| Código SH | 619565 |
| Teor De Acetato De Vinilo Em Peso | 18 |
| Fluxo De Fusão G 10 Min | 8 |
| Densidade G Cm3 | 0,941 |
| Ponto De Fusão C | 84 |
| Ponto De Congelação C | 64 |
| Ponto De Amolecimento Vicat C | 62 |
| Temperatura De Fragilidade C | -76 |
| Resistência à Tração Na Ruptura Mpa | 14 |
| Alongamento Na Ruptura | 800 |
| Módulo Flexural Mpa | 27 |
| Dureza Shore D | 34 |
| Índice De Refração | 1.497 |
Como fábrica acreditada de Copolímero de acetato de vinilo de etileno ELVAX 450, aplicamos protocolos de qualidade rigorosos - cada lote é submetido a testes rigorosos para garantir padrões de eficácia e segurança consistentes.
| Embalagem | ELVAX 450 Copolímero de Etileno Vinil Acetato fornecido como pellets em sacos de papel multiparede selados de 25 kg, garantindo manuseio seguro e proteção contra umidade. |
| Carga de contêiner (20' FCL) | 20 'FCL: copolímero ELVAX 450 EVA carregado em sacos em paletes, protegido para transporte seguro. |
| Envio | ELVAX 450 é um copolímero não perigoso de etileno e acetato de vinila fornecido como pelotas sólidas. Envie em embalagens limpas e secas para evitar contaminação e absorção de umidade. Evite a exposição ao calor excessivo e luz solar direta durante o trânsito. Nenhuma declaração especial de mercadorias perigosas é necessária, mas as práticas padrão de manuseio e ventilação se aplicam. |
| Armazenamento | Armazene o copolímero de acetato de etileno e vinil ELVAX 450 em um recipiente original selado em uma área fria, seca e bem ventilada, longe da luz solar direta, fontes de calor e chamas abertas. Mantenha separado de oxidantes fortes. Evite o armazenamento prolongado acima de 50 ° C (122 ° F) para evitar fusão ou bloqueio. Mantenha a temperatura ambiente e a baixa umidade para uma estabilidade ideal. |
| Prazo de validade | O prazo de validade é normalmente de dois anos a partir do envio, quando armazenado em contêineres originais fechados em condições frias e secas. |
Em linhas de vedação de caixas e caixas onduladas de alta velocidade, o ELVAX 450 é carregado como a espinha dorsal do ligante em 30-40% em peso da fórmula adesiva total. O teor nominal de comonómero de acetato de vinilo 18% em peso e a taxa de fluxo de fusão 8 g/10 min a 190°C/2,16 kg por ISO 1133-1:2022 colocam este grau entre dois modos de falha concorrentes. Os graus com acetato de vinilo abaixo de 12% em peso retêm a cristalinidade excessiva do polietileno e não conseguem molhar a placa reciclada revestida de argila, produzindo a liberação interfacial em vez de rasgar a fibra. Grados com acetato de vinilo acima de 28% em peso produzem adesão aceitável a substratos polares, mas deprimem o ponto de amolecimento de anel e bola e podem sangrar através de 80-120 g/m² revestimentos kraft. O adesivo é composto em um misturador de lâmina sigma com revestimento a 140-160°C sob um cobertor de nitrogênio, com velocidade do rotor mantida a 30-60 rpm até que um derretimento livre de partículas seja alcançado, normalmente 35-50 min. A compostura contínua em uma extrusora de duplo parafuso co-rotativa com L/D 40:1 usa a temperatura da zona de alimentação 120°C, as temperaturas do meio do barril 145–165°C e a temperatura da matriz 155–170°C. Tempo de residência acima de 200°C inicia a desacetilação do mer de acetato de vinilo, liberando ácido acético que reduz a viscosidade de fusão, aumenta o número de ácidos e ataca acessórios de latão e cobre; as superfícies molhadas são, portanto, especificadas em aço inoxidável 316L ou aço cromado para ferramentas.
