Variable Volume Container with Retractable Diaphragm
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Solution Overview
Problem
Existing plastic containers fail to withstand high pressures and vacuums without distorting or cracking, which limits their ability to maintain product freshness and extend shelf life effectively, as they are prone to deformation and breakage under extreme conditions.
Innovation Solution
A variable volume container design featuring a retractable diaphragm with a ribbed region and flexible flexure zones that allows the container to reduce its interior volume under negative pressure, preventing sidewall deformation and cracking by moving the base upwards, thus maintaining structural integrity under vacuum and high-pressure pasteurization conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum sealing is applied to plastic containers, then product freshness is extended and air space is removed, but the container sidewalls distort and the container may crack
Solution Approach 1:
The container base is designed with a movable diaphragm that dynamically adjusts its position in response to pressure changes. Under vacuum conditions, the diaphragm moves upward to reduce container volume and prevent sidewall distortion. Under normal conditions, the diaphragm returns to its original position, maintaining the container's aesthetic appearance.
Solution Approach 2:
The container volume is changed as a parameter in response to pressure conditions. The variable volume design allows the container to reduce its internal volume under vacuum, preventing the sidewalls from collapsing or distorting while still achieving effective vacuum sealing for product preservation.
2Reliability
If high-pressure pasteurization is applied to kill bacteria, then product shelf life is extended, but the plastic container may crack or be destroyed
Solution Approach 1:
The movable diaphragm base provides dynamic structural adaptation during high-pressure pasteurization. The flexible base absorbs and distributes the extreme pressure forces, preventing stress concentration that would cause cracking. The diaphragm's ability to move and flex allows the container to withstand 90,000 pounds of rapidly pulsing water pressure without structural failure.
3Quantity of substance
If thin-walled containers are used, then material cost is reduced, but the containers distort easily under pressure
Solution Approach 1:
The container base is segmented into a diaphragm portion and a ribbed region with flexure zones. This segmentation allows the thin-walled container to maintain overall structural stability while the specific base segments provide the necessary flexibility and movement capability under pressure conditions.
Solution Approach 2:
The diaphragm base is designed as a flexible element that can move and deform elastically under pressure. This flexible base design allows thin-walled containers to withstand vacuum and high-pressure conditions without permanent deformation or cracking, as the flexible diaphragm absorbs the stress.
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 container maintains side wall integrity and aesthetic appearance even under full vacuum conditions, allowing for effective vacuum sealing and high-pressure pasteurization without cracking, while reducing costs associated with traditional methods.
Implementation Method 1
The flexible diaphragm moves from a first position under normal atmospheric pressure to a retracted second position (toward the top of the container) under negative pressure
Implementation Method 2
The two flexure surfaces allow the ribs to twist and roll upward and downward in response to a change of the internal pressure of the container and prevents cracking of the base and prevents deformations from occurring at the sidewall
Data Source
AI summary
A variable volume container comprises a sidewall, a base having a ribbed region, and a diaphragm. The ribbed region has a plurality of concentric ribs extending from the diaphragm, and flexure zones between each rib. The flexure zones allow for accordion-like movement of the diaphragm in response to the internal pressure of the container. The ribs are characterized has having a uniformly arced interior curved surface and a distorted arced exterior curved surface. The ribs are four to eight times the width of the flexure zones, and the flexure zones have an exterior surface shorter than its bottom surface. During vacuum sealing, these features allow the diaphragm to retract upward to reduce the volume of the container while maintaining shape and structural stability of the container. This is especially useful for food packaging operations where containers need to be able to withstand conditions such as high pressure, heat, and/or vacuums.