Extrusion blow molding of 5 L to 30 L tight-head jerrycans for Class 3 flammable liquids and Packing Group II/III corrosive chemicals requires a high-molecular-weight HDPE with sufficient melt strength to prevent parison sag across die gaps of 12–18 mm. Braskem HDPE SGF4950TT is run on accumulator-head shuttle blow molders with a barrel profile from 180 °C to 230 °C and a head temperature maintained at 210–220 °C; mold coolant inlet is held at 10–20 °C to stabilize the pinch-off weld and handle flash. The grade is typically characterized by a melt flow rate of 0.30 g/10 min at 190 °C/2.16 kg when tested to ISO 1133-1:2022 and a density of 0.949 g/cm³ to ISO 1183-1:2019. The finished containers are subjected to UN qualification under 49 CFR 178.509 for jerricans and ADR/RID 6.1.3 for European road transport, including leakproofness, hydraulic pressure, and drop tests at -18 °C. Because the grade is a high-molecular-weight blow molding resin, parison swell in production is compensated in tooling; die land length and converging angle are adjusted so that the final wall thickness in the body sidewall remains 0.8–1.6 mm. For aggressive solvent-based formulations, the addition ratio is maintained at 100 wt% SGF4950TT; for less aggressive lubricant and detergent formulations, up to 20 wt% clean in-house regrind from the same production line is introduced, but ESCR F50 tested to ASTM D1693-15 condition B must remain above 150 h. When the regrind fraction exceeds 20 wt%, the molecular weight distribution narrows and the low-temperature drop performance at -18 °C degrades because the regrind has been subjected to one additional thermal history. Process conflict arises at the pinch-off seam: the high molecular weight of SGF4950TT reduces parison sag but also raises the required clamping force at the mold parting line because the weld bead is thicker and slower to cool. The accumulator head is therefore run with a 30–45° converging die and a land length-to-die-gap ratio of 10:1 to 15:1, which stabilizes the parison and limits die swell variability to within ±2% of target diameter. If the head temperature is raised above 230 °C to reduce melt fracture, the ESCR F50 measured on the finished sidewall drops below the 150 h threshold, so production lines hold head temperature at 210–220 °C even when this increases extrusion backpressure. The terminal product range includes UN-marked 5 L, 10 L, 20 L, and 30 L jerricans with calibrated neck finishes and tamper-evident closures.

What Changes When SGF4950TT Is Processed into Off-Road Diesel Tanks with Carbon Black Masterbatch?

Blow molding of 50–250 L diesel fuel and hydraulic oil reservoirs for agricultural tractors and construction equipment introduces long cycle times and thick walls; wall thickness at the tank bottom can reach 4–8 mm. The addition ratio of SGF4950TT is 100 wt% in the virgin layer, with 2.0–2.5 wt% carbon black masterbatch compounded into the melt phase when UV stabilization is required; regrind from rejected tanks is held at or below 5 wt% because fuel swell under ASTM D543-21 immersion testing alters dimensional stability more severely in regrind-containing walls. Processing takes place on single-station accumulator-head blow molders with a clamp force of 300–600 t and parison programming that varies the die gap from 18 mm at the top pinch to 8 mm at the tail to maintain sidewall uniformity. The mold is maintained at 15–25 °C; the blow air is introduced at 0.6–0.9 MPa through a blow pin that is kept free of residual melt to avoid microvoids at the insert. The grade’s high molecular weight provides melt strength sufficient to support parison lengths above 1.5 m without tensile thinning. For EU off-road equipment, plastic fuel tanks are evaluated under ECE R34.03 for fire resistance, and hydraulic reservoirs are typically qualified to OEM-specific pressure pulse and vibration schedules. Published comparative data for SGF4950TT in diesel versus gasoline permeation are limited; gasoline applications with high aromatic content require fluorination or coextruded barrier structures. Finished parts are 60–250 L diesel tanks with integrated baffles, fuel sender flanges, and roto-molded inserts, as well as 30–80 L hydraulic fluid reservoirs.

