Chevron Phillips Chemical HDPE 9062 is a high-density polyethylene resin supplied in pellet form for extrusion blow molding of industrial containers, intermediate bulk container liners, multilayer fuel system components, and fluid reservoirs. Gravimetric density is 0.954 g/cm³ when tested according to ASTM D1505-18, and melt mass-flow rate is 0.45 g/10 min under 190 °C and 2.16 kg using ASTM D1238-20. These values place the material in a high-molecular-weight HDPE category where melt stability and parison hang time are weighted more heavily than spiral flow. On a production-scale accumulator-head blow molding line with an 80 mm extruder screw and 25:1 L/D, melt pressure during stable extrusion is maintained between 18 MPa and 24 MPa. The product does not require forced-air drying under ordinary ambient storage; if pellet surface moisture exceeds 200 ppm, pre-drying at 80 °C for 2 h is recommended to suppress parison pinholes and surface splay.

What Is the Standard Property Window for Blow Molding Grade HDPE 9062?

Lot-to-lot certification values are reported against the test methods shown in Table 1. The density tolerance of ±0.002 g/cm³ around the nominal 0.954 g/cm³ directly influences top-load capacity and permeation; an increase to 0.956 g/cm³ typically raises flexural modulus but reduces environmental stress crack resistance. The melt index range of 0.40 to 0.50 g/10 min has been observed across shipments; material at the upper bound flows more readily in thin sections but may display shorter parison hang time. Tensile yield strength measured on compression-molded plaques according to ASTM D638-22 falls between 28 MPa and 32 MPa. Flexural modulus at 2 % secant obtained by ASTM D790-17 is typically 1,100 MPa to 1,300 MPa. Notched Izod impact at 23 °C under ASTM D256-10 ranges from 4.5 kJ/m² to 6.0 kJ/m². Vicat softening temperature under ASTM D1525-17e1 with a 10 N load is reported in the 125 °C to 130 °C range. These values are representative of the product family and must be confirmed against each certificate of analysis.

Extrusion blow molding operations with shuttle or accumulator-head machines have shown that HDPE 9062 processes more consistently with a five-zone barrel temperature gradient than with a flat thermal profile. A feed-to-die program of 180 °C, 200 °C, 210 °C, 210 °C, and 205 °C is commonly used for a 60 L drum tool. Reducing the die temperature below 190 °C triggers sharkskin on the parison surface at shear rates above 800 s⁻¹; the defect transfers to the inner container wall and reduces ESCR when later tested by ASTM D1693-15. Raising melt temperature above 220 °C increases oxidative gel formation and parison drawdown. Screw speeds in the 20 min⁻¹ to 40 min⁻¹ range with a 60 mm barrier screw generate melt pressures between 20 MPa and 30 MPa. Blow mold temperatures are held between 10 °C and 30 °C; lower mold temperatures accelerate solidification and can improve dimensional stability, but they reduce weld-line elongation and surface gloss.

Melt Temperature, Parison Control, and Extruder Hydraulics

Parison wall thickness is controlled by die gap, extruder output, and melt viscosity. HDPE 9062 exhibits die swell in the 35 % to 45 % range at blow molding shear rates of 500 s⁻¹ to 1,500 s⁻¹, so tooling dimensions are normally undersized. In accumulator-head machines with 30:1 L/D, preform pressure drop across the die is typically 12 MPa to 18 MPa. A 10 % reduction in melt temperature from 210 °C to 200 °C extends parison hang time by approximately 15 % but increases melt pressure by 10 % to 18 %. Operators monitor wall thickness distribution by sectioning shot-weight samples and adjusting the parison programmer channel. When barrel zone overshoot exceeds 5 °C, localized gel contamination may appear as pinholes or black specks in the finished container; this requires purging with high-viscosity polyethylene before restarting.

Injection molding of HDPE 9062 is possible but constrained by the same molecular weight that provides parison stability. Multi-cavity closure tools with flow length-to-wall thickness ratios above 150:1 typically require melt temperatures between 220 °C and 230 °C and injection pressures above 80 MPa. Even under those conditions, cycle time is governed by packing and cooling, and throughput may be lower than that of a high-flow HDPE with melt index above 8 g/10 min. When processed on a hydraulic reciprocating screw with 120 t clamp force and 35 mm screw diameter, short shots are observed if the barrel temperature falls below 210 °C. These limitations do not prohibit injection molding but require mold-flow simulation and prototype tooling trials to define a stable window.

