Blow Molding Container Positive Pressure Method
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Solution Overview
Problem
Conventional methods for manufacturing containers with content fluids face issues such as shrinkage and deformation over time, leading to potential leakage and loss of upright stability, and require additional equipment and costly nitrogen for pressurization, while also struggling with regulating head space volume during blow molding.
Innovation Solution
A blow molding method that uses the content fluid as a pressure medium, where the container is sealed with the fluid inside and then pressurized by reducing the container's volume through invertible deformation, maintaining pressure without external nitrogen and ensuring a predetermined head space volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the container wall thickness is reduced to achieve weight reduction, then the weight of the container is decreased, but the buckling strength is deteriorated causing deformation or breakage under load
Solution Approach 1:
The container is pre-pressurized with inert gas before filling with the content fluid. This preliminary pressurization creates internal pressure that counteracts external loads during transportation, preventing buckling and deformation of the thin-walled container structure.
Solution Approach 2:
The invention changes the pressure parameter inside the container by introducing inert gas pressurization. This parameter change (from atmospheric pressure to positive pressure) significantly improves the mechanical strength and buckling resistance of the thin-walled container without requiring additional structural reinforcement.
2Strength
If liquid nitrogen is added to pressurize the container, then the buckling strength is improved, but the device complexity and production cost increase
Solution Approach 1:
The container structure itself serves the dual purpose of holding the content fluid and providing the pressurization medium through the inert gas. The inert gas is integrated into the filling process, eliminating the need for separate pressurization equipment and operations.
Solution Approach 2:
The invention merges the pressurization function with the filling function by using inert gas that is introduced during the filling process. This combination eliminates the need for separate pressurization equipment and simplifies the overall system architecture.
3Shape
If a preform is molded by biaxial stretch blow molding, then the container shape is formed, but shrinkage and deformation occur over time causing the container to lose upright stability
Solution Approach 1:
The container is pre-pressurized with inert gas before filling with the content fluid. This preliminary pressurization creates internal pressure that counteracts external loads during transportation, preventing buckling and deformation of the thin-walled container structure.
Solution Approach 2:
The invention changes the pressure parameter inside the container by introducing inert gas pressurization. This parameter change (from atmospheric pressure to positive pressure) significantly improves the mechanical strength and buckling resistance of the thin-walled container without requiring additional structural reinforcement.
4Adaptability or versatility
If the container is filled with content fluid after molding, then the filling flexibility is maintained, but the head space volume regulation becomes difficult
Solution Approach 1:
The invention uses a feedback mechanism where the inert gas pressure is monitored and adjusted during the filling process to maintain the predetermined head space volume. The pressure control system responds to volume changes and adjusts the gas flow accordingly to achieve precise head space regulation.
Solution Approach 2:
The invention replaces mechanical head space regulation methods with a pressure-based control system. By controlling the inert gas pressure, the head space volume is automatically regulated without complex mechanical adjustment mechanisms, maintaining both flexibility and precision.
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 method prevents shrinkage and deformation, maintains container stability, and ensures reliable sealing until capping, while reducing production costs and complexity by eliminating the need for external pressurization and ensuring consistent head space volume.
Implementation Method 1
a molding step of molding a container by blow molding using a liquid as a pressure medium
Implementation Method 2
due to vapour pressure of the added liquid nitrogen, the inside of the container is placed under a pressurized state
Data Source
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AI summary
A method for placing an inside of a container (1041, 10, 141, 241) under a positive pressure, comprising: a molding step (2, 6) of molding the container (1041, 10, 141, 241) by blow molding using a liquid as a pressure medium; a sealing step (2, 6), after the molding step (2, 6), of sealing a mouth portion (132, 142, 2032, 232, 2, 2) of the container (1041, 10, 141, 241) in a state where the container (1041, 10, 141, 241) is filled with the liquid; and a positive pressurization step (2, 6), after the sealing step (2, 6), of placing the inside of the container (1041, 10, 141, 241) under the positive pressure due to reduction in volume of the container (1041, 10, 141, 241) resulting from after-shrinkage of a circumferential wall of the container (1041, 10, 141, 241).