PCC (Iran) HDPE BG-HD 62N07 UV is a high-density polyethylene extrusion blow moulding resin supplied with a combined ultraviolet stabilizer package. The grade is intended for production of rigid industrial containers, jerry cans, and transport drums that remain in outdoor storage or direct sunlight during service. According to published technical documentation for this grade, the base resin exhibits a nominal density of 0.962 g/cm³ when tested in accordance with ISO 1183-1:2019 and a melt mass-flow rate of 7.0 g/10 min at 190 °C under 21.6 kg load using ISO 1133-1:2022, condition G. The high-load melt flow value indicates a medium-high molecular weight distribution formulated for controlled parison sag and adequate melt strength in large-part blow moulding. The product is typically offered as natural or black pellets; the black variant generally includes carbon black as a secondary light screen, while the ultraviolet stabilizer package contributes radical scavenging and hydroperoxide decomposition during prolonged weathering.

What Distinguishes BG-HD 62N07 UV from Non-UV HDPE Blow Moulding Resins?

The principal differentiation is stabilisation rather than base polymer architecture. A non-UV HDPE 62N07 may exhibit equivalent density, melt flow, tensile yield, and environmental stress-crack resistance under indoor laboratory conditioning, yet can fail earlier outdoors because the polyethylene backbone undergoes photo-oxidative chain scission. The UV-stabilised version incorporates hindered amine light stabilisers and, in the carbon black variant, a pigment dispersion that reduces light transmission through the container wall. Specification sheets for outdoor HDPE packaging frequently require accelerated weathering verification using ASTM G154 or ISO 4892-3; however, published data for this specific configuration is limited, and users should request lot-specific weathering data when outdoor exposure exceeds 12 months at elevated solar irradiance. Comparative damage modes include surface crazing, gloss loss, and a decline in tensile elongation at break after repeated exposure cycles.

On production-scale accumulator-head blow moulding machines with screw diameters of 60 mm to 90 mm and length-to-diameter ratios of 24:1 to 30:1, the resin processes within a hopper-to-die temperature profile of 180 °C to 220 °C. Melt temperature measured at the die is typically held between 190 °C and 210 °C to avoid parison tearing and surface melt fracture. Die head temperature is commonly set 5 °C to 10 °C below the maximum barrel temperature to increase melt strength. Accumulator head pressure should remain below the machine manufacturer’s maximum limit, commonly 25 MPa to 35 MPa. Parison programming is used to adjust wall thickness distribution in closure, shoulder, and chime areas of drums. Blow air pressure between 0.5 MPa and 0.8 MPa and mould cooling water at 15 °C to 30 °C are standard starting conditions. Pre-drying is generally unnecessary for high-density polyethylene, but free surface condensation on cold pellets can introduce moisture-related parison pinholes and inconsistent wall thickness.

When Surface Condensation on Pellets Disrupts Continuous Blow Moulding

Polyethylene is not hygroscopic in the manner of polyamide or polyethylene terephthalate; however, cold pellet surfaces in a warm, humid warehouse can carry free water into the feed throat. If relative humidity exceeds 80% and pellets have been stored below 10 °C, a hopper dryer operating at 70 °C to 80 °C for 0.5 h to 1.0 h can remove surface moisture before extrusion. The operational risk is not hydrolytic degradation but steam generation at the feed section causing screw slip and irregular parison extrusion. Resulting defects on single-station or double-station shuttle blow moulding equipment with clamp forces from 150 kN to 2,000 kN may include narrow parison thinning bands, pinhole clusters near the pinch-off, and reduced top-load resistance after moulding. If moisture-related defects persist, feed throat temperature should be checked with a contact thermocouple and pellet surface condensation should be confirmed by visual inspection under plant lighting.

The rheological profile of BG-HD 62N07 UV is best interpreted through its high-load melt flow value of 7.0 g/10 min at 190 °C/21.6 kg. The grade shows pronounced shear thinning during extrusion while retaining sufficient zero-shear viscosity to support a large parison during accumulator discharge. This balance is achieved by controlling the high-molecular-weight fraction and molecular weight distribution. In blow moulding, parison sag is a function of extensional viscosity and hang time. For a 30 L jerry can with a parison hang time of 5 s to 8 s, excessive sag produces thin sidewalls, while insufficient sag limits pinch-off flash removal and can increase clamp wear. The recommended die gap is typically 1.5 mm to 3.0 mm for shot weights from 200 g to 2,000 g, with parison programming stroke adjusted to maintain diameter swell between 20% and 40%. Melt fracture and shark-skin surface defects are controlled by maintaining die exit shear rates within the grade’s stable processing window; when surface texture appears, the first parameter adjustment is raising die temperature by 5 °C rather than increasing barrel melt temperature across all zones.

