Multilayer blown film sealant layers for refrigerated and frozen food packaging are formulated with Borealis Queo VLDPE 0230, a metallocene-catalysed ethylene–1-octene copolymer having a nominal density of 902 kg/m³ under ISO 1183-1 and a melt flow rate of 0.5 g/10 min under ISO 1133-1:2022. Addition levels in the inner sealant skin of a three-layer PE film typically range from 15 wt % to 30 wt %, with the balance comprising a Ziegler–Natta or metallocene LLDPE having a density of 0.918–0.922 g/cm³. At these loadings the seal initiation temperature measured on a laboratory heat-seal press at 2 bar jaw pressure and 0.5 s dwell according to ASTM F2029 is shifted downward by approximately 8 K to 12 K relative to the unmodified LLDPE control, while the plateau seal strength remains above 6 N/15 mm over a 90–130°C jaw temperature window. The low melting peak associated with the branched ethylene–octene architecture allows the skin layer to wet the opposing substrate before the coextruded core layer softens, which reduces burn-through defects on high-speed vertical form-fill-seal lines.

Regulatory verification for this sealant application requires compliance with FDA 21 CFR 177.1520(c), where the olefin polymer specification covers ethylene–1-octene copolymers with density below 0.94 g/cm³, and with Commission Regulation (EU) No 10/2011, Annex I, applying an overall migration limit of 10 mg/dm² tested under EN 1186-1. The conversion method on production-scale three-layer lines uses a die gap of 1.8–2.2 mm, a blow-up ratio of 2.5:1 to 3.0:1, and a melt temperature of 220–240°C. Low bubble stability becomes evident above 35 wt % Queo 0230 if the external cooling air temperature exceeds 18°C, and the die lip should be kept above 200°C to prevent melt fracture at a screw speed corresponding to 0.8–1.2 kg/h/mm of die circumference. Terminal product types include stand-up pouches for frozen vegetables, flow-wrap packs for frozen seafood, lidding film for processed meat trays, and block-bottom bags for quick-service restaurant supply chains.

What Limits Draw-Down Stability in Sub-30 µm Extrusion Lamination on Aluminium Foil and Polyester?

Extrusion lamination with unfilled Queo VLDPE 0230 is run as either 100 wt % neat resin or as a dry blend containing 20–40 wt % Queo 0230 with LDPE for higher melt strength. On a high-speed line with a single-screw extruder of 30:1 to 33:1 L/D and a die gap of 0.6–0.8 mm, the melt temperature is held between 290°C and 315°C to achieve the necessary draw-down to 12–25 g/m² at 150–300 m/min. The key processing conflict is the narrow molecular weight distribution of the metallocene polymer: low-coat-weight draw-down is accompanied by a rapid transition to draw resonance if the air gap exceeds 150 mm or if the melt temperature drops below 285°C. Neck-in is controlled by maintaining the die edge bead geometry and by adding 20–40 wt % LDPE, which increases the extensional viscosity and stabilizes the molten curtain.

Compliance for liquid-packaging board and medical lamination structures is assessed under FDA 21 CFR 176.170(c) for indirect additives used in paper and paperboard, and under EU No 10/2011 where the final laminate includes direct food-contact layers. In practice, the resin supplier’s declaration of compliance should be accompanied by an EN 1186 migration test on the final laminate, because the coating weight and the board furnish influence the overall migration. Terminal product types include aseptic beverage carton laminates, foil-based sachets for dried soups and sauces, instrument-wrapping film for hospital sterilization, and lamination webs for photo paper. The maximum practical coating weight is typically above 40 g/m²; at higher weights the melt curtain becomes unstable unless the chill-roll temperature is kept below 15°C and the line speed is reduced below 120 m/min.

Three-layer stretch hood film for pallet unitization is produced by blending 60–80 wt % Queo 0230 with 20–40 wt % of a C₄ or C₆ linear-low-density polyethylene. The film typically has a thickness of 60–120 µm and is converted at a blow-up ratio of 3.5:1 to 4.0:1, a die gap of 2.0–2.5 mm, and a melt temperature of 200–220°C. The low density of Queo 0230 reduces the tensile modulus to 50–60 MPa in the machine direction under ISO 527-3, while elongation at break exceeds 700 %. At a maximum line speed of approximately 120 m/min, the film must retain sufficient cling for pallet wrapping without delamination when stretched at a pre-stretch ratio of 150–250 % on a rotary hood applicator.

Regulatory compliance for industrial stretch hood applications is generally limited to REACH Annex XVII restrictions, EU Directive 94/62/EC on packaging and packaging waste, and declarations under RoHS Directive 2011/65/EU where the wrapped goods are electrical or electronic articles being shipped. The use of polyisobutylene tackifier masterbatch at 1–3 wt % is line-specific; above 3 wt %, reel blocking can occur when storage temperature exceeds 40°C. Terminal products include pallet hoods for compression-wrapped chemical sacks, construction blocks, beverage bottles, and corrugated tray stacks. Failure modes observed on production lines include uneven cling causing film tails at high-speed banding and dart drop values below 900 g on 80 µm film when the LLDPE content exceeds 40 wt %.

