Borealis HDPE HE3366 Downstream Application Sections

Melt Index and Die Swell Control in Household Chemical Bottle Moulding

When HE3366 is run on continuous shuttle extrusion blow-moulding lines equipped with a 24:1 L/D grooved-barrel screw in the 60–80 mm diameter range, the published nominal melt flow rate of 0.6 g/10 min at 190 °C/2.16 kg under ISO 1133-1 and nominal density of 956 kg/m³ under ISO 1183-1 set the control envelope for parison formation. The melt should be maintained at 195–210 °C at the die adapter, with the die head temperature held 10–15 °C below the adapter setpoint to stabilize die swell. Parison programmers with 10–20 thickness steps are used to compensate for variable blow-up ratio in flat-oval and offset-neck containers; die gap adjustments of 0.5 mm are typically required when the die swell diameter at the die exit changes by more than 0.5 mm from the validation baseline. Blow air pressure is set between 0.55 MPa and 0.80 MPa, and mould cooling water is controlled at 8–16 °C to limit shrinkage-driven ovality. Batch-to-batch variation in MFR of ±0.05 g/10 min is considered acceptable without parison reprogramming; variation beyond that value requires verification of screw torque, head pressure, and drop-impact performance.

Compliance for household chemical containers is anchored to REACH 1907/2006, CLP 1272/2008, and the Packaging and Packaging Waste Directive 94/62/EC; where a child-resistant closure is part of the assembled system, the closure and bottle combination must be tested under ISO 8317. The compounding ratio for a single-layer detergent bottle is 100 wt% HE3366 as received, or 95–98 wt% HE3366 with 2–5 wt% white PE masterbatch for opacity; closed-loop regrind is limited to 0–5 wt% for labelled high-gloss surfaces and may be raised to 10–15 wt% only in the core of an unlabelled layer. Terminal articles include 250 mL to 5 L detergent, fabric softener, and surface cleaner bottles, including trigger-sprayer and offset-neck formats. Operational boundaries include exclusion of amine-based antistats due to surface transfer that interferes with pressure-sensitive label adhesion, and avoidance of silicone processing aids above 0.1 wt% unless downstream corona treatment is specified.

On accumulator-head machines producing industrial chemical jerricans with shot capacities between 1.5 kg and 10 kg, HE3366 is run at melt temperatures of 190–205 °C and a mould cooling water inlet of 10–20 °C. Accumulator drop speed and die gap are programmed with 20–64 points to prevent thinning at the chime and top shoulder. The moulding process includes a post-mould hydraulic pressure test according to the design-type approval for UN 3H1, followed by a leakproofness test and a 1.2 m drop test after conditioning at −18 °C for 24 h when the container is destined for dangerous goods transport. Screw speed on 20:1 to 24:1 L/D barrier screws is typically reduced to 40–60 rpm to avoid polymer degradation at the higher shear rates generated in the accumulator head. Wall thickness distribution is verified by sectioning at the chime, sidewall, and shoulder, with minimum sidewall thickness controlled by the design-type drop test and hydraulic pressure requirements rather than a single fixed value; converters frequently set a minimum of 2.0 mm at the chime for 20 L jerricans.

For dangerous goods packaging, the relevant performance standard is the UN 3H1 design type under 49 CFR §178.509 for US shipments and ADR 6.1.5.2 for European road transport, including leakproofness, hydraulic pressure, stacking, and drop testing. The recommended blend ratio is 70–85 wt% virgin HE3366 with 15–30 wt% internally generated regrind from trimmed tails and rejected containers; regrind is reintroduced after dedusting and a minimum of 20 minutes at 80 °C hopper drying when ambient humidity exceeds 60% RH. Carbon black masterbatch at 2–2.5 wt% is added for outdoor storage, and thermal stabilizer masterbatch at 0.1–0.3 wt% is added when the jerrican will be exposed to sustained temperatures above 45 °C. Terminal articles include 5 L, 10 L, 20 L, and 25 L stackable jerricans for water-based chemical formulations, industrial cleaners, and concentrated intermediates. Compatibility testing with aliphatic or aromatic solvents must be performed separately because HDPE can exhibit environmental stress cracking or permeation in contact with low-molecular-weight hydrocarbons unless fluorination or an internal barrier layer is used.

Why Does Parison Sag Constrain Multilayer Cosmetic Bottle Production?

The limiting defect in small-volume multilayer cosmetic bottle production is not melt fracture but parison sag, which is controlled by the bimodal molecular weight distribution of HE3366 and by maintaining die head temperature in the range of 190–205 °C. On co-extrusion blow-moulding lines with 3–5 extruders feeding a 5-layer annular die, HE3366 is used in the skin and inner layers, with EVOH barrier at 3–6 wt% of total structure and maleated polyolefin tie resin at 2–4 wt%. The outer HE3366 layer is metered at 90–100 wt% virgin resin, colour masterbatch at 0.3–0.8 wt%, and no closed-loop regrind when surface gloss or silk-screen adhesion is critical; regrind containing EVOH is limited to 10 wt% of the core layer only. Parison programming with 30–64 points is synchronized to the container’s shoulder and base geometry to prevent thickness drops below 0.4 mm in the wall. Blow air at 0.4–0.7 MPa and polished aluminium moulds at 8–12 °C are used to obtain reproducible surface quality.

Cosmetic finished articles fall under Regulation (EC) No 1223/2009, Article 17, for the safety assessment of the cosmetic product in contact with the packaging; packaging manufacture should be conducted under a quality management system aligned with ISO 22716. Compatibility screening evaluates migration of the masterbatch colourants and any external lacquers under 40 °C storage for 3 months, and closure torque retention is measured according to the assembled bottle-neck specification. Terminal articles include 15–500 mL lotion, toner, serum, and cosmetic squeeze bottles with snap-on or screw closures; the structure is also used for translucent tinted extrusion blow-moulded tubes where the HE3366 layer contributes stiffness and drop strength. Operational boundaries include avoidance of regrind from EVOH-containing offcuts in the outer surface layer because gel-like defects and delamination can appear during post-mould cooling, and exclusion of organic pigments that exceed the colourant purity limits set by Regulation (EC) No 1223/2009 Annex II.

