LyondellBasell Icorene 3560 BUE 5127 is a linear low-density polyethylene resin supplied by LyondellBasell. The 3560 series designation places the material within the supplier’s butene-copolymer LLDPE portfolio, and the BUE 5127 suffix identifies a specific additive/stabilizer formulation. The base resin is produced by low-pressure catalytic copolymerization of ethylene and a short-chain α-olefin, giving a linear backbone with short-chain branches. That architecture distinguishes the material from high-pressure low-density polyethylene, which contains long-chain branches, and from high-density polyethylene, which has a higher crystallinity at comparable molecular weight.

The supplier’s technical literature for the 3560 series commonly lists a density range of 0.918 g/cm³ to 0.936 g/cm³ and a melt index range of 0.5 g/10 min to 3.5 g/10 min at 190 °C under 2.16 kg load when evaluated according to ISO 1133-1:2022. For the exact BUE 5127 suffix, published single-point property data is limited; final specifications should be taken from the current certificate of analysis rather than from family-level ranges. The two primary lot-release parameters for 3560-series film grades are density and melt index. Density is determined by ISO 1183-2:2019, while melt index is measured by ISO 1133-1:2022 using an 8.0 mm die insert. These values are insufficient to predict all processing behavior, so downstream converters routinely add capillary rheometry and gel count analysis to control film appearance.

What Distinguishes Butene-Based LLDPE 3560 from High-Pressure LDPE and Hexene-Copolymer Resins?

At equivalent density, the butene-copolymer backbone of the 3560 series produces different solid-state and melt-phase behavior compared with LDPE and higher α-olefin LLDPE. The table below provides a representative property envelope derived from published film-resin data; it is not a specification for the BUE 5127 suffix.

Compared with high-pressure LDPE, the 3560 series exhibits a more pronounced yield point and higher tensile strength at equivalent density, because the linear backbone permits higher crystallinity and better orientation during film stretching. LDPE conversely displays higher melt strength and better optical clarity in some applications due to long-chain branching. Compared with hexene- or octene-copolymer LLDPE, the butene comonomer gives a shorter branch length and lower toughness at comparable density; Dart impact and tear initiation values are typically lower, but bubble stability in air-cooled blown film lines is often improved. This makes the grade suited to applications where machine-direction orientation and throughput stability are more critical than extreme impact resistance.

Mechanical response in film form is thickness-dependent. At a nominal thickness of 25 µm, the 3560 series typically shows tensile yield stress between 10 MPa and 18 MPa in the machine direction and elongation at break above 500% when measured according to ISO 527-2:2012. Dart impact strength under ASTM D1709-16a Method A commonly falls within 90–200 g, while transverse-direction tear values remain lower than those of hexene-copolymer LLDPE at equivalent density. The BUE 5127 additive package may shift ultraviolet stability and optical haze without materially changing the base density or melt index. Because butene LLDPE has a broader short-chain branching distribution than higher α-olefin resins, slow crack growth resistance and notched tear response are comparatively lower. In heavy liquid packaging or lamination films requiring sustained puncture resistance, the resin is therefore typically used in a coextruded structure with a tougher hexene or metallocene LLDPE layer rather than as the sole layer.

Melt Strength, Bubble Geometry, and the Role of BUE Stabilization

Rheological testing under ISO 1133-1:2022 is supplemented by shear-thinning indices from capillary rheometry. The 3560 series generally exhibits moderate pseudoplasticity, with a melt flow ratio between 25 and 35 when comparing 21.6 kg and 2.16 kg extrudate mass values at 190 °C. Apparent viscosity at 100 s⁻¹ typically falls between 1.0 kPa·s and 2.5 kPa·s for similarly structured butene LLDPE film grades, and at 1000 s⁻¹ the viscosity commonly falls to between 0.3 kPa·s and 0.7 kPa·s. Die swell is lower than that of high-pressure LDPE but higher than that of many metallocene LLDPE grades. In a 65 mm grooved-feed extruder with an L/D of 30:1, melt temperatures at the adapter are commonly held at 195–220 °C. The BUE stabilization package is designed for polyolefin film extrusion; sustained melt temperatures above 260 °C should be avoided because antioxidant depletion accelerates and gel accumulation may occur. Pre-drying is not normally required unless storage relative humidity exceeds 60% and surface condensation is present.

