UN-rated jerrycans blow-moulded from PetroChina Fushun HDPE 2908 are produced on shuttle-type extrusion blow moulding machines fitted with grooved feed bushings and barrier screws having L/D ratios between 24:1 and 30:1. The grade is typically controlled to a melt mass-flow rate of 0.7–1.0 g/10 min under ISO 1133-1:2022 at 190 °C/2.16 kg, which provides sufficient parison sag resistance for 5 L through 30 L containers while retaining adequate extruder throughput. Qualification for dangerous goods packaging is governed by UN 1H1/1H2, ADR/RID/IMDG Code periodic retests, and ISO 16101:2014 chemical compatibility assessments. Production formulations in this segment use 100 phr virgin 2908, 15–30 wt% post-industrial regrind of the same grade, 2.0–4.0 wt% carbon black or UV masterbatch where the container is stored outdoors, and 0.02–0.06 wt% polymer processing aid to delay melt fracture. Barrel profiles are set from 175 °C in the feed throat to 205–210 °C at the die head; melt temperature above 215 °C produces visible surface tack and prolonged cooling time, while melt below 170 °C elevates die head pressure and creates weak pinch-off weld lines. Die gap is maintained at 1.8–2.5 mm, blow pressure between 0.6 MPa and 0.9 MPa, and mould temperature between 10 °C and 25 °C to achieve a stable parison swing and prevent post-mould shrinkage. The terminal parts are closed-head and open-head jerrycans from 5 L to 25 L, stackable 30 L drums, and returnable industrial containers used for lubricants, agricultural chemicals, and solvent-free cleaning agents. A known operational boundary is that thin-wall containers below 1.0 mm nominal wall require a higher-flow grade or sequential coextrusion; 2908 is not selected for injection-moulded caps or thin-wall pails because the low MFR limits fill performance in multi-cavity injection tools.

What Changes When 2908 Is Coextruded into High-Strength Liner Film?

In heavy-duty liner film, PetroChina Fushun HDPE 2908 is typically coextruded as the stiffening layer with LDPE or LLDPE skins to raise modulus while avoiding the dart-impact loss associated with a monolithic HDPE film. Compliance for industrial non-food liners is usually demonstrated through ISO 527-3:2018 tensile properties, ISO 7765-1:1988 free-falling dart impact, and REACH Article 33 communication for SVHC content; food-contact use requires additional validation under 21 CFR 177.1520 and is not implied by the grade alone. The production recipe commonly uses 70–85 wt% 2908, 15–30 wt% LLDPE or LDPE, 0.05–0.10 wt% hindered phenolic antioxidant, and 0.1–0.3 wt% antiblocking masterbatch in the skin layer. Blown film lines for this grade use a 30:1 L/D barrier screw, a die gap of 1.2–1.8 mm, a die diameter between 150 mm and 300 mm, and a blow-up ratio of 3:1 to 4:1. Melt temperature is held at 190–210 °C, while frost line height is maintained between 4 and 8 die diameters; a frost line below 3 die diameters increases bubble instability and blocking, whereas a frost line above 8 die diameters reduces bubble track stability at high output. The terminal products include flexitank inner liners, FIBC inner liners, temporary landfill and containment films, and industrial bag-in-box liners for non-hazardous chemical powders.

Monofilament lines processing PetroChina Fushun HDPE 2908 usually select a die land ratio of 8:1 to 12:1 to suppress melt fracture before the yarn enters the water quench. The grade’s controlled MFR under ISO 1133-1:2022 allows a draw ratio of 6:1 to 10:1 in the first hot-air stage without filament breakage; a second relaxation godet at 0.9:1 to 1.1:1 is used to reduce fibrillation in the final yarn. The formulation is typically 97–99 wt% 2908, 1–3 wt% UV-stabilized black or green masterbatch, 0.1–0.3 wt% processing lubricant, and 0.02–0.05 wt% antioxidant. Extrusion is performed on a single-screw extruder with a 30:1 L/D screw, melt temperature between 190 °C and 210 °C, and water quench temperature controlled to 30–50 °C. The first-stage draw oven is set at 90–120 °C, and the annealing oven at 100–115 °C for 0.5–2.0 s residence time. Compliance for finished ropes and nets is evaluated under ISO 2307:2019 for rope breaking load, ISO 1805:2006 for netting yarn breaking load and elongation, and ASTM D3218-07(2018) for polyolefin monofilament specification. Terminal products are high-tenacity rope cores, industrial gill netting, agricultural shade cloth, woven geotextile yarn, and brush bristle substitutes. A practical production constraint is that draw resonance appears when the first-stage draw ratio exceeds 10:1 and water quench temperature deviates by more than ±2 °C from the set value; published data for this specific configuration is limited, and line validation is required per die-hole diameter.

