LyondellBasell Icorene 3560 ATC 9804 is a linear low density polyethylene (LLDPE) resin produced within the Icorene product family. The grade designation follows LyondellBasell's alphanumeric convention in which the terminal numeric sequence 3560 is consistent with a nominal melt mass-flow rate of 3.5 g/10 min when determined under ASTM D1238 at 190 °C/2.16 kg; the suffix ATC identifies a pre-compounded additive package, and 9804 designates the production campaign or lot-specification code. Classification as an LLDPE places the material in the ethylene-α-olefin copolymer class with a density envelope that, for grades exhibiting the 3560 flow index, typically falls between 0.918 g/cm³ and 0.922 g/cm³ per ASTM D792 Method D. Published technical datasheets for the exact ATC 9804 configuration remain the controlling documents; the following discussion references data representative of the medium-flow LLDPE class where grade-specific values are not publicly indexed. The 3.5 g/10 min flow index positions the resin in the medium-flow segment of the LLDPE grade slate, below typical rotomolding grades (5.0–7.5 g/10 min) and above cast-film extrusion grades (1.0–2.5 g/10 min). This intermediate viscosity profile supports transitions across injection molding, thin-walled container production, and monolayer cast film without requiring masterbatch-driven viscosity modification. The ATC additive designation in LyondellBasell nomenclature commonly includes an antiblock component (synthetic silica or talc at 500–1500 ppm), a thermal stabilization package (hindered phenol/phosphite synergy), and, in selected campaign variants, a slip agent (erucamide or oleamide at 300–800 ppm).

What Limits the 3560 Melt Index in High-Shear Extrusion and Injection Moulding?

LLDPE resins in the 3.0–4.0 g/10 min melt index window exhibit a characteristic shear-thinning response that differs from low-density polyethylene (LDPE) of equivalent flow index because the linear molecular architecture lacks long-chain branching. Under capillary rheometry at 190 °C, the apparent viscosity of a 3.5 g/10 min butene-LLDPE typically declines from approximately 1200 Pa·s at 100 s⁻¹ to approximately 180 Pa·s at 1000 s⁻¹; an equivalent-MI LDPE shows a steeper viscosity drop across the same shear range due to branch-induced relaxation. On single-screw extrusion lines with L/D 24:1–30:1 and barrier screw elements, melt temperatures of 230–260 °C at the die are required to prevent sharkskin melt fracture. The critical shear rate for onset of surface melt fracture in narrow-MWD LLDPE generally falls between 100 s⁻¹ and 400 s⁻¹ depending on die temperature and additive package; fluoropolymer processing aid (PPA) at 200–400 ppm shifts the onset toward 500–1000 s⁻¹ by coating the die land. For injection molding, the 3.5 g/10 min flow index permits filling of thin-walled parts at injection pressures of 70–100 MPa and a barrel profile of 180–220 °C from feed to nozzle. Clamp force requirements scale with projected area; a mould surface of 0.1 m² generally requires 450–600 tonnes for this viscosity class when processing wall sections of 1.5–2.0 mm. Screw compression ratios of 2.5:1–3.0:1 with check-ring clearances below 0.05 mm maintain shot-weight consistency. Short-shot defects in thin-wall production have been documented when mould temperature falls below 10 °C on unheated tooling; maintaining core temperatures of 20–30 °C reduces premature freeze-off in gates below 0.8 mm diameter.

Mechanical characterization of medium-flow LLDPE in the 0.918–0.922 g/cm³ density envelope follows ASTM D638 for tensile properties using Type IV specimens at 50 mm/min. Yield stress under these conditions typically falls between 10 MPa and 14 MPa, with elongation at break above 800 %; secant modulus at 1 % strain ranges from 180 MPa to 240 MPa. The low-temperature ductility benchmark per ASTM D746 for butene-LLDPE is routinely below −60 °C, and the material retains impact functionality in freezer applications down to −40 °C when molded without excessive cooling stress. Vicat softening temperature per ASTM D1525 under 10 N load lies in the 95–110 °C band. These values are class-typical and must be confirmed against the certificate of analysis for campaign 9804. Dart impact resistance on 25 µm cast film per ASTM D1709 Method A for butene-copolymer LLDPE without antiblock typically spans 80–150 g. The presence of the ATC antiblock component at the higher end of the incorporation range (above 1000 ppm) may reduce dart impact by 5–15 % relative to the unfilled polymer through stress concentration at particle-polymer interfaces. Elmendorf tear strength per ASTM D1922 for the same gauge generally reports 100–200 g in machine direction and 200–400 g in transverse direction; the anisotropic tear imbalance is characteristic of blown-film orientation, whereas cast film processed from the 3560 grade shows a lower MD/TD tear ratio.

