Evasin EV-4451F

A Decision Guide Based on Performance Parameters: In the field of high-performance barrier packaging, Ethylene-Vinyl Alcohol Copolymer (EVOH) is a core material in multi-layer co-extrusion processes due to its excellent gas barrier properties. The EVASIN series, a leading EVOH brand in the market, offers various grades with ethylene content ranging from 29% to 44%. For packaging manufacturers, choosing the right grade is not only crucial for the shelf life of the final product but also directly impacts processing stability and overall costs.   1. The Deep Connection Between Ethylene Content and Gas Barrier Performance Ethylene content is the most fundamental indicator determining the physical properties of EVOH. EVASIN grades are usually named according to their ethylene content. Changes in ethylene content directly alter the crystallinity of the polymer, which in turn affects its oxygen permeability. ♣ Low Ethylene Content (EVASIN EV-2951F, 29% mol): When the ethylene content is low, the hydrogen bonding between molecules is stronger, resulting in higher crystallinity. This gives it extremely high barrier properties in a dry state. The oxygen transmission rate of Evasin EV- 2951F is only 0.2 cm³·20µm / m²·24hrs·atm. For meat, high-end refrigerated foods, or chemicals that are extremely sensitive to oxygen and require a very long shelf life, the 29% content grade is the preferred choice. However, it should be noted that low-ethylene-content EVOH has a higher melting point (188℃), a narrower processing temperature range, and is relatively more sensitive to humidity.     ♣ High Ethylene Content (Evasin EV-4451F, 44% mol): As the ethylene content increases, the barrier performance decreases. The oxygen transmission rate of Evasin EV-4451F is 1.8, which is 9 times that of Evasin EV-2951F. However, high ethylene content provides better flexibility, a wider processing window, and superior humidity resistance. In storage environments with high humidity (above 65% RH), the barrier performance of high-ethylene-content grades decreases less significantly. ♣ Selection Logic: If your product needs to be stored at room temperature for more than 12 months, you should prioritize models with a 29% - 32% content; if your production line requires high processing flexibility, or the product requires moderate barrier properties (such as films for daily chemical products), then models with 38% - 44% content offer better cost-effectiveness and ease of processing.   2. Melt Index and Mechanical Compatibility with Processing Technology When selecting a model, in addition to the final performance, the compatibility of the material with existing extrusion equipment and compounding processes must also be considered. The melt index is a core parameter for measuring resin fluidity, directly determining the extrusion pressure, shear heat, and film uniformity.     ♣ Applications of Low Melt Index Models (MI 1.7 - 1.9): Evasin EV3251F (MI 1.7) and Evasin EV3851VS(Evasin EV3851FS) (MI 1.8) are typical low melt index specifications. These materials have high viscosity and melt strength in the molten state, making them ideal for blown film processes. In the blown film process, high melt strength ensures the stability of the film bubble, preventing rupture or uneven thickness under high-speed traction. In addition, low melt index materials also help to form a more stable melt curtain in the cast film process. ♣  High Melt Index and Special Process Models (MI 4.01 - 4.3): Under 210℃ testing conditions, the MI of EV 3251F reaches 4.01, while EV 3251FT reaches 4.3. The higher fluidity makes it more suitable for high-shear cast film processes or co-extrusion. For complex multi-layer structures (such as 7-layer or 9-layer films), high-fluidity EVOH can better match the adjacent adhesive layers and support layers (such as PE or PP), reducing dead spots and crystal formation in the flow channel. ♣ Consideration of Melting Point: The melting point difference between different models can be as high as 23℃ (165℃ vs 188℃). When selecting a model, you must confirm the heating system and die temperature control accuracy of your extruder. If choosing EV 2951F, the processing temperature usually needs to be set between 210℃ and 230℃.  Improper temperature control can easily lead to material degradation and carbonization.   3. Targeted Model Recommendations for End-Use Packaging Scenarios ♣ Meat and Dairy Vacuum Packaging: This application requires extremely high oxygen barrier properties, typically using a PA/EVOH/PE structure. EV 2951F is the benchmark in this field, maximizing the inhibition of aerobic bacteria growth. If deep drawing is involved, EV 3251FT is recommended. The "T" designation usually indicates optimization for thermoforming processes, providing better uniform stretching distribution and preventing thinning and embrittlement of the barrier layer at the container corners. ♣ MAP and Lidding Films: For MAP packaging of fresh fruits and vegetables, a certain gas exchange balance is required. EV 3851F/V provides moderate barrier properties, preventing large amounts of external oxygen from entering while also assisting in gas regulation within the overall structure. ♣ Pesticide and Chemical Anti-Permeation Bottles: In these applications, the focus is on blocking organic solvents and odors. Evasin EV4451F is often used in blow molding to produce multi-layer plastic bottles due to its good chemical resistance and processing stability. Although its oxygen barrier properties are slightly inferior, it performs excellently in blocking hydrocarbon permeation, and its stability under high humidity ensures the safety of chemical products in warehouse storage environments. ♣ Pipes and Underfloor Heating Systems: In non-packaging applications, such as the oxygen barrier layer in underfloor heating pipes, long-term heat stability and flexibility are usually required. EV 4451V, with its lower melting point and higher ethylene content, exhibits excellent compatibility in simultaneous processing with polyolefin pipes.   ♠ During B2B procurement and production preparation, it is recommended to follow the following process for initial model selection: Clarify barrier requirements: Based on O2 sensitivity. Choose 29% for extremely high barrier, 32%-38% for general barrier, and 44% for high moisture resistance/flexibility requirements. Matching processing technology: For blown film extrusion, prioritize low MI grades (1.7-1.9); for cast film or complex co-extrusion, select high MI grades (4.0 or higher). Confirm equipment temperature control: Ensure the extruder can stably provide the required melting temperature for the specific grade (especially for grades with 29% content).   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com