LyondellBasell Icorene 3560 BEI 2142 is identified as a linear low density polyethylene grade within the Icorene portfolio. The full designation carries the grade identifier 3560, the BEI suffix, and the 2142 campaign or packaging code; public technical data sheets for this exact configuration are not uniformly available. Incoming inspection should therefore not rely on class-average values. The grade should be treated as a linear low density polyethylene with melt index and density to be confirmed from the certificate of analysis against the target conversion window. The following sections address class-level branching architecture, processing constraints, standards, and candidate conversion routes relevant to the grade.

What Structural Variables Place LLDPE Outside the Processing Window of High-Pressure LDPE?

High-pressure low density polyethylene produced in autoclave or tubular reactors contains long-chain branches that lower shear viscosity at high shear rates and support lower head pressure during extrusion. Linear low density polyethylene produced by low-pressure coordination catalysis instead derives its short-chain branching from deliberate comonomer addition. The Icorene 3560 BEI 2142 grade, as linear low density polyethylene, is expected to fall within the typical density band of 0.915 g/cm³ to 0.940 g/cm³ when measured by ISO 1183-1:2019 or ASTM D1505-18, but this class range is not a substitute for grade-specific data. The lower long-chain branching content in LLDPE reduces shear thinning relative to high-pressure LDPE. At equivalent output through a film die, the linear low density grade may therefore generate higher die pressure and greater shear heating, which influences melt fracture onset when spiral mandrel die gaps are set too narrow for the grade.

The BEI suffix may indicate a butene-based comonomer system, though this must be verified from the certificate of analysis. Butene-, hexene-, and octene-based LLDPE grades differ in tensile toughness, dart impact, and tear resistance; at comparable density and melt index, shorter butene branch lengths generally yield lower dart impact and Elmendorf tear values than hexene or octene copolymers. Compared with high-density polyethylene, which has a higher crystallinity and a density above 0.940 g/cm³, linear low density grades provide lower stiffness and greater puncture and tear resistance in film structures. Compared with high-pressure LDPE, linear low density grades can support downgauging but also raise melt fracture risk and reduce melt clarity unless die geometry and process temperatures are adjusted. Within the linear low density family, metallocene grades produce narrower molecular weight distribution and more uniform comonomer incorporation than conventional Ziegler-Natta grades. Published data for this specific Icorene configuration is limited, so exact differentiation from other Icorene grades should be based on grade-specific certificates of analysis and lot rheology.

The melt mass-flow rate of an LLDPE grade determines whether the material is suited to blown film, cast film, injection molding, or rotational molding. A grade with a melt mass-flow rate below 2 g/10 min at 190°C and 2.16 kg tends to require high melt temperatures in injection molding but improves melt strength in blown film; a grade above 10 g/10 min flows more easily but may reduce toughness. Without the grade-specific value for the Icorene 3560 BEI 2142, these classifications remain provisional.

During blown film conversion on single-screw extruders with screw diameters from 45 mm to 90 mm and L/D ratios from 30:1 to 44:1, linear low density grades respond to changes in die gap, frost line height, and internal bubble cooling differently than high-pressure LDPE. Production-scale trials commonly set the die gap between 1.5 mm and 2.0 mm for LLDPE to reduce die exit shear stress and delay sharkskin melt fracture. For a given die gap, increasing output raises wall shear stress; critical wall shear stress for LLDPE is often reported in the class-level range of 0.1 MPa to 0.3 MPa, though this threshold shifts with melt temperature, die design, and polymer process aid type. These values are not specific to the Icorene 3560 BEI 2142 lot and should be mapped on the target line using capillary rheometry or dynamic shear rheology per ASTM D3835-16.

On barrier screws with Maddock mixers, higher LLDPE melt viscosity can increase melt temperature by 5°C to 15°C above the barrel set point at high screw speeds. This offset should be confirmed with an infrared melt thermocouple at the die inlet because excess shear heating can initiate gel formation and degrade optical quality. If the extruder is equipped with a vented barrel, vent flow should be monitored for resin backflow at elevated screw speeds. Fluoropolymer processing aids are frequently used at 100 ppm to 1,000 ppm to reduce die lip build-up and melt fracture in LLDPE film extrusion. The exact loading must be validated on the production line because excess processing aid can delay surface haze reduction and interact with corona treatment. Batch-to-batch melt mass-flow rate should be checked by ASTM D1238-23 at 190°C and 2.16 kg before starting a campaign.

Moisture uptake in linear low density polyethylene is generally low, but cold pellet surfaces can collect condensation in humid plants. If surface moisture exceeds approximately 0.05% by weight, drying at 60°C to 70°C for 2 h to 4 h in a desiccant dryer reduces steam-related film defects and surface specking.

Blown Film Die Gap, Frost Line Height, and Screw Speed as Grade-Dependent Variables

In blown film, the frost line height for linear low density grades is generally higher than for high-pressure LDPE at equivalent output because the lower long-chain branching reduces strain hardening and slows bubble cooling. A dual-lip air ring or internal bubble cooling system may be required to stabilize the bubble when gauge is reduced below 50 µm. Blow-up ratio is typically maintained between 2.0:1 and 3.5:1 for linear low density film to balance tear and impact directionality; however, actual operating values for the Icorene 3560 BEI 2142 grade must be established through on-line trials. Film thickness control requires stable melt temperature at the die lips. If melt temperature varies by more than ±5°C, gauge variation can increase and dart impact values per ASTM D1709-22 can shift.

