Dairy spread portion packs, frozen dessert tubs, and microwave-safe side-dish containers are injection-moulded in thin-wall tooling with nominal wall stocks between 0.45 mm and 0.70 mm. Direct food-contact grades must comply with FDA 21 CFR 177.1520(c) olefin polymer specifications and Commission Regulation (EU) No 10/2011 with overall migration below 10 mg/dm² under aqueous, acidic, and fatty simulats. Lotte Chemical Titan HDPE HI2000 enters this segment as a high-flow injection-moulding HDPE with a certified melt-flow rate of 20 g/10 min at 190 °C/2.16 kg tested to ISO 1133-1:2022, which allows filling of multi-cavity hot-runner tools at lower hydraulic pressure than conventional 8 g/10 min HDPE. On a 1600 kN hydraulic toggle machine with a 20:1 L/D general-purpose screw and a two-drop valve-gate hot-runner manifold, the melt profile is set at 195/205/215/220 °C from feed throat to nozzle, with the nozzle held at 225 °C to prevent gate freeze during valve sequencing. Injection speed is maintained at 120–160 mm/s, on-cavity hold pressure at 45–60 MPa for a hold time of 0.5–0.9 s, and mould coolant temperature at 15–25 °C. White masterbatch based on titanium dioxide in an LLDPE carrier is metered at 1.5–3.0 wt%; loadings above 3.0 wt% reduce weld-line tensile strength in the sidewall-to-base junction, as measured by ISO 527-2/1B. The main processing conflict is the narrow temperature window between complete cavity packing and oxidative gel formation: residence times above 20 min at melt temperatures above 235 °C increase visible black speck formation in translucent white tubs, while melt temperatures below 190 °C produce short shots in the 0.45 mm shoulder section on the same tool. For food-contact approval, the converter is responsible for verifying the final article under EU 10/2011 Annex IV migration testing with fatty simulants, not merely relying on resin certification.

What Limits High-Cavitation Closure Moulding with 20 g/10 min HDPE?

Beverage closures with 30/25 mm neck finishes and tamper-evident bands are moulded in high-cavitation tools ranging from 64 to 144 cavities, using valve-gate hot runners and stack moulds. The processing target is not merely cavity filling; it includes gate freeze-off after packing, band stretching during ejection, and removal torque consistency on the finished closure. HI2000 is used at 100% resin for short-shelf-life still-water and dairy closures; for aggressive environments or higher ESCR, converters let down 5–15 wt% of a fractional-melt HDPE or a 1-butene copolymer with a density of 0.952–0.955 g/cm³ to raise environmental stress crack resistance. Slip masterbatch containing erucamide at 1.0–2.0 wt% is dosed separately to reduce cap-on-bottle torque; higher slip levels can migrate to the top sealing surface and cause seal leakage. Barrel profiles on a 2000 kN hybrid machine are set at 210/220/225/230 °C, hot runner at 230 °C, and mould chiller at 8–12 °C to freeze gates within 1.5–2.5 s. Injection velocity is set at 180–250 mm/s, with hold pressure limited to 35–50 MPa because higher hold pressures pack the tamper-evident band and increase ejection pin penetration. Cycle time is 6–9 s for 1.8–2.2 g shot weights. The gate quality is tested by dropping closures from 1.5 m onto concrete; brittle gate fracture indicates insufficient hold or excessive melt temperature. For child-resistant closures, final assembly is tested to ISO 8317:2015. Food-contact status is governed by FDA 21 CFR 177.1520(c) 3.2a and EU 10/2011; any organoleptic change in bottled water is evaluated under EN 1622:2006.

