INEOS HDPE K38-20-160 is specified with a nominal density of 0.938 g/cm³ and a melt flow rate of 0.20 g/10 min measured at 190 °C/2.16 kg under ISO 1133-1:2022. The downstream application tracks below are limited to demonstrable conversion routes for high-molecular-weight HDPE: extrusion blow moulding, sheet extrusion and thermoforming, corrugated conduit production, large-part blow moulding, automotive reservoir moulding, and blown film extrusion. Each entry carries the regulatory frame, formulation addition boundary, production line configuration, and finished-article class required for downstream sourcing evaluation.

Extrusion Blow Moulding of UN-Certified Industrial Liquid Containers

The extrusion blow moulding of UN-rated containers from K38-20-160 is governed by the UN Model Regulations Chapter 6.1 for rigid plastics packagings, with performance qualification under 6.1.5.1 drop test, 6.1.5.2 leakproofness test, and 6.1.5.3 hydraulic pressure test. Transport-specific variants such as ADR/RID and IMDG require the same UN design type marking, commonly 3H1 for non-removable-head jerrycans, and stacking resistance validated according to the package design height and gross mass. The formulation addition ratio on qualified lines is 100 wt% virgin K38-20-160, with clean, dry same-grade regrind permitted at 0–20 wt% for non-aggressive filling goods; regrind fractions above 20 wt% are not typical for -18 °C drop-test service because of reduced environmental stress cracking resistance and weld-line impact strength. Carbon black masterbatch is introduced at 2.0–2.5 wt% only when UV resistance is specified, and calcium carbonate or other mineral fillers are excluded because they degrade the UN 6.1.5.1 low-temperature drop performance.

The production process is executed on shuttle-type extrusion blow moulders fitted with accumulator heads, typically using an 80 mm extruder with 24:1 L/D and grooved feed section. Melt temperature is maintained at 180–210 °C, with the die gap set between 2–4 mm and a 100-point parison programmer controlling wall distribution across the pinch-off and handle zones. Blow pressure is held at 0.6–0.8 MPa, mould temperature at 8–15 °C, and cycle time for a 20 L container ranges from 45–75 s depending on wall thickness and cooling configuration. Terminal finished product types include 5–30 L UN 3H1 jerrycans, 60 L closed-head drums, and narrow-neck industrial chemical bottles used for liquid agrochemicals, detergents, and water-based industrial formulations. A production-scale failure mode observed with this grade is parison sag and uneven wall thickness when accumulator head temperature drifts above 210 °C; this defect is controlled by a 10–30 °C downward melt profile from the die head to the extruder metering zone rather than by increasing die gap alone.

Thermoforming of heavy-gauge K38-20-160 sheet for lead-acid battery trays and secondary containment pallets begins with sheet extrusion followed by plug-assisted forming. The governing compliance frame is ISO 527-3 for tensile properties of plastics sheet, ISO 6603-2 for multiaxial impact behaviour, and ASTM D1693-15 for environmental stress cracking resistance under Condition B. The formulation addition ratio is 100 wt% virgin K38-20-160, or 75–90 wt% virgin with 10–25 wt% clean edge-trim regrind from the same sheet line. Antistatic masterbatch is added at 1–3 wt% only where static dissipation is specified for battery handling, and UV stabilizer is added at 0.2–0.5 wt% for outdoor containment service. Low-molecular-weight process lubricants are excluded because they migrate to the sheet surface and reduce thermoforming weld strength. The production route uses a 90 mm single-screw extruder with 30:1 L/D, barrier screw, and Maddock mixing section; melt temperature is controlled at 200–230 °C, the chill roll stack is set at 40–60 °C, and sheet thickness is maintained between 1.5–6.0 mm. Radiant heating brings the sheet to 160–190 °C before plug-assisted forming with an aluminium plug held at 110–130 °C. Finished article types include lead-acid battery trays, corrosion-resistant containment pallets, chemical storage cabinet liners, and automotive underbonnet protector panels.

What Limits the Regrind Fraction When K38-20-160 Feeds Corrugated HDPE Conduit Dies?

