LyondellBasell Icorene 3545 ORE 3904 Polyethylene, Linear Low Density is identified as a grade designation within the Icorene series of ethylene-α-olefin copolymers. The suffix “ORE 3904” denotes a grade-specific formulation or stabilisation package, and public technical literature for this exact configuration is limited. Therefore, engineering values used for tool design, part qualification, or regulatory assessment should be taken from the current LyondellBasell product data sheet and the batch certificate of analysis rather than from generic LLDPE nominal values. The material class falls within the linear low density polyethylene density range of 0.918 to 0.940 g/cm³. The grade is commonly discussed in rotomoulding powder contexts, but the physical form, intended conversion process, and stabilisation package for the ORE 3904 variant must be confirmed with the supplier before specifying silo storage, feeding, grinding, or drying equipment.

Specification Profile and Required Test Standards

The specification framework for an LLDPE rotomoulding powder is built around melt mass-flow rate, density, environmental stress cracking resistance, low-temperature ductility, tensile properties, and powder particle size distribution. Melt mass-flow rate is reported at 190°C under a 2.16 kg load using ASTM D1238 or ISO 1133-1; this value controls whether the powder can flow into deep ribs, narrow cavity sections, and moulded-in inserts before the melt temperature reaches the oxidation limit. Density is measured by ASTM D1505 or ISO 1183-1. Environmental stress cracking resistance is commonly tested under ASTM D1693, Condition B, in 100% Igepal at 50°C. Low-temperature brittleness is assessed by ASTM D746 or ISO 974. Tensile yield strength and elongation at break are evaluated by ASTM D638 or ISO 527-2, and flexural modulus by ASTM D790 or ISO 178.

On a production-scale shuttle arm or carousel rotational moulding line, the powder is charged into a heated mould and formed into a hollow shell by sequential melting and consolidation. Wall thickness distribution is controlled by powder dry flow, peak internal air temperature, mould surface temperature, and cooling rate. Fines below 100 µm can reduce bulk density and increase electrostatic adhesion to the mould surface, while coarse particles above 500 µm may remain unmelted in corners, ribs, and kiss-off regions. The sieve fraction between 35 mesh (500 µm) and 100 mesh (150 µm) is commonly monitored because it influences both powder flow and particle coalescence. Published data for this specific Icorene configuration is limited; an incoming-inspection plan should therefore include ASTM D1921 sieve analysis and ASTM D1895 bulk density on every lot, with acceptance limits derived from the supplier’s certificate of analysis and the moulder’s historical process capability.

What Limits Rotational Moulding Cycle Efficiency in Icorene 3545 ORE 3904?

Cycle efficiency is bounded by the temperature interval between particle coalescence and oxidative degradation. For LLDPE rotomoulding powders, oven set temperatures are commonly held between 260°C and 310°C, while the internal air temperature in the mould is raised to 190°C to 210°C. The upper limit is determined by oxidation-induced rheological shifts, discolouration, and pinhole formation; the lower limit is set by incomplete wetting at knit lines, corners, and inserts. Complex aluminium or steel tools may require internal air temperature control within ±5°C to avoid underflow at the parting line or excessive shrinkage in thick bosses. Cooling must be sequenced so that release occurs below the recrystallisation range, but not so rapidly that warpage exceeds drawing tolerance. Because published data for this exact configuration is limited, the oven profile and cooling ramp must be established on the actual moulding machine using an internal air probe and mould surface thermocouple rather than relying on class-level datasheet values.

Polyethylene is not hygroscopic in the manner of polyamide or thermoplastic polyester, but condensation on cold powder can introduce steam marks and pinholes during melting. In high-humidity storage, powder should be allowed to reach ambient temperature before silo discharge, and hopper temperature should be maintained above the dew point. Regrind from post-industrial parts may be added only after verifying melt flow rate and sieve distribution. Regrind additions above 20 wt% can increase pinhole density and reduce environmental stress cracking resistance unless the regrind is screened to remove fines and thermally damaged particles, and unless the blend is re-qualified by ASTM D1238 and ASTM D1921.

When Icorene 3545 ORE 3904 Is Compared with High-Pressure LDPE and HDPE

Unlike high-pressure LDPE, which contains long-chain branching, linear low density polyethylene has a predominantly linear backbone with short-chain branches introduced by α-olefin comonomer. At equivalent melt flow rate and density, LLDPE typically provides higher tensile strength, puncture resistance, and environmental stress cracking resistance than LDPE, but lower melt strength during thermoforming and blow moulding. Compared with HDPE, LLDPE has lower flexural modulus, lower Vicat softening temperature, and higher low-temperature impact toughness. These differences arise from lower crystallinity and from the distribution of short-chain branches. The comparison below shows class-level values and is not a substitute for the official Icorene 3545 ORE 3904 datasheet.

For outdoor hollow parts such as storage tanks, agricultural reservoirs, and industrial containment shells, the ORE 3904 suffix may indicate a stabiliser package selected for ultraviolet resistance. Stabilisation is not a permanent property; it is consumed by UV exposure, heat, and extraction. Parts intended for prolonged outdoor service must be tested under the proposed exposure conditions. Compliance statements for food-contact or potable-water service must be obtained in writing from LyondellBasell. Typical polyethylene grades are evaluated under FDA 21 CFR 177.1520, EU Regulation No 10/2011, REACH, and RoHS, but coverage for this exact grade should not be inferred from similarity to other LLDPE grades. Published data for this specific configuration is limited; therefore, mould-flow simulation, stacking calculations, and failure-mode analysis should use the production-lot certificate of analysis rather than generic class values. The operational boundary in prolonged outdoor service is set by stabiliser depletion rate, not by initial tensile property, and long-term heat ageing or accelerated weathering data is required for service-life prediction.