Indian Oil (IOC) HDPE G-LENE C43D006 is a high-density polyethylene resin supplied under the G-LENE polymer family. Commercial literature for the grade lists a nominal density of 0.943 g/cm³ when tested to ISO 1183-1:2019 Method D and a melt mass-flow rate of 0.6 g/10 min when tested to ISO 1133-1:2022 at 190 °C/2.16 kg. These figures place the material in a low-melt-flow film extrusion class rather than in the higher-flow injection moulding segment. The polymer architecture combines controlled comonomer incorporation and broad molecular weight distribution; full molecular weight distribution data are not always disclosed in public technical literature, so the certificate of analysis should be consulted for lot-specific rheology. In packaging operations, C43D006 is selected for liner bags, carrier film, and heavy-duty packaging where bubble stability and puncture resistance influence line yield. The grade is not a general-purpose injection material: its low melt flow restricts thin-wall cavity filling and increases hydraulic injection pressure in hot-runner molds. It also differs from high-density blow moulding grades optimized for parison hang time, although certain small-container blow moulding lines may run C43D006 after die swell and pinch-off validation. Published data for the complete shear viscosity curve of C43D006 is limited, which makes laboratory capillary rheometry on retained pellets a required step before designing die gaps below 0.8 mm.

When high-stalk bubble geometry determines output limits

On a 65 mm grooved-barrel extruder with 24:1 L/D and a dual-lip air ring, the observed processing envelope for C43D006 spans 190 °C to 215 °C at the adapter. Reducing melt temperature from 210 °C to 190 °C raises head pressure by 15–25 bar; pressure transducers upstream of the screen pack are used to track the increase. A die gap of 0.8–1.2 mm is typical for film thicknesses between 10 µm and 50 µm. At gaps below 0.6 mm, melt fracture and shark-skin surface defects appear unless a fluoropolymer process aid is added at 0.1–0.3 wt%. At gaps above 1.4 mm, machine-direction orientation drops, and dart impact measured by ASTM D1709-15 Method A declines because the frost line height no longer produces sufficient strain hardening. Frost line height is maintained at 5–8 die diameters for blow-up ratios between 2.5:1 and 4.0:1; high-stalk operation keeps the stalk stable by adjusting inner bubble air pressure. On one production line, asymmetric air-ring flow produced a wandering frost line and thickness variation of ±8% before air-ring cleaning; this variation appeared as intermittent transverse-direction tear weakness when tested by ASTM D1922-15. Extruder output on the 65 mm system is governed by back pressure and motor load rather than melt temperature alone. When extruder amps approach nameplate rating, reducing screw speed by 5–10 rpm is more effective than lowering barrel temperatures because lower melt temperature further increases viscosity. Stable bubble geometry is not solely resin-dependent; dies with worn lips or uneven air distribution dominate defects once melt temperature is within the specified envelope. Converters evaluating the grade for monolayer film often set screen packs to 80/120/80 mesh to raise back pressure and homogenize melt; clogged screens increase pressure drop and require replacement after 2–4 hours depending on regrind content.

Complete shear viscosity and melt strength data for C43D006 are not published in open technical literature; plant trials and laboratory rheometry on retained pellets are therefore required before designing die lips. A capillary rheometer with a 1 mm diameter die and 20:1 length-to-diameter ratio provides shear viscosity data at 190 °C, 210 °C, and 230 °C. The onset of melt fracture can be estimated from critical shear stress data; if no C43D006-specific data are available, linear low density polyethylene data should not be used as a substitute because the molecular weight distribution differs. Oscillatory shear tests in a parallel-plate rheometer under nitrogen at 190 °C characterize storage modulus and transition behavior; broad molecular weight distribution HDPE shows a shallow frequency dependence in terminal loss modulus. Lot-to-lot variation in melt flow rate usually falls within the mill specification window but can still alter head pressure by 10–15 bar on a 65 mm extruder when switching between lots at the low and high ends of the melt-flow band. Incoming quality control should retain pellets from each lot for 6 months to allow comparative rheology if film mechanical properties shift. These tests are not substitutes for full product certification; they provide process diagnostics.

Melt fracture on high-stalk lines is usually preceded by a rise in melt pressure oscillation of 2–4 bar and periodic haze bands in the bubble. Die lip deposition from oxidized process aid can produce transverse lines; cleaning with a soft copper tool is preferred over steel to avoid lip damage. If melt pressure oscillations persist after cleaning, the feed section temperature should be checked because uneven pellet preheating can produce melt temperature variation of 3–5 °C at the die. These field observations are most relevant for lines running monolayer film at high output; coextrusion lines may mask the surface defects but retain the underlying pressure instability.