Preços competitivos do Copolímero de acetato de vinilo de etileno ELVAX 450 que se ajustam ao seu orçamento - termos flexíveis e orçamentos personalizados para cada pedido.
Para amostras, preços ou mais informações, entre em contato conosco em +8615380400285 Ou envie para sales2@liwei-chem.com.
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Pagamento flexível, preço competitivo, serviço premium - Consulte-nos agora!
ELVAX 450 is an ethylene vinyl acetate copolymer resin whose vinyl acetate comonomer content is controlled to a nominal 18 wt% and whose melt mass-flow rate is controlled to a nominal 8 g/10 min when measured at 190 °C under 2.16 kg in accordance with ISO 1133-1:2022 or ASTM D1238-20. The resin has a typical density of 0.94 g/cm³ at 23 °C per ISO 1183-1:2019. The grade belongs to the 18 wt% vinyl acetate series of the Elvax product line, in which molecular weight is varied independently of comonomer level. This product-line architecture separates polarity and adhesion effects, controlled by vinyl acetate content, from flow-related processing effects, controlled by molecular weight and chain architecture. The 8 g/10 min melt mass-flow rate places the material between high-flow Elvax 440 at a nominal 30 g/10 min and low-flow Elvax 460 at a nominal 2.5 g/10 min. That intermediate flow position allows the grade to be considered for extruded sheet, profile, cast film, compounding, and adhesive applications requiring moderate melt strength without the high pressure drop and shear heating associated with fractional-MFR resins.
Vinyl acetate content in EVA is the primary structural variable controlling polarity, crystallinity, and low-temperature flexibility. Lower-VA grades in the 9–12 wt% range retain higher crystallinity, higher stiffness, and better hydrocarbon compatibility; they are commonly selected for wax modification, sealants requiring higher heat resistance, and compounds in which compatibility with polyethylene is more important than adhesion to polar substrates. Higher-VA grades in the 25–33 wt% range have lower crystallinity, lower softening point, and stronger adhesion to glass, aluminum, and polar films; these are widely used in photovoltaic encapsulant film and high-tack adhesive systems. The 18 wt% comonomer level is an intermediate plateau: polarity is sufficient to improve adhesion and reduce stiffness relative to polyethylene, while crystallinity remains high enough to maintain elevated-temperature dimensional stability and surface dryness. The result is a formulation window in which final adhesion, stiffness, and optical characteristics are governed by additive selection rather than by the base resin alone. Surface wetting tension can be evaluated per ISO 8296:2003, but values vary with corona treatment and additive migration.
At the molecular level, the 18 wt% vinyl acetate level disrupts ethylene crystallite formation and broadens the melting range. Differential scanning calorimetry per ASTM D3418-21 shows a melting profile dependent on cooling rate and nucleation; no single peak temperature is a sufficient acceptance criterion. The glass transition of this grade is broad and typically well below −25 °C, but the exact value depends on comonomer sequence distribution and thermal history. Vinyl acetate content is routinely determined by infrared spectroscopy using ASTM D5594 or an equivalent validated internal procedure. When the grade is compared with unmodified polyolefins, the polar ester groups increase compatibility with fillers, carbon black, and polar modifiers; when compared with higher-VA copolymers, the 18 wt% level reduces moisture sensitivity and surface blocking. Published data for this specific configuration is limited; critical thermal-transition values should be generated on production lots and not copied from generic EVA literature.
