On high-output cast coextrusion lines operating at 450–650 m/min, LyondellBasell Icorene 3560 CM BWN 8402 is metered as the primary skin or core layer resin for machine wrap where balanced dart impact, stretch retention, and cling behaviour are required. The standard compliance position for the formulation relies on FDA 21 CFR 177.1520(c) for olefin polymers in food-contact layers, EU 10/2011 with overall migration below 10 mg/dm², and, for European bale-wrap films, EN 14932:2018 where silage sealing performance is specified. In a typical core formulation the LLDPE content is held between 70 wt% and 90 wt%; the remainder is split between a higher α-olefin metallocene LLDPE at 10–25 wt% for puncture energy and a polyisobutylene-based cling masterbatch at 2–5 wt% to raise the cling force measured under ASTM D5458-95. The extruder profile is set from 180°C in the feed throat to 240–260°C at the adapter, with a flat die gap of 0.4–0.7 mm and chill-roll surface temperature maintained at 18–28°C. Edge trim is refed at 10–15 wt% only after control of gel count and moisture, because excessive trim recirculation raises the hydrolyzed additive fraction and destabilizes cling on the inner roll. The downstream converting step consists of slitting and winding on high-speed turret winders with lay-on pressure controlled to 0.2–0.4 N/mm; the finished articles include hand-grade stretch wrap for manual pallets, pre-stretched machine film for automatic wrappers, and agricultural bale-wrap tubes. Operational boundaries are visible at the pre-stretch limit: above 250–300% pre-stretch the butene-based LLDPE network shows a loss of elastic recovery and the film enters irreversible strain hardening, so converters requiring 400% pre-stretch use an octene mLLDPE-rich formulation. Published data for this specific Icorene configuration under ultra-high-speed cast lines above 700 m/min is limited; die-lip buildup and air-knife oscillation must be validated on the specific line.

What Limits Neck-In on Extrusion Coating Lines Above 300 m/min?

At die gaps below 0.5 mm and line speeds above 300 m/min, paperboard liquid-packaging and industrial lamination structures demand a measured blend rather than a neat butene LLDPE, because the neat resin exhibits excessive neck-in, edge bead formation, and draw resonance at low coat weights. The blend ratio is typically 65–80 wt% Icorene 3560 CM BWN 8402 and 20–35 wt% high-pressure LDPE selected for melt strength from an autoclave reactor grade; an adhesion promoter or corona treatment is applied to the paperboard substrate, and a polyethyleneimine primer at 0.02–0.05 g/m² dry film weight is used for foil structures. Compliance for direct food contact is assessed against FDA 21 CFR 177.1520(c), EU 10/2011, and for liquid-packaging board specifically the supply chain applies ISO 1872-1:2018 for polyethylene designation and ISO 1133-1:2022 for melt mass-flow rate. Extrusion coating is run through a 90–150 mm single-screw extruder with a 28:1–30:1 L/D ratio, a coathanger die with internal deckles, and a 0.5–0.8 mm die gap; melt temperature at the die is maintained between 285°C and 320°C to maximize adhesion and oxidative bond strength to paperboard without triggering excessive gel formation. The coating weight window is 15–30 g/m²; below 12 g/m² the low melt strength of the butene LLDPE fraction increases edge tear and void count, while above 35 g/m² the high chill-roll heat load can produce gloss loss and gauge bands. The downstream converting process includes extrusion lamination to aluminium foil, gravure or flexo printing, and cutting into blanks for aseptic cartons, paper cups, and industrial paper sacks. Neck-in typically measures 35–60 mm per side depending on air gap and line speed; closed-loop deckle adjustment and edge bead reduction are required for stable coating at 300 m/min and above.

Pulverizing LyondellBasell Icorene 3560 CM BWN 8402 for rotational moulding alters apparent density and melt flow behaviour, so the powder is screened through a 600 μm sieve to maintain a bulk density above 0.35 g/cm³ before dry blending. The formulation can be a 100 wt% LLDPE powder with a hindered amine light stabilizer masterbatch at 0.25–0.6 wt%, a phenolic antioxidant at 0.1–0.3 wt%, and an external lubricant at 0.05–0.15 wt%; for chemical tanks requiring long-term aggressive media resistance, post-moulding fluorination or co-extruded liners are specified rather than additive-only approaches. The oven process is carried out in carousel or shuttle machines with forced-air temperature between 260°C and 300°C, a mould internal air temperature peak of 180–220°C, and a biaxial rotation ratio near 4:1 primary to secondary axis; the oven residence time is set to achieve a mould internal air temperature above the melting completion point for 20–40 min, but overcooking beyond 240°C internal air accelerates oxidative embrittlement and darkens the natural resin. After cooling with forced air and water mist, the part is removed from the mould and trimmed. Components produced include vertical chemical storage tanks, cylindrical horizontal sprayer tanks, agricultural water troughs, and intermediate bulk containers. Compliance for transport and storage units commonly references ASTM D1998-21 for polyethylene upright tanks, ISO 178:2019 for flexural modulus, ISO 179-1:2023 for Charpy impact, and FDA 21 CFR 177.1520(c) where potable water contact is claimed. Published data for this specific Icorene configuration in rotomoulding is limited, so each powder lot must be checked for dry flow and bulk density because the as-supplied pellet is not suitable for rotomoulding without pulverization.

