BASF Zhanjiang HDPE IL 8008 T is produced as a high-density polyethylene injection-moulding grade at the BASF Verbund site in Zhanjiang, Guangdong Province, China. The designation places the resin within the high-density polyethylene family under ISO 1043-1 and ISO 1872-1; density for this family is normally above 0.940 g/cm³ when conditioned and tested according to ISO 1183-1:2019. The public technical datasheet for this specific configuration is limited, and the melt mass-flow rate, molecular-weight distribution, additive composition, and mould shrinkage are not to be assumed from the grade code alone. The suffix T is not defined by the ISO 1872-1 designation system and may indicate a modified additive package, a production-site variant, or a colour/processing marker; confirmation should be obtained from the supplier certificate of analysis before tool design or production trials. In injection-moulding terms, the grade is differentiated from blow-moulding, film, and pipe resins by a melt-flow class that is typically optimised for spiral flow, thin-wall fill, and short cooling time rather than for parison stability or oriented film tear resistance. Those differences are not absolute; lot-specific data govern the final processing window.

Selection of screw geometry, hot-runner temperature profile, gate diameter, and shrink compensation depends on lot-specific melt volumetric flow rate and solid-state density. For high-density polyethylene injection grades, the specification framework should include melt mass-flow rate at 190 °C under 2.16 kg load, density, tensile yield stress, flexural modulus, and Charpy notched impact strength. The values listed in Table 1 are a generic medium-flow injection moulding envelope and are not a certificate of analysis for IL 8008 T.

Material Designation and Production-Line Boundary Conditions

At the Zhanjiang Verbund site, the grade is produced in an integrated petrochemical complex in which ethylene feedstocks, utilities, and logistics are co-located. The product is supplied as free-flowing cylindrical pellets with a high-density polyethylene bulk density typically between 0.54 g/cm³ and 0.60 g/cm³ for storage and conveying calculations. The pellet form is suited to pneumatic conveying; however, conveying air should be dried to a dew point below -20 °C where the surrounding warehouse humidity exceeds 60 % relative humidity. High humidity does not hydrolyse high-density polyethylene, but surface condensation on cold pellets can introduce moisture into the feed throat, causing splay, flow instability, or gate blush. If condensation is suspected, a hot-air or desiccant hopper dryer set to 80 °C for 2 h is normally sufficient; temperatures above 100 °C and residence times above 4 h can soften the pellets and create bridging in the hopper throat. The material should be kept away from direct sunlight and stored in sealed containers or silos to limit dust pickup and oxidation of any surface lubricants.

The following reference envelope is assembled from public classification data for high-density polyethylene injection-moulding resins. It is not a lot-specific datasheet for IL 8008 T.

Within this envelope, the melt mass-flow rate controls the filling length and the cycle time. A higher MFR improves thin-wall fill but reduces notched impact and environmental stress-cracking resistance. A density at the upper end of the range raises stiffness, barrier, and softening temperature but typically increases mould shrinkage anisotropy. For closures and thin-wall containers, the practical compromise is usually a medium-flow grade with a density close to 0.955 g/cm³; however, the actual selection for IL 8008 T must follow the supplier lot data. The processing response is not determined by density alone. Molecular-weight distribution, short-chain branching, and additive nucleation also change the shear viscosity curve and the onset of solidification.

What Mould Filling and Packing Parameters Are Documented for Thin-Wall Injection Moulding?

For thin-wall injection moulding of high-density polyethylene with nominal wall thickness between 0.8 mm and 2.0 mm, the melt temperature is generally set at the nozzle between 200 °C and 280 °C. The mould wall temperature is usually maintained between 10 °C and 40 °C. A general-purpose polyolefin screw with an L/D ratio of at least 20:1 and a compression ratio between 2.5:1 and 3.5:1 is used; a barrier screw may provide better melt homogeneity when masterbatch colour is metered at high speed. Back pressure is set at 5 bar to 15 bar, or 0.5 MPa to 1.5 MPa, to maintain screw recovery without excessive shear heating. Injection velocity is profiled so that the melt front advances rapidly through the first 80 % to 95 % of the flow path, then decelerates at the transfer point to avoid flash and burn marks at the end of fill. Injection pressure is often 600 bar to 1400 bar at the hydraulic system or 60 MPa to 140 MPa at the melt front, depending on tool restrictions.

Clamp force requirement is usually estimated at 3 kN/cm² to 5 kN/cm² of projected area for well-balanced HDPE parts. Hot-runner manifold temperature should be kept below 260 °C, and residence time should be limited to 5 min at temperature to prevent discoloration and odour. Failure modes observed on production lines operating toggle-clamp machines from 1200 kN to 4500 kN include gate blush, sink marks, and warpage. Gate blush is frequently caused by excessive injection velocity through a gate diameter below 0.8 mm or by a cold gate tip. Sink marks appear when packing time ends before the gate freezes; the gate-seal time can be established by plotting shot weight against packing time and maintaining packing beyond the weight plateau. Warpage in non-uniform wall sections is driven by differential shrinkage between thick and thin regions; packing pressure should be highest during the early stage after fill and then decay gradually rather than being held at a constant maximum. The screw cushion should be held between 2 mm and 5 mm to ensure consistent pressure transfer.