In hot-melt adhesive compounding, the melt mass-flow rate of the EVA raw material is one of the primary controls on finished adhesive viscosity. High-flow grades in the 150–500 g/10 min range lower application viscosity but reduce green strength and cohesive strength; low-flow grades below 3 g/10 min raise viscosity and improve toughness but restrict application equipment to heated hose and gear pump systems capable of high pressure. ELVAX 450 at 8 g/10 min is suited to the intermediate formulation space where both application viscosity and cohesive strength are specified. Finished adhesive viscosity is measured by rotational viscometry using ASTM D3236-88(2020) at controlled temperatures such as 150 °C, 160 °C, and 180 °C; acceptance limits are formulation-specific and depend on rosin ester or hydrocarbon tackifier, wax level, paraffin type, and filler. The 18 wt% vinyl acetate content provides compatibility with rosin ester and partially hydrogenated hydrocarbon tackifiers, but high wax loadings can produce phase separation that appears as surface bloom and viscosity drift. The rotoviscometer spindle and chamber must be calibrated with certified viscosity standards at the measurement temperature; otherwise batch-to-batch viscometer comparisons are not technically valid.
Adhesive open time and green strength are influenced by EVA molecular weight and crystallization rate. Compared with higher-flow grades in the same series, ELVAX 450 generally provides longer open time and higher green strength than Elvax 440, but shorter open time and lower cohesive strength than Elvax 460. Comparative values are measured by tensile lap-shear strength per ASTM D3163-01(2014) or by peel adhesion methods. The numerical differences depend on substrate, adhesive thickness, cooling rate, and tackifier package; they cannot be transferred from one production line to another without validation.
In single-screw extrusion of neat ELVAX 450, barrel temperatures are typically set from 140–155 °C in the feed zone to 180–200 °C at the die. The material should not remain above 220–230 °C for extended residence times because thermal deacetylation of the vinyl acetate comonomer can generate acetic acid and conjugated unsaturation, producing discoloration, gel particles, and a sharp acidic odor. A general-purpose screw with an L/D of 24:1 to 30:1 and a compression ratio near 3:1 is used for sheet and profile extrusion. Fine-mesh screen packs, often 40/60/80 mesh, are installed in cast film and sheet lines to trap gels; pressure drop across the screen pack should be recorded continuously with a melt-pressure transducer because progressive gel accumulation is not visible from motor load alone. When shutdown extends beyond 45 min, the barrel should be purged with a thermally stable polyolefin to minimize the formation of degraded residue on screw and barrel surfaces.
Within the 18 wt% vinyl acetate series, grade selection is primarily a molecular-weight and melt-flow decision. Table 1 reports nominal supplier literature values. The difference between ELVAX 450 and ELVAX 460 is approximately 3.2-fold in melt mass-flow rate; the difference between ELVAX 450 and ELVAX 440 is approximately 3.75-fold. These differences are significant in thin-gauge film and in pressure-limited extrusion because melt pressure and motor load do not scale linearly with MFR. A grade change from ELVAX 450 to Elvax 460 can require higher barrel set points or reduced throughput, while a change to Elvax 440 can improve line speed but may reduce bubble stability in blown film. The choice should be based on melt-pressure measurements and product performance testing, not on MFR alone.
| Grade designation | Vinyl acetate content (wt%) | Melt mass-flow rate (g/10 min) | Typical density at 23 °C (g/cm³) |
|---|---|---|---|
| Elvax 410 | 18 | 500 | 0.94 |
| Elvax 420 | 18 | 150 | 0.94 |
| Elvax 440 | 18 | 30 | 0.94 |
| Elvax 450 | 18 | 8 | 0.94 |
| Elvax 460 | 18 | 2.5 | 0.94 |
| Elvax 470 | 18 | 0.7 | 0.94 |
At production scale, the practical difference between ELVAX 450 and lower-flow grades appears as a line-specific pressure drop across the extruder head and die. A melt-pressure transducer placed before the breaker plate should be used to compare candidate grades under identical throughput and temperature conditions. Lot-to-lot MFR variation is reported on the certificate of analysis and should be monitored because a shift of 1 g/10 min can alter pressure-limited throughput in thin-gauge film. No universal correction factor is published; a trial on the target line is required before a permanent grade substitution.
