EVOH Fuel Container Layer Defect Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Blow molded containers made from EVOH-containing resin compositions face issues with appearance defects such as gels, seeds, and streaks due to melt molding, which impair both appearance and performance, and have inadequate self-purge features, leading to increased production costs and downtime.
Innovation Solution
Incorporating an unsaturated aldehyde, such as crotonaldehyde, within a specific concentration range (0.01 ppm to 100 ppm) in the EVOH layer, along with a conjugated polyene compound like sorbic acid, to inhibit oxidative degradation and improve self-purge capabilities, resulting in superior appearance characteristics and reduced production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If melt molding is conducted on EVOH-containing resin compositions, then the resin can be processed into blow molded containers, but appearance defects such as gels, seeds, and streaks occur
Solution Approach 1:
The patent applies preliminary action by adding specific additives (antioxidants, processing aids) to the EVOH resin composition before molding. These additives are pre-incorporated to prevent oxidative degradation and gel formation during the subsequent melt molding process, thereby maintaining both processability and appearance quality without requiring post-processing corrections
2Adaptability or versatility
If the melt molding apparatus is stopped and restarted for resin changes or maintenance, then operational flexibility is improved, but the remaining resin deteriorates and gels upon restarting
Solution Approach 1:
The patent applies preliminary action by incorporating heat stabilizers and antioxidants into the EVOH resin composition before storage. These additives are pre-positioned in the resin to actively prevent degradation during idle periods between production runs, allowing the resin to maintain its properties even when the apparatus is stopped and restarted for maintenance or resin changes
Solution Approach 2:
The patent applies self-service through the use of self-purge resin compositions that contain additives capable of automatically preventing gelation and degradation during idle periods. The resin composition itself provides the necessary protection against deterioration, eliminating the need for external purging operations or complex maintenance procedures, thereby enabling flexible production scheduling without compromising resin quality
3Reliability
If conventional EVOH-containing resin compositions are used, then basic barrier properties are achieved, but self-purge feature is insufficient leading to increased production costs
Solution Approach 1:
The patent applies self-service by developing EVOH resin compositions with enhanced self-purge capabilities through the incorporation of specific additives. These additives enable the resin to automatically maintain its flow properties and prevent gelation during idle periods, eliminating the need for lengthy purging operations before resin changes or after maintenance. This self-purging action significantly reduces production downtime and costs while maintaining the excellent gas barrier properties of EVOH
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 use of unsaturated aldehydes and conjugated polyene compounds in the EVOH layer effectively suppresses defects like gels and seeds, enhancing appearance and impact resistance while providing a favorable self-purge feature, thus reducing production costs and improving the overall quality of blow molded containers.
Implementation Method 1
Incorporating an unsaturated aldehyde, such as crotonaldehyde, within a specific concentration range (0.01 ppm to 100 ppm) in the EVOH layer, along with a conjugated polyene compound like sorbic acid, to inhibit oxidative degradation
Data Source
AI summary
A blow molded container including (A) a layer containing an ethylene-vinyl alcohol copolymer as a principal component, in which the layer (A) contains an unsaturated aldehyde, and the content of the unsaturated aldehyde in the layer (A) is 0.01 ppm or more and 100 ppm or less. The unsaturated aldehyde (II) is preferably an unsaturated aliphatic aldehyde. The unsaturated aldehyde (II) is preferably at least one selected from the group consisting of crotonaldehyde, 2,4-hexadienal and 2,4,6-octatrienal. The layer (A) preferably contains a conjugated polyene compound, and the content of the conjugated polyene compound in the layer (A) is preferably 0.01 ppm or more and 1,000 ppm or less.