Evasin EV3851FS

In the world of modern packaging and industrial design, finding a material that perfectly balances protection, durability, and processability is a constant challenge. Enter EVOH (Ethylene-Vinyl Alcohol Copolymer), a thermoplastic polymer that has quietly revolutionized how we preserve food, transport chemicals, and engineer high-performance fuel systems. But what exactly makes EVOH so unique, and why is it considered an elite barrier material? Let’s dive into the science, properties, and diverse applications of this remarkable polymer.     1.What is EVOH? EVOH is a thermoplastic copolymer comprised of ethylene and vinyl alcohol. Its molecular structure features a random, irregular distribution of these two components, carefully controlled during manufacturing to ensure optimal performance. The magic of EVOH lies in the interplay between its two monomers: Vinyl Alcohol (PVA properties): Provides exceptionally high gas barrier properties and high stiffness, though it suffers from poor flexibility and processing challenges on its own. Ethylene (PE properties): Delivers excellent processability and flexibility, though it has very low gas barrier capabilities on its own. By combining these two, EVOH achieves an incredible synergy: elite gas insulation coupled with the practical melting and shaping characteristics of traditional plastics.   2. Key Performance Characteristics EVOH stands out because of a highly specialized suite of physical and chemical traits: Unmatched Gas Barrier Properties EVOH provides an unparalleled shield against gases like oxygen, nitrogen, and carbon dioxide. For perspective, when looking at a standard film thickness of roughly 25.4 µm, EVOH maintains an oxygen transmission rate of just 0.4 to 1.5 cm³ / (m²·day), compared to Low-Density Polyethylene (LDPE) which lets through a massive 10,000 to 15,000  cm³ /(m²·day).  Flavor and Aroma Retention Because gases cannot easily pass through EVOH, it locks in the precise aroma and flavors of condiments, spices, and cosmetics, preventing external odors from contaminating the product.  Superior Chemical and Oil Resistance The presence of hydroxyl (-OH) groups creates powerful intermolecular hydrogen bonds, driving the Solubility Parameter (SP) of EVOH up to a high value of 19. Because most common organic solvents, oils, and fuels have much lower SP values, they cannot dissolve or easily penetrate EVOH, making it exceptionally oil-resistant.  Excellent Optical and Mechanical Qualities Products processed with EVOH boast high transparency and a glossy surface finish. Mechanically, it is highly rigid yet maintains excellent flexurability and toughness. Furthermore, its surface does not accumulate static electricity, making it safe for sensitive electronic component packaging.    3.The Ethylene Content Balancing Act When evaluating EVOH grades, the mole% of ethylene is the most critical metric, as it directly dictates the material's final behaviors:  Low Ethylene Content (e.g., 29–32 mol%): Yields the absolute highest gas barrier performance (lowest oxygen transmission) and higher melting points (~183°C to 188°C), but is slightly more rigid to process.  High Ethylene Content (e.g., 38–44 mol%): Drastically improves thermoplastic processability and flexibility. While the oxygen transmission rate increases slightly, it remains profoundly superior to virtually all other standard polymers (such as EVASIN EV-4405F/ Evasin EV3851FS ) .  Additionally, high-quality manufacturing requires strict control over residual acetyl groups. If too many acetyl groups remain on the molecular chain, they act as "blockers" that disrupt intermolecular bonding and degrade the polymer’s barrier integrity.    4.The Catch: Vulnerability to Moisture While EVOH is an absolute powerhouse against gases, it does have one structural Achilles' heel: water vapor.  Because of its hydrophilic hydroxyl (-OH) groups, EVOH exhibits a poor moisture barrier. When exposed to highly humid environments, its internal gas-blocking network softens.  The Solution: Co-Extrusion Architecture To overcome this, engineers never use EVOH entirely alone in moisture-exposed environments. Instead, it is integrated into a multi-layered, co-extruded structural sandwich alongside traditional hydrophobic (water-repelling) plastics like PE, PP, or PET.  Because EVOH’s high polarity (SP 19) makes it incompatible with the low-polarity surfaces of PE or PP, a specialized tie-layer (adhesive) is placed between them to prevent delamination.    5.Real-World Co-Extrusion Applications Thanks to versatile processing methods—including blown film extrusion, sheet co-extrusion, blow molding, and injection molding—EVOH can be tailored into various structures:  Ketchup Bottles: Designed as PP - Tie - EVOH - Tie - PP. The outer PP layers lock out moisture and allow squeeze-ability, while the internal EVOH core stops oxygen from spoiling the condiment.  High-Barrier Multi-layer Packaging Bags: Styled as PET - PE - Tie - EVOH - Tie - PE to provide pristine preservation for delicate or nitrogen-flushed food items like sliced meats.  Wine and Juice Cartons/Bottles: Built utilizing PE - Paper - PE - Tie - EVOH - Tie - PE structures.  Chemical Packaging & Automotive Fuel Tanks: Built with an HDPE - Tie - EVOH - Tie - HDPE matrix. EVOH’s supreme solvent resistance ensures volatile fuel vapors or hazardous chemicals cannot seep through the plastic walls into the environment.  Underfloor Heating Pipes (Radiant Piping): Often laid out as PP - Tie - EVOH to keep oxygen from penetrating the heating lines and causing internal system corrosion.  EVOH bridges the gap between raw structural strength and delicate environmental shielding. While it requires smart multi-layer engineering to stay protected from moisture, its peerless ability to halt gases, trap aromas, and resist harsh solvents makes it a foundational material in modern eco-friendly, long-shelf-life packaging designs.     Website: www.elephchem.com whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

