In machine-grade cast pallet wrapping, TUFLIN™ HS-7066 NT 7 is introduced as an additive-rich outer-skin modifier in five-layer coextruded film rather than as a single-layer polymer. Typical addition rates in the outer skin lie between 18 wt% and 25 wt% of total film mass; the metallocene-catalysed LLDPE core accounts for 50–60 wt%, and the reverse skin is blended from LDPE and non-slip LLDPE at 15–20 wt%. The 25 wt% ceiling is process-defined. On a five-layer cast line with 33:1 L/D barrier screws and 150 mm extruders running at 250–265°C die temperature, raising the HS skin layer to 30 wt% produces measurable die lip bloom and winder-side blocking; the migratory oleamide/erucamide slip package increases film-to-metal friction on idle rollers so severely that web wander exceeds 1.5 mm at 300 m/min and edge trim waste rises above 6%. The cast process uses a 0.5–0.8 mm die gap, 25–40 mm air gap, 18–24°C chill roll temperature, and dual-stack vacuum pinning to stabilise melt web boundaries before the primary nip. The winder is programmed with a taper target of 20–25%; higher taper on film younger than 72 h aggravates blocking because the slip additive has not completed its surface migration. Batch-to-batch variation in slip concentration can shift aged film-to-film COF by 0.03–0.05; therefore, incoming lots are screened after 72 h ageing using ASTM D1894-14. Property release testing references ASTM D5748-19 for protrusion puncture resistance, ASTM D882-18 for tensile elongation at break, ASTM D1922-15 for Elmendorf tear, and ISO 1133-1:2022 for melt mass-flow rate. Regulatory surveillance includes EU Packaging and Packaging Waste Directive 94/62/EC heavy-metal limits and Regulation (EC) No 1907/2006 (REACH) for SVHC content. Terminal products are machine-applied pallet wrap rolls in 18–23 µm thickness, slit to 450–500 mm web width, pre-stretched at 150–250% on turntable, rotary arm, and orbital wrappers used in logistics hubs. Published machine-specific data for this exact grade in five-layer cast pallet wrap is limited; the window above is derived from solution LLDPE cast film practice and should be confirmed on a pilot line.

What Governs Neck-in and Tear Propagation in Down-Gauged Hand Stretch Wrap?

Neck-in and tear propagation in hand stretch wrap are governed by melt elasticity, air-gap distance, and edge pinning, not by thickness alone. A starting formulation containing TUFLIN™ HS-7066 NT 7 at 55–65 wt%, a metallocene-catalysed LLDPE at 20–30 wt%, and an LDPE homopolymer at 10–15 wt% is run on a three-layer cast line with 30:1 L/D screws, die temperature 255–265°C, die gap 0.6–0.8 mm, and an air gap of 20–30 mm with compressed-air edge pinning. At 200 m/min, neck-in is kept below 8 mm per edge if the die lip exit temperature is held within ±3°C of the setpoint; deviations of ±5°C widen neck-in to 12–15 mm and shift shrinkage behaviour. Tear propagation is assessed after 72 h ageing because the migratory slip package in HS-7066 NT 7 changes surface crystallinity and interlayer entanglement; ASTM D1922-15 is used for Elmendorf tear, ASTM D5748-19 for puncture, and ASTM D882-18 for MD/TD elongation. The slip migration interval also imposes a packaging hold time: rolls wound before 48 h aging may display film-to-film kinetic COF above 0.45 on ASTM D1894-14, which alters hand unroll force. Downstream converters slit and rewind the hand wrap into 400–450 mm wide rolls of 10–15 µm film; terminal products are manual pre-stretch rolls used in low-throughput packaging stations where operator-applied extension is normally below 80%, not the 150–250% seen in machine wrap. Compliance for these industrial logistics films follows EU Packaging and Packaging Waste Directive 94/62/EC heavy-metal limits and Regulation (EC) No 1907/2006 for SVHC content; direct food contact is outside this scenario unless the final structure is separately certified under food-contact regulations.

Food-contact overwrap seal initiation and migration potential

Food-contact overwrap produced from a three-layer cast structure places TUFLIN™ HS-7066 NT 7 in the sealant layer at 70–85 wt% of that layer, diluted with 15–30 wt% LDPE to lower seal initiation. On a ram-type heat sealer, the layer reaches seal initiation below 105°C at 0.4 MPa pressure and 0.5 s dwell; seal strength is measured per ASTM F88/F88M-15 after 24 h. The HS slip package in the resin migrates to the surface and creates a non-blocking, low-COF overwrap; however, this migration kinetics imposes a 24–72 h ageing window before the target film-to-film COF of 0.15–0.25 under ASTM D1894-14 is reached. Converters that convert film into rollstock immediately after slitting may observe blocking because migrated slip has not yet formed a continuous surface layer. The cast process uses die temperature 240–260°C, a 0.5–0.6 mm die gap, 20–30 mm air gap, and a chill roll setpoint of 15–20°C for optical uniformity; gauge variation across the web is held below ±3% by automatic air-bolt profile systems. Tensile properties are additionally screened by ISO 527-3:2018 for thin-film elongation under machine and transverse directions. Direct food-contact suitability is evaluated under FDA 21 CFR 177.1520(c), EU Regulation 10/2011 with overall migration limit 10 mg/dm² and its Annex I simulant assignments, plus Regulation (EC) No 1935/2004 Article 3. Terminal products are transparent food-service and retail overwrap rolls of 8–15 µm, used for wrapping meat trays, cheese, and produce at chilled retail counters; the film is not specified for retort, microwave-in-pack, or hot-fill above 85°C because seal strength and migration behaviour are not validated for those thermal loads.

