Multi-material Cryogenic Elastomeric Closure for Sealing Integrity
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Solution Overview
Problem
Elastomeric closures for cryogenic containers lose integrity and allow contamination or evaporation at temperatures below −80° C. due to glass transition, as existing materials either become brittle or have undesirable properties like high cost and permeation issues.
Innovation Solution
A multi-material elastomeric closure combining a cryophilic elastomer with a non-cryophilic elastomer, where the cryophilic elastomer has a glass transition temperature at or below −80° C. and the non-cryophilic elastomer has a higher glass transition temperature, ensuring a complete seal and maintaining elastomeric properties at cryogenic temperatures through laminated or physically interlocked structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-cryophilic elastomer is used for the closure, then the closure provides good sealing and elastomeric properties at room temperature, but the closure becomes hard and brittle at cryogenic temperatures below −80° C. due to glass transition
Solution Approach 1:
The closure is constructed as a composite of two distinct elastomeric materials: a cryophilic elastomer (with Tg ≤ −80° C.) that maintains flexibility at cryogenic temperatures, and a non-cryophilic elastomer (with Tg > −80° C.) that provides superior sealing and elastomeric properties at room temperature. This composite structure allows each material to contribute its optimal properties for different temperature conditions, resolving the contradiction between room-temperature sealing integrity and cryogenic flexibility.
Solution Approach 2:
Different regions of the closure are assigned different material properties tailored to their specific functional requirements and operating conditions. The cryophilic elastomer is positioned to handle cryogenic temperature exposure, while the non-cryophilic elastomer is positioned to provide sealing at room temperature. This spatial differentiation of material qualities allows the closure to maintain appropriate properties across the full temperature range.
2Reliability
If a cryophilic elastomer with Tg below −80° C. is used, then the closure maintains elastomeric properties at cryogenic temperatures, but the closure becomes expensive and/or has undesirable properties such as insufficient permeation resistance
Solution Approach 1:
The composite structure allows the use of a cryophilic elastomer specifically for maintaining flexibility at cryogenic temperatures, while the non-cryophilic elastomer component provides the necessary permeation resistance and cost-effectiveness. This division of functional responsibilities among materials allows selection of cost-effective, high-performance materials for each specific function rather than requiring an expensive material that excels at all properties.
Solution Approach 2:
The closure design assigns specific functional qualities to specific material components: the cryophilic elastomer is optimized for low-temperature flexibility, while the non-cryophilic elastomer is optimized for permeation resistance and cost-effectiveness. This localized optimization allows each material to perform its specific function efficiently without requiring all materials to be expensive or possess all desirable properties simultaneously.
3Device complexity
If the closure is made of a single elastomeric material, then the closure is simple in structure, but the closure cannot maintain both sealing integrity at room temperature and flexibility at cryogenic temperatures simultaneously
Solution Approach 1:
The closure employs a composite of two elastomeric materials, each selected for its specific temperature-dependent properties. The non-cryophilic elastomer provides robust sealing at room temperature, while the cryophilic elastomer ensures flexibility and seal maintenance at cryogenic temperatures. This composite approach achieves reliable sealing across the full temperature range, accepting increased structural complexity as necessary to resolve the temperature-dependent performance contradiction.
Solution Approach 2:
The closure is segmented into two distinct material components, each responsible for specific temperature ranges and functions. This segmentation allows independent optimization of each material for its designated temperature regime, enabling the closure to maintain sealing integrity across the full temperature range from room temperature to cryogenic conditions.
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 multi-material closure maintains a secure seal and prevents contamination or evaporation at cryogenic temperatures, allowing for immediate removal of containers from lyophilization without warming, thus enhancing storage integrity and efficiency.
Implementation Method 1
the cryophilic elastomer has a glass transition temperature (Tg) at or below the cryogenic temperature to which the closure is to be subjected
Implementation Method 2
the non-cryophilic elastomer has a glass transition temperature (Tg) above a cryogenic temperature to which the closure is to be subjected
Data Source
AI summary
A multi-material, cryogenic, elastomeric closure is provided for sealing a container for samples of cryophilic biological materials, pharmaceuticals or the like. The closure includes at least one cryophilic elastomer having a glass transition temperature (Tg) below the cryogenic temperature to which the sample is to be subjected and at least one non-cryophilic elastomer having a Tg above the cryogenic temperature. The cryophilic and non-cryophilic elastomers are present in such a manner as to maintain a complete seal of the container opening at the cryogenic temperature.