Two-Part Elastomeric Plunger Overmolding for Thermal-Safe Electronics
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Solution Overview
Problem
Existing manufacturing processes for elastomeric plungers with embedded electronic components are incompatible with the thermal budgets of these components, leading to damage or destruction during the molding process.
Innovation Solution
A two-step manufacturing process involving molding a drug-contacting part with a first material at a high temperature, inserting ancillary components, and then overmolding with a second material at a lower temperature to form a non-drug-contacting part, ensuring the ancillary components survive the thermal exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single-step molding process is used to manufacture elastomeric plungers with embedded electronic components, then the manufacturing process is simple and fast, but the high temperature required for molding destroys the electronic components
Solution Approach 1:
The manufacturing process is divided into two distinct steps: first molding the elastomeric plunger body at high temperature, then separately molding the protective housing at lower temperature after inserting electronic components. This segmentation allows each step to be optimized for its specific requirements without compromising the other.
Solution Approach 2:
The electronic components are inserted into the plunger body before the second molding step, and the protective housing is molded around them at a lower temperature that preserves component integrity. This preliminary arrangement ensures the components are protected during the high-temperature first step while maintaining their functionality.
2Strength
If the molding temperature is increased to ensure proper curing of the elastomeric material, then the material achieves full functionality, but the electronic components are damaged due to excessive thermal exposure
Solution Approach 1:
Different regions of the plunger are subjected to different thermal conditions: the elastomeric body undergoes high-temperature curing to achieve full material functionality, while the protective housing and embedded electronic components experience lower-temperature curing to prevent thermal damage. This local differentiation resolves the contradiction between material curing and component protection.
Solution Approach 2:
The protective housing acts as an intermediary element that shields the electronic components from direct exposure to high temperatures during the first molding step, while still allowing the elastomeric material to cure properly. This intermediary structure enables both high-temperature material curing and low-temperature component protection.
3Adaptability or versatility
If electronic components are embedded directly into the elastomeric plunger body, then the plunger achieves enhanced functionality, but the components cannot withstand the molding temperature
Solution Approach 1:
The electronic components are nested within the plunger structure, surrounded by the protective housing that is molded around them. This nested arrangement allows the components to be integrated into the plunger for enhanced functionality while being protected by the housing from thermal damage during manufacturing.
Solution Approach 2:
The plunger is constructed as a composite structure combining the elastomeric body with a protective housing material that has different thermal properties. This composite construction allows the elastomeric portion to withstand high temperatures for proper curing while the protective housing protects electronic components from thermal damage.
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
Enables the successful integration of electronic components into elastomeric plungers by maintaining their operational integrity, allowing for enhanced functionality such as sensing and monitoring within injection devices.
Implementation Method 1
molding a drug-contacting part of the elastomeric container closure from a first material at a first temperature and for a first length of time, the exposure to the first temperature for the first length of time defining a first thermal exposure
Implementation Method 2
overmolding the drug-contracting part and the inserted ancillary components with a second material at a second temperature for a second length of time to form a non-drug-contacting part
Implementation Method 3
the overmolding includes a UV curing process of the second material
Data Source
AI summary
A technique of manufacturing an elastomeric container closure or plunger with embedded functional components to avoid thermal damage to the components is described. The technique includes molding a drug-contacting part from a first material at a first temperature and for a first length of time defining a first thermal exposure; after molding the drug-contacting part, inserting ancillary components into the drug-contacting part, where the ancillary components have an operational thermal budget less than the first thermal exposure; and overmolding the drug-contracting part and the ancillary components with a second material at a second temperature for a second length of time to form a non-drug-contacting part that mechanically connects the non-drug-contacting part and the drug-contacting part to form the elastomeric container closure and seals the ancillary components inside the elastomeric container closure. The overmolding defines a thermal exposure less than the operational thermal budget of the ancillary components.