In potable water and fuel gas distribution networks, Shanghai Jinfei HDPE HHM-TR210 is processed as a high-molecular-weight, multimodal pipe-grade resin on single-screw extruders with a grooved feed section and a 33:1 to 37:1 L/D ratio. The grooved-feed geometry increases solids conveying efficiency at screw speeds below 90 rpm and reduces output sensitivity to back-pressure fluctuation caused by screen pack blinding. Barrel temperatures are typically set from 180 °C at the feed zone to 230 °C at the metering zone, with a measured melt temperature at the die inlet maintained at 195–210 °C to avoid both melt fracture and excessive sag. A barrier screw with a Maddock mixing section disperses carbon black and stabiliser packages; screen packs of 60/80/100 mesh are installed upstream of a gear pump to dampen pressure variation below ±0.5 bar. The pipe is formed through a spiral mandrel die with a die land temperature of 200–215 °C, calibrated under vacuum in a first cooling tank at 15–25 °C, and subsequently cooled in spray tanks to a surface temperature below 60 °C before haul-off. Pressure pipe produced from this resin class is tested against ISO 4427 for water and ISO 4437 for gaseous fuels; hydrostatic design basis is established under ISO 9080:2022, with a minimum required strength of 10.0 MPa at 20 °C for a 50-year service life, corresponding to PE 100 classification under ISO 12162. Slow crack growth resistance is evaluated with the notched pipe test according to ISO 13479:2022, while resistance to rapid crack propagation is assessed at 0 °C using ISO 13477. Carbon black content for UV-stabilised black pipe is tested to ISO 6964 and is typically maintained between 2.0 wt% and 2.5 wt%, with dispersion rating verified under ISO 18553. Terminal products include SDR 11 to SDR 17.6 pipes in nominal diameters from 32 mm to 1200 mm, used for municipal water mains, irrigation laterals, and gas distribution laterals. Because HDPE does not require drying below 60 % relative humidity, surface moisture is removed by a pre-drying step at 80 °C for 2 h when storage RH exceeds 80 %. The grade should not be processed above 240 °C for extended residence times because oxidative chain scission increases melt flow and reduces hydrostatic strength; resin suppliers recommend purging with a non-abrasive HDPE if line stoppage exceeds 30 min.

What Limits Wall-Thickness Control in Large-Diameter Mining Slurry Pipe Extrusion?

Wall-thickness variation in large-diameter mining slurry pipe extrusion is governed by the interaction between melt elasticity, gravitational sag, and vacuum calibration efficiency. HHM-TR210, when run on a single-screw extruder with a 150 mm screw diameter and 33:1 L/D ratio, exhibits a process window in which the die temperature must remain between 190 °C and 205 °C: below this range, melt pressure rises above 350 bar and accelerates screw wear; above it, the unsupported parison between die exit and calibration sleeve sags non-uniformly, producing greater wall thinning at the 12 o'clock position. The problem is amplified for diameters above 800 mm and SDR values above 21. Processing lines are therefore equipped with multiple ultrasonic wall-thickness sensors spaced around the circumference at the puller, feeding closed-loop control to individual die gap adjustment bolts or heating zones on the die ring. HHM-TR210 has a sufficiently high zero-shear viscosity and shear-thinning behaviour that melt pump pressure fluctuation is controlled to ±0.3 bar, reducing short-term wall variation to below 1.5 % of nominal wall at the cold end. The calibration sleeve diameter is typically 1–2 % above pipe outer diameter, and first-tank vacuum is maintained at −0.2 bar to −0.4 bar relative to atmosphere, with water temperature at 15 °C to increase the frozen skin layer. In slurry transport applications, the pipe is subjected to internal pressure testing under ISO 1167-1 and resistance to slow crack growth under ISO 13479, because mine tailings slurries contain angular solids that impose tensile strain at the pipe inner wall. Published data for the specific abrasion resistance of HHM-TR210 under slurry conditions is limited; selection for mining tailings lines should be confirmed by a 1000 h hydrostatic test at 80 °C and 0.92 MPa hoop stress using the ISO 13479 notched pipe method. Terminal products are DN 315 to DN 1200 solid-wall HDPE tailings pipelines, dredge discharge lines, and mine dewatering mains, with butt-fusion joining according to ISO 21307 to avoid leak paths at the highly filled slurry flow boundary.

Extruded sheet and geomembrane liners represent a downstream use of HHM-TR210 in which the resin is processed on a single-screw extruder with a coat-hanger or fishtail die and a three-roll polishing stack. Sheet thicknesses from 2 mm to 10 mm are produced for chemical containment sumps, tank liners, and secondary containment basins where weld integrity and stress crack resistance are decisive. Melt temperature is maintained between 195 °C and 210 °C, die width is set 5–10 % above final sheet width to compensate for edge bead and neck-in, and roll-stack temperatures are kept at 80–100 °C to control surface gloss and minimise residual orientation. The sheet is cut and welded using hot wedge welding or extrusion welding in accordance with DVS 2207-1; weld peel and shear tests are conducted per ASTM D6392 or ASTM D4437 for geomembranes. Chemical resistance is evaluated by immersion in representative media under ASTM D543 or ISO 175, and environmental stress cracking resistance is measured with ASTM D1693 using 100 % Igepal CO-630 at 50 °C. A typical acceptance criterion for containment applications is a bent-strip ESCR time above 500 h for the base resin; grade-specific certificates from Shanghai Jinfei should be checked against this value because published data for this specific configuration is limited. Terminal products include extruded HDPE liner panels, sump liners, and weld-on pipe boot flashings for chemical process containment systems. This segment is less demanding in terms of long-term hydrostatic strength than pressure pipe but requires consistent carbon black dispersion and fusion weld quality, because a single weld defect becomes the primary leak path under low-pressure chemical exposure.