When 1–10 L agricultural chemical bottles are fluorinated in-line during blow molding, the inner wall polarity changes and the barrier performance against pesticide solvents is no longer controlled solely by the base resin’s crystallinity. The fabrication of such bottles from SGF4950TT is conducted on single-station extrusion blow molders with in-line fluorination ports positioned in the blow air circuit. The fluorination treatment modifies the inner surface of the HDPE wall to reduce solvent permeation for pesticide and herbicide formulations; the process uses a low-concentration fluorine-nitrogen gas mixture, typically below 1 vol% fluorine, for a short exposure window of 2–6 s during blow molding. Because fluorination changes surface polarity and can reduce seal integrity if overdosed, the treating gas ratio is controlled by mass flow meters and the bottle inner wall is not rinsed with aqueous systems unless the filler has validated closure torque. The formulation addition ratio is 100 wt% SGF4950TT for solvent-based agricultural formulations; color concentrate is limited to ≤2.0 wt% to avoid lowering ESCR F50 below 100 h under ASTM D1693-15 condition B. Wall thickness distribution is held at 0.8–1.5 mm in the panel and 1.2–2.0 mm at the handle pinch. Containers destined for the US market are evaluated against FIFRA 40 CFR 156 for label compliance and UN 49 CFR 173.24 for transport of hazardous materials; EU registrants follow CLP Regulation (EC) No 1272/2008 and UN ADR packaging instructions. The terminal product range includes 1 L, 2.5 L, 5 L, and 10 L HDPE bottles with barrier-treated interiors and child-resistant closure neck finishes.

Potable Water Cooler Bottles and NSF/ANSI 61 Extraction Limits

Blow molding of 19 L water cooler bottles and 10–20 L potable water vessels from SGF4950TT requires virgin resin only; regrind is excluded from the product-contact layer because NSF/ANSI 61 and EU Regulation (EU) 10/2011 migration limits apply to the finished article. The addition ratio is 100 wt% SGF4950TT, with no processing aids unless the specific additive is covered by a positive list under the relevant food-contact framework. The process uses reciprocating screw blow molders with a cooled blow pin and extended exhaust time to reduce cooling water carryover; mold temperature is held at 8–12 °C to minimize haze while maintaining sidewall thickness at 0.6–1.2 mm. Ultrasonic thickness gauging is performed at 12 points around the bottle circumference after molding to verify uniformity. The grade’s high ESCR supports repeated hot-fill washing cycles at 60–70 °C without stress crack initiation. US compliance is anchored to FDA 21 CFR 177.1520(c) 2.1 for polyolefins in contact with aqueous food, and NSF/ANSI 61 for water extraction; EU compliance uses Regulation (EU) 10/2011 with overall migration below 10 mg/dm². Finished articles include 5-gallon water cooler bottles, 10 L water storage containers, and water dispenser reservoirs.

For 200–1000 mL personal care bottles that incorporate post-consumer recyclate, the core layer is often compounded from SGF4950TT and a PCR stream that is screened before dosing. Monolayer and coextrusion blow molding of such containers uses the virgin grade as the skin layer to maintain stress crack resistance and surface gloss. The typical addition ratio is 70 wt% SGF4950TT as virgin skin and 30 wt% post-consumer HDPE regrind as core; if monolayer construction is used, the PCR fraction is capped at 25 wt% because higher levels increase the melt flow rate and reduce parison hang strength, causing uneven wall distribution below 0.4 mm in the shoulder region. The PCR stream is pre-dried at 80 °C for 2 h when ambient relative humidity exceeds 60% to prevent steam-induced pinholes; screens of 80–120 mesh are installed before the breaker plate to remove carbonized particles. Processing on high-output reciprocating screw blow molders uses a barrel profile of 190–220 °C and a mold temperature of 10–15 °C for surface gloss. The finished bottles are evaluated for cap torque retention and drop strength under ISTA 1A; packaging migration is assessed against EU Regulation (EU) 10/2011 for food-grade cosmetics where relevant, while the Cosmetic Products Regulation (EC) No 1223/2009 governs the final product safety. Terminal products include 250 mL, 500 mL, and 1000 mL HDPE bottles for shampoos, conditioners, and body wash.

Specifying HDPE SGF4950TT for Diesel Exhaust Fluid Packaging Lines

Packaging of 10 L, 20 L, and 200 L diesel exhaust fluid containers from HDPE SGF4950TT is driven by the need for stress crack resistance under intermittent exposure to 32.5 wt% aqueous urea. The grade is processed on accumulator-head blow molders with a melt temperature of 210–220 °C and a mold temperature of 15–20 °C; because DEF freezes at -11 °C, the container wall must survive expansion and contraction without cracking. The addition ratio is 100 wt% SGF4950TT for tight-head DEF jerricans; regrind use up to 15 wt% is validated only for the outer wall of coextruded containers and requires post-qualification testing to ISO 22241-3:2019 because extractables from regrind are not fully characterized. The production process includes in-line leak testing at 20–30 kPa and a post-mold dimensional stability check after 24 h at 23 °C to account for thermal shrinkage. Materials used for DEF storage are specified in ISO 22241-3:2019; HDPE is permitted provided the finished container resists urea solution stress cracking. The standard requires no contamination of the fluid by container extractables, so the grade must meet the cleanliness levels of ISO 22241-2:2019 for diesel exhaust fluid. Finished articles include 10 L and 20 L DEF jugs, 200 L drums, and 1000 L intermediate bulk container liners for agricultural and on-highway fleets.