On corrugated conduit lines processing K38-20-160, the relevant compliance standards are EN 13476-1 for structured-wall plastics piping systems, ISO 9969 for ring stiffness testing, and EN 1411 for impact resistance of thermoplastic pipes. The formulation boundary is set by the need to retain wall-thickness consistency in the corrugation roots. Reprocessed material from the same production line is introduced at 15–30 wt%, while carbon black masterbatch is added at 2.0–3.0 wt% to achieve a dispersed carbon black content of 2.0–2.5 wt% for outdoor UV stability. Regrind fractions above 30 wt% are not recommended because the lower melt strength of thermally aged material increases web sag between corrugator blocks, producing thin valley sections that fail EN 1411 impact at -10 °C. The downstream production process uses a single-screw extruder with 75 mm 25:1 L/D, grooved feed, melt temperature 190–210 °C, and corrugator die head held at 200–210 °C. Vacuum forming is applied at -0.02 to -0.06 MPa, haul-off speed is maintained at 0.5–2.5 m/min, and the mould blocks are water-cooled to 50–70 °C. Finished articles are corrugated land drainage pipe with 100–200 mm outer diameter, cable protection ducts, and low-pressure agricultural drainage lines. This grade is not designated for pressure pipe service under PE 100 classification, and published data for this specific configuration in potable water systems is limited.

When Composite IBC Inner Bottles Require Fluorination-Resistant HDPE Grades

Under UN Chapter 6.5, composite intermediate bulk container inner bottles moulded from K38-20-160 are type-approved as part of an assembly, commonly 31H1 for rigid plastic inner receptacle with outer steel frame. The performance test sequence includes bottom lift, top lift, stacking, drop, and leakproofness, with the drop test performed on the filled assembly at 0.8 m height for 1,000 L packaging. The formulation addition ratio is 100 wt% virgin K38-20-160 for solvent-containing or oxidizing liquids; 10–15 wt% same-grade regrind is permitted only for non-aggressive aqueous fluids. Fillers and external lubricants are excluded because accumulator head wall slip and parison sag change the final wall distribution. The production process is performed on large-part blow moulding machines with 120–150 mm extruders, 30:1 L/D, and accumulator capacity of 10–15 kg. Melt temperature is held at 180–200 °C, parison hang time is kept below 90 s, blow pressure is 0.5–0.7 MPa, and mould clamp force is 1,200–2,000 kN. Terminal products are 1,000 L inner bottles for composite IBCs used with water-based chemicals, mild acids, and alkalis. If surface fluorination is specified for permeation control, validation on the actual bottle geometry is required because published data for this specific bottle configuration is limited.

For automotive washer reservoir applications, K38-20-160 is validated against OEM component specifications rather than a single global standard. Typical qualification includes ISO 16750-4 environmental loads and OEM thermal cycle tests from -40 °C to 120 °C. The formulation addition ratio is 100 wt% virgin grade with 1.0–2.0 wt% carbon black masterbatch for UV resistance and 0.1–0.3 wt% antioxidant masterbatch in hot coolant service. The production route uses shuttle blow moulding with a 70 mm 24:1 L/D extruder, melt temperature 180–200 °C, mould temperature 15–30 °C, and blow air at 0.5–0.7 MPa. Finished articles are 3–7 L windshield washer reservoirs, coolant expansion tanks, and diesel exhaust fluid bottles, all requiring leak-tight weld seams and resistance to ethylene glycol at 121 °C. A production-line failure mode observed with this grade in coolant bottle moulding is weld-line cracking after rapid cooling; this is addressed by increasing mould temperature to 25–30 °C and reducing blow pressure to 0.5 MPa during the first 3–5 s of inflation.

Thin-Gauge HDPE Liner Film Collapses Without Controlled Blow-Up Ratio

Blown film extrusion of K38-20-160 for industrial liner and temporary containment applications is characterized under ASTM D1709-16a for dart drop resistance, ASTM D882-18 for tensile properties of thin sheeting, and ASTM D1238-20 for melt flow verification. The formulation addition ratio is 100 wt% K38-20-160, or 85–95 wt% K38-20-160 with 5–15 wt% LDPE to suppress melt fracture at high throughput. Carbon black masterbatch is added at 2.0–3.0 wt% for black construction film. The production process uses a bottom-fed blown film die of 150–300 mm diameter, die gap 1.2–2.0 mm, blow-up ratio 3.0–4.0, melt temperature 190–210 °C, frost line height 6–10 die diameters, and collapsing frames with wooden slats or non-marking rollers to avoid surface scoring. Terminal film types are 100–250 µm construction liners, contaminated soil containment sheeting, and temporary vehicle covers. The film is not recommended for potable water contact without NSF/ANSI 61 validation.