Copolímero de acetato de vinilo de etileno ELVAX 3180

In hot-melt mixing vessels operating on corrugated case sealing and perfect-binding lines, ELVAX 3180—characterized by a vinyl acetate content of 28 wt% and a melt flow index of 25 g/10 min under ISO 1133-1:2022 at 190 °C and 2.16 kg—functions as the primary polymer backbone for packaging adhesives that require low application viscosity and high substrate wetting on recycled board. The resin is blended in jacketed vertical or sigma-blade mixers at 150–180 °C with hydrocarbon tackifiers, paraffin or Fischer-Tropsch wax, and phenolic or phosphite stabilizers. Typical addition levels of ELVAX 3180 in packaging hot melts fall between 20 wt% and 40 wt% of total formulation mass; below 20 wt% cohesive strength and shear resistance decline, while above 40 wt% application viscosity can exceed 3,000 mPa·s at 175 °C and compromise slot-die uniformity. On a 200 L dual-blade production mixer, batch-to-batch viscosity drift is typically controlled within ±10% when incoming pellets are pre-dried below 0.05 wt% moisture and the discharge gate is heated to 165 °C. Compliance for food packaging is assessed under FDA 21 CFR 175.105 for adhesive components, FDA 21 CFR 177.1350 where ethylene-vinyl acetate copolymers are used in direct-contact layers, and EU Regulation 10/2011 for plastic materials intended for food contact. Viscosity control follows ASTM D3236-19, and heat resistance is measured by shear adhesion failure temperature according to ASTM D4498-07(2015). Downstream converting lines apply the melt through slot-die coaters, wheel applicators, or fiberized spray heads at 150–170 °C; adhesive pots require inert-gas blanketing when run times exceed 4 h to limit oxidative gel formation and skinning. Thermal degradation through deacetylation accelerates above 230 °C, releasing acetic acid that corrodes mild steel equipment and reduces adhesion to pH-sensitive kraft surfaces. Terminal product types include corrugated case and carton sealing, perfect-bound book spines, side-seam wet-strength packaging adhesives, and spiral-wound paper tube laminations.

Curtain-coating lines that apply paraffin-based moisture barriers to produce boxes encounter surface scuffing and flaking when unmodified paraffin wax is used at low temperatures. Adding ELVAX 3180 to a refined paraffin or microcrystalline wax at 2–10 wt% raises melt viscosity and improves adhesion to kraft linerboard without requiring solvent recovery. Formulation ratios are maintained at 1.5–5 wt% for lightweight board coatings and 5–10 wt% for heavily handled produce boxes where abrasion resistance is critical. Regulatory compliance for coated paper and paperboard includes FDA 21 CFR 176.170 and 176.180 for paperboard in contact with aqueous and fatty foods, EU Regulation 10/2011 for plastic layers in paperboard laminates, and REACH EC 1907/2006 for EU market entry. Moisture vapor transmission rate is measured by TAPPI T464 or ISO 2528:2017, and scuff resistance is evaluated by abrasion testing such as TAPPI T476. Blending is carried out in heated stainless steel tanks at 120–140 °C with low-shear propeller agitation for 45–60 min until visual clarity is achieved; the melt is then pumped through jacketed pipes to a curtain coater with die gap set between 0.25 mm and 0.50 mm. Board is coated at line speeds of 200–600 m/min, and the cooling section temperature is held below 10 °C to set the wax film before stacking. Terminal products include waxed corrugated produce containers, meat and poultry boxes, frozen seafood boxes, and paperboard slip sheets.

Solvent-borne laminating lines that run polyester-to-paper constructions require an adhesion promoter that can be dissolved without gel formation during continuous roll-to-roll coating. ELVAX 3180 is dissolved in aromatic/aliphatic solvent blends—typically toluene, methyl ethyl ketone, and acetone in a 60:20:20 ratio—to form a 20–35 wt% solids solution. The EVA addition level is commonly 15–25 wt% of total wet adhesive; higher loadings increase solution viscosity beyond 1,200 mPa·s and reduce gravure cylinder transfer. The vinyl acetate content promotes adhesion to polar substrates and improves cold-weather bond flexibility. Compliance for printed and food-contact laminates follows FDA 21 CFR 175.105 for adhesive components and EU Regulation 10/2011 for plastic layers in the final laminate. Manufacturing uses slow-speed high-torque dissolvers with jacketed cooling to keep solvent temperature under 35 °C, followed by cartridge filtration at 10 μm absolute. Laminating is performed on gravure or reverse-roll coaters at 0.8–2.5 g/m² dry adhesive weight, with drying ovens zoned from 60 °C to 95 °C. A final curing stage at 40–50 °C for 24–48 h is required to reach full bond strength. Terminal product types include film-to-paper pouches, aluminum foil lidding membranes, and metallized film laminates for dry food packaging.

