On three-layer blown-film lines rated for polyethylene, Borealis Queo 7030LA-P is assigned to the sealant layer in a 20:60:20 distribution, with a metallocene LLDPE core and an LDPE outer layer. The resin is an ethylene-1-octene copolymer with density 0.903 g/cm³ measured under ISO 1183-1 and a melting peak below 100°C by ISO 11357-3. The melt mass-flow rate is below 2.0 g/10 min at 190°C/2.16 kg under ISO 1133-1, which restricts neat extrusion to screws with moderate compression ratios and limits output in grooved-feed sections. The sealant layer extruder is typically a 25:1 L/D barrier screw with a Maddock mixing element; barrel zones are set between 185°C and 205°C, and the die head is held at 210±5°C. Predrying is not required below 60% RH. Above that threshold surface moisture is removed in a desiccant hopper at 50°C for 2 h before introduction to the feed throat. Blow-up ratio is kept between 2.0 and 2.8, with frost line height set at 5–8 times the die diameter. The melt curtain is stabilised with internal bubble cooling and a non-contact iris; gauge variation is held below ±5%. Heat-seal strength is measured according to ASTM F88/F88M-21 at a seal pressure of 0.275 MPa, dwell time of 0.5 s, and sealing temperatures between 85°C and 115°C. Hot tack is determined under ASTM F1921/F1921M-20 at 0.5 s seal time and 200 mm/s peel speed. Optical performance is quantified as haze under ASTM D1003-21 and 45° gloss under ASTM D2457-21. The resulting sealant web is used in frozen food bags, liquid detergent pouch laminates, and stand-up pouch insert films.

A limitation in high-speed packaging arises from tack at sealing jaw release. At seal temperatures above 110°C, the low melting peak of the VLDPE increases stringing on hot-knife sealing systems. Film producers mitigate this by blending 10–20 wt% LDPE into the sealant layer, which raises the seal initiation temperature by several degrees but reduces jaw contamination. The blend is also used when the sealant must be printed; corona treatment is set to 42–48 dyn/cm and measured by ASTM D2578-23. The addition of a slip agent above 1500 ppm is not recommended for sealant layers because it lowers hot tack and interferes with ink adhesion.

What Limits Adhesion to Aluminium Foil in Extrusion Coating?

In extrusion coating, adhesion to aluminium foil and polyester film is controlled by three variables: melt temperature at the die, air gap distance, and ozone concentration. When 7030LA-P is used as the sealant web, the resin is delivered to the die at 290–310°C, but the hold-up time in the extruder and adapter is limited to 3–4 min. The die gap is set at 0.8 mm, and the air gap is adjusted between 180 mm and 250 mm. Ozone generators are operated at 0.2–0.5 g/m³ to create polar carbonyl and hydroxyl groups on the melt curtain; adhesion to aluminium foil is typically brought above 3.0 N/15 mm when peel strength is measured by ISO 8510-2, provided the substrate has been corona pre-treated and the ozone dosage is maintained. Neck-in is monitored by comparing final web width with the die width and is typically held below 6% of the die width for neat grades. At air gaps above 250 mm, oxidative side reactions produce off-taste compounds in direct food contact structures; at air gaps below 180 mm, adhesion levels fall below the target for retort lidding. The chilled roll is maintained at 15–25°C to quench the amorphous phase and reduce blocking; a pressure of 0.4–0.6 MPa at the nip is sufficient to consolidate the web. The coated substrate is then rewound at 300–600 m/min. The sealant layer is typically applied at 15–25 g/m² on aluminium foil or PET and heat-sealed against PP or PE trays at 130–160°C for 0.5–1.0 s. Heat seal strength of the coated lidding is measured under ASTM F2029-16 at 140°C, 0.275 MPa, and 1 s dwell. Food contact status is established under Commission Regulation (EU) No 10/2011 and FDA 21 CFR 177.1520(c); the converter must verify that the final laminate meets overall migration and organoleptic requirements for the intended food category.

Compounding of 7030LA-P into polypropylene homopolymer is carried out on a co-rotating twin-screw extruder with a 40:1 L/D ratio, segmented kneading blocks in the first 10 barrel sections, and vacuum venting at 0.08 MPa absolute. Screw speed is set between 300 rpm and 450 rpm, and barrel zones are profiled from 170°C at the feed throat to 220°C at the die. The VLDPE is dry-blended with PP at 5–25 wt%, depending on the target notched impact strength. Below 5 wt%, the dispersed particle size is insufficient to improve low-temperature impact, while additions above 25 wt% reduce flexural modulus below 900 MPa and limit the compound to soft-touch applications. A typical neat PP homopolymer with notched Charpy impact strength of 3–4 kJ/m² at -20°C under ISO 179-1/1eA can increase to 8–12 kJ/m² at 20 wt% loading, but published data for this specific configuration is limited. The tensile modulus measured by ISO 527-2 can fall from above 1500 MPa for the neat PP homopolymer to below 1000 MPa at 25 wt% loading. Injection moulding of the compound uses a melt temperature of 210–240°C, a mould temperature of 30–50°C, and a clamp force sufficient to maintain 40–60 MPa cavity pressure. The compound is predried at 60°C for 4 h if exposed to high humidity. Automotive interior parts require VOC screening according to VDA 277; total carbon emissions typically increase unless the compound is purged with inert gas during extrusion.