For solid-dose pharmaceutical packaging, the extrusion blow-moulded bottle must meet compendial testing for extractables and polymer identity rather than a commercial shelf-life requirement alone. HE3366 is processed on cleanroom blow-moulding lines under ISO 14644-1 Class 8 at a minimum, with compressed air filtered through 0.2 µm hydrophobic cartridges and maintained at a dew point below −20 °C. The addition ratio is 100 wt% virgin HE3366; no regrind, colour masterbatch, antioxidant top-up, or processing lubricant is permitted unless the complete container system is revalidated under USP <661.1> and USP <661.2>. The base resin is referenced in 21 CFR §177.1520 for olefin polymers used in food-contact and pharmaceutical closures, and the finished container must be assessed against the relevant polyolefin monograph, such as Ph. Eur. 3.1.3. Manufacturing runs use validated extrusion temperatures, screw speed, and blow-pin temperatures; any change in these parameters requires a comparability protocol under ICH guidance. Terminal articles include 30–500 mL oral solid-dose bottles and desiccant-containing packs where moisture barrier is achieved through closure systems rather than the HDPE matrix alone.

Processing constraints are stricter than those for industrial containers. Crystallization shrinkage after demoulding can alter neck diameter by 0.05–0.10 mm, so cooling time and blow pin diameter must be controlled to maintain cap torque. Melt temperature is held at 185–200 °C, mould temperature at 5–15 °C, and blow air pressure at 0.5–0.75 MPa. Published data for HE3366 in long-term extractables studies under all compendial solvents is limited; converters must perform targeted extractables and toxicological evaluation under USP <1663> and USP <1664> for the final article. The primary operational boundary is that any post-mould additive from reprocessed material or non-approved masterbatch may increase extractable organic carbon and invalidate the container system, so dedicated resin handling and segregated granule conveying are mandatory.

If Automotive Washer Fluid Containers Are Moulded Without Barrier Additives

Aqueous windshield-washer formulations, screen wash concentrates, and service-fill maintenance fluids are filled into extrusion blow-moulded containers where the primary failure modes are environmental stress cracking at the molten pinch-off, drop impact at low temperatures, and cap seal leakage after repeated thermal cycling. HE3366 is processed with a melt temperature of 200–210 °C, blow air at 0.6–0.85 MPa, and mould cooling water at 10–20 °C; accumulator-head machines with 1.5–8 L shot capacity are used for containers between 1 L and 5 L. A post-mould leak detection station using pressure-decay with a test pressure of 35–50 kPa for 15–30 s is placed after deflashing. Wall thickness around the handle bridge and shoulder is controlled by 20–40 parison programming points; minimum wall thickness is maintained at 1.2 mm for high-stress handle sections.

The compounding ratio is 75–85 wt% virgin HE3366, 15–25 wt% closed-loop regrind from deflashed tails, blue or red PE colour masterbatch at 0.5–1.0 wt%, and UV stabilizer masterbatch at 0.3–0.5 wt% for containers stored outdoors before filling. Regulatory assessment is based on REACH 1907/2006 and the RoHS Directive 2011/65/EU for heavy metals in colourants and stabilizers; accelerated heat ageing of the finished container is performed under ISO 188 at 80 °C for 168 h, with tensile retention checked under ISO 527-2. Terminal articles include 1 L, 2 L, 3 L, and 5 L automotive windshield washer fluid bottles, screen wash refill packs, and pre-mixed coolant service containers. Incompatibility boundaries are specific: coolant containing ethylene glycol may reduce stress crack resistance at temperatures above 60 °C, and moulded-in handles must be tested for ESCR under ASTM D1693 condition B at 50 °C with a minimum F50 acceptance threshold set by the OEM specification.

Moulding open-top pails and wide-mouth jars for water-based paints, adhesives, and waterproofing membranes uses HE3366 in large accumulator-head machines with 2–10 kg shot capacity and clamp forces from 600 kN to 1200 kN. The melt temperature is held at 190–205 °C, and conformally cooled aluminium moulds at 8–15 °C are used to control pail wall thickness and top rim geometry. Parison programming with 20–64 points is required because the pail sidewall transitions from a thick rim to a thinner body; wall thickness is measured by ultrasonic gauge at 12 positions around the circumference. The blend ratio is 80 wt% virgin HE3366 and 20 wt% in-house regrind from punched-out top rims and rejected pails; an anti-static masterbatch may be added at 0.2–0.5 wt% when powders or fine-particle products are packaged. The process includes a top rim curling or trimming station, integral handle punching, and a vacuum leak test at −20 kPa for 10 s on finished pails.

Compliance for non-food industrial packaging is assessed under Directive 94/62/EC for heavy metal content and under RoHS Directive 2011/65/EU where colourants or stabilizers must meet restricted substance thresholds. Stacking compression is evaluated under ASTM D2659 at 23 °C and 50% relative humidity for 48 h; open-top pails must show top-load deflection below the contract limit without buckling or rim distortion. Terminal articles include 1 L, 5 L, and 10 L open-top pails, wide-mouth jars, and tamper-evident buckets for water-based coatings, tile adhesive, joint compound, and waterproofing products. Incompatibility boundaries include ketone-containing solvent-based paints, which can attack HDPE through sorption and softening, and sustained storage above 45 °C under stacked load, which may accelerate creep in the pail sidewall.