Multilayered Container Oxygen Barrier Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayered plastic containers with oxygen-barrier properties degrade under high-temperature and highly humid conditions, such as retort sterilization, leading to a loss of oxygen-barrier functionality and flavor retention, especially when using ethylene-vinyl alcohol copolymer and oxygen-absorbing resin compositions that generate bad-smelling components.
Innovation Solution
A multilayered container structure with a polyolefin inner and outer layer, adhesive layers, gas-barrier layers made of ethylene-vinyl alcohol copolymer, and an oxygen-absorbing layer containing an oxidizing organic component and transition metal catalyst, with an adsorbing agent between the gas-barrier and inner layers, maintaining a thickness of less than 430 μm to ensure effective oxygen absorption and retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an oxygen-absorbing resin composition containing ethylenically unsaturated hydrocarbons and a transition metal catalyst is used to remove oxygen, then oxygen-barrier property is improved, but bad-smelling components are generated which spoil the taste and flavor of the content
Solution Approach 1:
A gas-barrier layer comprising ethylene-vinyl alcohol copolymer is introduced as an intermediary between the oxygen-absorbing resin layer and the content. This gas-barrier layer selectively blocks oxidized and decomposed products (bad-smelling components) generated by the oxygen-absorbing resin from contacting the content, while still allowing the oxygen-absorbing resin to function effectively in removing oxygen.
2Reliability
If ethylene-vinyl alcohol copolymer is used as an oxygen-barrier layer, then oxygen-barrier property is improved, but the barrier property wanes under highly humid conditions
Solution Approach 1:
The patent uses a composite structure where the gas-barrier layer is formed by ethylene-vinyl alcohol copolymer. This specific copolymer composition provides excellent oxygen-barrier properties while maintaining stability under humid conditions, combining the benefits of both ethylene and vinyl alcohol components to achieve both high oxygen barrier performance and humidity resistance.
3Loss of substance
If the container wall is made thinner to reduce material usage, then manufacturing cost is reduced, but oxygen-barrier property and flavor retention deteriorate
Solution Approach 1:
The container wall is segmented into multiple functional layers: inner layer, gas-barrier layer, oxygen-absorbing resin layer, and outer layer. Each layer has a specific thickness and function, allowing the overall structure to achieve superior oxygen-barrier and flavor-retention properties while keeping the total thickness and material usage low.
4Productivity
If the thickness of the multilayered container is reduced, then productivity and economy are improved, but oxygen-barrier property and flavor retention under high-temperature sterilization deteriorate
Solution Approach 1:
The patent optimizes the thickness parameters of each layer within specific ranges: the gas-barrier layer is 3-20 μm, the oxygen-absorbing resin layer is 2-15 μm, and the inner and outer layers are each 50-200 μm. These parameter changes enable the container to maintain excellent oxygen-barrier and flavor-retention properties after high-temperature sterilization while achieving thin-wall construction for improved productivity and economy.
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 container maintains excellent oxygen-barrier and flavor-retention properties even under high-temperature and humid conditions, reducing the impact of oxidized and decomposed products on the content, while minimizing the thickness and amount of oxygen-absorbing resin used, thus offering economic and functional advantages.
Implementation Method 1
the gas-barrier layers 3a and 3b comprise an ethylene-vinyl alcohol copolymer... the oxygen-barrier property wanes if it is used under highly humid conditions
Implementation Method 2
there have also been proposed multilayered containers provided with a layer of an oxygen-absorbing resin composition that contains ethylenically unsaturated hydrocarbons and a transition metal catalyst... In order to remove oxygen remaining in the container or to remove oxygen infiltrating from the exterior
Implementation Method 3
the oxygen-absorbing layer 4 comprises an oxygen-absorbing resin composition that contains the ethylene-vinyl alcohol copolymer and an oxidizing organic component... At the time of absorbing oxygen, however, the oxygen-absorbing resin composition generates bad-smelling components which are the oxidized and decomposed products of low molecular weights
Implementation Method 4
an adsorbing agent is contained on the side inside of the gas-barrier layer 3a... the adsorbing agent is contained on the side inside of the gas-barrier layer 3a, the oxidized and decomposed products coming out of the structure are adsorbed by the adsorbing agent
Data Source
AI summary
A multilayered container includes at least a polyolefin inner layer; an adhesive layer; a gas-barrier layer; an oxygen-absorbing layer; a gas-barrier layer; an adhesive layer; a polyolefin outer layer, and having at least a body portion and a bottom portion, wherein the gas-barrier layers include an ethylene-vinyl alcohol copolymer, the oxygen-absorbing layer includes an oxygen-absorbing resin composition that contains the ethylene-vinyl alcohol copolymer and an oxidizing organic component, an adsorbing agent is contained on the side inside of said gas-barrier layer, the thickness of the multilayered container at the thinnest portion is not more than 430 μm, and the amount of oxygen absorbed after the heat-sterilization is not less than 23 cc per gram of the oxygen-absorbing resin composition. Despite of this decreased thickness, the multilayered container maintains excellent oxygen-barrier property and property for retaining flavor of the content even when it is subjected to the retort sterilization.