PetroChina Daqing HDPE DGDA6094 is a high-density polyethylene film resin produced at the Daqing Petrochemical Company complex in Heilongjiang Province, China, on a gas-phase polymerization platform. The product is supplied in pellet form for blown-film conversion and is specified principally by a nominal density of 0.950–0.952 g/cm³ measured according to ISO 1183-1:2019 and by a melt flow rate of 0.85–0.95 g/10 min determined at 190 °C under a 2.16 kg load according to ISO 1133-1:2022. The molecular weight distribution is controlled to provide sufficient melt strength for bubble stability on air-cooled film lines while retaining a lower melt viscosity than extrusion blow molding grades. Typical conversion applications include grocery sacks, merchandise bags, industrial liners, and stiff packaging films in which higher modulus and lower water-vapour permeability than LLDPE at equal gauge are required, when measured according to ISO 527-3 and ASTM F1249. The resin is not intended for injection molding, large-part extrusion blow molding, or pressure pipe service.

The short-chain branch concentration implied by the density is lower than that of conventional LLDPE and higher than that of fully linear HDPE pipe grades. This branch distribution affects the crystallization rate and the freeze-off point during bubble cooling, which in turn influences the practical maximum line speed on a given die. Because gas-phase polymerization yields a granular reactor product that is compounded with the stabilizer package and pelletized, batch-to-batch variation in melt flow rate and density is normally controlled within the producer’s release limits. Converters with narrow processing windows should obtain the extended processability data and a certificate of analysis for the specific lot before setting gauge and frost-line control limits.

How Is DGDA6094 Distinguished from Blow Molding and Pipe-Grade HDPE?

Unlike extrusion blow molding grades, which generally exhibit melt flow rates of 0.20–0.60 g/10 min and are formulated for parison stability at lower shear rates, DGDA6094 has a higher melt flow rate and is optimized for air-cooled bubble dynamics rather than parison sag resistance. Its density of 0.950–0.952 g/cm³ raises modulus and barrier relative to LLDPE, but it is below the density of pressure-pipe grades, where values above 0.959 g/cm³ and bimodal molecular weight distributions contribute to long-term hydrostatic strength and slow crack growth resistance. Pipe grades are classified under ISO 9080 and ISO 12162, whereas DGDA6094 is not assigned a PE100 or PE80 pressure-rating class. Injection molding HDPE grades with melt flow rates above 7 g/10 min flow readily into thin-wall tools but lack the melt strength required for stable blown film at die gaps below 1.5 mm.

Because DGDA6094 is a medium-molecular-weight film resin, processing it on injection lines or pellet-fed sheet lines designed for high-flow HDPE can produce melt-pressure instability and short shots if nozzle diameters and runner gates are not resized. Conversely, running a high-flow injection grade on a blown-film line usually causes bubble oscillation and poor gauge control at thicknesses below 25 µm. These differences are rheological rather than additive-driven, and changing barrel temperature alone does not convert one HDPE segment into another.

On monolayer blown-film lines equipped with spiral mandrel dies, DGDA6094 is usually processed at melt temperatures between 190 °C and 220 °C; the resin should not be pushed above 230 °C for extended residence periods in order to avoid oxidative gel formation. A typical die gap is 0.8–1.5 mm for finished gauges between 12 µm and 50 µm, with blow-up ratios between 3:1 and 5:1. On a 65 mm single-screw extruder with 30:1 L/D barrier screw and mixing section, bubble flutter is a characteristic failure when the frost line is held below approximately 5 die diameters; raising the frost line height to 8–10 die diameters and reducing cooling-air velocity stabilizes the bubble. The resin does not normally require pre-drying, because HDPE is not hygroscopic, but secondary pellet surface moisture after storage at relative humidity above 60 % can produce microstipple or surface roughness. When such defects appear, a 2 h hopper drying step at 60–80 °C may be applied before extrusion.

In the finished film, the density of DGDA6094 produces a secant modulus that is higher than that of conventional LLDPE film at the same thickness, which permits downgauging in sack formats where stiffness controls opening and handling. Gauge uniformity should be measured according to ISO 4593 or ASTM D6988; lines with internal bubble cooling and automatic air-ring control can generally hold gauge variation below ±5 %, but manually adjusted lines may show wider variation. For printing or lamination, corona treatment to a surface energy of 38–42 mN/m measured according to ISO 8296 is commonly used, though adhesion must be revalidated after line speed changes or additive migration. Water-vapour transmission rate should be measured according to ASTM F1249 if barrier specifications apply, because differences in film morphology and gauge control affect the final value.

Specification Release Limits and Compliance Verification

The certificate of analysis for DGDA6094 normally reports resin density and melt flow rate as release data, along with selected mechanical properties. The table provides representative published control ranges; lot-specific values must be obtained from the certificate because internal producer limits may be narrower than the commercial range.

Food-contact suitability is not established by the resin certificate alone. For articles sold in the United States, the finished package must comply with FDA 21 CFR 177.1520, including extraction testing appropriate to the food type and use temperature. In the European Union, the final article must satisfy EU Regulation (EU) No 10/2011 as amended, including overall migration limits of 10 mg/dm² and any specific migration limits applicable to the stabilizer package. Converters should also verify compliance with relevant national legislation for colourants, printing inks, and adhesives when the final film is printed or laminated.

The resin is not qualified for medical device or pharmaceutical packaging unless the final article is separately evaluated under ISO 10993-1 or the relevant pharmacopoeia. It is not intended for direct contact with high-fat foods at processing temperatures above 100 °C, because migration behaviour and organoleptic properties must be validated in the final package.

When DGDA6094 Is Blended with LLDPE for Impact Modification

Because HDPE and LLDPE are melt-compatible for practical purposes, converters may blend DGDA6094 with up to 30 wt% LLDPE to improve dart impact resistance measured according to ASTM D1709A and tear resistance measured according to ISO 6383-2, although the secant modulus measured according to ISO 527-3 and water-vapour transmission rate measured according to ASTM F1249 decline as the LLDPE fraction increases. At LLDPE addition levels above 50 wt%, the bubble stability characteristics shift toward the LLDPE regime, and the line may require a lower frost line, larger die gap, or different air-ring settings. The transition in properties is monotonic but not linear; the improvement in dart impact is usually proportionally greater at low LLDPE addition levels than the corresponding reduction in secant modulus. If octene-based LLDPE is used, machine-direction tear resistance may improve more than with butene-based LLDPE at equivalent addition, but published data for this specific configuration is limited. Additive packages should be checked when the blend is corona-treated or printed; excessive slip or antistatic migration to the surface can reduce ink adhesion and lamination bond strength.

For continuous service above 60 °C, the modulus and creep resistance of DGDA6094 decline sharply, and the resin is not recommended for hot-fill containers, retortable pouches, or aggressive hot-fluid transport. It is also unsuitable for buried pressure-pipe applications, where long-term hydrostatic strength under ISO 9080 and environmental stress cracking resistance under ASTM D1693 or ISO 22088-1 are mandatory. Outdoor films must contain UV stabilizers; unstabilized natural resin should not be exposed to prolonged sunlight. Storage should be kept below 50 °C and away from direct sun, and opened packaging should be resealed to prevent dust pickup. In coextrusion, the HDPE layer should not be paired with barrier polymers that require melt temperatures above 240 °C unless degradation products and interlayer adhesion are evaluated, because the processing window may be narrowed to the lower-temperature polymer’s limit.