Flexible Elastomer Seal for Electrical Contacts in Injection Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for sealing electrical contact elements during partial encapsulation in injection molding machines often result in free spaces due to dimensional tolerances, leading to incomplete sealing, increased production costs, and potential damage to metal conductors, necessitating labor-intensive post-processing to remove ridges formed by low-viscosity molding compounds.
Innovation Solution
A flexible sealing element made from materials like elastomers, specifically silicone, with slots or recesses that deform elastically to completely enclose electrical contact elements, ensuring a tight seal without forming ridges and allowing for reuse, thus eliminating the need for post-processing and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rigid inserts with openings are used to seal contact elements, then the contact elements are protected from molding compound, but dimensional tolerances create free spaces that allow low-viscosity molding compound to enter and form ridges
Solution Approach 1:
The patent employs a flexible sealing element made of elastomeric material that can deform elastically to conform to the contact element and fill gaps caused by dimensional tolerances. This flexible membrane approach allows the sealing element to adapt to variations in contact element dimensions while maintaining complete sealing, preventing molding compound from entering through free spaces.
Solution Approach 2:
The sealing element's physical state is changed from rigid to flexible by selecting elastomeric materials with appropriate durometer values. This parameter change enables the sealing element to undergo elastic deformation under compression, allowing it to compensate for dimensional variations and achieve reliable sealing without creating ridges.
2Reliability
If metal inserts are used to seal contact elements, then sealing is achieved, but the connecting conductors can be damaged or bent during insertion
Solution Approach 1:
The flexible elastomeric sealing element replaces rigid metal inserts, eliminating the risk of damaging or bending connecting conductors during insertion. The soft, compliant material deforms around the conductor rather than forcing it into a rigid opening, thus protecting the conductor while still achieving complete sealing.
Solution Approach 2:
The patent uses composite material construction with an elastomeric base material combined with reinforcing fibers or fillers to achieve both flexibility and sufficient mechanical strength. This composite approach allows the sealing element to be soft enough to protect conductors during insertion while maintaining durability and sealing effectiveness throughout the molding process.
3Duration of action of stationary object
If thermoplastic inserts are used for sealing, then they can be reused, but they deform under the temperature and pressure of injected molding compound
Solution Approach 1:
The patent selects elastomeric materials with appropriate durometer values and thermal properties that maintain dimensional stability under the temperature and pressure conditions of injection molding. The elastomeric material's cross-linked polymer structure prevents permanent deformation while allowing elastic recovery, enabling repeated use without loss of sealing capability.
Solution Approach 2:
The elastomeric sealing element incorporates reinforcing materials such as fiberglass, aramid fibers, or mineral fillers to enhance dimensional stability and resistance to thermal and pressure-induced deformation. This composite construction allows the sealing element to maintain its shape and sealing properties under harsh molding conditions while remaining reusable.
4Reliability
If rigid sealing structures are used, then complete sealing is achieved, but labor-intensive post-processing is required to remove formed ridges
Solution Approach 1:
The flexible elastomeric sealing element deforms elastically to create a uniform seal around the contact element, distributing the molding compound pressure evenly and preventing the formation of ridges or excess material accumulation. This eliminates the need for post-processing ridge removal operations, improving production efficiency while maintaining complete sealing.
Solution Approach 2:
The elastomeric material's viscoelastic properties allow it to flow and conform during injection molding, then recover to maintain a uniform seal. This parameter change in material behavior prevents rigid contact between the sealing element and contact element, avoiding the formation of ridges that would require post-processing removal.
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 flexible sealing element effectively prevents plastic molding compound from entering the contact area, maintaining electrical conductivity, reducing production costs, and extending the lifespan of the sealing element by avoiding damage from the molding process, while ensuring complete encapsulation without the need for additional holding means.
Implementation Method 1
the sealing element is elastically deformed under the action of a compressive force such that it rests sealingly against the contact element
Data Source
Figure 1~4
Figure 5
AI summary
The sealing element (1) is made of a flexible material and has a groove (2,2a), in which the contact element is inserted in form-fit manner such that it is surrounded by the sealing element completely. The sealing element is deformed elastically by effecting a compressive force such that it is connected to the contact element in sealing manner.