LyondellBasell Icorene 3560 BWN 8832 linear low-density polyethylene is introduced into blown film formulations intended for primary food-contact packaging on three-layer coextrusion lines. In this application, the resin typically constitutes 70–80 wt% of the total polymer matrix, with the balance supplied by a tubular high-pressure LDPE having a melt-flow rate of 0.3–0.5 g/10 min at 190 °C/2.16 kg; the LDPE fraction is incorporated to raise bubble stability during high-stalk extrusion and to dampen extensional viscosity fluctuations at the die lip. Additive loading is controlled through a slip/antiblock masterbatch dosed at 2–4 phr, yielding final erucamide concentrations of 500–1,000 ppm and synthetic-silica antiblock concentrations of 1,500–2,500 ppm; the masterbatch carrier resin is an LDPE selected to avoid phase separation during film re-grind. At line start-up, the extruder barrel is purged with a melt-index grade LDPE for 10–15 min, and in-process samples are checked for melt-flow rate according to ISO 1133-1 at 190 °C/2.16 kg to confirm consistency before layer-to-layer ratio changes. Regulatory compliance for direct food contact in the European Union is evaluated under EU 10/2011 with total migration measured by EN 1186 and specific migration limits for slip and release agents verified by EU 10/2011 Annex II; for U.S. distribution, the resin is assessed as an olefin polymer under 21 CFR 177.1520(c), with extraction tests designed for room-temperature, refrigerated, and frozen-fill conditions. Processing on production-scale equipment is normally performed on a 65 mm grooved-feed extruder with L/D 25:1, barrel temperature profile of 160–175–185–190 °C from feed to metering, adapter and die temperatures of 195–205 °C, a die diameter of 250 mm, a die gap of 1.8–2.2 mm, and a blow-up ratio of 2.0:1–2.6:1; air-ring air temperature is held at 8–15 °C to limit bubble chatter without inducing condensation on humid production days. In high-humidity environments above 60% RH, the chilled air supply is dew-point controlled to 5–10 °C to avoid moisture condensation on the bubble surface. Corona treatment is set at 38–42 dyne/cm when the film is to receive flexographic or rotogravure printing, and the film is slit to roll widths compatible with horizontal and vertical form-fill-seal conversions. The terminal product range includes bread bags from 25–40 µm, frozen vegetable and fruit pouches from 50–90 µm, fresh produce pillow bags from 20–35 µm, and general food-contact liners for boxes and trays.

What Limits Draw-Down and Puncture Retention in Machine-Stretch Hood Film?

Machine-stretch hood film produced from LyondellBasell Icorene 3560 BWN 8832 is formulated with the grade at 75–90 wt% of the polymer blend; the remaining 10–25 wt% is typically a high-pressure LDPE or a metallocene-catalyzed LLDPE selected to modify yield-stress and elastic recovery during pallet load compression. Tackification is achieved with polyisobutylene at 0.5–1.5 wt%, while antiblock is limited to 1,000–2,000 ppm to preserve cling force after repeated stretching. Compliance testing follows ISO 527-3 for tensile modulus and elongation at break, ASTM D882 for thin-film tensile properties, ISO 7765-1 for puncture resistance at low speed, and ASTM D5458 for cling and release forces when the film is stored at 23 °C and 50% RH. The film is produced on high-stalk blown film lines with a die gap of 2.0–2.4 mm, blow-up ratio of 3.5:1–4.5:1, and melt temperature of 195–210 °C; the high stalk is maintained by operating the extruder at a screw speed of 80–100 rpm on a 70 mm L/D 28:1 line to avoid melt-flow instabilities that produce gauge bands. Melt temperature is controlled within ±5 °C because high-stalk bubble geometry magnifies gauge variation when die temperature drifts. Downstream conversion includes slitting, pre-stretching at 30–60% elongation on a pallet wrapper, and sealed corner formation; the finished hood is applied to pallet loads of beverage cans, lightweight bottles, construction elements, and white goods. A known operational boundary is that the film should not be stored above 45 °C because cling additives migrate to the film surface and can cause blocking on the roll; corona treatment is not applied because it degrades cling performance.

Greenhouse Cover Film Ageing Resistance and Dust Retention Under Multilayer Coextrusion

Agricultural greenhouse film built around LyondellBasell Icorene 3560 BWN 8832 is configured as a three-layer coextrusion, with the grade accounting for 70–80 wt% of the total polymer feed and allocated primarily to the core and the inner layer to provide tear resistance and sealing. A high-pressure LDPE fraction of 15–25 wt% is placed in the outer layer to improve bubble stability, while a metallocene-catalyzed LLDPE at 5–10 wt% is added to the core to increase dart impact strength and reduce crack propagation. UV stabilizer packages are added as masterbatch at 3–5 phr, delivering hindered-amine light stabilizer concentrations of 0.2–0.5 wt% and UV absorber concentrations of 0.1–0.3 wt%; anti-dust and anti-drip additives are incorporated in the outer and inner layers, respectively, at 1–2 wt%. The product is tested according to EN 13206 for covering films for greenhouses, ISO 4892-2 xenon-arc weathering, EN ISO 527-3 tensile properties, and ISO 7765-1 impact resistance after 1,000–3,000 h of accelerated ageing. Processing is carried out on a three-layer blown film line with die diameter 300–350 mm, die gap 2.0–2.6 mm, blow-up ratio 2.8:1–3.4:1, and melt temperature 195–210 °C; frost line height is maintained below 3 die diameters to balance transverse and machine direction orientation. Terminal product types include greenhouse covers from 150–200 µm, low tunnel covers from 80–120 µm, side-roll ventilation curtains, and silage films from 50–100 µm when a black pigmented layer is coextruded.