Spiral Flow and Gate Freeze in Thin-Wall Closure Moulds

Melt-flow analysis of Icorene 3560 CM BWN 8402 in thin-wall lids and overcap production centres on shear-thinning behaviour and rapid gate freeze at low melt temperature. The formulation is normally used at 100 wt% as supplied; where a scratch-resistant or softer sealing surface is required, converters may blend 10–20 wt% low-density polyethylene or a thermoplastic elastomer, but the blend depresses container heat resistance and changes the seal initiation temperature. Mould filling is performed on reciprocating-screw injection moulding machines sized to suit the shot weight; clamp force in the 300–800 t range is common for multi-cavity lid tools with 8–24 cavities. Barrel temperatures are profiled from 180°C at the rear zone to 220–240°C at the nozzle, with the mould surface held at 10–30°C and injection speed set to produce a cavity fill time below 0.5 s. Gate diameter for a 0.6–1.2 mm side wall is typically 0.8–1.5 mm; sub-gate or pin-gate locations must be dimensioned to avoid excessive shear heating, which can create localised melt fracture and flow lines. The industry standard specimen moulding procedure is ISO 294-1:2017, tensile testing is conducted to ISO 527-1:2019 and ISO 527-2:2012, and slow-rate heat resistance is checked with ISO 306:2022; food-contact compliance is anchored to FDA 21 CFR 177.1520(c) and EU 10/2011. Finished products include dairy tub lids, convenience-food overcap rings, housewares with living hinges, and tamper-evident closures. The main operational boundary is warpage after demoulding; because butene LLDPE exhibits post-mould shrinkage, stabilisation requires a hold time of 3–6 s/mm wall thickness and an ejection temperature below 60°C to preserve flatness.

Because masterbatch production depends on carrier viscosity remaining close to the letdown resin, LyondellBasell Icorene 3560 CM BWN 8402 is employed as a carrier in colour and additive concentrates intended for LLDPE blown and cast film dilution ratios between 2 wt% and 5 wt%. The formulation places the carrier content between 60 wt% and 80 wt%, active pigment or additive solids between 20 wt% and 40 wt%, and a process wax or fatty acid amide between 0 wt% and 3 wt%; the wax content must remain below the point at which screw slip and die-lip drool appear. Compounding is performed on a co-rotating twin-screw extruder with a 36:1–48:1 L/D ratio, side feeding of pigments after polymer melting, and a screw speed of 400–800 rpm; melt temperature is held below 230°C to avoid degradation of phthalocyanine and azo pigments, and die pressure is stabilised by vacuum venting at -0.08 MPa gauge before the kneading block. The melt is filtered through a screen changer with 100–200 μm mesh before strand pelletizing and centrifugal drying. The carrier grade is controlled to ISO 1133-1:2022 for melt mass-flow rate, ISO 178:2019 for flexural modulus, and ISO 4892-2:2013 for UV ageing of the final moulded article; colour fastness is specified by ISO 105-B02:2014 for textile applications and ISO 4892-2:2013 for plastics. Finished product forms include single-pigment colorant masterbatches for film tinting, antistatic concentrates for food-packaging liners, slip/antiblock concentrates for cast film, and carbon black masterbatches for agricultural film. A critical incompatibility is the combination with high-melt-flow metallocene carriers; if the carrier melt index diverges by more than 1.5 g/10 min from the letdown film resin, the pigment dispersion index rises and visible agglomerates may survive the final film draw.

When Frost Line Height Exceeds 12 Die Diameters in Heavy-Duty Sack Film

At blow-up ratios above 2.5:1 in high-impact heavy-duty sack and liner lines, bubble stability of Icorene 3560 CM BWN 8402 is controlled by the distance between die exit and the frost line, because butene LLDPE has lower melt strength than LDPE and becomes susceptible to bubble sway when the frost line is raised above 12 die diameters. The formulation is run at 80–100 wt% LLDPE for high toughness and dart impact, with 0–20 wt% high-pressure LDPE to stabilise the bubble and improve thick-gauge gauge uniformity; a slip/antiblock masterbatch is added at 1–3 wt%, while a UV stabiliser masterbatch is added at 2–5 wt% only for agricultural or external exposure films. Extrusion is carried out on a single-screw blown film line with a 24:1–30:1 L/D grooved-barrel or smooth-bore extruder, a die gap of 1.8–2.4 mm, a blow-up ratio of 2.0:1–3.0:1, and an internal bubble cooling system where thickness is above 100 μm; the melt temperature at the die is maintained at 190–220°C. Frost line height is normally set between 6 and 10 die diameters for balanced film optics and bubble stability; above 12 die diameters the bubble enters a low-stress state with visible oscillation, and the layflat width variation increases to ±1.5% or more. The film is converted through in-line winding, flexographic printing, and bag-making with bottom sealing or gusseting. Finished articles include heavy-duty shipping sacks, tubular industrial liners, agricultural greenhouse covers, and construction film. Mechanical compliance is tested according to ASTM D1709-16a for dart drop, ASTM D882-18 for tensile and elongation, ISO 527-3:2018 for film tensile properties, and ISO 6383-1:2015 for tear resistance. The upper service temperature is limited by the Vicat softening range and oxidative stabiliser package; continuous exposure above 60°C is not recommended without a stabiliser review.