When Corrugated Drainage Pipe Must Balance Flexural Modulus and ESCR

Non-pressure corrugated drainage pipe manufactured from PetroChina Fushun HDPE 2908 is run on single-screw extruders feeding a continuous corrugator; the process window is narrower than blow moulding because the corrugator vacuum must hold the melt against the mould blocks without tearing or thinning the trough. Formulations in this segment use 95–97 wt% 2908, 2–5 wt% carbon black masterbatch for UV stabilization, and 0.02–0.05 wt% processing aid; carbon black above 5 wt% reduces corrugator throughput and increases surface roughness, while below 2 wt% does not provide reliable outdoor UV resistance. Melt temperature is controlled at 185–210 °C; vacuum at the corrugator blocks is set from -0.03 MPa to -0.06 MPa, and cooling water is held at 10–20 °C. Product validation follows ISO 9969:2016 for ring stiffness, EN 13476-2:2018 for structured-wall drainage pipe, and ASTM F2306/F2306M for corrugated HDPE pipe and fittings. The resulting end products are corrugated agricultural drainage pipe, cable protection conduit, stormwater retention chambers, and subsoil drainage laterals. This is not a pressure water or gas pipe resin; the grade has no PE100 or PE80 designation and must not be used where a pressure-rated pipe body is required. Process operators monitor melt temperature at the die with an infrared sensor because a melt temperature swing of more than ±5 °C changes vacuum hold depth and leads to intermittent block-hole tearing in the corrugation valleys.

Twin-Sheet Thermoforming of Chemical Containment Pallets from Dense Polyethylene Sheet

Sheet lines running PetroChina Fushun HDPE 2908 extrude at 190–210 °C onto a three-roll polishing stack held at 70–90 °C; the sheet is then twin-sheet thermoformed at a core temperature of 135–165 °C. Formulation consists of 97–99 wt% 2908, 0.05–0.15 wt% antioxidant, 0.5–2.0 wt% colorant or antistatic masterbatch, and 20–40 wt% in-house regrind. Thermoforming uses plug-assisted twinsheet tooling with aluminium temperature control at 60–80 °C; wall thickness above 2 mm is common for chemical containment service. Compliance is commonly assessed with ISO 1183-1:2019 for density, ISO 179-1:2010 for notched impact, and EN 13575:2012 for static-pile load performance on pallets. Terminal products include twin-sheet chemical containment pallets, secondary spill trays, machine-side drip trays, and reusable acid/alkali collection basins. Outdoor use without carbon black stabilization leads to UV embrittlement within a service window that varies by thickness and exposure, so applications are usually indoor or covered.

Drawing Raffia Tape Without Sacrificing Tensile Impact Retention

Raffia tape production from PetroChina Fushun HDPE 2908 uses a flat film die of 900–1400 mm width, water quench at 25–40 °C, and slitting before hot-air drawing. The tape compound is composed of 95–98 wt% 2908, 0–10 wt% calcium carbonate masterbatch where stiffer tape is needed, 1–3 wt% UV masterbatch, and 0.05–0.10 wt% antioxidant. Orientation is performed in a hot-air oven at 120–140 °C using a draw ratio of 6:1 to 8:1, followed by 0.5–1.0% relaxation to control shrinkage. Tensile properties for tape and woven fabric are checked under ISO 527-3:2018 and ISO 1805:2006, and the finished flexible intermediate bulk container fabric may require ISO 21898:2004 where FIBC certification is specified. The end products are woven sacks for fertilizers and chemical powders, FIBC bulk bag outer fabric, industrial tarpaulins, and agricultural ground cover tape. Draw ratios above 8:1 increase linear tensile strength but reduce transverse split tear resistance; below 6:1 the tape retains high impact but shows elevated elongation and lower creep stability. The process boundary is therefore a draw-ratio window of roughly 6.5:1 to 7.5:1 for balanced woven fabric performance, and published data for this specific configuration is limited because tape width, oven residence time, and water bath temperature interact with die gap.