Multi-layer PET Container Design for Barrier and Clarity
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Solution Overview
Problem
Current PET containers face issues with reduced crystallinity, haze, delamination, and barrier efficiency, particularly at the gate area, which affect their shelf life and appearance, especially when subjected to heat and environmental factors.
Innovation Solution
A multi-layer container design featuring a single layer of inactive material transitioning into a multi-layer structure with outer and inner active materials, optimized through co-injection processes to enhance crystallinity, reduce haze, and improve barrier properties, including a simultaneous or sequential co-injection process for forming the preform.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If thermal processing is used to increase PET polymer crystallinity, then crystallinity is improved, but haze increases and clarity deteriorates
Solution Approach 1:
The container is divided into multiple sections with different material compositions: a single-layer portion and a multi-layer portion. This segmentation allows different regions to serve different functions - the single-layer portion maintains clarity while the multi-layer portion provides enhanced barrier properties and heat resistance.
Solution Approach 2:
Different portions of the container are assigned different material qualities. The single-layer portion is optimized for optical clarity, while the multi-layer portion is optimized for barrier efficiency and thermal stability. This local differentiation resolves the contradiction by applying the right material properties to the right locations.
2Reliability
If multi-layer structure is implemented to improve barrier efficiency, then barrier properties are enhanced, but device complexity increases
Solution Approach 1:
The multi-layer structure is segmented into specific portions rather than applying complexity throughout the entire container. The single-layer portion maintains simplicity while the multi-layer portion provides enhanced barrier properties where needed, thus improving reliability without uniformly increasing complexity.
Solution Approach 2:
The complex multi-layer structure is applied locally to specific portions of the container where barrier efficiency is most critical, rather than throughout the entire structure. This localized approach enhances reliability while minimizing the overall increase in device complexity.
3Ease of manufacture
If single layer material is used for the finish, then manufacturing simplicity is maintained, but barrier efficiency at the gate area deteriorates
Solution Approach 1:
The container structure is segmented into a single-layer finish portion for manufacturing simplicity and a multi-layer portion for enhanced barrier efficiency. This segmentation allows the finish to remain easy to manufacture while the multi-layer section provides superior barrier properties at critical areas.
Solution Approach 2:
The finish is assigned a simple single-layer structure for ease of manufacture, while the multi-layer structure is applied locally to portions requiring superior barrier efficiency. This local differentiation resolves the contradiction between manufacturing simplicity and barrier performance.
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 multi-layer design reduces heat-induced degradation, minimizes haze, enhances barrier efficiency, and extends product shelf life by creating a tortuous path for gases to penetrate, while maintaining clarity and recyclability.
Implementation Method 1
enhances barrier efficiency, and extends product shelf life by creating a tortuous path for gases to penetrate
Implementation Method 2
A multi-layer preform and container. A multi-layer container design featuring a single layer of inactive material transitioning into a multi-layer structure with outer and inner active materials, optimized through co-injection processes
Implementation Method 3
Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth
Implementation Method 4
Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching an injection molded PET preform along a longitudinal axis and expanding the PET preform along a transverse or radial axis to form a PET container. The combination promotes what manufacturers define as biaxial orientation of the molecular structure in the container.
Data Source
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AI summary
A container including a finish at a first end of the container defining an opening. A base is at a second end of the container that is opposite to the first end. A shoulder extends from the finish. A body defines an internal volume and extends from the shoulder to the base. A single layer material portion of the container extends from the first end to form at least a portion of the finish. A multi-layer material portion of the container extends from the single layer material portion to the second end of the container and across the base. A transition area is spaced apart from the first end where the single layer material portion transitions to the multi-layer material portion.