Korea Hanwha LLDPE 3224 is supplied as a linear low-density polyethylene with a nominal density of 0.922 g/cm³ under ISO 1183-1 and a melt flow index of 2.0 g/10 min under ISO 1133-1:2022 at 190 °C with a 2.16 kg load. Commercial conversion of the grade centers on thin-gauge blown film and cast film structures where the density and melt flow combination influences dart impact, tear propagation, and seal behavior. The neat resin does not require predrying; only hygroscopic additive masterbatches require drying at 70–80 °C for 2–4 h when exposed to relative humidity above 60 %.

On single-screw blown film lines producing food-contact packaging at thicknesses of 20–80 µm, LLDPE 3224 is extruded at a melt temperature of 185–210 °C. The die gap is set to 1.2–1.8 mm, and the blow-up ratio is held between 2.2:1 and 3.0:1. Frost line height is maintained at 6–10 die diameters above the air ring to stabilize bubble geometry and reduce blocking. Compliance is governed by FDA 21 CFR 177.1520(c) for direct food contact and EU Regulation 10/2011 with overall migration below 10 mg/dm² under EN 1186-1. The blend ratio at the hopper is 100 parts by weight LLDPE 3224, with optional 10–25 parts by weight LDPE film grade to increase melt strength and improve gauge uniformity, 0.5–1.0 wt% synthetic silica antiblock masterbatch, and 0.1–0.3 wt% erucamide slip concentrate where coefficient of friction reduction is required. Fluoropolymer polymer processing aid is introduced at 0.5–1.0 wt% of a 2 % active masterbatch, equivalent to 100–200 ppm active PPA, when sharkskin melt fracture becomes visible at high throughput. Downstream conversion uses a single-screw extruder with 25:1–30:1 L/D, a 20/40/20 mesh screen pack, and a spiral mandrel or side-fed annular die. Terminal product types include bread bags, frozen vegetable pouches, produce bags, and lightweight carrier films.

What Happens to Seal Initiation Temperature When LLDPE 3224 Replaces LDPE in Extrusion Lamination?

Extrusion lamination and extrusion coating with LLDPE 3224 are run at melt temperatures of 265–295 °C. This is close to the upper thermal limit of the grade, so residence time is held below 10 min and screw speed is selected to limit melt temperature overshoot above 300 °C. Thermal degradation produces gel clusters that deposit at the die lip and create coating voids. Compliance for food-contact laminates requires FDA 21 CFR 177.1520(c) for the sealant web and FDA 21 CFR 175.105 for the adhesive tie layer, with EU Regulation 10/2011 covering the finished multilayer structure. Compounding for the sealant web is 70–80 wt% LLDPE 3224 combined with 20–30 wt% LDPE extrusion-coating grade. The LDPE fraction is required because LLDPE 3224 alone exhibits higher neck-in and lower draw stability in the air gap, especially at coating weights below 15 g/m². Low levels of fluoropolymer polymer processing aid at 200–400 ppm active are included to suppress melt fracture at line speeds above 150 m/min. Slip and antiblock packages are either omitted or kept below 0.1 wt% to avoid reducing seal strength. The downstream process consists of a coextrusion coating die with 0.6–0.8 mm die gap, air gap 150–250 mm, chill roll temperature 15–25 °C, and line speeds of 100–300 m/min. Adhesion to BOPET, BOPP, and metallized substrates is supported by corona treatment to a minimum surface energy of 38–42 mN/m before lamination and, where specified, ozone treatment of the melt curtain. Finished product types include stand-up pouch sealant webs, lidding films, and non-retort snack packaging laminates. Published data for monolayer LLDPE 3224 extrusion coating on high-speed aluminum foil structures is limited; the standard industrial remedy is the specified LDPE addition.

When LLDPE 3224 is compounded for agricultural greenhouse and mulch film, the additive loading and service exposure differ from packaging film. Compliance for non-food agricultural film falls under REACH Regulation (EC) No 1907/2006. Mechanical characterization is performed under ISO 527-3 tensile testing, and accelerated weathering uses ISO 4892-2. The formulation addition ratio is 88–95 wt% LLDPE 3224, with 4–8 wt% HALS-based UV stabilizer masterbatch, 1–3 wt% NIR-blocking additive masterbatch for greenhouse thermal retention, and 2–4 wt% pigment masterbatch where light diffusion or photoselective properties are required. Hygroscopic stabilizer concentrates must be dried at 70–80 °C for 2–4 h before blending if exposed to relative humidity above 60 %. Failure to dry these concentrates is observed on production lines as surface haze, plate-out, and feed-zone slippage. Downstream conversion is performed on three-layer blown film coextrusion lines with die gap 1.8–2.6 mm, blow-up ratio 2.0:1–2.8:1, melt temperature 190–215 °C, and film thickness 50–200 µm for greenhouse covers and 25–40 µm for mulch. The converted film forms are greenhouse covers, low tunnels, silage pit covers, and mulch films.

Heavy-Duty Sack Compound Geometry and Tear Balance on IBC Blown Film Lines

Industrial refuse sacks and construction films using LLDPE 3224 are compounded with high-density polyethylene to raise modulus and reduce creep under load. The compliance framework for these non-food films is based on ASTM D1709-16a dart impact, ASTM D1922 Elmendorf tear resistance, and ISO 527-3 tensile properties as batch release criteria. At the weigh-batch level, the ratio is 60–80 wt% LLDPE 3224 and 20–40 wt% HDPE film grade, with 2–4 wt% carbon black masterbatch where outdoor weathering resistance is needed and 5–10 wt% calcium carbonate masterbatch where stiffness and unit cost reduction are prioritized. Calcium carbonate loading above 15 wt% is avoided because dart impact and transverse-direction tear drop sharply in 50–120 µm films. Downstream production is run on high-stalk blown film lines equipped with internal bubble cooling, die gap 1.6–2.4 mm, blow-up ratio 2.5:1–3.5:1, and melt temperature 200–220 °C. The high-stalk bubble is held at a neck height of 6–8 die diameters to balance machine-direction and transverse-direction tear. Exceeding a blow-up ratio of 3.5:1 can destabilize the bubble when the HDPE fraction is above 30 wt% because the blend melt strength increases non-linearly with HDPE content. Terminal product types include refuse sacks, construction sheeting, industrial liners, and heavy-duty carrier sacks.

In cast film conversion, LLDPE 3224 is cooled by contact with a chilled roll rather than by air, producing a smoother surface and lower haze than blown film at equivalent gauge. Food-contact cast overwrap and hygiene packaging require FDA 21 CFR 177.1520(c) and EU Regulation 10/2011 for the skin-contact outer layer, with ISO 1133-1:2022 used for incoming melt flow verification and ASTM D882-18 for tensile properties. The cast film formulation is built at 90–100 wt% LLDPE 3224, with 0.5–1.0 wt% synthetic silica antiblock masterbatch, 0.1–0.3 wt% slip concentrate, and optional 5–15 wt% metallocene LLDPE where lower seal initiation is required. Slip additive is kept below 0.5 wt% to avoid plate-out on the chill roll and loss of corona treatment. The line configuration uses die gap 0.8–1.2 mm, air gap 80–120 mm, chill roll temperature 18–25 °C, melt temperature 220–250 °C, and line speed 200–500 m/min. End products are hygiene packaging overwrap, textile packaging film, and base film for adhesive lamination.