Multilayered Plastic Container Barrier Layer Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multilayered plastic containers with decreased thickness and weight are prone to interlayer peeling and cracking when subjected to impact, such as falling, due to stress concentration at the boundary between multilayered and single-layered portions, particularly in the bottom area.
Innovation Solution
A multilayered plastic container design featuring inner and outer layers of polyethylene terephthalate polyester resin with an intermediate barrier layer of a polyethylene terephthalate and barrier resin mixture, where the lower end of the intermediate barrier layer is positioned outside the grounding portion in the radial direction and between the grounding and valley portions in the axial direction, effectively preventing cracks and interlayer peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the container wall thickness is decreased to reduce material cost and weight, then the weight and material cost decrease, but the barrier property and impact resistance deteriorate
Solution Approach 1:
The patent employs a multilayered composite structure consisting of an inner layer, intermediate barrier layer, and outer layer made from different resin materials. The inner and outer layers provide mechanical strength while the intermediate barrier layer provides gas and water vapor barrier properties. This composite structure allows the container to maintain excellent barrier performance with reduced overall wall thickness, thereby reducing weight while preserving reliability.
Solution Approach 2:
The patent applies different resin materials and layer configurations to different regions of the container. Specifically, the intermediate barrier layer is positioned at specific heights (lower end at grounding portion level or outside it in radial direction, and at central portion between grounding portion and uppermost end of valley or higher in axial direction) to provide localized barrier enhancement where needed, while maintaining overall lightweight design.
2Weight of moving object
If the container wall thickness is decreased to reduce material cost and weight, then the weight and material cost decrease, but the drop impact resistance deteriorates
Solution Approach 1:
The multilayered composite structure with inner layer, intermediate barrier layer, and outer layer provides enhanced impact resistance. The different resin materials in each layer absorb and distribute impact energy differently, preventing crack propagation and interlayer peeling that would occur in single-layer thin-walled containers.
Solution Approach 2:
The strategic positioning of the intermediate barrier layer's lower end at or outside the grounding portion in the radial direction and at the central portion between grounding portion and uppermost end of valley or higher in the axial direction creates localized reinforcement zones. This positioning prevents stress concentration at critical impact points during drops, thereby improving impact resistance without increasing overall wall thickness.
3Weight of moving object
If the container wall thickness is decreased, then the weight decreases, but interlayer peeling and cracking occur under impact
Solution Approach 1:
The patent strategically positions the intermediate barrier layer's lower end at specific locations (at or outside grounding portion in radial direction, and at central portion between grounding portion and uppermost end of valley or higher in axial direction). This localized positioning ensures that the intermediate layer extends sufficiently into high-stress regions without requiring increased overall wall thickness, preventing interlayer peeling and cracking at critical zones during impact while maintaining lightweight design.
Solution Approach 2:
The multilayered composite structure with carefully selected resin materials for each layer provides inherent interlayer bonding stability. The inner and outer polyester resin layers bond effectively with the intermediate barrier layer, creating a cohesive structure that resists delamination under impact loads, even with reduced wall thickness.
Data Source
Figure 1
Figure 2
AI summary
A multilayered plastic container comprising, in at least a side wall portion of the container, an inner layer and an outer layer of a polyester resin, and an intermediate barrier layer of a barrier resin, wherein the lower end of the intermediate barrier layer in the radial direction of the container is positioned on the grounding portion of the container bottom portion or outside of the grounding portion of the container bottom portion in the radial direction of the container, featuring very excellent barrier property and drop impact resistance despite of its decreased thickness and weight.