When the T-Suffix Additive Package Changes Crystallisation Kinetics and Ejection

Published data for the exact T-suffix composition of IL 8008 T is limited. If the suffix denotes a nucleating agent, the crystallisation onset can shift to a higher temperature during cooling. That shift can reduce the cooling time required before ejection but may also increase differential shrinkage in parts with abrupt wall-thickness changes. If the suffix denotes an antistatic package, surface resistivity falls, but the additive may migrate over time and alter adhesion of labels, inks, or caps. If the suffix denotes a mineral filler such as talc, density and flexural modulus increase while weld-line strength and notched impact generally decrease. Because these effects are additive-dependent, the moulding trial should compare filled weight, part dimensions, warpage, and drop-impact performance against a control lot without the T-suffix package. Ejector force should be monitored; higher nucleation or filler can reduce demould sticking but can also make the outer skin more brittle at sharp corners. Ejection velocity below 10 mm/s at the first stage and draught angles above 1.5° help avoid stress whitening on the surface.

Process compatibility requires attention to purge discipline. The resin should not be purged with PVC or acetals without thorough cleaning; excessive residence time, especially above 260 °C, can degrade heat stabilizers and lower molecular weight. The use of reclaimed material in direct food-contact applications is not permitted unless the recycling process is approved under the relevant regulatory framework. For melt-compounding of high loadings of mineral filler or conductive carbon black into HDPE, a twin-screw extruder with 40:1 L/D and side feeding is typically used; this step is not expected for the neat IL 8008 T pellet supply.

Regulatory compliance must be verified against the lot-specific certificate. The matrix below lists candidate frameworks rather than certified compliance statuses.

Compliance with food-contact regulations is not inferred from the polymer structure alone. Colour masterbatches, process aids, antistatic additives, and lubricants must also be assessed under the applicable migration test regime. For parts intended for repeated use, the overall migration test under EU Regulation 10/2011 uses simulants and time/temperature conditions specified in Annex III; the data must be generated on the finished article or a representative plaque, not on the neat resin pellets. Mould shrinkage for high-density polyethylene injection grades is typically between 1.2 % and 3.0 % in the flow direction and between 0.8 % and 2.5 % transverse to flow, depending on packing pressure, wall thickness, and additive nucleation. Shrinkage should be measured after 48 h at 23 °C and 50 % relative humidity on plaques or parts of the intended geometry. Post-mould annealing up to 80 °C can accelerate dimensional stabilisation but may produce a step change in part size if the entire batch is not annealed under the same profile.

Comparative Melt Property Envelope Against Blow-Moulding, Film, and Pipe Grades

The operational difference between an HDPE injection grade and a blow-moulding grade is primarily melt strength. Injection grades are supplied in a melt mass-flow range commonly between 4 g/10 min and 20 g/10 min at 190 °C and 2.16 kg, while blow-moulding grades often fall between 0.2 g/10 min and 1.0 g/10 min. The higher MFR of injection grades reduces flow resistance in thin-wall tools but gives lower parison stability and lower melt strength, making the material unsuitable for large blow-moulded containers unless specifically validated. Film grades are designed for dart impact, tear resistance, and bubble stability; they often use broad or bimodal molecular-weight distributions that increase melt relaxation and toughness. Pipe grades are also often bimodal and may carry PE100 or PE100-RC classifications under ISO 9080; they are not interchangeable with injection grades in spiral-flow-limited tools because their lower MFR may require higher melt temperatures and higher injection pressures.

Pipe-grade HDPE under PE100 classification is required to demonstrate a minimum hydrostatic strength of 10 MPa at 20 °C and 50 years under ISO 9080; injection-moulding grades are not subjected to that long-term pressure test. Environmental stress-cracking resistance under ASTM D1693 condition B is generally lower for high-MFR injection grades than for pipe grades; the narrow molecular-weight distribution that improves injection mould surface finish can reduce slow-crack-growth resistance. Compared with polypropylene homopolymer, HDPE injection grades typically have lower flexural modulus 900–1500 MPa versus 1200–1800 MPa under ISO 178:2019, lower Vicat softening temperature 120–130 °C versus 150–160 °C under ISO 306:2022, better Charpy notched impact below 0 °C 3–8 kJ/m² versus 1–4 kJ/m² under ISO 179-1:2010, and higher density 0.952–0.965 g/cm³ versus 0.900–0.910 g/cm³ under ISO 1183-1:2019. Compared with LLDPE, HDPE has higher crystallinity and higher tensile yield stress, typically 23–32 MPa under ISO 527-2:2012 versus 8–20 MPa for LLDPE film grades, but lower puncture and tear resistance because LLDPE short-chain branches dissipate stress more effectively.

Batch-to-batch variance of high-density polyethylene injection grades is usually controlled through reactor melt index and density; however, incoming lot confirmation should include melt mass-flow rate, density, and a short-shot moulding check. During a production campaign, the machine operator should record lot number, hopper residence time, melt temperature at the nozzle, injection peak pressure, cushion position, gate-seal time, and part weight at intervals not exceeding 30 min. When a new lot is introduced, the first 10 to 20 shots may show minor dimensional drift; parts from those shots should be quarantined until dimensions and weight stabilise. Surface contamination, odour, and plate-out should be investigated as possible indications of additive migration, degradation, or masterbatch incompatibility.