicating with the mold cavity and a vacuum source (10), where fiber material (14) is inserted into the mold cavity prior to the process of filling said mold, and where a negative pressure is generated in the vacuum channels (2) and thus in the mold cavity with the result that liquid polymer is drawn from the polymer source (7) via the inlet channels (3, 21, 22) into the mold cavity. One or more of the inlet channels (3, 21, 22) can also communicate with a vacuum source, and/or one or more of the vacuum channels (2) can also communicate with a polymer source (7).