LyondellBasell Icorene 3546 YEW 2183 is a linear low-density polyethylene (LLDPE) rotational moulding powder supplied under the Icorene 3546 base-resin family. The alphanumeric suffix YEW 2183 identifies a formulation variant that may include a specific colourant, antioxidant system, and ultraviolet stabilizer package; it is not a nominal melt-flow or density designation. The product is distributed as a powder for carousel, shuttle, and rock-and-roll rotational moulding machines in which oven residence time, mould rotation rate, and peak internal air temperature control particle coalescence and wall-build consistency. Industrial applications referenced in supplier technical literature include storage tanks, agricultural reservoirs, marine fenders, container bodies, playground enclosures, and industrial housings. The powder form reduces the need for secondary size reduction in many rotomoulding operations, but particle size distribution, bulk density, and moisture content must be controlled because they directly influence fill mass and the onset of sintering at internal mould surfaces.

What Is the Published Property Profile of Icorene 3546 YEW 2183?

The table below compiles typical values from supplier-published property literature. The density and melt flow rate define the grade as a medium-density LLDPE with a moderate viscosity suitable for rotational moulding. Density is reported at 0.936 g/cm³ and melt flow rate at 4.5 g/10 min under 190 °C/2.16 kg load. These two values are not sufficient to set a processing window; they must be combined with powder particle size distribution data from the certificate of analysis and with part-level mechanical testing at the intended wall thickness.

The environmental stress-crack resistance reported under ASTM D1693 is a notched constant-strain test in 100% Igepal CO-630 at 50 °C. An ESCR value exceeding 1000 h indicates resistance to slow crack propagation in detergent and surfactant exposures, but the result should not be treated as a service-life prediction for arbitrary chemical mixtures. The high elongation at break and moderate flexural modulus are appropriate for large hollow parts that require impact toughness and the ability to conform to demoulding stresses without brittle fracture.

For multi-cavity moulds, the dry-flow behaviour of the powder is as important as the melt index. General rotomoulding practice for LLDPE powders in this density class uses ASTM D1895 to measure apparent density, and a representative sample is often specified to pass 35 mesh (500 µm) at 90% minimum. Coarse particles require longer sintering time, while excessive fine particles increase static adhesion and dusting, producing uneven wall thickness in deep parting-line channels. Published data for this specific configuration is limited; the supplier’s particle size distribution certificate should be compared with the minimum fill-path diameter of the mould.

When Mould Geometry Pushes Peak Internal Air Temperature Beyond 220 °C

Production-scale experience with rotomoulded LLDPE in the 0.930–0.940 g/cm³ density range indicates that peak internal air temperature (PIAT) is a better control variable than oven temperature alone. For a medium-wall tank of approximately 3 mm nominal wall thickness, PIAT values between 195 °C and 210 °C typically yield acceptable particle coalescence and internal surface finish. Below 185 °C, incomplete sintering persists at sharp mould angles and around insert bosses, producing microporosity and notch-sensitive regions that reduce impact performance. Above 220 °C, thermal-oxidative degradation of the polymer and stabilizer package can produce yellowing, gloss loss, and a measurable decline in tensile elongation at break. The process window is consequently narrower than that of some high-density polyethylene rotomoulding grades, and validated oven profiles should not be transferred between moulds of different wall thickness without adjusting dwell time, airflow, and rotation ratio.

Moisture absorbed on the powder surface can generate steam during oven residence and create internal voids; powder should be kept dry and pre-dried when storage relative humidity exceeds 60%. Long melt-contact with transition-metal fittings such as unclad copper, brass, or manganese-containing alloys can catalytically accelerate oxidative degradation. In shuttle machines, the exhaust temperature profile should be tuned so the powder reaches a sintered state before the exhaust air deviates by more than 10 °C from the established profile. Published machine-specific data for Icorene 3546 YEW 2183 is limited; prototype runs are required.

Molecular Architecture Differences Among LLDPE, LDPE, and HDPE

The use of an α-olefin comonomer, usually 1-butene, 1-hexene, or 1-octene, generates short-chain branches along a linear backbone. These branches interrupt crystal packing and lower density relative to homopolymer HDPE while preserving the tensile and slow crack growth characteristics associated with linear polymer chains. Low-density polyethylene produced by high-pressure radical propagation contains long-chain branching and a broad molecular weight distribution; this architecture provides higher melt strength and better drawdown but generally lower tensile, puncture, and environmental stress-crack resistance than LLDPE of the same density. HDPE has minimal short-chain branching and develops higher crystallinity, higher flexural modulus, lower permeability, and higher heat distortion resistance, but it can exhibit lower ESCR and lower low-temperature impact toughness than a medium-density LLDPE.

The short-chain branching distribution is not fully specified by density. Two LLDPE formulations may have identical density but different comonomer placement, catalyst systems, and branch-length distributions, which change the rate of tie-molecule formation and the balance of stiffness to slow crack growth. Icorene 3546 YEW 2183 is placed in the medium-density LLDPE range at 0.936 g/cm³, yielding an intermediate flexural modulus that is lower than typical HDPE rotomoulding grades and higher than conventional LDPE. When compared with a general-purpose rotomoulding HDPE near 0.945 g/cm³, a density increase of approximately 0.009 g/cm³ may be accompanied by a significantly larger flexural modulus difference; therefore, direct substitution of Icorene 3546 YEW 2183 into a mould originally designed for HDPE requires wall thickness compensation rather than a simple resin change.

The YEW 2183 variant should be treated as a complete formulation. If a hindered-amine light stabilizer is present, outdoor weathering resistance is improved relative to unstabilized polyethylene, but the stabilizer content and pigment classification are not always disclosed in standard property datasheets. Long-term outdoor performance should be verified by ASTM D2565 or ISO 4892-2 accelerated weathering with colour and tensile elongation retention measured on rotomoulded specimens. The pigment package may influence the acceptable food-contact declaration and the recycling stream identification. Published data for the exact formulation is limited in public databases; the supplier’s formulation disclosure and regulatory certificate are controlling.

Regulatory Screening for FDA and EU Food-Contact End-Uses

Compliance is evaluated at the finished-article level, not by the base resin alone. Polyethylene copolymers may be eligible for food-contact use under FDA 21 CFR 177.1520 when the material meets the specified density and extractives limitations; however, colourants and stabilizers in the complete Icorene 3546 YEW 2183 formulation require separate clearance or confirmation. Under European Union legislation, the base polymer is evaluated against EU Regulation No 10/2011 migration limits, and the additive package must be included in the Union List or otherwise authorized. REACH SVHC screening is based on supplier declarations and may not capture downstream processing aids. RoHS compliance for finished polyethylene is normally confined to pigments and additives because lead, cadmium, hexavalent chromium, mercury, and brominated flame retardant limits are usually not exceeded by unmodified polyethylene.

Substitution of Icorene 3546 YEW 2183 into an existing HDPE rotational moulding programme requires a stiffness correction. Because the flexural modulus of this LLDPE is lower than a typical 0.945 g/cm³ HDPE rotomoulding grade, flat panels are more prone to warpage and top-load deformation unless vertical ribs, step flanges, or increased nominal wall are introduced. The material’s high environmental stress-crack resistance and low-temperature ductility are useful for agricultural tanks exposed to intermittent freezing and detergent washdown. In field audits of multi-cavity moulds, lower modulus LLDPE powders of this class have shown reduced demoulding force at equivalent release-agent dosage, but cooling-rate uniformity becomes more important to avoid dimensional variation. Published data for this specific product configuration is limited to supplier technical reports and third-party qualification records; production trials on the intended mould are required before large-scale substitution.