What distinguishes C43D006 from high-MFI and pipe-grade HDPE?

Higher-flow HDPE grades with melt indices from 8 g/10 min to 30 g/10 min are designed for injection moulding; they exhibit lower melt strength, which permits easy cavity filling but reduces film impact. C43D006 resides in a low-MFI region where extensional viscosity and bubble stability control economics. At equal film thickness, the lower-MFI resin typically shifts failure from brittle puncture to ductile deformation when tested by ASTM D1709-15 Method A. Against high-density pipe grades with density above 0.950 g/cm³, C43D006 has lower density and higher flexibility, but there is no public data establishing C43D006 as PE100 or PE80 under ISO 9080:2022. Compared with linear low density polyethylene film grades, C43D006 has higher modulus and lower clarity, so it is used for opaque industrial films rather than transparent display packaging. In blow moulding, the resin’s low melt flow increases parison melt strength and may improve melt extensibility, but the same property raises extrusion torque and can overload small accumulator heads. Converters switching from standard blow moulding HDPE should measure head pressure and parison sag; a die swell increase is possible because of higher molecular weight. The differentiation from other products in the G-LENE range is primarily based on melt flow and density; higher-density grades are selected where stiffness and chemical resistance dominate, while higher-MFI grades are selected where cycle time and multi-cavity filling dominate. C43D006 is positioned for monolayer film and sheet, not for pipe, injection moulding, or rotational moulding.

Certificate of Analysis Parameters and Release Boundaries

Lot acceptance for C43D006 is based on mill certificates that report melt flow, density, tensile yield, and sometimes film dart impact. The table lists standard methods and application boundaries used by downstream quality-control laboratories for incoming resin checks. These methods are standard HDPE release protocols; actual product specification may include additional internal IOC limits not reproduced here. The presence of this table does not imply all listed methods are required for every shipment; regulatory compliance and customer specifications determine the test plan.

Because film test values depend on gauge, blow-up ratio, frost line height, and die gap, incoming pellet tests should not be used to predict finished film values without calibration on the target line. Laboratory film samples are normally prepared on a 45 mm blown-film line with controlled die gap and blow-up ratio; values from cast film or compression molding are not equivalent. Conditioning at 23 °C and 50% relative humidity for 40 h follows ISO 291:2008; failure to condition film specimens can shift tensile yield by several percent because HDPE properties are temperature-dependent.

Pellets are supplied in 25 kg bags and should be stored below 40 °C and protected from UV exposure. Moisture uptake is not a primary degradation route for HDPE; pre-drying at 70–80 °C for 2–4 hours is indicated only when storage has exceeded 60% relative humidity or when surface condensation is visible. The resin is compatible with typical HDPE process aids, but amine-based additive packages should be avoided in high-temperature purging because decomposition products can initiate surface oxidation and increase gel counts. Let-down ratios for masterbatch should be verified by trial; at addition levels above 5 wt%, low-molecular-weight carrier resins can shift the melt flow index and reduce bubble stability. For purging, a higher-MFI HDPE purge grade is preferred over PVC or acid-containing purge compounds. Extended residence time above 230 °C causes thermo-oxidative chain scission and crosslinking; gel particles then appear in the film and tear strength measured by ASTM D1922-15 shows local failures. During lot changes, hopper and feed throat should be drained to avoid mixing with polypropylene or moisture-laden regrind. Reclaimed C43D006 film can be reintroduced into the film layer at levels up to 10–20 wt% only if the reprocessed pellets are free of paper labels and adhesive residues; higher addition reduces dart impact and increases dimensional variation. When blend ratios exceed 20 wt%, tensile yield may decrease and color variation becomes visible in unpigmented film.

The grade cannot be considered a certified food-contact resin solely from pellet compliance; conformity is established on the finished article after converting additives, masterbatch, and printing inks are accounted for. Under FDA 21 CFR 177.1520, HDPE homopolymers and copolymers may be used in contact with food, subject to extraction limits and end-use conditions; compliance is converter-specific. Under EU 10/2011, overall migration must not exceed 10 mg/dm². For industrial chemical packaging, compatibility testing with the packaged substance is required because environmental stress cracking resistance varies with chemical type, concentration, and temperature. The use of C43D006 in potable water pipe is not supported by published data; pipeline applications demand PE100 or PE80 certification through long-term hydrostatic strength testing under ISO 9080:2022. For medical packaging, biological reactivity and particulate limits apply; no public data establishes C43D006 as USP Class VI material. These boundaries must be evaluated before substitution in regulated applications. RoHS heavy-metal restrictions are generally satisfied by unpigmented HDPE, but final article compliance depends on colorants and additives; testing is performed according to IEC 62321 or customer-specific methods.