Bag-in-Bag Dispensing System for Uniform Fluid Delivery
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Solution Overview
Problem
Existing collapsible container designs for dispensing liquids, particularly in the semiconductor industry, face issues with non-uniform collapse and contamination due to gas permeation through fluoropolymer materials, leading to incomplete dispensing and recycling challenges.
Innovation Solution
A 'bag-in-bag' assembly with an inner fluoropolymer container and an outer polyethylene container, where the pressurization fluid does not directly contact the inner container, and a concentric arrangement with a highly gas-impermeable barrier reduces microbubble formation, ensuring uniform dispensing and minimizing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pressurization fluid is provided directly to the space between the inner dispense bag and rigid outer container, then the bag collapses to dispense fluid, but the collapse is non-uniform causing excess fluid to remain in the bag
Solution Approach 1:
The system is divided into three distinct segments: an inner flexible dispense bag, a middle pressurization bag, and an outer rigid container. This segmentation allows the pressurization fluid to be contained separately in the middle bag, enabling uniform compression of the inner dispense bag without direct contact between pressurization fluid and dispense fluid, thereby achieving complete and uniform dispensing while minimizing fluid waste.
Solution Approach 2:
The inner dispense bag is nested within the middle pressurization bag, which is in turn nested within the outer rigid container. This nested configuration allows the pressurization bag to uniformly compress the dispense bag from all sides, ensuring complete collapse and dispensing of contents while preventing fluid entrapment.
2Reliability
If pressurization fluid is a gas that permeates through fluoropolymer container walls, then the gas diffuses into the flexible container, but micro-bubbles form within the dispense fluid causing contamination
Solution Approach 1:
The middle pressurization bag acts as an intermediary barrier between the pressurization gas and the inner dispense bag. This intermediate layer prevents direct contact and gas diffusion into the dispense fluid, eliminating microbubble formation while still allowing mechanical compression to dispense the fluid completely.
Solution Approach 2:
By segmenting the system into separate bags with distinct functions, the pressurization function is isolated from the dispense fluid containment function. This prevents harmful gas diffusion while maintaining the ability to completely dispense the fluid through mechanical compression.
3Reliability
If fluoropolymer materials are used for the flexible container, then the material is compatible with dispense photoresist, but the material allows gas permeation causing contamination
Solution Approach 1:
The system separates the material compatibility function from the gas barrier function by using different materials in different layers. The inner bag uses fluoropolymer for chemical compatibility with photoresist, while the middle pressurization bag provides the gas barrier function, preventing gas diffusion into the dispense fluid.
Solution Approach 2:
The system employs a composite structure with multiple material layers, each optimized for its specific function: fluoropolymer for chemical compatibility and polyethylene for gas impermeability. This composite approach resolves the contradiction between material compatibility and gas barrier properties.
4Object-affected harmful factors
If a dual wall flexible bag with inner polyethylene and outer polyethylene/nylon laminate is used, then gas permeation is resisted, but bonding to highly gas impermeable materials is difficult due to different melt temperatures
Solution Approach 1:
Instead of attempting to bond materials with vastly different melt temperatures in a single structure, the system segments the gas barrier function into a separate middle pressurization bag. This eliminates the bonding difficulty while maintaining gas resistance, as each bag can be manufactured independently with appropriate materials.
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 solution enables complete and uniform dispensing of liquids while reducing contamination and recycling issues, maintaining device integrity and flexibility, and minimizing costs.
Implementation Method 1
a pressurization fluid is provided to an interior space of the outer flexible container to force the liquid out of the dispense container
Implementation Method 2
the pressurization gas can diffuse into the flexible container, thereby causing micro-bubbles to form within the contained dispense fluid and contaminating the dispense fluid
Implementation Method 3
the pressurization gas can diffuse into the flexible container
Data Source
AI summary
A bag-in-bag-in-bottle assembly formed by a flexible dispensing container with a dispensing fitment. The dispensing container is positioned adjacent or sandwiched between one or more flexible pressurization containers having a separate inlet/outlet path through a second fitment. The bag-in-bag assembly can then be placed in a containment vessel with the fitments mounted such that it is accessible on the vessel. A liquid can be extracted from the dispensing container by introducing a fluid into the pressurization container(s) with enough pressure to force the liquid out through the dispensing fitment. A contoured dispensing head may be coupled to the bag-in-bag-in-bottle assembly using a cam actuation arrangement for simultaneously locking the pressurization, vent and fluid extraction couplings.