Chemical Resistance and Environmental Stress-Crack Testing in Rigid Container Service

Rigid containers made from BG-HD 62N07 UV are evaluated for environmental stress-crack resistance because the primary failure mechanism in industrial liquid packaging is not tensile overload but slow crack growth under hoop stress and surfactant or hydrocarbon exposure. The grade is typically characterised by an environmental stress-crack resistance value of >100 h F50 under ASTM D1693 with 100% Igepal CO-630 at 50 °C. This test separates high-density polyethylene blow moulding resins from lower-ESCR injection moulding grades, which may fail before 50 h under identical conditions. For aggressive fluids such as concentrated hypochlorite, agricultural emulsifiable concentrates, or aromatic-containing solvents, specific chemical resistance testing should be performed using the actual packaged formulation at the intended storage temperature. ESCR data in a standard wetting agent does not guarantee resistance to all oxidising or solvent systems. Wall stress in a filled drum is also a function of container design, not resin selection alone; finite element analysis of chime, handle, and pinch-off areas should incorporate the grade’s flexural modulus and creep rupture data.

Short-term mechanical testing of compression-moulded or injection-moulded specimens does not fully represent blow-moulded part performance, but it provides specification control. When tested according to ISO 527-2, the material typically shows tensile stress at yield of 29 MPa and tensile elongation at break above 800%. Flexural modulus tested under ISO 178 is typically 1500 MPa. Notched Izod impact resistance at 23 °C under ISO 180/A is reported at 6 kJ/m², and Vicat softening temperature A50 under ISO 306 is approximately 128 °C. These values are representative of the high-density polyethylene class and should not be interpreted as specification limits. For blow-moulded containers, the relevant performance values are often determined on finished articles: drop impact at -20 °C, hydraulic burst pressure, stacking load, and closure torque retention.

Food-contact and potable-water suitability for BG-HD 62N07 UV must be confirmed with the supplier for the specific stabilizer package and colour concentrate. High-density polyethylene used in food packaging in Europe is generally assessed under EU Regulation 10/2011 for overall migration and specific migration of additives; in the United States, base HDPE may fall under FDA 21 CFR 177.1520, but carbon black and UV stabilizers require compositional verification. The product may also require documentation under REACH and RoHS for heavy metals and restricted substances. End users manufacturing UN-certified dangerous goods packaging should not substitute this resin without completing design-type testing under ADR/RID/IMDG or applicable UN packaging codes, because resin approval alone does not confer certification to the finished container.

Comparing Resin Classes Across Shear and Elongational Flow Fields

The differentiating role of BG-HD 62N07 UV becomes visible when its high-load melt flow and melt strength are compared with other high-density polyethylene classes. Injection moulding resins with a density near 0.954 g/cm³ and a melt flow rate of 20 g/10 min at 190 °C/2.16 kg flow easily into multi-cavity tools but lack the parison hang-time stability required for a 20 L jerry can. Blown film grades with a melt flow rate of 0.2 g/10 min at 190 °C/2.16 kg and density near 0.949 g/cm³ provide excellent toughness in thin packaging films but are difficult to extrude through an accumulator head at commercial output. Rotational moulding powders and pipe extrusion grades similarly fall outside the target rheological and stabilisation window for large-part blow moulding.

Operational boundaries include the following: this resin is not intended for injection moulding, film extrusion, pipe extrusion, or rotational moulding; the high melt strength and ultraviolet stabilizer package are not optimised for those processes. Avoid blending with amine-based or sulfur-containing masterbatches that can interact with phenolic or phosphite stabilizers and shift oxidation induction time. Avoid drying temperatures above 80 °C because pellet softening and bridging can occur in the hopper. For black containers, carbon black dispersion quality should be checked by microscopy or filter pressure tests because poorly dispersed carbon black can create pinholes and reduce environmental stress-crack resistance. For outdoor service in high-altitude or high-UV regions, end users should request accelerated weathering data and consider additional opaque pigmentation or increased wall thickness rather than relying solely on the stabilizer package. Processing trials on single-station extrusion blow moulding machines should begin with a screw speed producing a shear rate near the supplier’s recommended range, and melt temperature should be verified with a needle pyrometer at the die exit to prevent thermal degradation from residence times beyond 10 min during cycle interruptions.