On a three-layer blown film line with 80 mm grooved-feed extruders, a 400 mm die diameter, BUR 2.2–2.8, and frost-line height 500–700 mm, TUFLIN™ HS-7066 NT 7 is added at 25–35 wt% of the total formulation; the remainder of the blend is LDPE at 55–65 wt% and EVA with 14–18% vinyl acetate at 8–12 wt%. The blown-film route provides biaxial orientation sufficient for temporary protection film applied to polycarbonate sheet, float glass, and acrylic panels during storage and site transport. The target thickness of 25–50 µm is controlled by gravimetric yield, and the film is tested for Elmendorf tear using ASTM D1922-15 and haze using ASTM D1003-13; haze above 5% is rejected when the film is specified for optically clear glazing surfaces. Surface tension after corona treatment must remain above 38 dyn/cm for masking adhesion, but the migratory slip package in HS-7066 NT 7 can depress retreatment effectiveness if the film is stored longer than 90 days; converters therefore re-confirm wetting tension by ASTM D2578-17 before slitting. Regulatory compliance for the protection film follows Regulation (EC) No 1907/2006 for SVHC content; Directive 2011/65/EU may apply only if the protection film is incorporated into electrical or electronic equipment. Terminal products are surface protection rolls in 1500–2000 mm slit widths with solvent-free adhesive coating applied downstream by converters, not by the film producer.

Stretch hood load retention after 200% pre-stretch and winder taper control

Stretch hood load retention after 200–250% pre-stretch is measured with ASTM D5459-17 for machine-direction elastic recovery and permanent deformation; load retention loss above 12% after 30 min indicates unsatisfactory elastic recovery for palletized building insulation or brick packs. A five-layer cast structure for hood film uses TUFLIN™ HS-7066 NT 7 in the outer skin at 20–25 wt%, a metallocene-catalysed LLDPE core at 45–50 wt%, and a blended LDPE/plastomer inner skin at 25–30 wt%. The outer skin is the blocking-critical surface: the HS package must complete its diffusion to the surface before film-to-film contact at the winder; rolls wound with taper above 35% at line speeds above 250 m/min exhibit blocking layers within the first 20 mm of core diameter. The cast film line uses a 0.9–1.2 mm die gap, die temperature 260–270°C, MDO pre-stretch ratios of 160–220%, and a layflat width of 1.8–2.2 m before weld-bar conversion. The weld bar operates at 150–180°C and must deliver a seal that does not fail during vertical hood application; weld seam strength is verified by ASTM F88/F88M-15 on 25 mm specimens. Terminal products are stretch hood bags or continuous hood stock applied by stretch hooders in construction material packaging, appliance logistics, and palletized beverage lines. Published data for the exact TUFLIN HS-7066 NT 7 hood structure is limited; the above parameters are therefore screened against general cast film practice and should not be used as a release specification without pilot verification. Compliance is assessed under EU Packaging and Packaging Waste Directive 94/62/EC and Regulation (EC) No 1907/2006.

When TUFLIN HS-7066 NT 7 Is Diluted as a Low-Seal-Temperature Sealant Web in Laminated Dry-Food Packaging

When TUFLIN™ HS-7066 NT 7 is diluted to 15–25 wt% in a cast sealant web blended with 70–80 wt% LDPE and 5–10 wt% EVA, the seal initiation temperature shifts low enough for lamination to metallized oriented polypropylene or PET without distorting the print web. The cast sealant web is extruded through a 0.5 mm die gap at 240–260°C with 25–35 mm air gap and 15–20°C chill roll; it is then adhesive-laminated in-line before pouch conversion. Seal bar temperature at the converter is set at 105–120°C with 0.35–0.55 MPa pressure and 0.4–0.8 s dwell; seal strength is measured per ASTM F88/F88M-15. The HS additive package continues to migrate after lamination, so finished pouches should not be stacked under high humidity above 60% RH until the 72 h ageing window has closed or the outer slip effect may cause inter-pouch slippage. Direct food-contact suitability is evaluated under FDA 21 CFR 177.1520(c) and EU Regulation 10/2011 with overall migration limit 10 mg/dm². Terminal products are dry-food pouches for granular products such as rice, pulses, or powdered beverage mixes; the sealant web is not specified for retort, microwave, or high-grease-fatty-food contact above 40°C unless specific migration testing is completed on the final laminate.