When ELVAX 450 is compounded with filler, carbon black, or polyolefin modifiers in a co-rotating twin-screw extruder, the melt temperature is often 10–20 °C above the set barrel temperature because of viscous dissipation. Therefore the barrel profile should be limited to 170–190 °C in the mixing zones and the screw speed adjusted to keep the melt thermocouple below 220 °C. A twin-screw extruder with an L/D of 40:1 and side feeding at the downstream port is used when mineral fillers above 20 wt% are introduced. Screw elements should be selected for distributive mixing rather than high-intensity kneading when temperature-limited compounding is required; high-shear kneading blocks can accelerate deacetylation and generate gel particles. Specific energy input is optimized by measuring melt temperature and specific throughput, not by maximizing screw speed. Venting, when used, should be located behind a melt seal to avoid pellet carryover. Production lines processing this grade have shown that the most common failure is not feed bridging but thermally degraded residue accumulation at the screw tips and mixer elements; this failure can be detected by a slow rise in melt pressure over a run and by black specks in the extrudate.
In polyolefin modification, ELVAX 450 is added at 5–30 wt% to LLDPE or HDPE to improve impact properties and stress-crack resistance. Mixing quality in pellets should be assessed by scanning electron microscopy or by solvent extraction of residual monomers, not by visual clarity alone. Notched Izod impact values must be measured per ISO 180:2019 or ASTM D256-23, and the numerical improvement depends on EVA content, processing conditions, and test temperature. At low temperatures below −40 °C, even 18 wt% vinyl acetate may not provide sufficient impact in thick sections; higher-VA or lower-MFR grades should be evaluated. This boundary is not a limitation of ELVAX 450 alone but a consequence of crystallinity and glass-transition behavior.
In injection molding, ELVAX 450 is processed with a melt temperature typically between 170 °C and 210 °C and a mold temperature between 20 °C and 40 °C. The 8 g/10 min melt mass-flow rate is high enough to fill moderate-flow thin-wall tools but low enough to maintain a stable melt cushion. Injection speed, hold pressure, and screw recovery should be set to limit melt residence time because the same thermal deacetylation boundary applies. Clamp force requirements are determined by projected part area and cavity pressure; no single clamp-force value is specified for the resin. Shrinkage and warpage are dependent on part thickness, mold cooling, and post-molding crystallization; mold shrinkage should be measured on a prototype tool, not assumed from generic polyolefin data. For molded parts requiring low-temperature flexibility, the material offers a useful combination of flexural compliance and surface dryness compared with higher-VA grades.
For food-contact applications, the base EVA resin may be evaluated under FDA 21 CFR 177.1350, which covers ethylene-vinyl acetate copolymers and extractives limitations. The evaluation applies to the base polymer only; tackifiers, waxes, slip agents, and other additives must be assessed separately. In photovoltaic encapsulant service, 18 wt% vinyl acetate is less common than 28–33 wt% because lower VA content increases crystallinity, reduces optical transmission after crosslinking, and raises thermal transition temperatures. If ELVAX 450 is used in a peroxide-cured encapsulant or crosslinked compound, dicumyl peroxide loadings are process-sensitive and must be matched to residence time and oven temperature. Cure state should be measured by moving-die rheometry per ASTM D5289-19, not inferred from hardness or color alone. The crosslinked system must be validated for long-term heat and moisture aging; published data for this specific configuration is limited.
Storage and handling boundaries are relevant because surface moisture, thermal history, and regrind level affect process stability. Pellets should be stored in a dry, covered area away from direct sunlight and ignition sources. If transferred from cold storage to a warm processing area, the material should be allowed to stabilize to ambient temperature before feeding to prevent hopper condensation. Pre-drying at 55–65 °C for 2–4 h in a desiccant dryer is used after exposure above 60% RH. Regrind use should be limited to 20 wt% unless the final application is validated by mechanical testing against the relevant product specification. Reclaim from heated storage should be monitored for acetic acid odor and discoloration because both indicate partial deacetylation. The resin should not be exposed to open flame, strong oxidizing agents, or sustained melt temperatures above 200 °C.