Film-grade processing of the 3560 series typically uses a die gap of 1.2–2.0 mm and a blow-up ratio of 2.0–3.0. At these settings, the resin maintains bubble stability at film thicknesses between 20 µm and 80 µm without excessive die pressure. Die pressure on a 65 mm grooved-feed blown film line with a 1.2 mm die gap should be monitored; pressures above 400 bar can indicate insufficient melt temperature or restrictive screen packs. The resin should not be dry-blended with halogenated flame retardants or strong oxidizing agents without prior thermal stability testing. Published data for the exact BUE 5127 suffix in low-output cast film lines is limited.

When the 3560 BUE 5127 Grade Is Run on High-Stalk Blown Film Equipment

When the 3560 BUE 5127 grade is run on high-stalk blown film equipment with die diameters of 150–250 mm, the frost line height is typically set at 500–900 mm above the die face to permit melt elongation before crystallization. A dual-lip air ring delivering chilled air at 8–15 °C is often used to stabilize the bubble, and the die gap is normally 1.4–2.0 mm for film gauges from 20 µm to 80 µm. The recommended blow-up ratio lies between 2.0 and 3.0. Under these conditions, the resin can be drawn at moderate line speeds; however, excessive frost line heights above 900 mm may increase transverse-direction gauge variation and bubble sway. Blow-up ratios above 3.2 can improve transverse-direction tear but may raise puncture variability and reduce line stability. Published data for this exact BUE 5127 suffix on large-diameter high-stalk lines is limited, so start-up parameters should be confirmed by trial on the target equipment.

In heavy-duty shipping sacks, the resin is converted into coextruded film structures where its puncture energy absorption, measured according to ASTM D5748-19, supports retention of filled goods under compression. Typical gauge for this application is 60–120 µm, and the grade may be blended with 10–30 wt% LDPE to increase bubble stability on older lines. In agricultural stretch film, the grade is used as a blending component to modify cling and unwind force; converter evaluations normally include ASTM D1894-14 for coefficient of friction and ASTM D5459-94 for machine-direction stretch. For non-food industrial liners, the resin is processed at film thicknesses of 40–120 µm and can be filled with calcium carbonate masterbatch up to 10 wt% before tear initiation values measured under ASTM D1922-15 show pronounced decline. The exact additive suffix BUE 5127 may influence color and UV stability; converters should request a weathering test report when outdoor storage is intended.

In lamination and food packaging, the resin is used in sealant or sub-surface layers where its seal initiation temperature, commonly measured by heat-seal testing under ASTM F88/F88M-21, is lower than that of high-density polyethylene but higher than some metallocene LLDPE sealants. This property permits coextrusion with polyamide or EVOH barrier layers without premature seal failure. Direct food-contact status must be confirmed with the supplier because the BUE additive package may require migration evaluation.

The resin falls within the olefin polymer classes referenced by 21 CFR 177.1520 and EU 10/2011.

The base polyolefin of the 3560 series is generally covered by the olefin polymer classes in 21 CFR 177.1520(c), provided the finished food-contact article meets the extractable or end-use limitations of that section. Under EU Regulation (EU) No 10/2011, compliance requires migration testing of the finished article; the overall migration limit for plastics intended for food contact is 10 mg/dm² of food contact surface area. The BUE 5127 additive package must be reviewed against the supplier’s Regulatory Data Sheet, because certain stabilizers may have specific migration limits or may not be listed in all jurisdictions.

Operational boundaries include avoiding prolonged melt temperatures above 260 °C, avoiding direct contact with strong oxidizers, and verifying UV stabilization for outdoor service. The resin is not recommended for continuous hot-fill or retort applications unless the specific grade is explicitly listed for such use; published data for the BUE 5127 suffix in retort pouches is limited.