Slow crack growth and environmental stress crack resistance govern service life in containers that hold agricultural emulsions, surfactants, or fuel system fluids. HDPE 9062 is evaluated by ASTM D1693-15, in which notched specimens are immersed in a nonylphenoxy poly(ethylene oxide) detergent at 50 °C; the F50 failure time on compression-molded plaques exceeds 100 h in many production lots. Molded-part ESCR is influenced by residual stress orientation and wall-thickness variation, so correlation with field life requires part-level testing under ISO 16770. The tie-molecule population and branching distribution of HDPE 9062 differentiate it from a standard unimodal HDPE resin with equivalent density and melt index, but published data for the specific molecular configuration is limited. Each container lot must be qualified in the intended service fluid rather than relying solely on laboratory detergent tests.

When ESCR Requirements Exceed Those of General-Purpose Unimodal HDPE

Differences in ESCR become most apparent when comparing HDPE 9062 with general-purpose blow molding HDPE of similar density and melt flow. The performance gap is attributed to higher tie-molecule probability and broader molecular weight distribution, which slow crack propagation under stress. In ASTM D1693-15 testing, general-purpose unimodal HDPE copolymers often show shorter F50 failure times, but published data for this specific configuration is limited. For quantitative slow crack growth data, ISO 16770 full-notch creep testing at 80 °C and 4 MPa provides a sharper distinction between resins within a narrow density range. Selecting HDPE 9062 for a 60 L drum is justified when the product must survive intermittent contact with aggressive surfactants and stacked storage loads; if the application is purely dry-goods packaging without chemical exposure, a lower-ESCR HDPE with density 0.962 g/cm³ may be evaluated for higher top-load stiffness.

Compared with a lower-density medium-density polyethylene grade at 0.940 g/cm³, HDPE 9062 provides higher flexural modulus as determined by ASTM D790-17 and higher column crush resistance as determined by ASTM D2659-16. A container wall produced from HDPE 9062 can often be down-gauged while maintaining column crush performance. Conversely, the medium-density polyethylene grade may exhibit longer slow crack growth resistance under low stress but lower top-load capacity. Compared with linear low-density polyethylene at density 0.920 g/cm³, HDPE 9062 offers higher stiffness and lower water-vapor transmission when measured by ASTM E96/E96M-16, but lower puncture resistance and low-temperature toughness. High-flow HDPE injection molding grades with melt index above 8 g/10 min are not suitable substitutes because their low melt strength permits parison sag in blow molding tools. HDPE 9062 is therefore positioned between standard high-density HDPE blow molding resins and higher-melt-strength fractional-melt grades, with a nominal density of 0.954 g/cm³ and flexural modulus near 1,200 MPa.

Conditional Restrictions in Moisture Uptake, Regrind, and Ultraviolet Exposure

HDPE 9062 is not intended for continuous service above 60 °C under stress, because creep resistance and pressure rating decline as temperature increases. It is also not a UV-stabilized formulation; outdoor exposure exceeding 12 months requires addition of 2.0 wt% carbon black masterbatch or a hindered amine light stabilizer package, with accelerated weathering verification under ASTM G154-16. Regrind incorporation above 30 wt% may reduce ESCR and notched impact by more than 20 %; converters should requalify parts according to ASTM D1693-15 and ASTM D256-10 whenever regrind fraction changes by more than 10 wt%. Blending with non-HDPE polyolefins or ethylene-vinyl acetate above 5 wt% can shift the viscosity distribution and produce parison instability. The resin is also not recommended for thin-wall injection molding with flow length-to-wall thickness ratios above 150:1; its melt mass-flow rate of 0.45 g/10 min imposes high injection pressure and cycle-time penalties.

Regulatory status is lot-dependent and must be confirmed against the producer’s certification for the destination market. In the United States, olefin homopolymer resins intended for food contact may be used under 21 CFR 177.1520(c) provided that the finished packaging meets extractives limitations for the intended conditions of use A through H. For EU food contact, compliance with Commission Regulation (EU) No 10/2011 and its amendments is typically evaluated against the overall migration limit of 10 mg/dm²; specific migration of antistatic additives, neutralizers, and colorants requires separate verification. RoHS Directive 2011/65/EU Annex II limits for cadmium, lead, mercury, and hexavalent chromium apply to electrical and electronic equipment applications; typical HDPE 9062 analyses show cadmium below 100 mg/kg and lead below 1,000 mg/kg. REACH Regulation (EC) No 1907/2006 registration applies to polymer constituents, but formulated mixtures may require additional assessment. Table 2 summarizes these standard designations.