EVOH Resin Viscosity Control via Iron-Alkali Catalyst
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
EVOH resin compositions face challenges in long-run melt formability due to viscosity increases during high-temperature processing, leading to contamination and reduced productivity in complex forming apparatuses, especially when subjected to higher functional requirements.
Innovation Solution
Incorporating an iron compound and an alkali metal compound at a specific weight ratio into the EVOH resin composition, which decreases viscosity over time, thereby improving long-run formability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If EVOH resin is melted at high temperature for processing, then the resin can be formed into final products, but the viscosity increases with time due to oxidation and crosslinking reactions
Solution Approach 1:
The patent converts the harmful oxidation reaction into a beneficial effect by intentionally introducing a small amount of iron compound (0.01-5 ppm) that catalyzes controlled oxidation. This controlled oxidation prevents unwanted crosslinking and maintains viscosity stability during long-run processing, transforming the harmful oxidative degradation into a protective mechanism.
Solution Approach 2:
The patent changes the chemical composition parameters by adding specific compounds (iron compound at 0.01-5 ppm and alkali metal compound at 0.1-100 ppm) to modify the resin's behavior during processing. These parameter changes enable the resin to maintain stable viscosity characteristics under high-temperature processing conditions.
2Duration of action of moving object
If the resin composition is improved for long-run melt formability, then the viscosity decreases with time during heating, but the forming apparatus with higher functional requirements causes resin stagnation and contamination
Solution Approach 1:
The iron compound in the resin composition converts the harmful stagnation effect into a beneficial one by catalyzing controlled oxidation during periods of stagnation in complex forming apparatus. This prevents the resin from undergoing harmful crosslinking reactions that would increase viscosity and cause contamination, thereby maintaining resin quality even in apparatus with higher functional requirements.
3Adaptability or versatility
If conventional resin compositions are used in complex forming apparatus with higher functional requirements, then the apparatus can handle diverse feed block and die shapes, but resin deterioration occurs due to stagnation in the internal structure
Solution Approach 1:
The iron compound converts the harmful effect of resin stagnation in complex forming apparatus into a beneficial controlled oxidation process. This ensures that even when resin stagnates in the intricate internal structure of high-functionality forming apparatus, the viscosity remains stable and contamination is prevented, maintaining reliability across diverse forming operations.
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 EVOH resin composition exhibits superior long-run formability with decreased viscosity during melt forming, enhancing productivity and reducing contamination issues in complex forming processes.
Implementation Method 1
the viscosity of the EVOH resin composition decreases with time during the heating
Data Source
AI summary
A melt-formable ethylene-vinyl alcohol copolymer composition contains: (A) an ethylene-vinyl alcohol copolymer; (B) an alkali metal compound; and (C) an iron compound; wherein the weight ratio of the alkali metal compound (B) to the iron compound (C) on a metal basis is 10 to 100,000. The viscosity of the melt-formable ethylene-vinyl alcohol copolymer composition decreases with time during melt forming, rendering it excellent in long-run formability.