Borealis Queo mLLDPE 1007 is an ethylene-1-octene copolymer produced by continuous solution polymerisation with a single-site metallocene catalyst. The resin is supplied as free-flowing pellets with a nominal density of 910 kg/m³ according to ISO 1183-1:2019 and a nominal melt mass-flow rate of 7.0 g/10 min at 190 °C under 2.16 kg load according to ISO 1133-1:2022. The base stabilisation package contains a processing stabiliser and acid scavenger; slip and antiblock additives are excluded from the standard grade. The single-site catalyst yields a polydispersity index below 3.0 when measured by high-temperature gel permeation chromatography in 1,2,4-trichlorobenzene at 150 °C. The product is used in blown-film, cast-film, extrusion-coating, injection-moulding and compounding operations where seal initiation below 95 °C under ASTM F1921-18, haze below 5% on 25 µm monolayer blown film under ASTM D1003-21, and extractables compliance under FDA 21 CFR 177.1520 or Regulation (EU) No 10/2011 must be validated.

The melting peak, determined by ISO 11357-3:2018 at a heating rate of 10 K/min, is typically near 104 °C. The melting endotherm is narrower than that of Ziegler-Natta C8-LLDPE grades, whose peak melting temperatures commonly fall between 120 °C and 124 °C. Continuous service above 65 °C in load-bearing parts is not recommended unless the final part is validated under the relevant end-use creep or ageing standard. The low melting peak is a deliberate consequence of the high octene-1 comonomer content and is not an indication of reduced molecular weight.

What separates metallocene-catalysed octene copolymers from Ziegler-Natta C8-LLDPE in sealant layers?

In a three-layer blown-film sealant layer, the narrower comonomer distribution reduces the fraction of high-melting, low-comonomer crystallites that delay seal completion. Heat-seal initiation temperature is defined as the minimum bar temperature required to reach 15 N/25 mm seal strength under ASTM F1921-18. Seal strength after conditioning for 24 h at 23 °C and 50% relative humidity is measured according to ASTM F88/F88M-21. On production-scale form-fill-seal machines with dwell times from 0.2 s to 0.5 s, the lower seal initiation permits a bar setpoint reduction of 10–15 °C compared with a 920 kg/m³ gas-phase C4-LLDPE. This narrows the thermal stress on the outer polyamide or polyester layer and may reduce odour; odour is quantified by VDA 270 C3 when required by the packaging specification. Published data for this specific resin in 25 µm monolayer films is limited; therefore, seal-through-contamination claims must be validated on the target film structure.

The hot-tack plateau shifts to lower temperatures because chain interdiffusion at the seal interface is controlled by the narrow melting endotherm. Hot-tack strength measured with a J&B hot-tack tester at 0.5 N/mm² sealing pressure and 0.5 s dwell can be used to quantify the plateau. Comparative profiles generally show that metallocene grades preserve a wider hot-tack window than Ziegler-Natta resins of the same density, but the absolute plateau depends on film thickness, chill-roll temperature and external antiblock concentration.

Pre-drying is not normally required for Queo mLLDPE 1007 when pellets are stored below 60% relative humidity and above 10 °C. If pellet surfaces are exposed to condensation during transfer from an unheated silo to a warm melt room, moisture absorption can generate surface defects in extruded films. In such conditions, desiccant drying at 60–70 °C for 2–4 h with a dew point of -20 °C or lower is recommended. The resin should not be processed at melt temperatures above 240 °C for prolonged periods because low density and narrow molecular weight distribution accelerate chain scission and gel formation. Residence times above 5 min at 240 °C in injection-moulding barrels have been associated with yellowing; yellow index is measured according to ASTM E313-20 on compression-moulded plaques.

Blown-film bubble stability at 2.0 BUR on grooved-feed extruders

On 50 mm grooved-feed extruders with L/D 30:1 and barrier screws, melt pressure measured at the die inlet typically falls 8–12% below that of a 920 kg/m³ Ziegler-Natta C8-LLDPE because the 910 kg/m³ density and narrower molecular weight distribution lower high-shear viscosity. A die gap of 1.2 mm to 1.8 mm is used with blow-up ratios from 2.0:1 to 2.5:1. Bubble stability remains acceptable when melt temperature is held between 195 °C and 215 °C. Below 190 °C, the lower melt strength of the metallocene resin can cause bubble sag and gauge-band formation at 2.5:1 BUR; above 225 °C, oxidation by-products increase and die-lip build-up rates rise. Internal bubble cooling is recommended when film thickness exceeds 60 µm at line speeds above 120 m/min to limit blocking and improve bubble symmetry.

Melt fracture is not observed at shear rates below 500 s⁻¹ in laboratory capillary rheometry according to ISO 11443:2021; however, the addition of fluoroelastomer processing aid may be necessary on high-output grooved-feed lines with die shear rates above 1,000 s⁻¹. The processing aid concentration is typically 400–800 mg/kg and is selected to match the metallocene resin’s narrow molecular weight distribution.