Morphology control is achieved through the viscosity ratio between the VLDPE and PP matrix. If the PP melt-flow rate is below 10 g/10 min, the dispersed VLDPE phase tends to coalesce, reducing impact performance. A matrix PP with an MFR of 25–35 g/10 min is preferred, particularly for thin-wall injection moulding of food containers and appliance frames. The extruder screw speed must be high enough to generate local shear rates above 500 s⁻¹ in the kneading blocks; lower shear processing produces visible gels in the moulded part. The antioxidant package is selected from phenolic and phosphite systems; amine-based antiozonants are avoided because they can produce colour shift under UV exposure.

When High-Draw Cast Film Lines Run 7030LA-P in Hygiene Backsheet Applications

Cast film lines processing 7030LA-P in hygiene backsheet and medical packaging operate at line speeds above 300 m/min. Draw resonance is suppressed by adjusting the chill roll gap to 0.6–0.8 mm and maintaining a melt temperature of 235–250°C at the die. The melt web is pinned to the chill roll by an air knife pressure of 0.2–0.4 MPa and an electrostatic pinning system operating at 8–15 kV. Chill roll surface temperature is set between 20°C and 35°C; lower temperatures increase coefficient of friction and cause blocking on the winder, while higher temperatures reduce clarity. Film thickness in hygiene applications is typically 12–25 µm, controlled by a gravimetric dosing system and a motorised die bolt system with average thickness variation below ±3%. The resin is blended with 10–30 wt% LDPE or metallocene LLDPE to stabilise cast film web tension and reduce edge trim losses. Tensile properties are measured by ISO 527-3 at 500 mm/min; elongation at break in the machine direction is typically above 500%. Elmendorf tear strength is measured by ISO 6383-2; machine-direction tear values decline as line speed increases because of molecular orientation. The calender stack is set to 35–45°C for annealing before winding. The film is used as a breathable outer cover adhesive lamination film after micro-embossing, and in some lines it is coextruded with a filled polyethylene layer to achieve controlled water vapour transmission. For medical device packaging, validation is required under ISO 11607-1; seal strength and microbial barrier testing are carried out on the finished pouch. Published data for this specific configuration is limited; line trials are required to confirm the target moisture vapour transmission rate measured by ISO 15106-3.

Low-Voltage Cable Jacketing and Bedding Compounds

Low-voltage cable jacketing compounds incorporating 7030LA-P are compounded in a two-step process: first, a masterbatch of carbon black and antioxidant is dispersed into the VLDPE; second, the masterbatch is let down into LDPE or LLDPE at 5–15 wt%. Compounding is performed on a reciprocating single-screw kneader or a co-rotating twin-screw extruder with a 28:1 L/D ratio and melt temperatures not exceeding 230°C. The added VLDPE improves low-temperature elongation of the jacketing compound under IEC 60811-505 at -40°C. Volume resistivity is evaluated by IEC 62631-3-1; the carbon black dispersion is critical and is assessed by particle counting under ISO 18553. The compound must not be processed with amine-based antiozonants or copper inhibitors because such additives are not required in low-voltage PE jackets and can cause colour contamination. Cable extrusion lines use a 20:1 L/D screw with a compression ratio of 3:1, a screen pack of 80/120/80 mesh, and a crosshead die held at 200–220°C. The conductor preheat temperature is set to 100–120°C. Line speed for 1.5 mm² installations is typically 600–1200 m/min, depending on insulation wall thickness. The final cable jacket is tested for abrasion resistance by IEC 60811-401 and for heat ageing at 100°C for 168 h with retention of tensile properties above 75%.

Injection moulding of low-durometer dispensing fitments and cap liners from 7030LA-P-rich compounds presents specific chill and release requirements. The resin is blended with polypropylene at 15–25 wt% and a migratory slip additive at 0.5–1.0 wt%. Melt temperature is kept at 200–220°C, and mould temperature is kept below 30°C to avoid sticking. Demoulding requires draft angles of 1–3° and a release coating on polished cores. The compound is tested for torque retention after cap application by ASTM D2063-20. The process window is narrower than for random copolymer PP because the lower crystallisation temperature of the VLDPE extends the time required for the part to reach ejection rigidity. Non-packed melt at the gate can cause sink marks; hold pressure is set to 50–70% of the injection pressure and held for 2–4 s. Drying is not required below 60% RH; above that threshold the blend is dried for 1.5 h at 50°C.