Mould Insert Holder Dynamics for Epoxy Resin Shrinkage
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Solution Overview
Problem
The existing moulding process for GIS insulators results in poor adhesion and imperfections due to differential shrinkage between epoxy resin and metallic inserts, leading to mechanical integrity issues and potential failure.
Innovation Solution
A mould with movably supported insert holders and a biasing mechanism that allows inserts to move relative to the mould body in the direction of shrinkage, accommodating thermal expansion differences and ensuring secure positioning during the cooling phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metallic inserts are fixed with respect to the mould during the moulding process, then the inserts maintain their position, but the differential shrinkage between epoxy resin and metallic inserts causes poor adhesion and micro-voids at the interface
Solution Approach 1:
The insert holder is made movable relative to the mould body, allowing it to dynamically adjust its position during the cooling and shrinking phase. The holder can move in the direction of shrinkage to accommodate the differential contraction between the epoxy resin and metallic inserts, thereby maintaining continuous contact and preventing adhesion failures while still providing positional stability during injection.
2Reliability
If heating is applied to control shrinking during the moulding process, then adhesion between epoxy resin and metallic inserts is improved, but the process complexity and energy consumption increase
Solution Approach 1:
The invention extracts the shrinkage control function from the thermal field and transfers it to the mechanical field. Instead of using heating devices to control shrinking, the solution uses a movable insert holder that mechanically accommodates the natural shrinkage of the epoxy resin, thereby improving adhesion without adding thermal control complexity.
3Ease of manufacture
If metallic inserts are held fixed relative to the mould, then positioning is simplified, but traction forces during cooling cause stresses at the insert-resin interface leading to potential failure
Solution Approach 1:
The insert holder transitions from a static fixed position to a dynamic movable position during cooling. This allows the holder to follow the shrinkage of the epoxy resin, reducing traction forces and interface stresses while maintaining proper insert positioning throughout the moulding process.
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 enhances the mechanical integrity of GIS insulators by reducing traction forces between inserts and epoxy resin, resulting in improved adhesion and reduced micro-voids, leading to superior mechanical strength and reliability.
Implementation Method 1
a biasing means to bias each insert holder to a first position relative to the mould body
Implementation Method 2
during the cooling phase of the moulding process, the differences in thermal expansion coefficients causes the epoxy resin to shrink more than the metallic inserts and the mould
Data Source
AI summary
The invention relates to a mould for moulding a component with one or more inserts, the mould comprising a mould body for defining in part the shape of the component, and at least one insert holder for holding an insert within the mould body. Each insert holder is movably supported such it can move relative to the mould body in a direction of shrinkage of the component, and wherein the mould further comprises a biasing means to bias each insert holder to a first position relative to the mould body. The invention also relates to a method of moulding.