Radial Filtration Vent for Medical Device Packaging
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Solution Overview
Problem
Current gas sterilization packaging materials, such as Tyvek®, are prone to seal failures under elevated temperatures and steam, are expensive, and require large surface areas for effective gas flow, while also posing contamination risks due to fiber detachment during opening.
Innovation Solution
A radial filter vent design incorporating a gas diversion layer and a filtration media sheet with a tortuous path to enhance gas flow and microbial barrier efficiency, using materials like sintered porous polyethylenes and open cell foamed polymers to reduce surface area and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Tyvek® spun bonded polyolefin is used as a permeable membrane wall component, then gas sterilization and microbial barrier properties are achieved, but seal failures occur due to elevated temperatures and steam
Solution Approach 1:
The patent extracts the vulnerable Tyvek® material from the seal-critical regions and replaces it with heat-resistant materials. The breathable membrane is positioned away from sealed edges, and heat-resistant barriers are inserted between the membrane and sealed edges to prevent thermal degradation and seal failure during sterilization processes.
Solution Approach 2:
The patent employs composite material structures combining Tyvek® breathable membrane with heat-resistant materials such as polypropylene or polyester. This composite approach allows the package to maintain gas permeability where needed while providing thermal resistance at seal-critical locations, resolving the contradiction between breathability and seal reliability under heat.
2Reliability
If nonwoven sheet material made of individual fibers is used, then gas sterilization is permitted, but small fibers may detach and contaminate the sterilized article during opening
Solution Approach 1:
The patent applies different material qualities to different locations: heat-resistant and low-fiber materials are positioned at seal edges and opening areas where fiber detachment risk is highest, while the breathable membrane material is positioned in regions where gas flow is needed but contamination risk is lower. This localized material selection prevents fiber contamination during opening while maintaining sterilization functionality.
3Speed
If large surface area of breathable membrane is used, then gas flow rate is improved, but material cost and exposure to porous surfaces increase
Solution Approach 1:
The patent transitions from two-dimensional membrane area expansion to three-dimensional gas flow pathways by creating multiple stacked breathable membrane layers and incorporating vertical gas flow channels. This dimensional change allows sufficient gas flow rates to be achieved with reduced lateral membrane area, thereby reducing material cost and exposed porous surface area while maintaining sterilization effectiveness.
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 design improves gas flow rates and maintains or enhances microbial barrier properties, reducing contamination risks and costs by utilizing less material and minimizing exposure to porous surfaces.
Implementation Method 1
a filter sheet disposed between (a) and (b), the filter sheet having a first surface and an opposing second surface circumscribed by a perimeter edge... the filter media may provide a tortuous path against ingress of microbes into contents held within a sterilized package
Implementation Method 2
a gas passageway is defined from the opening through a portion of the second surface of the filter sheet and extending through the filter perimeter edge or a distal portal area of said filter sheet... sterilizing gas may flow back and forth through the opening and the perimeter edge
Data Source
AI summary
A gas sterilization package component having (a) a gas diversion wall stock for at least a portion of a container, the wall stock having an opening therethrough; (b) a gas diversion layer; (c) a filter sheet disposed between (a) and (b), the filter sheet having a first surface and an opposing second surface circumscribed by a perimeter edge; and wherein the first surface of the filter sheet is attached to a surface of said gas diversion layer and the second surface of the filter sheet is sealed to a surface of the wall stock whereby an opening in the wall stock is covered by the filter sheet and a gas passageway is defined from the opening through a portion of the second surface of the filter sheet and extending through said filter perimeter edge.