Overmoulded Header Seal Plug Cavity Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for alternative designs for headers and associated components for implantable medical devices, particularly those that can effectively isolate internal components from conductive bodily fluids while maintaining reliability and efficiency in connection and sealing.
Innovation Solution
The method involves molding a header for an implantable medical device using a silicone mold with a polyoxymethylene insert and epoxy material, incorporating pins and seal plugs to define precise features such as set screw holes and a ridge, ensuring fluidic sealing and secure attachment to the device housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a traditional molding process is used for headers, then manufacturing simplicity is maintained, but manufacturing precision and feature definition are insufficient
Solution Approach 1:
The molding process is divided into two distinct stages: first forming the header body in the mold cavity, then forming the seal plug in a separate insert cavity. This segmentation allows each stage to be optimized independently, with the insert providing precise feature definition for the seal plug while the main cavity forms the header body, thereby achieving high manufacturing precision without excessive overall process complexity.
Solution Approach 2:
The insert is pre-positioned in the mold cavity before the seal plug material is injected. This preliminary action ensures that the insert is already in the correct position to define the precise features of the seal plug, eliminating the need for post-molding adjustments and ensuring high manufacturing precision from the first production cycle.
2Reliability
If seal plugs are added after header molding, then manufacturing precision of the header is maintained, but reliability of fluidic sealing is compromised
Solution Approach 1:
The header body and seal plug are formed in the same molding cycle using a combined mold cavity and insert cavity system. The material is injected to fill both cavities simultaneously, creating an integrated header assembly with the seal plug already in place. This merging ensures the seal plug is permanently integrated into the header, guaranteeing fluidic sealing reliability while maintaining manufacturing simplicity through a single-step process.
Solution Approach 2:
The insert acts as an intermediary tool that defines the precise geometry of the seal plug during molding. By using the insert as a mediator, the seal plug is formed with exact dimensional accuracy and proper positioning within the header, ensuring reliable fluidic sealing without requiring separate assembly operations.
3Manufacturing precision
If the insert is entirely contained in the mold, then manufacturing precision of the seal plug is improved, but ease of manufacture decreases due to insert removal complexity
Solution Approach 1:
The insert is completely removed from the molded header after the molding cycle is complete. This extraction allows the insert to be reused in the next production cycle, maintaining manufacturing precision for the seal plug geometry while managing the removal complexity as a routine part of the production process. The insert is taken out through the mold opening mechanism, which is designed to accommodate this extraction step.
Data Source
AI summary
A method includes providing a mold defining a mold cavity for receiving material to be molded into a molded part, positioning an insert at least partially in the mold such that a portion of the insert defines a portion of the mold cavity, and injecting the material into the mold cavity to substantially fill the mold cavity to form the molded part. The molded par can then be removed from the mold and the insert can be removed from the molded part. The mold can include silicone and the insert can include polyoxymethylene.