Blow-Molded Container With Localized Oxygen-Scavenger Layers
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Solution Overview
Problem
Conventional plastic blow-molded containers lack the ability to selectively position barrier layers, such as oxygen scavengers, within the container wall, leading to high costs due to unconcentrated additives and inefficient use of materials.
Innovation Solution
A method for manufacturing containers that involves injecting polyethylene terephthalate with a concentrated oxygen scavenger in specific regions of the container wall, reducing the additive content to less than 0.1 wt. % while maintaining shelf life, using a two-phase injection system to minimize scrap material with additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional plastic blow-molded containers include additives such as oxygen scavengers to improve shelf life, then shelf life is improved, but the cost of the container greatly increases due to high cost of additives and they make up greater than 1.0 wt. % of the container
Solution Approach 1:
The patent applies local quality by concentrating the oxygen scavenger additive in a specific intermediate portion of the container wall, rather than distributing it uniformly throughout. This creates a localized barrier layer that provides the necessary shelf life protection while significantly reducing the total amount of expensive additive required from greater than 1.0 wt. % to less than 0.1 wt. % of the container
Solution Approach 2:
The patent creates a composite structure with three distinct portions: an inner portion, an intermediate portion containing the concentrated oxygen scavenger additive, and an outer portion. This composite material approach allows the container to achieve enhanced shelf life protection through the barrier layer while using minimal amounts of the expensive additive material
2Reliability
If conventional plastic blow-molded containers include unconcentrated additives to improve shelf life, then shelf life is improved, but the cost of container greatly increases due to high cost of additives
Solution Approach 1:
The patent implements local quality by placing the oxygen scavenger additive only in the intermediate portion of the container wall, creating a localized barrier layer. This concentrates the protective function in a specific region rather than distributing the additive throughout the entire container, thereby reducing the total quantity of expensive additive needed while maintaining shelf life protection
Solution Approach 2:
The patent changes the concentration parameter of the oxygen scavenger additive from a low, distributed concentration (greater than 1.0 wt. % uniformly distributed) to a high, localized concentration (less than 0.1 wt. % total but concentrated in the intermediate portion). This parameter change achieves the same protective effect at lower cost
3Ease of manufacture
If conventional methods for manufacturing plastic blow-molded containers lack the ability to selectively position a barrier layer, then manufacturing is simpler, but the ability to concentrate barrier materials is lost
Solution Approach 1:
The patent applies segmentation by dividing the container wall into three distinct portions: an inner portion, an intermediate portion containing the barrier layer, and an outer portion. This segmentation allows precise positioning of the oxygen scavenger additive in the intermediate portion while maintaining compatibility with standard injection molding processes, achieving both manufacturing feasibility and precise barrier layer placement
Solution Approach 2:
The patent implements preliminary action by incorporating the oxygen scavenger additive into the plastic resin during the preform injection molding step, before the blow molding process. This preliminary incorporation ensures that the additive is already positioned in the correct intermediate portion of the preform, and this positioning is maintained through the subsequent blow molding process into the final container
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
Reduces material costs and maintains or improves shelf life by concentrating barrier materials, allowing for efficient reuse of scrap material without additives, thus enhancing container performance and reducing production expenses.
Implementation Method 1
The injection system may then be used to inject a first material into a first mold to form a top portion of a preform. The first material and a second material may then be injected into the first mold to form a bottom portion of the preform.
Implementation Method 2
The preform may then be disposed in a second mold and the preform may be blow molded into a finished container.
Data Source
AI summary
A method for manufacturing a container includes injecting a first material into a first mold to form a top portion of a preform. The first material and a second material are injected into the first mold to form a bottom portion of the preform. The preform is disposed in a second mold. The preform is blow molded into a finished container.