TotalEnergies HDPE 4206B BK is transferred directly to the extruder hopper of a 60–90 mm single-screw blow moulding machine with a grooved feed bushing and a 24:1–28:1 L/D screw. The barrel profile from feed throat to metering zone is held at 170–190 °C, while the accumulator head and die are trimmed to 195–205 °C. Screw speed is restricted to 40–70 rpm and back pressure is kept below 10 MPa to prevent carbon black agglomeration. The resin’s high-load melt flow rate under 21.6 kg load at 190 °C is the primary control variable for parison hang length. Where parison length exceeds 800 mm, die gap is reduced to 0.8–1.1 times the target wall thickness to compensate for draw-down. Blow pressure of 0.65–0.75 MPa is applied after a pre-clamp delay of 8–10 s. Cooling water at 10–12 °C is circulated through the mould core and cavity; demoulding is initiated when the part wall temperature falls below 85 °C. This process sequence is used for 20–30 L UN-certified jerrycans and industrial detergent containers. The black compound already contains carbon black at a dispersion level sufficient for outdoor UV resistance without a secondary masterbatch. Carbon black dispersion is checked under ISO 18553:2002, with a retained rating of ≤ 2.5 for lot acceptance. Drop testing after conditioning at −18 °C is conducted on filled and sealed containers according to ASTM D2463-15 and ADR 6.1.5.3. The same containers are evaluated for environmental stress-crack resistance under ASTM D1693-15 Condition B, with failure recorded only when two parallel cracks propagate through the wall within the tabulated test period.

What Limits the Vacuum Sizing Window in Corrugated Cable Duct Extrusion?

Corrugated duct made from TotalEnergies HDPE 4206B BK runs without a separate carbon black masterbatch, so the melt pressure at the extruder die should not exceed 25 MPa to prevent additive agglomeration at the breaker plate. A 50–75 mm single-screw extruder with a 30:1 L/D screw feeds a corrugator at a melt temperature of 200–215 °C. The vacuum forming blocks are held at −0.2 to −0.4 bar relative to atmospheric pressure, and the mould block temperature is kept between 45 °C and 60 °C through closed-loop oil heating. Wall thickness for IEC 61386-24 compliant conduits is typically 1.2–3.2 mm, depending on nominal outside diameter. In-line regrind of the perforated corrugator start-up scrap is limited to 10 wt%, because higher closed-loop regrind fractions reduce the high-load melt index stability and produce visible surface streaks. Throughput is controlled by a gravimetric feeder to maintain ± 0.5 % mass per meter of finished duct. The finished duct is tested for compression strength and impact at −5 °C under IEC 61386-24:2020. The black compound satisfies RoHS limits for lead, mercury, cadmium, and hexavalent chromium under EU 2011/65/EU Annex II. REACH SVHC screening is generally limited to carbon black-derived PAHs under EC 1907/2006 Annex XVII. Published data for this specific corrugated duct configuration with 4206B BK are limited outside the converter’s internal extrusion records.

Extruded sheet from TotalEnergies HDPE 4206B BK is produced on a 90–120 mm single-screw sheet line with a barrier screw and a horizontal three-roll stack. Die temperatures are kept at 205–220 °C, and the roll gap is set to 1.5–4.0 mm for automotive wheel arch liner stock. The chill rolls are maintained at 35–55 °C to control crystallinity and to avoid warpage during downstream plug-assisted forming. Extruder back pressure is limited to 15 MPa to reduce shear heating of the black compound. Sheet surface temperature before forming is brought to 150–165 °C using twin infrared heating banks; the thermoforming mould is heated to 60–80 °C. Plug speed is limited to 200–400 mm/s to avoid local thinning at the wheel arch draw core. The formed parts are trimmed on a CNC five-axis router, and in-process regrind is reintroduced at up to 30 wt% with virgin material. This regrind fraction is monitored by melt flow rate testing under 21.6 kg load and 190 °C after each shift. The formed wheel arch liners are tested for low-temperature notch impact after conditioning at −30 °C for 24 h; acceptance criteria reference ISO 179-1:2010 Charpy notched impact and ISO 8256-1:2004 tensile impact. Tensile properties are measured according to ISO 527-2:2012. For passenger-cabin-adjacent parts, flammability is assessed under ISO 3795:1989 with a burn rate threshold defined by the vehicle manufacturer.

The comparative processing matrix below consolidates the melt temperature windows, critical control thresholds, and test methods used for the downstream routes described above.

Spiral-Wound Drainage Pipe Melt String Strength and Butt-Fusion Margin

For large-diameter spiral-wound pipe, TotalEnergies HDPE 4206B BK is extruded through a 50–70 mm profile die into a rotating drum winder. The melt strand is deposited at 195–210 °C onto the previously welded convolution. The drum surface is preheated to 40–60 °C with infrared panels to prevent cold-joint formation. The weld line temperature is verified with an infrared pyrometer at 200 °C before the compression roll. The winding pitch is adjusted to produce pipe with an internal diameter of 300–1,200 mm, and the strand compression roller applies 0.15–0.30 MPa contact pressure. The finished pipe is butt-fusion welded at 220 ± 5 °C using a hydraulically controlled welding machine; the fusion pressure is held at 0.15 MPa during the heating phase and released during the soak phase. Ring stiffness is measured under ISO 9969:2016 and creep ratio under ISO 9967:2016. The black compound provides UV stabilization for outdoor storage of pipe sections. However, published data for this specific spiral-wound configuration with 4206B BK are limited outside the manufacturer’s standard pipe test reports. The material should not be processed above 230 °C, because higher melt temperatures risk visible degradation of carbon black dispersion and a measurable drop in hot-tack string strength.

Thermoformed Boot Liners Require a Regrind Protocol and the Finished Part Must Survive a 48-Hour ESCR Check

Black HDPE 4206B BK is used in automotive boot liners and luggage-compartment trays because the material tolerates closed-loop thermoforming regrind without losing dimensional stability. Extruded sheet is run at a melt temperature of 200–215 °C and is fed into a contact-heat thermoforming press. The sheet is preheated to 158–168 °C, and the forming plug is coated with a PTFE release layer to reduce sticking of the black compound. Oven residence time is 180–240 s for 2.5 mm gauge sheet. The tooling is water-cooled to 45–65 °C to stabilize the final grain depth. Regrind generated from trim stations is passed through a screen changer with a mesh size of 120 µm and reintroduced at 25–30 wt%. The melt flow rate of the blend is measured every 2 h under 21.6 kg load and 190 °C; a deviation greater than ± 10 % from the virgin lot value triggers replacement of the regrind feeder. Finished parts are subjected to a 48 h environmental stress crack resistance test in 10 % Igepal CO-630 solution at 50 °C, following the test geometry of ASTM D1693-15. The same parts must pass a flat-unfold extraction test for volatile organic compounds if they are installed in the passenger cabin; the test method is VDA 277:1995 total emission. In multi-layer constructions involving an outer polypropylene film, the polyethylene substrate contributes to formability but published adhesion values for this exact construction remain limited.