HANWHA EVA 1528 (em inglês)

Hanwha EVA 1528 is specified with a nominal vinyl acetate content of 15 wt% and a melt mass-flow rate of 2.8 g/10 min at 190°C/2.16 kg under ISO 1133-1:2022. In three-layer agricultural cover film, the grade is run as the core layer at 30–50 wt% of total film mass, with the outer skins at 20–35 wt% each from LLDPE or LDPE to preserve dart impact and film flexibility. The EVA core raises light transmission and reduces frost-crack sensitivity at low installation temperatures, but the processing window is narrow: a three-layer coextrusion blown film line with die gap 1.6–2.5 mm, barrel temperatures 160–190°C, die temperature 185–205°C, and blow-up ratio 2.0:1–2.5:1 is used. Above 210°C, acetic acid evolution from the VA groups increases, producing die-lip corrosion and film haze; therefore, the upper die zone is held below 205°C. The layer distribution is controlled by gravimetric hoppers with a batch tolerance of ±1.5 wt%. Anti-fog and anti-drip additives are commonly introduced into the EVA core at 0.5–1.2 wt% of the middle layer. Terminal products include single-season greenhouse tunnels, multi-season low tunnels, and side-curtain films. The relevant compliance reference is EN 13206 for plastic covering films for agricultural use, with mechanical checks under ISO 527-3:2018, haze under ASTM D1003-21, and dart impact under ASTM D1709-22.

What Prevents Stable Bubble Formation in Collation Shrink Film with 15 wt% VA?

Blends with 70–85 wt% EVA 1528 and 15–30 wt% octene LLDPE at nominal density 0.914–0.920 g/cm³ are processed on a double-bubble biaxial orientation line. The EVA 1528 portion raises shrink tension and improves seal-jam strength after shrink-tunnel exposure at 120–150°C, but draw resonance appears when orientation temperature falls below 75°C because molecular mobility is insufficient; above 96°C, bubble stability is lost due to reduced melt strength. The orientation window is therefore held at 80–95°C with internal bubble pressure 0.15–0.35 MPa and orientation ratios of 4.0:1–4.5:1 in machine direction and 3.5:1–4.0:1 in transverse direction. The double-bubble line requires a first blown bubble with water-quench calibration, a reheat zone with infrared heating panels, and a second bubble with air cooling. Terminal product thickness after slitting is 35–60 µm; downstream users convert the film into multipack bottle collation, printed overwrap for beverage cans, and protective sleeve wrap. Compliance includes FDA 21 CFR 177.1350 for EVA copolymers in food-contact overwrap and EU Regulation 10/2011 with overall migration below 10 mg/dm². Shrink behavior is measured under ASTM D2732-23, tensile properties under ISO 527-3:2018, and haze under ASTM D1003-21. Published data for this specific grade in double-bubble configuration is limited; the numerical window is consistent with EVA copolymers of similar viscosity and VA content.

In crosslinked polyolefin foam compounds, EVA 1528 is used as the high-hardness backbone at 55–70 phr, with EVA 28 at nominal VA content 28 wt% at 30–45 phr to retain flex-crack resistance. A typical compound contains azodicarbonamide at 2.8–4.5 phr, dicumyl peroxide at 0.9–1.4 phr, ZnO at 1.0–1.5 phr, stearic acid at 0.3–0.6 phr, and calcium carbonate at 0–15 phr. The processing conflict is thermal: ZnO shifts azodicarbonamide decomposition onset into the 155–170°C range, while dicumyl peroxide requires 170–180°C for rapid crosslinking. This overlap is monitored on a moving die rheometer at 170°C; if the cure plateau begins more than 30 s after gas evolution, cell coalescence and sheet collapse occur. Mixing is conducted in an intermeshing Banbury-type mixer with a discharge temperature of 100–110°C, followed by a two-roll mill at 90–100°C to homogenize the sheet stock. Pressing is performed in a daylight press at 155–170°C and 15–25 min cycle time. Terminal products include footwear midsole sheets, sandal sheet stocks with Shore C hardness 55–65, and gym mat underlay. Compliance is based on REACH Regulation (EC) No 1907/2006 and RoHS Directive 2011/65/EU for heavy metals; foam density is checked under ISO 845:2006, compression set under ISO 1856:2018, and hardness under ASTM D2240-21.

