On five-layer cast stretch film lines used for pallet unitization, TotalEnergies Lumicene Supertouch mLLDPE 18ST05 is processed at nominal density 0.918 g/cm³ by ISO 1183-1 and melt flow rate 0.5 g/10 min by ISO 1133-1:2022 at 190 °C/2.16 kg. The low MFR requires die-zone melt temperature set points in the range of 245 °C to 265 °C on extrusion lines equipped with 90 mm 30:1 L/D grooved-feed extruders and positive-displacement melt pumps. Chill roll temperature is controlled between 18 °C and 25 °C; higher roll set points increase blocking tendency and degrade film haze consistency under ASTM D1003-21. Die gap is maintained at 0.6 mm to 0.8 mm, and melt pressure is held below 350 bar when line speed does not exceed 600 m/min. At film gauges below 12 µm, sharkskin is controlled with fluoropolymer process aid additions of 300 ppm to 800 ppm; the onset of melt fracture is gauge-dependent and occurs earlier than with C4-LLDPE grades having MFR of 1.0 g/10 min to 2.0 g/10 min. Pre-stretch ratios from 200% to 300% on rotary-arm wrappers expose the film to rapid strain hardening demands; 18ST05-containing structures tend to show high puncture and tear propagation resistance but lower strain hardening than LDPE-rich formulations. When gauge is reduced from 20 µm to 15 µm, converters validate performance with ASTM D5748-18 puncture tests and ISO 6383-2 Elmendorf tear tests at production-speed sampling intervals. Roll hardness is controlled by lay-on pressure settings matched to winder diameter; excessive nip pressure causes blocking in the core layer, particularly when the film is stored above 30 °C. This application is processing-critical because the combination of 0.5 g/10 min MFR, 0.918 g/cm³ density, and narrow metallocene composition distribution creates a narrow window between melt fracture, low-temperature gauge variation, and blocking.

What Makes 18ST05 Suitable as a Sealant Web in Frozen Food Lamination?

Lamination converters select the grade for the inner sealant web when an adhesive lamination structure is built as PET or OPP / adhesive / mLLDPE. The seal initiation temperature is characterized by ASTM F1921-18 hot tack and seal strength is measured by ASTM F88/F88M-21 at 200 mm/min; the narrower melting distribution of the metallocene resin shifts the sealing plateau to a lower temperature than C4-LLDPE webs of equivalent density. On solventless laminators running 1,200 m/min, the low gel count reduces optical defects in transparent structures, but the sealant web must be corona treated to 42 dyn/cm to 46 dyn/cm, measured by DIN 53364 or ASTM D2578-17, before adhesive application. The resulting composite is used for frozen food such as IQF vegetables, seafood, and ready-to-bake dough, where seal integrity below −25 °C is evaluated by drop impact tests at line audit intervals. Sealant layer thickness in such structures typically ranges from 25 µm to 60 µm, with 18ST05 comprising 60 wt% to 100 wt% of that layer. Food-contact status is supported by EU Regulation (EC) No 1935/2004, EU Regulation (EU) No 10/2011 Annex I, and FDA 21 CFR §177.1520(c) for olefin polymers under applicable conditions of use; individual conversion conditions still require a supplier compliance letter because printing inks, adhesives, and coating systems are outside the resin supplier’s control. Because the mLLDPE has a lower crystallinity level relative to 0.920+ g/cm³ copolymers, the sealant web follows package contours with a lower secant modulus, characterized by ISO 527-3 on 100 mm/min crosshead speed. Film blocking after slitting is managed by anti-block masterbatch dosing into the sealant layer at levels determined by rewind tension; excessive dosing above 4 wt% can lower seal strength below process capability limits.

When 18ST05 Replaces C4-LLDPE in Heavy-Duty Sack Blown Film

On heavy-duty form-fill-seal sack lines producing 25 kg to 50 kg industrial packaging, replacing a conventional C4-LLDPE with 18ST05 requires adjustment of both blend ratio and blown film line parameters. The resin is typically introduced at 20 wt% to 40 wt% in the middle layer of a three-layer A/B/A structure, with outer layers containing LDPE or HDPE to maintain bubble stability. Die gaps are set between 1.6 mm and 2.2 mm, blow-up ratio is held between 2.0 and 2.5, and frost line height is raised by 1 to 2 die diameters relative to C4-LLDPE to reduce bubble oscillation. The film is tested for dart impact using ASTM D1709-22 method A and Elmendorf tear using ISO 6383-2; the low MFR of 0.5 g/10 min increases melt pressure on 75 mm 30:1 L/D grooved-feed extruders, where screen packs of 20/40/60 mesh are common. End-use performance in heavy-duty sacks is assessed by drop testing of filled sacks according to ISO 7965-1:2022, with ten-drop staircase methods used on production floors to determine safe fill weights for granulate, fertilizer, and construction additives. The resin’s narrow comonomer distribution improves puncture robustness against irregular fill particles, but the absence of long-chain branching reduces bubble stability unless die temperatures remain above 210 °C. Pre-drying is not required below 50% storage relative humidity; if outdoor silo condensation occurs, a desiccant hopper dryer set to 60 °C to 70 °C with a −20 °C dew point for 2 hours is used to prevent surface moisture defects. These line modifications are considered deep-dive control points because the processing window is narrower than for conventional LLDPE, and gauge uniformity at 150 µm total thickness is checked continuously by beta scanning systems.