Thermal Oxidative Stability and Rotomolding Cycle Boundaries

Rotomolding processors utilizing the 3.5 g/10 min flow index must accommodate cycle times that exceed those of the 5.0–7.5 g/10 min grades typically specified for the process. Oven set temperatures of 280–300 °C with an internal air temperature peak of 195–205 °C yield adequate coalescence at wall sections of 3–4 mm; the lower melt index prolongs bubble dissolution time and requires an extended internal air plateau duration of 8–12 minutes compared to 5–7 minutes for a 6.0 g/10 min grade. Thermal degradation onset, measured by oxidative induction time per ASTM D3895 for the hindered-phenol/phosphite package, commonly exceeds 35 minutes at 200 °C in oxygen, which protects the resin through the rotomolding plateau but does not permit indefinite dwell. Internal air temperature overshoot above 210 °C produces visible yellowing (ΔYI above 2 per ASTM E313) and embrittlement because primary antioxidant depletion accelerates carbonyl formation. Documented line-side failures include part brittleness at corners where wall thickness drops below 2.5 mm due to uneven particle distribution; grinding the resin to 35-mesh powder (500 µm) with maximum 2 wt% retained on a 355 µm sieve improves flow and reduces corner voids. The ATC thermal stabilizer package is formulated for single-pass thermal history; multiple regrind cycles beyond three passes at 25 % regrind inclusion accelerate crosslinking and gel formation.

Regulatory status of Icorene 3560 ATC 9804 follows the olefin polymer framework of FDA 21 CFR 177.1520 for food-contact applications provided the end-use temperature and food-type limitations for the specific olefin subclass are satisfied. European food-contact conformity is evaluated under EU Regulation (EU) No 10/2011 with overall migration limits of 10 mg/dm² per the EN 1186 series. The resin is listed in the REACH inventory as an exempt polymer under Article 2(9); monomers and additives remain registered intermediates. RoHS Directive 2011/65/EU compliance for lead, mercury, cadmium, hexavalent chromium, PBB and PBDE is maintained by additive selection within the ATC package, with typical heavy-metal concentrations below 10 ppm by XRF screening. Specific lot-level declarations should be obtained from LyondellBasell technical service for medical or pharmaceutical packaging use.

When Hexene-Based LLDPE Grades Replace the 3560 in High-Clarity Cast Film

Direct substitution trials in which a hexene-copolymer LLDPE of equivalent 3.5 g/10 min melt index replaces the butene-copolymer 3560 typically produce a measurable change in optical and tear property balance. Hexene comonomer incorporation at 8–12 wt% lowers crystallinity and yields film haze on 25 µm cast samples of 2–4 % per ASTM D1003 versus 4–8 % for butene-based film. The substitution is not neutral in process economics because hexene grades trade at a 5–10 % price premium in European markets. The 3560 ATC 9804 therefore occupies a cost-positioned niche in applications where the higher clarity of hexene LLDPE is unnecessary — such as pigmented agricultural film, industrial liners, and mailer overwrap. In blown-film coextrusion, the narrower molecular weight distribution of the 3560 class relative to LDPE limits bubble stability at blow-up ratios above 2.5:1; equipment configured with internal bubble cooling (IBC) and die gaps of 1.2–1.8 mm mitigates the effect. Cast-film substitution of a 2.0 g/10 min LDPE with the 3560 at 10–15 wt% addition in a three-layer A/B/A structure is documented to reduce neck-in during edge trimming by approximately 15 % relative to a full-LDPE configuration, measured under line speeds of 80–120 m/min.

Processing limitations of the 3560 ATC 9804 resin arise chiefly from the antiblock component and the intermediate melt index. On cast film lines running at line speeds above 150 m/min, the synthetic silica antiblock at the high end of the addition range contributes to die-lip plate-out within 4–6 hours of continuous operation, requiring periodic manual cleaning of the die lip. Pre-drying is not required under normal warehouse humidity below 60 % RH; surface moisture adsorbed at higher relative humidity can generate splay defects in injection moulded parts, responding to 2–3 hours at 80 °C tray drying. The resin is not recommended for blow moulding applications requiring parison stability because the melt strength at 190 °C is approximately 40–60 % lower than an equivalent-MI LDPE, leading to parison sag in containers above 5 L capacity. Extended residence at melt temperature above 240 °C for more than 8 minutes should be avoided; purging with a 2.0 g/10 min LDPE purge compound after shutdown is standard practice. Colour-compounding operations should incorporate masterbatch at 2–4 wt% using a carrier resin with equivalent or higher melt index; mixing in a single-screw extruder at L/D 24:1 with distributive mixing elements (Maddock or pineapple type) yields Delta E values below 1.0 CIE units across a 100 kg batch when let-down ratios are maintained within ±0.2 wt%.

Published data for the exact ATC 9804 campaign configuration is limited to the supplier's regional technical documentation; the additive package ratios are not itemised in public literature, and users requiring confirmation of slip or antiblock species for regulatory dossiers must request the lot-specific safety data sheet and EU Food Contact Declaration from LyondellBasell. Comparative field observations from converted articles in agricultural tank production indicate that the 3.5 g/10 min grade tolerates 15–20 % LLDPE-LDPE blending without significant loss of Environmental Stress Crack Resistance when tested per ASTM D1693 Condition B in 10 % Igepal CO-630. ESCR values for the neat resin in this class commonly exceed 1000 hours at 50 °C, although the ATC antiblock loading can reduce this by 10–20 % in thin sections below 2 mm. In 1000-litre intermediate bulk container liners processed by rotomolding, wall-thickness variation across the top and bottom chimes is documented at 6–8 % coefficient of variation when powder grinding is maintained at 35 mesh and the mould rotation ratio is held at 4:1 primary-to-secondary axis speed; published data for this specific configuration is limited.