Halogen-Free Sheathing Compounds: ATH Absorption, Venting, and Oxygen Index

EVA 1528 enters low-smoke zero-halogen cable sheathing as part of the polymer fraction at 20–40 wt% of the polymeric matrix. The remaining polymer fraction is typically EVA 28 and/or LLDPE, with aluminum trihydrate at 150–180 phr and magnesium dihydrate at 30–50 phr as fire-retardant fillers. The technical role of EVA 1528 is filler wetting: the 15 wt% VA content wets untreated ATH surfaces better than non-polar LLDPE, raising the maximum filler absorption before pressure builds at the die. Twin-screw compounding is carried out on a 40:1 L/D co-rotating twin-screw extruder with side feeding of ATH after the polymer melt seal, barrel temperatures 140–170°C, screw speed 300–450 rpm, and a vacuum vent of -0.08 MPa to remove water released from filler surfaces. ATH decomposition begins near 180–200°C; processing above 175°C produces moisture porosity and pinholes in the extruded sheath. The compounded pellets are then applied by a 90 mm single-screw extruder with a low-compression barrier screw at melt temperature 160–175°C. Terminal products include building control cable sheathing, low-voltage power cables for public infrastructure, and shipboard cable jackets. Compliance is anchored to the following matrix.

In cast and blown coextruded packaging structures, EVA 1528 is run as the sealant layer at 70–90 wt%, blended with a slip and anti-block masterbatch at 3–5 wt% and a polyolefin tie resin where layer adhesion is required. The seal initiation temperature of the grade, measured under ASTM F2029 heat-seal conditions at 0.275 MPa and 0.5 s dwell, is typically 85–95°C, and a stable heat-seal plateau is achieved at 110–130°C. The production process is a three-layer cast film line with die gap 0.5–0.8 mm, chill roll temperature 18–25°C, and line speed 150–300 m/min; additive migration to the seal surface is controlled by limiting slip additive to 500–1000 ppm. Terminal products include lidding films for dairy multipacks, frozen vegetable pouches, and overwrap for medical devices. Compliance is governed by FDA 21 CFR 177.1350 for EVA copolymers and EU Regulation 10/2011, with specific migration limits verified under EN 1186-1:2002 and overall migration under EN 1186-2:2002; heavy metal release is checked under 94/62/EC packaging waste directive where applicable.

When EVA 1528 Is Selected as a Carrier for Mineral-Filled Masterbatches

For additive masterbatches requiring high mineral loading and low die swell, EVA 1528 is used as carrier at 55–75 wt% of the masterbatch, with the active pigment or stabilizer at 20–35 wt% and dispersant wax at 2–5 wt%. The 15 wt% VA content avoids blocking and provides a wider compatibility window with LDPE and LLDPE than higher-VA carriers; melt viscosity also permits adequate filler wetting without excessive shear heating. Production uses a co-rotating twin-screw extruder with 32:1 L/D, screw speed 400–600 rpm, melt temperature 150–180°C, and a strand die feeding a pelletizer. Terminal products include TiO₂ concentrates for cast film, blowing agent concentrates for profile extrusion, and silica anti-block masterbatches for blown film. The carrier itself is covered by FDA 21 CFR 177.1350, but the final food-contact status depends on the active additive and the end-use film’s migration profile under EU Regulation 10/2011. Residence time above 5 min at 180°C is avoided to prevent VA degradation and gel formation.

Keep the Die Temperature Below 205°C When EVA 1528 Runs in Technical Sheet and Profile Lines

EVA 1528 is used as a blend component at 10–30 wt% in LDPE/LLDPE technical sheet and profile compounds to increase flexibility and environmental stress-crack resistance. The extrusion process is run on a single-screw extruder with 30:1 L/D, barrel temperatures 150–190°C, die temperature 185–205°C, and calender stack rolls at 30–60°C for sheet thickness 0.5–3.0 mm. Draw ratio is limited by the grade’s melt index; above 4:1 haul-off, edge tear initiates in thin sheet. Terminal products include spacers for flat-panel packaging, gaskets for non-pressure drainage systems, and temporary protection sheet. Compliance for non-food technical uses is based on RoHS Directive 2011/65/EU for lead, mercury, cadmium and hexavalent chromium and REACH Regulation (EC) No 1907/2006 SVHC screening; mechanical property checks use ISO 527-2:2012 for yield stress and ISO 178:2019 for flexural modulus.