Chevron Phillips 7105GLT is a hexene-copolymer linear low-density polyethylene designed for blown film extrusion, with nominal melt index 0.50 g/10 min at 190°C/2.16 kg under ISO 1133-1 and nominal density 0.918 g/cm³ under ISO 1183-1. The following application routes address six downstream converting segments, each stated with compliance framework, formulation loading window, production equipment constraints, and converted article classes.

Heavy-Duty Shipping Sack Lines and the Hexene Comonomer Toughness Threshold

In heavy-duty shipping sack conversion, 7105GLT is blended as the primary hexene-LLDPE toughness component in monolayer and coextruded webs where filling operations generate puncture from polymer granules, mineral fillers, or crystalline fertilizer prills. The hexene comonomer creates longer short-chain branches than butene-copolymer LLDPE at equivalent density, increasing tie-molecule formation and raising dart impact energy absorption measured according to ASTM D1709-16A / ISO 7765-1 and Elmendorf tear resistance measured according to ASTM D1922-15 / ISO 6383-2. Sacks intended for exported chemical goods are additionally drop-tested under ASTM D5276-19 or ISTA 1A loaded-container protocols. A starting formulation loading is 70–85 wt% 7105GLT, 10–25 wt% fractional-melt LDPE with nominal melt index 0.25 g/10 min, and 2–4 wt% carbon black/UV masterbatch for outdoor storage; closed-warehouse polymer pellet sacks reduce the pigment masterbatch to 0.5–1.5 wt% clarity-neutral antiblock.

On a production-scale blown film line using a 90 mm grooved-feed extruder with 30:1 L/D barrier screw and Maddock mixing tip, a 250 mm die with 1.8–2.5 mm die gap is operated at 2.0:1–2.8:1 blow-up ratio. Melt temperature at the adapter is maintained between 200°C and 230°C; screen-pack pressure typically remains below 40 MPa, and excursions above that threshold are treated as screen blinding caused by pigment agglomeration rather than resin viscosity drift. Bubble stability is preserved by holding the frost line low enough to suppress machine-direction splitiness; lines without internal bubble cooling require a 15–25% reduction in haul-off speed when processing at the upper end of the 7105GLT loading window. Converted articles include gusseted heavy-duty shipping sacks in 80–200 µm, FIBC outer liners, valve sacks for polymer granules, cementitious dry-mix bags, and mineral filler packaging.

Why Is Tear Propagation Resistance Critical in Silage Barrier Film?

Agricultural silage films manufactured from hexene LLDPE grades are selected when repeated handling on stony ground and conventional bale wrapping machinery produces flex-crack and puncture. 7105GLT contributes low-temperature flexibility and tear resistance, but the film must retain sufficient oxygen barrier to support ensiling fermentation; the balance is controlled by film gauge and comonomer architecture rather than densification of the polymer. Silage cover and bag film is qualified under EN 13207:2018 for thermoplastic silage films and tubes, with tensile properties measured using ISO 527-3 and tear properties using ISO 6383-2. A production formulation for a 120–180 µm monolayer silage sheet is 80–90 wt% 7105GLT, 5–15 wt% LDPE at 0.25 g/10 min, 1–2 wt% HALS UV masterbatch, and 0.5–1.0 wt% carbon black masterbatch for storage beyond 12 months. In white/black coextruded silage film, the outer white layer carries 5–7 wt% titanium dioxide masterbatch.

Downstream conversion runs on a 70 mm extruder with a 250 mm die, 1.6–2.2 mm die gap, and 2.0:1–2.5:1 blow-up ratio. With a dual-lip air ring and internal bubble cooling, output is constrained primarily by bubble stability at the selected frost-line position; without internal bubble cooling, output is limited by bubble chatter when frost-line height exceeds 4 die diameters. Terminal products include bunker silo cover sheet, silage bag tube, round-bale cover film, and temporary grain storage coverage.

Frozen food converting operations that run 7105GLT in monolayer or coextruded web are primarily concerned with dart impact brittleness at -20°C and seal integrity through frost-laden product. The hexene comonomer architecture preserves cold-temperature impact because secondary crystallization during frozen storage is less severe than in higher-density or butene-copolymer LLDPE of comparable melt index. Food-contact compliance is anchored to FDA 21 CFR 177.1520 and EC No 10/2011, with overall migration verified under the time and temperature conditions assigned to frozen, non-acidic food simulants and against the 10 mg/dm² limit. A starting formulation for IQF bag-in-box liners is 90 wt% 7105GLT with 10 wt% LDPE, 0.5–1.0 wt% antiblock masterbatch, and 0.5–1.0 wt% slip masterbatch; printed frozen food pouches use 60–80 wt% 7105GLT and 15–30 wt% LDPE to improve seal initiation while retaining cold-impact resistance.