When the 910 kg/m³ density specification constrains stiffness in form-fill-seal packaging

If a converter replaces a 918–920 kg/m³ C8-LLDPE with Queo mLLDPE 1007, the lower density reduces secant modulus. Film stiffness measured according to ISO 527-3:2018 on 25 µm cast film is typically 10–15% lower than that of a conventional C8-LLDPE of equivalent thickness. This decrease is acceptable in sealant layers of three-layer coextrusions where the core or outer layer provides bending stiffness, but it may be limiting in monolayer form-fill-seal structures that rely on machinability. In such cases, film thickness must be increased by 2–3 µm or the resin blended with 10–20% of a higher-density LLDPE to restore stiffness; the blend ratio is verified by measuring secant modulus and penetration force according to ASTM D5748-18. Published data for this specific configuration is limited, so each target package must be tested on the actual form-fill-seal line at the intended packaging speed.

The lower seal initiation temperature does not remove the need to measure secant modulus; form-fill-seal machinability is governed by bending resistance and must be tested on the actual line. The film’s static and dynamic coefficients of friction are controlled by external slip additives because the base grade does not contain erucamide or oleamide. Coefficient of friction is measured according to ISO 8295:1995 after 72 h ageing at 23 °C and 50% relative humidity.

Injection-moulding applications use melt temperatures between 200 °C and 220 °C and mould temperatures between 15 °C and 30 °C. The melt mass-flow rate of 7.0 g/10 min under ISO 1133-1:2022 is used to predict thin-wall fill; actual fill is validated by injection-moulding spiral flow testing. The low density and high comonomer content reduce flexural modulus as measured by ISO 178:2019 relative to polypropylene and HDPE. Shrinkage is typically 1.8–2.2% in the flow direction and 1.4–1.8% in the transverse direction when measured according to ISO 294-4:2018 on 2 mm plaques. Tool design must account for post-moulding crystallisation because the metallocene resin continues to crystallise after ejection. Compounding operations use Queo mLLDPE 1007 as a carrier resin for colour masterbatch and additive concentrates in high-shear twin-screw extruders with L/D 40:1 and screw speeds from 400 rpm to 800 rpm.

In masterbatch production, the lower melting peak permits concentrate dilution at lower temperatures, but the base stabilisation package is not designed for multiple heat histories. Remelting through more than two additional extrusion cycles at 220 °C can shift melt flow rate upward by more than 15%; this shift is quantified by ISO 1133-1:2022 before concentrate release.

In thermoplastic olefin compounds, Queo mLLDPE 1007 is used at addition levels from 5 wt% to 25 wt%. The low density and high comonomer content reduce flexural modulus according to ISO 178:2019 while improving notched Izod impact according to ISO 180:2019 when compounded with isotactic polypropylene. In twin-screw compounding, the resin is fed downstream of the polypropylene melt to limit exposure of the metallocene chains to high barrel temperatures. At addition levels above 25 wt%, the compound may exhibit visible anisotropy in injection-moulded plaques because the dispersed elastomer domains elongate under high shear; domain size and distribution are evaluated by scanning electron microscopy after staining with ruthenium tetroxide. Published data for this specific configuration is limited.

Dart impact resistance shifts from bending-dominated to tensile-dominated as film thickness increases

Dart impact strength is determined according to ASTM D1709-16ae1 Method A on 25 µm monolayer blown films. The metallocene resin typically shows higher puncture resistance than conventional C4-LLDPE because the octene-1 comonomer and narrow molecular weight distribution increase tie-chain density and reduce interlamellar voiding. In film structures from 25 µm to 100 µm, the fracture mechanism shifts from a bending-dominated response to a tensile-dominated response; this shift is captured by instrumented puncture testing according to ISO 7765-1:1988 and by Elmendorf tear testing according to ASTM D1922-15. Machine-direction tear strength in blown film usually falls below transverse-direction tear strength because orientation in the machine direction aligns the lamellar structure; the ratio of MD to TD tear strength is commonly 0.6–0.8 when the blow-up ratio is 2.0:1.

Seal strength is reported as the maximum force per 25 mm width after sealing at 0.3 MPa for 1.0 s. At a bar temperature of 95 °C, the seal strength typically exceeds 10 N/25 mm; at 85 °C, partial seals below 5 N/25 mm may occur if the film surface contains high levels of external slip additive. Therefore, the decision to seal below 90 °C must be validated with the final film formulation using ASTM F2029-16 for heat-seal strength measurement at the production machine’s actual dwell time.

The resin can be assessed for food-contact compliance under Regulation (EU) No 10/2011 for plastics intended to come into contact with food. Conformity depends on migration testing with food simulants 3% w/v acetic acid, 20% v/v ethanol and 95% v/v ethanol under time-temperature conditions that reflect the intended use; the overall migration limit of 10 mg/dm² applies. In the United States, the base resin may be listed under FDA 21 CFR 177.1520, but the final article’s compliance is the responsibility of the converter and requires extraction testing according to the specified conditions in 21 CFR 176.170(c). The grade is not intended for long-term implantable medical devices; biocompatibility testing according to ISO 10993-5 and ISO 10993-10 must be completed on the finished component before use in medical packaging or medical device applications. Direct contact with strong oxidising agents and halogenated solvents is not recommended. Published data for this specific configuration is limited in the open literature; therefore, the values cited above are nominal processing references and should be verified against the current Borealis technical datasheet for the production campaign.