Open-head industrial pails with capacities between 10 L and 25 L are a primary injection-moulded packaging application for LyondellBasell HDPE H5623X01. Datasheet values for density at 0.956 g/cm³ per ISO 1183-1 and melt flow rate at 2.3 g/10 min per ISO 1133-1 under 190°C/2.16 kg support filling of thick-walled pail bodies with nominal wall sections from 2.2 mm to 4.0 mm. A 20 L open-head pail typically requires a shot mass of 1.2–1.6 kg; the injection unit is specified with shot capacity at least 20% above part mass so that melt cushion remains between 3 mm and 8 mm. Barrel temperatures are profiled from 180°C in the feed zone to 220–240°C in the metering zone, with the nozzle held at 215–235°C. Screw configuration for pail moulding favours a compression ratio of 2.8:1 to 3.2:1, L/D ratio of 20:1 to 24:1, and a pin-type mixing section of 6–8 rows. Injection fill time is profiled so that the flow front reaches the lip ring in 0.8–1.2 s; switch-over occurs at 95–98% of cushion volume, followed by holding pressure of 30–50 MPa until gate freeze. Core cooling water is set to 10–20°C and cavity water to 8–18°C. Clamp force for a single-cavity pail tool is generally 500–800 tonnes, with total cycle time of 35–50 s depending on lip-ring thickness and demoulding temperature. A process boundary appears when part ejection is attempted above 80°C surface temperature: lip ovality can exceed 3 mm and must be corrected with post-mould cooling fixtures holding the pail for 45–90 s.

Dangerous-goods pails are qualified under UN 1A2/Y packaging requirements. Drop testing follows 49 CFR 178.603; filled pails conditioned at −18°C are dropped from 1.2 m for packing group II when the filled-density product does not exceed 1.2 g/cm³. Stack testing follows 49 CFR 178.606, applying the equivalent load of a 3 m stack of filled containers for 28 days at 40°C. Formulation ratios are kept within defined limits: colour masterbatch at 1.0–2.5 wt%, UV stabilizer masterbatch at 0.3–0.8 wt% for outdoor storage, and clean in-house regrind at 15–30 wt%. Regrind above 30 wt% is constrained by notched impact loss and visible flow lines at the sidewall-to-bottom transition when pigment dispersion is poor. The terminal article is an integrally coloured open-head pail with gasketed lid seat, used for water-based emulsions, lubricant additives, and industrial cleaning compounds.

What changes when H5623X01 moves into 32-cavity closure tools?

Closure moulding shifts the control variable from part mass to gate-to-gate balance. In a 32- or 48-cavity hot-runner tool producing 0.8–2.8 g HDPE closures, shot-to-shot mass deviation is maintained below 0.5% by holding melt cushion at 3–6 mm and applying decompression of 8–12 mm after plastication. Barrel temperatures are profiled from 170°C in the feed zone to 210–230°C at the nozzle; mould cooling water is set to 10–15°C. Cavity pressure at transfer is 25–45 MPa. Cycle time for a 0.8 g tamper-evident band closure can run 5.5–7.5 s; a thicker linered cap with wall thickness 1.2–1.6 mm for UHT dairy packs extends to 9–12 s. Formulation ratios include white titanium dioxide masterbatch at 0.6–1.2 wt% and slip/antiblock masterbatch at 0.1–0.3 wt% only when top-load removal torque on a 28 mm PCO 1881 finish exceeds 1.0 N·m. Compliance for food-contact closures references FDA 21 CFR 177.1520; EU migration testing under EU 10/2011 uses overall migration limits of 10 mg/dm² in food simulants assigned by contact type. For dairy closures, sensory evaluation by DIN 10955 at 40°C for 10 days is added when taste or odour transfer is a release criterion. Torque retention after application is measured by ASTM D2063. Throughput of 32 cavities at 6 s cycle consumes approximately 16–20 kg/h; if hopper residence time exceeds 45 min at 230°C, melt discolouration begins at hot-runner drops, and valve-gate tips should be purged with high-viscosity HDPE before restart.

