Double Container Inner-Bag Structure for Humidity-Resistant Gas Barriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing double containers face issues with gas barrier property deterioration under high humidity, pinch-off part cleavage during biaxial stretch blow molding, and difficulty in introducing outside air into the intermediate space between the inner bag and outer shell.
Innovation Solution
A double container design with an inner bag comprising an inner layer, gas barrier layer, and outer layer, and a preform configuration with a thicker bottom part to suppress pinch-off part cleavage, along with controlled heating to facilitate outside air introduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas barrier layer is placed on the outermost surface of the inner bag, then the gas barrier function is maximized, but the gas barrier property deteriorates under high humidity environment due to exposure to moisture
Solution Approach 1:
The patent introduces an outer layer as an intermediary protective barrier between the gas barrier layer and the humid environment. This outer layer acts as a shield that prevents direct contact between moisture and the gas barrier layer, thereby maintaining the gas barrier function under high humidity conditions while preserving the outermost gas barrier configuration for optimal performance
2Ease of manufacture
If biaxial stretch blow molding is performed with a tubular molded body loaded inside the preform, then the container structure is formed, but the pinch-off part of the tubular body may cleave due to vigorous stretching
Solution Approach 1:
The patent applies preliminary reinforcement to the pinch-off part by forming a thickened bottom part in the preform before the biaxial stretch blow molding process. This pre-reinforcement ensures that the pinch-off part has sufficient strength to withstand the vigorous stretching during molding without cleaving, while still allowing the container formation process to proceed effectively
3Stability of the object's composition
If the outer shell is maintained in its original state during content reduction, then structural stability is provided, but it becomes difficult to introduce outside air into the intermediate space between the inner bag and outer shell
Solution Approach 1:
The patent applies local quality by providing a localized flexible portion in the outer shell at the bottom region. This flexible portion differs from the rigid main body of the outer shell, allowing it to deform and create space for outside air introduction while the rest of the outer shell maintains its original stable structure. This resolves the contradiction by providing different properties in different locations
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 maintains gas barrier property under high humidity, prevents pinch-off part cleavage, and ensures smooth introduction of outside air, enhancing the manufacturing process efficiency and container performance.
Implementation Method 1
a biaxial stretch blow molding step of biaxially stretching the preform by blowing air thereinto with the preform being heated and softened
Data Source
AI summary
The present invention provides a double container capable of suppressing the deterioration of the gas barrier property under high humidity environment. According to the present invention, provided is a double container comprising a container body, wherein the container body has an outer shell and the inner bag, the container body is configured such that the inner bag contracts as content is reduced, and the inner bag comprises an inner layer, a gas barrier layer, and an outer layer, in order from an inside of the container body.