Heavy-Duty Sack Film Dart Impact and Tear Balance at 20–40 wt % Queo 0230 Loading

Heavy-duty sack film for export chemical packaging incorporates 20–40 wt % Queo 0230 into a polyethylene blend containing LLDPE and HDPE. On a three-layer blown film line with die gap 2.0–2.4 mm, blow-up ratio 2.2:1, and melt temperature 190–210°C, the addition increases dart impact strength under ISO 7765-1 Method A from approximately 600 g at 20 wt % loading to above 800 g at 40 wt % loading for a 60 µm film, while reducing Elmendorf tear strength under ISO 6383-2 in machine direction by roughly 15–25 % over the same gradient. This trade-off is the central formulation conflict: loading must be raised to meet the dart-drop requirements for dangerous goods packaging, but excessive loading weakens the oriented tear paths near the stitched closure area of a pasted-valve sack.

Compliance for this application includes UN Recommendations on the Transport of Dangerous Goods, 23rd revised edition for inner liners, ISO 21898 for flexible intermediate bulk containers, and ASTM D5748 for puncture resistance assessment. The downstream production process uses a coextrusion line with internal bubble cooling and a frost line height of 600–900 mm; the film is then printed, gusseted, and converted into flat or gusseted tubes. Terminal product types include FIBC liners for polymer granules, fertiliser sacks, construction rubble bags, and chemical export sacks. The addition of Queo 0230 above 40 wt % is generally limited by the resulting loss of film stiffness; the 1 % secant modulus under ISO 527-3 falls below 150 MPa, which can cause the open-mouth bag to collapse during automatic filling.

Compounding for low-temperature ductility in polypropylene-based thermoplastic olefins uses 5–20 wt % Queo VLDPE 0230 as an ethylene–octene impact modifier. The resin contributes a low-glass-transition energy-absorbing phase to a homopolymer or copolymer polypropylene matrix, shifting the brittle–ductile transition under ISO 179-1 Charpy notched impact testing to below 0°C at 10 wt % loading and to below −20°C at 20 wt % loading, depending on matrix melt flow rate and nucleating agent content. The compounding line comprises a co-rotating twin-screw extruder with L/D 44:1, barrel temperatures from 170°C to 200°C, melt temperature 200–220°C, and screw speed 400–600 rpm. The Queo pellets are added via the main feed throat with the PP resin to avoid low-melting pellet agglomeration that can occur in downstream side-feeding ports.

Regulatory compliance for automotive interior and appliance compounds includes REACH Annex XVII for restricted substances, RoHS Directive 2011/65/EU for electrical and electronic equipment, and, where relevant, VDA 277 or VDA 278 for volatile organic compound and fogging emissions. In practice, molders observe reduced flowability above 20 wt % loading, and flexural modulus under ISO 178 decreases below 900 MPa for a 20 wt % modified PP homopolymer, limiting its use in structural clips but favouring large-area trim parts. Terminal product types include automotive door panel lower sections, battery cover trays, appliance housings, garden furniture, and collapsible crates. At screw speeds above 600 rpm, suboptimal phase dispersion may occur if the melt temperature drops below 190°C; resulting injection-moulded parts show inconsistent impact values due to coarse elastomer domains above 2 µm.

If Removable Surface Protection Films Demand Low Residue After Storage at 60°C

Cast surface protection film for stainless steel sheet and polycarbonate glazing is extruded from a formulation containing 60–100 wt % Queo 0230, with the balance an LDPE or PP modifier to adjust unwinding force. The cast line uses a slot die with die gap of 0.5–0.7 mm, a chill-roll temperature of 20–30°C, and line speeds of 100–250 m/min. The low crystallinity and low modulus of Queo 0230 allow the film to conform to micro-rough surfaces without the use of solvent-based wetting agents. Peel force on stainless steel after 24 h at 23°C is typically in the range of 1.0–3.0 N/25 mm under ASTM D3330 Test Method F, but the precise value depends on chill-roll replication and additive bloom. The film is corona-treated on one side if subsequent printing or lamination is required; the untreated surface is placed against the protected substrate.

The relevant compliance framework for temporary surface protection films includes REACH Annex XVII for restricted additives, RoHS Directive 2011/65/EU where the film is applied to electronic displays or sheet metal for electrical cabinets, and ISO 9001 for lot consistency of peel force. Terminal product types include stainless steel sheet protective masking, polycarbonate and acrylic sheet masking, pre-coated aluminium panel protection, and glass edge protection during transit. Storage of the film at temperatures above 60°C for more than 72 h may increase unwind blocking if the storage core is wound above 600 N/m; low residue formulations therefore limit the initial peel-force increase to 0.5 N/25 mm after ageing by keeping the cling additive content below 2 wt %.