EVOH Resin with Fluorine Microparticles for Extrusion
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Solution Overview
Problem
EVOH resins face issues such as die build-up and screw sticking during extrusion processes, leading to reduced mechanical strength and visual appearance of films, which existing technologies have not adequately addressed.
Innovation Solution
Incorporating fluorine-containing micro-particles into the EVOH resin composition, which are partially miscible with ethylene vinyl alcohol copolymer, to improve precipitation at the die and reduce screw sticking, while maintaining or enhancing mechanical properties and film flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fluorinated polymers are combined with EVOH to improve precipitation at die and reduce screw sticking, then processability is improved, but immiscibility adversely affects appearance and mechanical properties
Solution Approach 1:
The patent changes the particle size parameter of fluorinated polymer to microparticle scale (1-20 μm), which fundamentally alters the immiscibility problem. At this scale, the fluorinated microparticles can be dispersed throughout the EVOH matrix without forming large segregated phases that would harm mechanical properties. This parameter change enables both improved processability (reduced screw sticking) and maintained mechanical integrity
Solution Approach 2:
The patent creates a composite material system where fluorinated microparticles are dispersed in an EVOH matrix. This composite structure combines the benefits of fluorinated polymers (low friction, reduced sticking) with the strength of EVOH, while the microparticle scale ensures adequate dispersion and bonding. The composite achieves synergistic effects where the fluorinated microparticles improve processability without sacrificing the mechanical properties of the continuous EVOH phase
2Productivity
If conventional EVOH extrusion is used to maintain material simplicity, then manufacturing cost is reduced, but die build-up and screw sticking occur reducing productivity
Solution Approach 1:
The patent applies partial action by incorporating only a small amount of fluorinated polymer (1-20 wt%) as microparticles rather than using bulk fluorinated polymer. This partial incorporation is sufficient to reduce screw sticking and improve extrusion efficiency, while minimizing the complexity addition to the resin composition. The microparticle form ensures that even at these low concentrations, the fluorinated polymer effectively coats screw surfaces and reduces sticking
Solution Approach 2:
The fluorinated microparticles act as an intermediary substance between the EVOH resin and the screw/die surfaces. Rather than directly modifying the EVOH bulk properties (which would require high concentrations and complex formulations), the microparticles mediate the interaction with processing equipment, reducing friction and sticking while maintaining the simplicity of the base EVOH composition
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 fluorine-containing micro-particles in the EVOH resin composition results in films with improved strength, flexibility, and processability, characterized by reduced die precipitation and screw sticking, with specific properties such as Charpy impact strength and elongation at breakage within desired ranges.
Implementation Method 1
Incorporating fluorine-containing micro-particles into the EVOH resin composition, which are partially miscible with ethylene vinyl alcohol copolymer
Data Source
AI summary
The instant disclosure relates to ethylene vinyl alcohol copolymer resin composition and/or pellets thereof including one or more fluorine-containing micro-particles. The ethylene vinyl alcohol copolymer resin compositions and/or pellets thereof may have a melting pressure of 1.7 to 7.0 MPa at a shear rate of 20 s−1 and a melting point temperature of 190° C. EVOH films formed from the EVOH may have a Charpy impact strength of at least 2.3 KJ/m2 according to ISO 179-1 at 23° C. and an elongation at break of at least 17.8% according to ISO 527-2 at 23° C.