On high-output upward blown film lines equipped with 65 mm grooved-feed single-screw extruders with 30:1 L/D barrier screws, Lotte Chemical HDPE 7000F is processed as a 100 wt% virgin resin stream or with up to 20 wt% internally recovered post-industrial film edge scrap. The grade’s nominal melt flow rate of 0.04 g/10 min at 190 °C/2.16 kg under ISO 1133-1:2022 and nominal density of 0.950 g/cm³ under ISO 1183-1:2019 require from the processor a melt temperature window of 180 °C to 210 °C; melt pressure before the screen pack is maintained below 350 bar when a 1.2 mm die gap and 3:1 blow-up ratio are selected. Opacity and opening force are set with 2.0 wt% of a 50 wt% titanium dioxide masterbatch and 1.5 wt% of a 5 wt% silica antiblock masterbatch, both pre-blended through gravimetric dosing rather than single-level screw feeding. Film produced at 18 µm gauge is evaluated for tensile properties under ASTM D882-18 and for dart impact under ASTM D1709-15; converted bags are checked against EN 13590:2003 for carrier bag handle load and dimensional stability. Food-contact production is authorized under FDA 21 CFR 177.1520, olefin polymers, and under EU Regulation (EU) No 10/2011, with overall migration limited to 10 mg/dm² per EN 1186-1:2002. Terminal product types include T-shirt carrier bags, vest carrier bags, and perforated roll produce bags.

What Limits Film Gauge Reduction in High-Density Refuse Sack Extrusion?

In high-density refuse sack extrusion, gauge reduction is controlled less by the resin melt index than by the melt tension, die-lip shear history, and bubble cooling rate. Lotte Chemical HDPE 7000F is extruded at 80 wt% with 20 wt% of a butene-LLDPE of 0.918 g/cm³ density and 1.0 g/10 min melt flow rate under ISO 1133-1:2022; the LLDPE component is added to stabilize transverse direction tear propagation on thin gauge sidewalls, but above 30 wt% LLDPE the film tensile modulus measured under ISO 527-3:2018 declines to a level where stack-load resistance in refuse sacks becomes insufficient. For non-standard blend ratios above that ceiling, published data for this specific configuration are limited and site-specific validation is required. Production-scale observation on a 65 mm single-screw line with 24:1 L/D and internal bubble cooling shows that a die gap of 1.0 mm, blow-up ratio of 4:1, and melt temperature of 200 °C allow 8 µm gauge film to be run at 180 kg/h without bubble chatter; when melt temperature exceeds 210 °C, bubble diameter oscillation appears and leads to gauge bands below 6 µm. Refuse sacks made from this construction are tested under EN 13592:2017 for mechanical strength and under ASTM D1922-23 for Elmendorf tear. Terminal product types include star-seal kitchen refuse sacks, drawstring household sacks, and industrial can liners.

Blown film for IQF produce packaging is extruded with Lotte Chemical HDPE 7000F at 85 wt% combined with 15 wt% metallocene-catalyzed LLDPE and 0.8 wt% food-grade slip masterbatch to maintain seal initiation on horizontal form-fill-seal lines. Melt temperature is held at 195 °C with a die gap of 0.8 mm and a frost line height of 420 mm; chill air at 5 °C stabilizes the bubble at a 2.8:1 blow-up ratio. This configuration reduces blocking tendency in converted reels while preserving low-temperature dart impact measured under ISO 7765-1:1988. Compliance for direct food contact is established under FDA 21 CFR 177.1520 and EU Regulation (EU) No 10/2011, with overall migration tested under EN 1186-1:2002 at 10 mg/dm². The film is corona-treated to 38 dyn/cm before flexographic printing and is converted on form-fill-seal equipment running at 40 m/min; seal strength is measured under ASTM F88/F88M-21 at an upper seal jaw temperature of 115 °C. Terminal product types include IQF vegetable pouches, freezer film bags for chilled produce, and tamper-evident pillow packs for frozen bakery items.

Tubular Liner Extrusion for Flexible Intermediate Bulk Container Discharge Protection

Flexible intermediate bulk container liners are extruded as 80 µm tubular film from 100 wt% Lotte Chemical HDPE 7000F with 3.0 wt% antistatic masterbatch and 0.4 wt% process stabilizer masterbatch. The antistatic loading is controlled by gravimetric mass balance because excess above 4.0 wt% reduces melt extension and produces bubble flutter on a 70 mm 28:1 grooved-feed single-screw extruder. Extrusion at 200 °C through a 1.1 mm die gap with a 3.2:1 blow-up ratio and internal bubble cooling yields a surface resistivity of 10^9–10^11 Ω per IEC 61340-2-3:2016, suitable for hygienic discharge of mineral and chemical powders without electrostatic bridging. For non-food industrial use, conformity is assessed under REACH Regulation (EC) No 1907/2006 and Directive 2011/65/EU RoHS; food-contact versions require FDA 21 CFR 177.1520. Terminal product types include FIBC inner liners, drum liners for thermoplastic masterbatches, and box liners for fine mineral fillers.

When HDPE 7000F Is Down-Gauged to 8 µm for Retail Produce Film

When Lotte Chemical HDPE 7000F is down-gauged to 8 µm for retail produce film, the process operates within a narrow window where melt tension must be matched to die lip cleanliness and bubble internal pressure. The formulation is 100 wt% HDPE 7000F with 0.5 wt% slip masterbatch and 1.0 wt% antiblock masterbatch; raising antiblock above 1.5 wt% increases visible haze and reduces transverse direction tear strength under ASTM D1922-23. Extrusion on a 50 mm 24:1 barrier screw at 190 °C with a 0.6 mm die gap and a 4.0:1 blow-up ratio is used to achieve gauge control of ±0.5 µm; melt temperature deviation beyond ±5 °C from the set point triggers melt resonance or low melt strength, causing hole formation and reel blocking. Optical density sensors monitor film thickness across the bubble circumference and automatically adjust the air ring; surface treatment is set to 36–40 dyn/cm for water-based ink adhesion. Compliance for direct fruit and vegetable contact is assessed under FDA 21 CFR 177.1520 and EU Regulation (EU) No 10/2011. Terminal product types include single-roll perforated produce bags, pre-opened produce bags for automatic retail scales, and light-duty retail carrier film.

Paper-Like Stiffness and Deadfold in Single-Web Food Packaging Films

In single-web food packaging films, the high modulus of Lotte Chemical HDPE 7000F is used to produce paper-like stiffness and deadfold without the moisture sensitivity of paper. The resin is processed at 100 wt% or combined with 10 wt% high-pressure LDPE to broaden the sealing window on vertical form-fill-seal lines; slip masterbatch is limited to 0.3 wt% to avoid uncontrolled rewind tension variation during slitting. Cast film extrusion at 210 °C onto a 60 °C chill roll through a 0.4 mm die slot and a draw ratio of 4:1 produces 20 µm film; heat seal initiation is above 125 °C, so conversion requires cold-seal adhesive coating or a coextruded seal layer when high-speed wrapping is specified. Compliance is under FDA 21 CFR 177.1520 and EU Regulation (EU) No 10/2011. Terminal product types include twist wrap for confectionery, cold-seal overwrap for bakery trays, and paper-replacement wrap for boxed frozen foods.