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

In the vast plastics industry, the choice of polymer is crucial in determining the performance and cost of the final product. This discussion will compare two kinds of polypropylene, Braskem Polypropylene RP 225M and ADMER QB520E, which are suited for different jobs. RP 225M, a medium-flow random copolymer, sees use in film applications because of its good optical clarity and slip. QB520E, on the other hand, is a unique maleic anhydride-grafted homopolymer PP-based adhesive resin focused on adhesive applications in multilayer structures. If you're looking for the right material for flexible packaging, textile applications, or composite structures, this comparison guide will provide clear insights to help you make an informed choice.   1. Core Performance Comparison: RP 225M vs QB520E 1.1 Flowability and Density Features Braskem RP 225M ADMER QB520E Emphasis/Differences Mel Flow Rate (MFR) 8.0 g/10 min 1.8g/10min RP 225M has higher flowability, suitable for thin-walled or high-speed extrusion processes (such as films); QB520E has lower flowability, which is beneficial for improving melt strength and adhesion. Density 0.902g/cm3 0.90g/cm3 Both have very similar densities, falling within the typical polypropylene density range. 1.2 Mechanical Strength and Rigidity Features Braskem RP 225M ADMER QB520E Emphasis/Differences Tensile Yield Strength 28 MPa 24 MPa RP 225M has a slight edge in tensile strength, which may provide better load-bearing capacity in single-layer flexible packaging. Flexural Modulus 900 MPa N/A / Cantilever Impact Strength 30 J/m 470 J/m2 QB520E exhibits extremely high impact strength, consistent with its application as an adhesive layer in bottles, sheets, etc., where high toughness is required to withstand impacts. Elongation at Break 12%(Yield) 280% (Fracture) QB520E's elongation at break is significantly higher than RP 225M's yield elongation, confirming its high toughness and flexibility, ideal properties for an adhesive resin.   2. In-Depth Application Analysis: Identifying Your Needs 2.1 Braskem RP 225M: Transparency, Sliding, and Heat Sealing RP 225M is a product tailored for single-layer flexible packaging and textile applications. Key Features: Excellent Optical Properties: As a random copolymer, it inherently possesses better transparency and gloss than homopolymers, meeting the demands of high-definition packaging. Excellent Sliding Properties (Low Coefficient of Friction): Contains sliding agents and anti-blocking agents to ensure smooth operation on high-speed packaging machinery, preventing film sticking. Good Heat Sealing Properties: The lower initial heat-sealing temperature (111°C) helps improve packaging efficiency. Suitable Applications: Various flexible packaging films (flat extruded and blown films) 1717, especially for inner or middle packaging requiring high transparency and ease of handling, as well as textile applications. 2.2 ADMER QB520E: The "Glue" for Multilayer Structures QB520E is essentially an adhesive resin designed to solve the problem of direct bonding between different polymer layers. Key Characteristics: Strong Bonding: Utilizing maleic anhydride grafting technology, it can form strong chemical bonds with polar materials (such as EVOH or PA (polyamide)) and non-polar PP substrates, creating a high-barrier, high-strength multilayer structure. High Toughness: Extremely high impact strength (470 J/m²) and elongation at break ensure that the composite material will not delaminate under impact or bending. Processing Stability: Maximum processing temperature up to 300°C provides safety for multilayer co-extrusion. Applications: Primarily used in co-extrusion processes as an adhesive between PP and EVOH/PA barrier layers. Typical products include: Multilayer Barrier Bottles and Sheets: Used for packaging with high barrier requirements, such as for food and cosmetics. Multilayer Blown Films and Pipes: Ensures the integrity and durability of pipe and high-barrier film structures.   3. Production and Safety Considerations 3.1 Processing Recommendations RP 225M: Use planar film extrusion or blown film extrusion processes. High MFR is beneficial for processing. QB520E: Although it has low flowability, it does not require pre-drying, simplifying preparation for multilayer co-extrusion processes. Its melt viscosity-shear rate profile (rheological profile) helps to precisely control layer thickness in co-extrusion. Attention should be paid to the maximum temperature limit (300°C) to avoid decomposition. 3.2 Safety and Regulations RP 225M: Not recommended for packaging or products that come into contact with parenteral solutions or the human body. QB520E: Regarding food contact conditions, its components have relevant compliance statements in the EU and US FDA (as an adhesive), but the manufacturer is responsible for ensuring that the final application complies with all food contact regulations.   4. Summary and Recommendations Your final choice depends on your product structure: If you need to manufacture a single-layer packaging film with good clarity, rigidity, and slip resistance, RP 225M is ideal. If you need to manufacture a multi-layered structure (such as plastic wrap or barrier bottles) that includes a barrier layer (such as Ethylene-VinylAlcohol Copolymer (EVOH) /PA), QB520E is a key material to ensure strong adhesion and high toughness between different layers.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com