Displaceable Base Thermoplastic Container Pressure Control
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Solution Overview
Problem
Current container designs lack precise control over residual vacuum, zero gauge pressure, or positive gauge pressure within thermoplastic containers after filling, especially at ambient external temperature and pressure, which can lead to structural issues and product preservation challenges.
Innovation Solution
The design involves a thermoplastic container with a displaceable base that can be mechanically adjusted after filling and capping to reduce internal volume, creating specific pressure conditions by optimizing the size and shape of the base, allowing for precise control of vacuum or pressure levels through displacement of a truncated cone mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the container base is designed to be displaceable to control internal vacuum, then pressure control precision is improved, but device complexity increases
Solution Approach 1:
The container base is designed as a displaceable component that can be mechanically actuated to change the internal volume of the container. This dynamic adjustment allows precise control over internal pressure conditions (vacuum, zero gauge pressure, or positive gauge pressure) after filling and capping, resolving the contradiction between pressure control precision and device complexity by implementing a simple mechanical displacement mechanism rather than a complex active control system.
Solution Approach 2:
The invention changes the physical parameter of internal volume by displacing the base of the container. This parameter change directly controls the internal pressure state, enabling precise adjustment between vacuum, zero gauge pressure, and positive gauge pressure conditions. The base displacement mechanism provides a straightforward method to achieve desired pressure levels without complex control systems.
2Reliability
If active base designs are used to reduce internal vacuum, then pressure control is improved, but manufacturing complexity increases
Solution Approach 1:
The base is designed as a movable component that can be actuated during or after the filling process to achieve desired pressure conditions. This dynamic base design provides reliable pressure control while maintaining manufacturing simplicity, as the base displacement can be achieved through straightforward mechanical means rather than complex integrated systems.
Solution Approach 2:
The base displacement can be performed as a preliminary action during the filling process or as a subsequent step after capping. This flexibility in timing allows the base to be displaced at the most convenient moment in the manufacturing sequence, simplifying the overall manufacturing process while ensuring reliable pressure control.
3Reliability
If the container volume is reduced to create vacuum, then product preservation is improved, but structural integrity may be compromised
Solution Approach 1:
The internal volume of the container is changed by displacing the base, which creates the desired vacuum or pressure conditions for product preservation. This parameter change is achieved through a controlled mechanical displacement that does not compromise the structural integrity of the container, as the base displacement is a reversible and controlled process that maintains the container's structural strength.
Solution Approach 2:
The base displacement mechanism is designed to cushion and protect the container structure during the volume reduction process. By controlling the displacement process and using appropriate mechanical means, the structural integrity of the container is preserved while still achieving the necessary volume reduction for product preservation.
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
This approach enables precise control over internal pressure conditions, enhancing structural integrity, product preservation, and preventing over-pressurization or spilling, while allowing for customized pressure states to suit various applications.
Implementation Method 1
the container begins to cool to ambient temperature, resulting in an internal vacuum within the container at an ambient external temperature and pressure
Implementation Method 2
air having a pressure between 300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform
Implementation Method 3
The container is configured to shrink during cooling such that the total interior volume decreases by about 1%, or about 0.5% to about 1.5%, during cooling
Implementation Method 4
molecularly orienting the polyester material in an axial direction generally corresponding with the central longitudinal axis of the container
Implementation Method 5
the stretched preform within the mold cavity to a length approximately that of the intermediate container thereby molecularly orienting the polyester material
Data Source
AI summary
A method of forming a container and filling the container with a product. The method includes heat-set blow molding the container from a preform and hot-filling the container with the product such that the product occupies about 95% or more of a total interior volume of the container. A headspace volume is defined between a top fill line of the product and a brim of the container. The headspace volume is less than about 5% of the total interior volume of the container. The container is capped and allowed to cool. The container is configured to shrink during cooling such that the total interior volume decreases by about 0.5% to 1.5% during cooling. A base of the container is displaced after hot-filling and capping to reduce the total interior volume by less than about an additional 0.5% to 4%. The hot-filling, capping, cooling, and displacing of the base creates a pressure change within the container.