Returnable logistics crates: gate-freeze depth, rib fill and EU heavy-metal limits

Ventilated distribution crates of 600×400 mm footprint are moulded from HDPE H5623X01 at shot weights of 1.6–2.9 kg depending on rib density and base design. Filling of rib sections with nominal wall thickness from 1.2 mm to 2.0 mm requires melt temperature of 230–250°C and injection speed of 40–70 mm/s. Flow-length-to-wall-thickness ratios above 350:1 in rib corners are sensitive to gate freeze-off; gate diameter is therefore held at 2.5–3.5 mm, and packing pressure is ramped from 45 MPa down to 20 MPa over 3.0–5.0 s. Clamp force calculations for a two-cavity crate tool assume 0.45–0.65 tonnes/cm² of projected area. Tools with 1,200–1,500 cm² per cavity are run on 500–700 tonne machines. Two-circuit mould temperature control is standard: cavity temperature at 12–18°C, core at 8–14°C. Melt-flow index shift after processing is recorded; an increase above 10% relative to virgin indicates molecular weight reduction from excessive shear in hot-runner channels. Regrind from post-industrial crate scrap is added at 20–50 wt%. At 50 wt% regrind, flexural modulus measured by ISO 178 falls to 1,000–1,100 MPa, which remains acceptable for closed-loop retail logistics but below typical specifications for high-stack agricultural crates. Drop testing is performed under ISO 2248. Compliance includes EU 94/62/EC packaging heavy-metal limits, where the sum of lead, cadmium, mercury and hexavalent chromium is below 100 mg/kg, and REACH Article 33 communication when any SVHC exceeds 0.1 wt%. Terminal products are returnable crates, pallet boxes, and distribution trays with moulded-in barcode pads.

Thin-wall dairy tubs and lids of 0.8–1.2 mm nominal wall are produced in stack moulds with 4+4 or 6+6 cavity configurations. Machine selection follows screw recovery rather than clamp force because projected-area-to-shot-volume ratio is high. At 1.1 mm wall, a 500 g tub and lid set is injected at 80–120 mm/s screw speed with melt temperature of 200–220°C. Cooling time is set at 3.5–6.0 s; ejection is enabled when core-side surface temperature is below 70°C. High-speed filling creates shear heating of 8–15°C across the runner, so nozzle temperature is offset −10°C from the melt set-point to avoid surface splay in the tub base. Masterbatch letdown is 0.8–1.5 wt%; titanium dioxide levels above 3.0 wt% generate melt-pressure rises of 8–15% and require screw back pressure reduction from 0.8 MPa to 0.5 MPa to prevent vent flow. Food-contact compliance includes EU 10/2011, FDA 21 CFR 177.1520, and China GB 4806.7-2016; organoleptic transfer is tested by DIN 10955 at 40°C for 10 days. Tear strength of the lid nubbin is validated on specimens cut from the hinge area using ASTM D638 Type IV. The terminal product is a dairy or margarine tub with snap-on lid, where the hinge must survive 20 opening cycles without stress whitening. Pre-drying is not required when polymer is stored in closed silos below 60% relative humidity; if pellet surface moisture exceeds 0.05 wt%, splay appears and the material must be dried at 80°C for 2 h.

When oxidizer-containing crop-protection formulations contact moulded-in threads

Measuring chambers and overcap shells for agrochemical products require chemical resistance to dilute hydrocarbons, ester solvents, and oxidizer-based disinfectants. H5623X01 is used for injection-moulded measuring chambers and overcap shells with wall thickness from 1.8 mm to 3.5 mm. Melt temperature is set at 220–240°C and cycle time is extended to 18–30 s to permit adequate crystallinity and keep post-mould shrinkage below 1.5%. Dimensional stability after 48 h at 50°C in contact with 5% sodium hypochlorite is assessed by measuring thread diameter change; maximum acceptable increase is 0.35 mm on a 45 mm neck finish. Compliance for crop-protection packaging may include UN marking for limited quantity or full dangerous goods depending on formulation. Stress-cracking resistance is screened by ASTM D1693 Condition B in 10% Igepal CO-630 at 50°C. Antioxidant masterbatch is added at 0.2–0.5 wt% when product contact involves metal ion contamination above 1 ppm, particularly copper from pump parts. Published data for long-term ESCR of H5623X01 in ester-based agricultural emulsions is limited; pilot trials with the final formulation are required before conversion from fluorinated HDPE or PA barrier structures. Moulded-in threads with 0.8 mm root radius may crack if ejection is forced before 10 s cooling; 1.2–1.5 mm root radii are used for oxidizer-contact parts. The terminal products are graduated dosing cups, overcap shells, and secondary thread adapters for crop-protection and industrial disinfectant packs.