Blown film lines for this segment typically use a 50–80 mm extruder, 1.2–2.0 mm die gap, and 2.0:1–2.5:1 blow-up ratio with automated gauge control holding thickness variation to ±4%. A low frost-line position prevents haze bands; corona treatment is maintained at 38–40 mN/m for ink adhesion on printed webs. Terminal film structures include frozen vegetable bags, bag-in-box liners for IQF seafood, frozen meat pouches, and peelable lidding base web where the sealant layer is coextruded.

When Blown Film Replaces Cast Structures in Pallet Unitization

Pallet load containment requirements expose a processing conflict: blown stretch film must balance machine-direction elongation with transverse-direction tear resistance, while cast stretch film derives cling from low melt-temperature processing. 7105GLT in blown pallet unitization film delivers elevated dart impact and puncture resistance, but the converter must operate at a higher blow-up ratio than conventional packaging film to prevent anisotropy. Cling and mechanical properties are measured under ASTM D5458-95 for peel cling, ASTM D882-18 / ISO 527-3 for tensile elongation, and ASTM D5748-19 for protrusion puncture resistance. A formulation window for blown stretch is 80–95 wt% 7105GLT with 5–15 wt% metallocene LLDPE or LDPE as cling/viscosity modifier and 1–2 wt% tackifier masterbatch where base resin cling is insufficient. Published data for the exact cling retention of 7105GLT in high-speed pre-stretch equipment is limited; converter trials should screen tackifier additions in 5 wt% steps before locking the formula.

Downstream film is produced on a 70 mm barrier-screw blown film line with 1.5–2.2 mm die gap and 2.8:1–3.2:1 blow-up ratio, with melt temperature held at 190–210°C to limit oxidative viscosity drift. On webs wider than 1,000 mm, film thickness variation above ±6% produces camber at the pre-stretch rollers; production lines therefore use a segmented air ring or automatic die lip control to maintain gauge uniformity. Converted articles include hand stretch film, machine stretch wrap for logistics centers, and stretch hood film for pallet stabilization.

Adhesive Lamination Web Stock and Heat-Seal Integrity

Adhesive lamination web stock based on 7105GLT functions as the sealant or print-side substrate in flexible packaging laminates bonded to BOPP, PET, or aluminium foil with solventless adhesive. The primary technical requirements are heat-seal initiation temperature, hot-tack window, and coefficient of friction after lamination. Seal strength is tested under ASTM F88/F88M-21, hot tack under ASTM F1921-20, and coefficient of friction under ASTM D1894-14; food-contact status is established under FDA 21 CFR 177.1520 and EC No 10/2011. A sealant web formulation uses 60–75 wt% 7105GLT with 25–35 wt% LDPE at 0.25 g/10 min to reduce seal initiation temperature by 5–10°C relative to a 100% 7105GLT control, with 0.5–1.5 wt% antiblock concentrate and 0.5–1.0 wt% slip concentrate.

Production of the blown web runs at 25–50 µm thickness on a 50–80 mm extruder with 1.2–1.6 mm die gap and 2.2:1–2.7:1 blow-up ratio. In-line corona treating is maintained at 38–42 mN/m before winding; lamination is subsequently performed at 150–250 m/min using solventless adhesive, with bond strength measured by ASTM D1876-08 T-peel. Terminal laminates include stand-up pouch sealant web, bakery film laminate, detergent pouch inner web, and coffee bag liner film.

Form-fill-seal industrial liner lines using 7105GLT monolayers are configured for high hot-tack strength and low gel count because seal failures at production speeds above 40 bags/min generate immediate line stoppage. The hexene-copolymer molecular architecture provides a wider hot-tack window than butene LLDPE of equivalent melt index, which allows seal jaws to operate at lower temperature set points without generating stringing. Hot-tack force is measured under ASTM F1921-20, seal strength under ASTM F88/F88M-21, and chemical-regulatory status for EU shipments is assessed under REACH (EC) No 1907/2006; food-contact liners are evaluated under FDA 21 CFR 177.1520. A typical high-speed FFS liner formulation is 85–95 wt% 7105GLT with 5–15 wt% LDPE and 0.5–1.0 wt% polymer processing aid, while thick 100–150 µm chemical drum liners can be run at 100% 7105GLT.

On a 60 mm 24:1 L/D extruder with a 150 mm die, 1.8 mm die gap, and 2.0:1 blow-up ratio, melt temperature is held at 195–215°C. Die lip purge is scheduled after 72 hours of continuous operation because LLDPE melt fracture and die lip deposit increase surface roughness that reduces seal transfer efficiency. Seal jaw set points are 115–130°C with 0.5–1.0 s dwell; hot-tack is measured at 0.2 s after seal release. Terminal articles include chemical drum liners, FIBC inner liners, bulk box liners, and heavy-duty refuse sacks.