Agricultural silage films coextruded on three-layer blown lines use 18ST05 as a puncture-resistant core layer in white/black and transparent barrier structures. The line setup generally includes a die diameter of 250 mm to 400 mm, die gap of 1.8 mm to 2.5 mm, blow-up ratio of 2.0 to 3.0, and total film thickness of 100 µm to 180 µm; UV stabiliser masterbatch is metered into the outer layers at rates determined by exposure period and regional solar intensity. The film’s suitability for silage covering is based on the balance between puncture resistance and tear propagation, measured with ISO 6383-2 and ASTM D5748-18 after UV ageing according to ISO 4892-2, because field failures occur when solar degradation reduces tear resistance before silage removal. Published data for this specific 18ST05 configuration is limited, so converters run side-by-side outdoor exposure trials before replacing conventional C4-LLDPE or EVA blends. The low MFR requires higher barrel temperatures in the core extruder, but the metallocene resin allows reduction in core layer gauge from 40 µm to 30 µm in some structures without a measured loss in dart impact. Film blocking during roll storage is managed by adding anti-block masterbatch at 2 wt% to 4 wt% into the outer layers and quarantining rolls under covered storage at 20 °C to 30 °C.

Collation Shrink Film Edge Seal Behaviour

Collation shrink lines using 18ST05 in outer layers are set to a die gap of 1.0 mm to 1.6 mm and a blow-up ratio of 2.5 to 3.5 to create orientation balance for shrink sleeves around bottled water or canned goods. The resin’s 0.918 g/cm³ density produces a lower shrink force than higher-density LLDPE, so the edge seal on a packaging machine must be re-optimized with jaw temperature settings between 140 °C and 170 °C, depending on film thickness and line speed. Seal strength is checked with ASTM F88/F88M-21 at 200 mm/min, while shrink percentage is controlled by oil bath immersion conditions described in ISO 14616:2016 for polyethylene shrink films. On high-speed lines beyond 40 cycles/min, the low MFR influences seal dwell time; if the hot-wire seal contact time is too short, cold peel occurs at the overlap edge. A common structure is 20 µm to 30 µm three-layer film with 18ST05 in the outer layers and an LDPE-rich core. Optical properties after orientation are influenced by die lip cleanliness and chill temperature; haze is measured in accordance with ASTM D1003-21 and tracked from the extruder to the inspector rewinder. This configuration is shallower than cast stretch processing, but the shrink edge seal remains a critical control point because intermittent jaw temperature drift above 170 °C causes seal burn-through on thin outer layers.

Dielectric welding compatibility in bag-in-box film is process-defined.

Bag-in-box converters replacing EVA or C4-LLDPE with 18ST05 in the inner sealing layer encounter different dielectric welding behaviour because the nonpolar polyolefin has a low dielectric loss factor. Radio-frequency welding is therefore not an acceptable sealing method; heat-seal and ultrasonic welding are preferred. Ultrasonic welding equipment with 20 kHz or 35 kHz horns and anvil gap set to 0.05 mm to 0.15 mm produces consistent fitment weld strengths when the film thickness is 80 µm to 120 µm and the sealant layer is at least 30 µm thick. Seal strength is validated according to ASTM F88/F88M-21, and drop testing of filled bags is conducted using ASTM D5276-19. The low density of 0.918 g/cm³ supports stress-crack resistance in liquid fill, but environmental stress cracking in aggressive liquids must be evaluated via ASTM D1693-21 bent strip testing with the specific fill fluid at service temperature. The grade is not suited for retort applications above 100 °C; continuous-use temperature for LLDPE in food-contact service is below 100 °C under many EU and FDA conditions of use. Published data for 18ST05 in bag-in-box applications is limited, so converters must perform migration testing under Commission Regulation (EU) No 10/2011 for specific food simulants and time-temperature conditions. This limitation is stated to prevent misuse in hot-fill or retort formats where seal creep and film softening occur before the end of shelf life.