UN 1H2 open-head pails, stacking load, and drop-test compliance

In open-head pail production, the 20–25 L injection-moulded body is specified when dimensional stackability and closure integrity are required. HI2000 is formulated with 1.5–2.5 wt% carbon black masterbatch and 0.1–0.3 wt% of a primary/secondary antioxidant package; the high-flow base resin permits filling of the rim and bail-ear sections at 1.2–1.8 kg shot weights without excessive shear heating. Moulding is performed on an accumulator-assisted injection machine with a 2000–4000 kN clamp, a 120–150 mm screw, and a cold sprue bush feeding a ring gate near the pail rim. Barrel zone settings are 200/215/225/230 °C, melt cushion is kept below 5 mm, and mould temperature is controlled at 10–20 °C through turbulent-flow water channels. Injection pressure normally peaks at 90–120 MPa, with hold phase 50–70 MPa for 12–20 s; gate seal must be confirmed by weight stability across 10 consecutive shots. The UN 1H2 removable-head packaging designation requires conditioning and drop testing under ASTM D5276; the commonly cited test point for Packaging Group II solid materials is a 1.2 m free-fall onto a rigid steel plate after conditioning at -18 °C. Stacking performance is evaluated under ASTM D4577 at 40 °C for 24 h; pails made with HI2000 are typically filled to 75% of the maximum gross mass and stacked to 1.5 m height. Excessive carbon black above 2.5 wt% reduces low-temperature impact and creates visible weld lines at the bail-ear junctions.

When HI2000 replaces 3–5 g/10 min HDPE in ventilated agricultural crates

Bakery trays, mushroom crates, and beverage crates are injection-moulded as single-shot items with perforated sidewalls and integrated stacking lugs. The replacement of a 3–5 g/10 min HDPE with HI2000 allows the nominal wall thickness to be reduced from 2.5 mm to 2.2 mm, provided that top-load requirements are re-certified to ASTM D642. A typical ventilated mushroom crate with a 3.5 kg shot weight is processed on a 6500 kN machine at a melt temperature of 200–220 °C; the mould is cooled with water at 20–35 °C, and cycle time falls between 20 s and 30 s. For outdoor service, a UV-stabilizer masterbatch containing a hindered amine light stabilizer is dosed at 2.0–3.5 wt%, and carbon black is added at 2.0 wt% in parallel for black crates; the two masterbatches are metered separately to avoid pellet mixing errors. The principal processing limitation is warpage of the bottom deck: with the high-flow resin, the hold pressure should be reduced to 30–45 MPa and the mould temperature kept below 35 °C, otherwise post-ejection corner lifting exceeds 3 mm on a 600 mm long crate and is visible on flat-table inspection. Impact performance is checked with ISO 6603-2 puncture tests on the sidewall rib junctions; published data for this specific grade in ventilated crate geometry is limited, so the test report for the final moulded crate carries the compliance burden.

Storage boxes with latch hinges, drawer organizers, and clothes hangers use HI2000 without filler or with 1.0–2.0 wt% colour masterbatch. The high melt-flow index permits filling of long draw cores for hanger hooks and latch undercuts at melt temperatures of 190–210 °C. Mould surface texture is the dominant variable controlling sink mark visibility; on polished cavities, gate blush appears at injection speeds above 150 mm/s, so speeds are limited to 80–120 mm/s. No food-contact testing is required in this segment unless the article is marketed as reusable kitchenware, in which case the final article is subject to EU 10/2011 and FDA 21 CFR 177.1520(c). Warpage of long flat lids is controlled by maintaining uniform cavity wall temperature within ±5 °C and by avoiding hold pressures above 40 MPa.

Talc-filled overcap formulations and gloss-level control on textured cavity surfaces

For aerosol overcaps, deodorant cap assemblies, and cosmetic jar closures, talc-filled HDPE compounds are used to increase modulus and reduce cycle time. HI2000 is let down with 10–20 wt% talc masterbatch and 0.5–1.0 wt% pigment masterbatch; talc additions above 20 wt% cause excessive gate wear and reduce weld-line elongation. The injection moulding machine is a 1000 kN hydraulic unit with a 20:1 L/D screw, running a melt temperature of 200–210 °C and a mould temperature of 15–25 °C. Textured cavity surfaces are vapour-honed or acid-etched; the high-flow base resin fills the texture at lower pressure than 8 g/10 min HDPE, but mould release becomes more difficult because the low-viscosity melt penetrates deeper into texture peaks. A mould-release agent is not used in food-contact overcaps; instead, draft angles are increased to 2–3° on sidewalls and the ejection speed is limited to 30–50 mm/s. The final article is tested for cap-on-bottle insertion force with a force gauge calibrated to 0.1 N.