Extrusion Blow Moulding of 220 L Tight-Head Drums and Intermediate Bulk Container Liners

Large-part extrusion blow moulding of HHM-TR210 is carried out on accumulator-head machines with a shot size of 10–30 kg, clamp force of 80–150 t, and a parison programmer controlling die gap to maintain wall thickness in the final drum. The resin’s high melt strength and high viscosity allow a melt temperature of 190–210 °C at the accumulator discharge; lower temperatures produce excessive melt pressure and uneven parison inflation, while higher temperatures reduce parison sag resistance and widen the pinch weld. Blow air pressure is set at 0.6–0.8 MPa with pre-blow and final blow stages separated by 0.5–1.0 s to limit surface defects in the pinch weld zone. Mould temperature is held at 10–20 °C to accelerate solidification but not below the dew point, which can produce surface pitting on humid shift operations. Cycle times for a 220 L tight-head drum typically range from 120 s to 180 s depending on wall thickness and cooling water flow. The terminal product is tested as dangerous-goods packaging under the UN 6.1/6.5 scheme; drop impact at −18 °C is performed per ASTM D2463 or ISO 2248, with a minimum drop height of 1.2 m for 220 L capacity. Stacking load resistance is evaluated under ASTM D2659 at 40 °C for 28 days. This application is only feasible when the supplier lot has a swell ratio and melt strength within the blow moulding range; if a lot falls outside the established viscosity window, pinch weld thinning and neck flash detachment become the primary failure modes. The HHM-TR210 designation does not itself guarantee blow moulding suitability for all lot-to-lot variations, so incoming melt flow and density certificates must be checked against the converter’s machine-specific process capability study.

Thermoforming of HHM-TR210 extruded sheet is used for containment pallets, battery acid trays, and chemical drip pans where the process is limited by the resin’s high melt viscosity compared with lower-molecular-weight HDPE grades. Sheet surface temperature must reach 160–180 °C in the heating station; below 160 °C, plug-assisted vacuum forming produces microcracks at the corners, above 180 °C the sheet sags unevenly and may contact heating elements. A twin-sided ceramic or quartz heater array with a power density of 30–50 kW/m² is used, and the sheet is heated in two stages to reduce surface-to-core temperature differential. Mould temperature is maintained at 60–80 °C to permit part release but not so high that post-form shrinkage exceeds 2 % in the machine direction. The terminal product is tested for stress cracking resistance under ASTM D1693 and for drop impact under ASTM D1998 for upright storage tanks and trays. Post-form annealing at 80 °C for 2 h reduces residual orientation and raises chemical resistance by reducing internal stress. Published data for the specific thermoforming behaviour of Shanghai Jinfei HHM-TR210 is limited; run-in trials on a production line with temperature profiling and grid strain analysis are recommended.

When HHM-TR210 Replaces Conventional HDPE in Thick-Wall Injection-Moulded Fittings

The replacement of a conventional pipe-grade HDPE with HHM-TR210 in thick-wall injection-moulded fittings is constrained by high melt viscosity and long cooling time, but it is feasible on reciprocating-screw machines with a screw L/D ratio of 20:1 to 24:1, low compression ratio of 2.0:1 to 2.5:1, and clamp force above 500 t for large branch fittings. Melt temperature is held at 220–240 °C, injection pressure at 80–120 MPa, and holding pressure at 60–100 MPa for 15–30 s, depending on wall thickness and gate geometry. Mould temperature is maintained between 10 °C and 40 °C; higher mould temperatures improve weld line strength but extend cycle time. Because thick-walled fittings can develop sink marks, gate sizing and holding pressure profiles are adjusted to compensate for volumetric shrinkage of approximately 12–16 % during crystallisation. The moulded fitting is pressure tested under ISO 1167-1, and butt-fusion joint tensile strength is verified by ISO 13953 for welded assemblies. The process is limited by slow flow lengths, so wall thickness above 50 mm is generally avoided unless special low-shear gates and hot runners are used. When compared with pipe-grade HDPE, the HHM-TR210 lot must be checked for MFR at 190 °C/5 kg and density according to ISO 1133-1 and ISO 1183-1, because a reduction in melt flow below established machine capability will increase filling pressure and can freeze off the gate before packing is complete. Terminal products include butt-fusion and electrofusion tap saddles, branch saddles, and flange adaptors in DN 110 mm to 500 mm water and gas distribution networks.