Heavy-duty sacks require seal integrity from –20 °C to 40 °C

In heavy-duty sack and liner markets, LyondellBasell Icorene 3560 BWN 8832 is combined with high-density polyethylene at 60–80 wt% LLDPE and 20–40 wt% HDPE to raise modulus and reduce elongation under fill-weight load; where outdoor storage is required, carbon black masterbatch is dosed at 2–3 phr for UV protection. Film properties are evaluated under ISO 527-3 tensile, ASTM D1709 dart drop impact using Method A, ISO 6383-2 tear resistance, and ASTM F88 seal strength; heavy-duty sack construction may also require burst strength testing under ASTM D3786 or filled-bag cyclic drop testing across a –20 °C to 40 °C temperature range. Conversion on production-scale blown film lines uses a die gap of 1.6–2.0 mm, a blow-up ratio of 1.8:1–2.2:1, and film thickness from 100–250 µm; internal bubble cooling is employed at output rates above 180 kg/h to prevent blocking and to maintain gauge variation below ±8%. The bubble is gusseted before the nip, and the film is converted by bottom-seal or side-seal bag machines with hot-bar temperatures of 150–175 °C and dwell times of 0.6–1.2 s. Terminal products include flexible intermediate bulk container liners, fertilizer sacks, polymer granule shipping bags, construction material bags, and heavy-duty refuse sacks. The known processing boundary for this blend is the drop in dart impact if the HDPE fraction exceeds 40 wt%; therefore the ratio is verified by melt-flow ratio and density checks on every silo transfer.

Extrusion lamination and coating operations utilize LyondellBasell Icorene 3560 BWN 8832 in sealant-layer formulations where the resin is blended with a high-pressure LDPE extrusion coating grade at 20–40 wt% LLDPE and 60–80 wt% LDPE; the limited LLDPE fraction is due to higher viscosity and neck-in on conventional flat dies unless die-lip geometry is modified. Compliance for food laminates is governed by EU 10/2011 and FDA 21 CFR 177.1520, while seal strength is tested under ASTM F88 after sealing at 115–135 °C and 0.2–0.4 s dwell; interlayer adhesion is measured with ASTM F904 and should remain above 2.0 N/15 mm on metallized polyester. The coating process is run on a 90 mm single-screw extruder with L/D 30:1, melt temperature of 260–285 °C at the die, die gap of 0.6–0.8 mm, and chill-roll temperature of 15–20 °C; the melt curtain is air-knife stabilized to reduce edge neck-in. Corona treatment of the coated surface is set to 40–44 dyne/cm for subsequent printing or adhesive lamination. Terminal products include paper/foil/polyethylene laminations for snack packaging, multiwall bag inner plies, and liquid-tight sachet structures. Published data for this specific configuration is limited because most extrusion coating lines are optimized for LDPE; trials should therefore include 20–40 N/mm die-pressure monitoring and optical inspection for melt fracture.

When the Resin Is Deployed as a Sealant Web in High-Speed Vertical Form-Fill-Seal Packs

High-speed vertical form-fill-seal packaging using LyondellBasell Icorene 3560 BWN 8832 as the sealant web requires the resin to be coextruded or blended to maintain hot-tack strength at short dwell times. The formulation addition ratio is 80–100 wt% of this grade, with 0–20 wt% metallocene-catalyzed LLDPE added when the line speed exceeds 80 bags/min; slip and antiblock additives are maintained at 500–1,000 ppm erucamide and 2,000–3,000 ppm synthetic silica to prevent block before the forming shoulder. Compliance for dry and frozen food contact follows FDA 21 CFR 177.1520 and EU 10/2011, while seal performance is measured under ASTM F1921 hot-tack force and ASTM F2029 heat-seal strength; a minimum hot-tack value of 0.5 N/25 mm is required at 110–140 °C on production samples. The film is converted on VFFS machines with seal-bar temperature of 120–150 °C, dwell time of 0.2–0.4 s, and sealing pressure of 0.2–0.4 N/mm²; film gauge ranges from 30–80 µm, and the coefficient of friction is controlled to 0.25–0.45 dynamic as measured by ISO 8295 to maintain reliable tracking over the forming collar. Terminal finished product types include frozen seafood bags, cereal and granola pouch liners, dry pet-food bags, and granular food pillow packs. The operational boundary is that hot-tack strength declines above 160 °C due to melt thinning at the seal interface; therefore VFFS sealing temperatures should not exceed 155 °C on lines without closed-loop temperature control.