Compounding plants that produce color or additive concentrates for polyethylene film and injection molding can use ELVAX 3180 as a high-wet-out carrier resin at addition levels between 40 wt% and 80 wt% of the masterbatch. The EVA carrier is combined with organic or inorganic pigments at 20–50 wt%, PE wax at 5–10 wt%, and a stearate or amide dispersant at 0.5–2 wt%. ELVAX 3180 reduces melt viscosity more effectively than linear low-density polyethylene carrier, which improves pigment dispersion in high-torque mixing zones and reduces screen-pack pressure. Material compliance for masterbatches is verified under REACH EC 1907/2006, RoHS Directive 2011/65/EU when concentrates are supplied for electrical/electronic plastic parts, and FDA 21 CFR 177.1350 when the final article is a food-contact polyethylene film. Heavy metal and specific migration limits are tested according to EN 71-3 for toy applications and EU Regulation 10/2011 for food-contact film. Production is performed on a co-rotating twin-screw extruder with L/D ratio of 40:1 or 44:1, screw speed of 400–600 rpm, and temperature zones set from 120 °C at the feed throat to 180 °C at the die plate. Water-ring pelletizing is used; pellet moisture is reduced to below 0.08 wt% in a centrifugal dryer. Processing incompatibility is observed when the EVA carrier is used above 20 wt% in highly isotactic polypropylene masterbatches, where interfacial separation and surface bloom may occur. Terminal product types include white and black masterbatches for blown polyethylene film, additive concentrates for stretch film, and pigment concentrates for injection-molded caps and closures.

ELVAX 3180 can be processed as the heat-seal layer in coextruded or monolayer cast film lines at 20–60 wt% in blends with LDPE, or as a 100 wt% resin where low seal initiation temperature is required. The material has a melting range that typically begins near 75–85 °C; heat-seal initiation on cast film falls within 85–105 °C for the neat resin depending on film thickness and chill roll temperature. Blending with LDPE at 50 wt% shifts seal initiation upward by 10–20 °C while improving blocking resistance. Food-contact extruded films are evaluated under FDA 21 CFR 177.1350 for ethylene-vinyl acetate copolymers, EU Regulation 10/2011 for overall migration at 40 °C/10 days in 3% acetic acid and 50% ethanol simulants, and ISO 1133-1:2022 for melt flow index. Heat-seal strength is tested according to ASTM F88/F88M-21 on a 25.4 mm wide seal strip peeled at 300 mm/min. Cast-film extrusion uses a single-screw extruder with L/D ratio of 30:1 or a coextruder for seal layers, with barrel temperatures between 190 °C and 230 °C, die gap set at 0.4–0.8 mm, and air gap kept under 10 cm to reduce melt sag. The chill roll is held at 15–25 °C to prevent blocking; moisture must be below 0.05 wt% before extrusion to avoid bubble defects and acetic acid odor. Published data for this specific grade in monolayer cast-film heat-seal trials is limited; seal-initiation values should be confirmed on a pilot line before full production. Terminal product types include lamination sealant webs for frozen food, medical device overwrap, and paperboard blister lidding films.

Compression-molded cap liner operations that require low-torque mold release and reliable sealability incorporate ELVAX 3180 into low-density polyethylene or polypropylene-based closure compounds at 10–25 phr. The EVA component reduces seal initiation temperature and improves sealing to glass and polyethylene terephthalate finishes. Blowing-agent systems—usually azodicarbonamide at 0.5–2 phr or sodium bicarbonate/citric acid blends—are added when expanded liner structures are required. Closure sealing materials intended for food and beverage use are tested under FDA 21 CFR 177.1210 for closure sealing gaskets, FDA 21 CFR 177.1520 for olefin polymers in the base resin, and EU Regulation 10/2011 for plastic materials and articles. Production uses low-shear intensive mixers at 120–160 °C, followed by a single-screw extruder for pelletization. Liner forming is done by compression molding at 170–190 °C with clamp force sufficient to maintain 5–15 MPa cavity pressure; demolding requires mold surface coatings because the low melting point of ELVAX 3180 can increase tack. Terminal product types include tamper-evident induction-seal liners, crown cap gaskets, and aluminum screw cap liners for edible oil and dairy closures.