At constant screw speed, substituting an LLDPE grade for a high-pressure LDPE grade can raise extruder head pressure enough to reduce output. Processors often compensate by increasing die gap or raising melt temperature, but elevating melt temperature above 240°C risks oxidative degradation if the antioxidant package is insufficient. The upper processing temperature should be taken from the grade-specific technical data sheet, which is currently limited for this exact configuration. Melt pressure at the die inlet should not exceed the equipment-rated limit; if melt pressure rises above 35 MPa on a given blown film die, the screen pack, die gap, and temperature profile should be reviewed before further speed increase.

Cast film lines equipped with slot dies and chill roll temperatures between 15°C and 30°C may require wider die gaps for LLDPE than for high-pressure LDPE to maintain edge stability and reduce die streak lines. Chill roll adhesion and surface haze depend on the additive package, especially slip and antiblock loadings. If the grade is downgauged below 30 µm, film tension and winding pressure must be adjusted to prevent blocking and core crush.

Compliance verification for a linear low density polyethylene grade generally proceeds through the test methods listed in the matrix below. Lot-specific results should be compared with the certificate of analysis for the Icorene 3560 BEI 2142 product.

Regulatory status cannot be inferred from the resin family alone. If the grade is intended for food contact, the converter must obtain written confirmation against 21 CFR 177.1520 for olefin polymers and, where applicable, Regulation (EU) No 10/2011 with specific migration limits. REACH registration and SVHC declarations must be confirmed through supplier documentation. RoHS Directive 2011/65/EU applies to finished electrical and electronic equipment rather than to raw resin; therefore a RoHS declaration requires article-level testing.

When the 3560 BEI 2142 Designation Is Evaluated for Injection Molding or Rotational Molding

Not all linear low density polyethylene grades suit all conversion routes. Injection molding of LLDPE with a low melt flow rate can require higher barrel temperatures and reduced screw rotation to avoid shear-induced gel. For injection molding machines with clamp force between 500 kN and 15,000 kN, the grade should be trialed on a screw with a compression ratio from 2.5:1 to 3.5:1 and a non-return valve clearance maintained below 0.15 mm to prevent leakage and shot weight drift. Cavity filling pressure and gate freeze time should be monitored because linear low density grades solidify differently from high-pressure LDPE in thin-walled sections. Barrel temperatures are generally set between 180°C and 240°C, with mold temperatures between 15°C and 40°C; exact values for the 3560 BEI 2142 product should be taken from the certificate of analysis.

Surface blemishes in injection molded linear low density parts may arise from excessive injection velocity or insufficient mold venting. Vent grooves should be maintained at a depth of 0.02 mm to 0.04 mm for low-viscosity melts; for higher-viscosity LLDPE, larger or cleaner vents may be necessary. The process window should be confirmed by recording cavity pressure curves and comparing part weight stability across shots.

Rotational molding of linear low density grades is generally associated with melt flow rates in the lower range, between 2 g/10 min and 6 g/10 min at 190°C and 2.16 kg. The 3560 BEI 2142 designation may fall within this class, but the certificate of analysis is required to confirm. In rotational molding, peak internal air temperature is often targeted between 200°C and 260°C, depending on part thickness and oven residence time. Insufficient sintering time at peak temperature produces pinholes, while excessive time at peak temperature can embrittle the part. Ground powder for rotational molding typically has a nominal particle size between 500 µm and 1,000 µm. If the grade is used in rotationally molded tanks or containers, environmental stress crack resistance should be evaluated per ASTM D1693-21 or ISO 22088-2:2006. Differences from other products appear in mold release, warpage, and low-temperature impact. Linear low density grades with butene comonomer typically require longer cooling times than high-density polyethylene because lower crystallinity slows solidification, and dimensional stability after ejection should be verified against the mold drawing tolerance.

Lot-to-lot variance in melt mass-flow rate should be checked before starting a production campaign because linear low density grades can shift processing behavior when the melt flow rate moves by more than 0.5 g/10 min at 190°C and 2.16 kg. If such a shift is observed, the feed throat temperature and screw speed should be adjusted first; downstream adjustments to die temperature alone may not restore bubble stability in blown film. Avoid mixing Icorene 3560 BEI 2142 with high-pressure LDPE reclaim unless the blend ratio is fixed and the mixture is re-characterized per ASTM D1238-23 and ISO 1183-1:2019, because long-chain branch content and comonomer distribution alter the shear-thinning response and weld line strength. Pre-drying is generally unnecessary for dry, ambient-stored linear low density polyethylene, but if pellet surface moisture exceeds approximately 0.05% by weight, a desiccant dryer at 60°C to 70°C for 2 h to 4 h is recommended. Amine-based additives should be avoided unless their interaction with the antioxidant package is documented, because they may alter oxidative-induction time behavior and produce surface deposits. Published data for this specific configuration is limited; therefore process qualification should proceed from direct resin characterization against the target line.