LyondellBasell Icorene 3560 G GRN 6107 is supplied as a linear low-density polyethylene compound in which the designation GRN 6107 identifies a green pigmentation package rather than a stand-alone base resin property. The uncolored analogue is Icorene 3560 G; the colored variant should be treated as a filled system because the pigment introduces ash, nucleation sites, and a discrete dispersed phase. Classification under ASTM D883 and ISO 472 places the grade in the ethylene/α-olefin copolymer family, with a class-defining density below 0.940 g/cm³. Since public datasheets for color-compounded grades often omit colorant-induced shifts in melt flow rate, density, and mechanical response, the producer’s certificate of analysis is normative. The material is intended for opaque applications where an integral green color eliminates post-mold painting or film lamination. The absence of a published datasheet for this exact colorant combination means that published data for this specific configuration is limited; therefore, process parameters and property values are discussed at the LLDPE class level and linked to standard test methods.

What Melt-Rheology and Screw-Recovery Limits Arise with Colored LLDPE?

Melt flow characterization is performed according to ISO 1133-1 at 190 °C under 2.16 kg. LLDPE injection-molding grades commonly show melt mass-flow rates between 1 g/10 min and 60 g/10 min, but the exact value for Icorene 3560 G GRN 6107 must be read from the batch certificate. Compared with a high-pressure LDPE of equal melt index, LLDPE exhibits higher shear viscosity and reduced melt extension. This produces longer screw-recovery times, higher drive torque, and a narrower bubble-stability window if the resin is diverted to film. On a single-screw injection molding machine, a 20:1 to 25:1 L/D general-purpose polyethylene screw with a compression ratio of 2.5:1 to 3.5:1 is suitable. A barrier screw improves plastication rate but may increase melt temperature. Melt temperatures above 250 °C accelerate thermo-oxidative degradation; oxidation induction time measurement by ISO 11357-6 is the appropriate screening tool. Total melt residence time should remain below 30 minutes at temperatures above 220 °C and below 15 minutes above 240 °C. These limits are class-level for stabilized LLDPE, and the specific stabilizer package of this colored grade may be more restrictive.

During production-scale injection molding of green LLDPE parts, regrind addition is typically restricted to 20 wt% or less because repeated extrusion consumes hindered phenolic antioxidants and may shift molecular weight distribution. Batch-to-batch variation in the color concentrate can change melt flow rate by 0.1–0.5 g/10 min as measured by ISO 1133-1. For a colored compound, mold deposit accumulation on vented barrels and ejector pins is more likely than for uncolored LLDPE; vent-lip residue should be inspected at each shift. Pellets may retain surface moisture above 0.05 wt%; splay and gate blush then appear in filled parts. A desiccant dryer set to 60–80 °C for 2–4 h with a dew point of −30 °C or lower is recommended if moisture content exceeds that threshold. The material should not be mixed with incompatible purge compounds containing ionomeric or polyamide residues; these can create delamination at the gate.

Gate design for LLDPE requires sufficient cross-section to avoid jetting and high shear heating. Edge gates with land lengths below 1 mm and gate diameters above 50% of wall thickness are common class-level starting points. The green pigment slightly increases high-shear viscosity; injection pressure at the screw tip should be limited to 100–140 MPa to avoid flash without starve-feeding the cavity. Pack pressure is generally maintained at 70–80% of injection pressure until gate freeze. Shear heating in the metering zone can drive melt temperature 10–20 °C above the set barrel value, especially on 25:1 L/D single-screw machines operating above 150 min⁻¹. Purging with high-viscosity HDPE after production is recommended before shutdown.

When Pigment Agglomerates Exceed 20 µm in Dispersive Mixing

Pigment dispersion controls impact response and weld-line strength. In a single-screw extruder or injection screw with insufficient back pressure, green pigment agglomerates larger than 20 µm can act as stress concentrators and reduce notched Charpy impact measured by ISO 179-1. For twin-screw compounding lines, a 40:1 L/D corotating machine with kneading blocks and reverse elements is commonly used to reach acceptable dispersive mixing. For single-screw processing, a 60/100/60 mesh screen pack and a restrictive breaker plate improve colorant distribution but raise back pressure and barrel residence time. Weld-line tensile strength tested by ISO 527-2 may fall below 70% of the un-welded value if the pigment is not fully dispersed. Mold shrinkage is not isotropic for this filled LLDPE; the green pigment can nucleate polyethylene crystallites and alter through-thickness shrinkage measured by ISO 294-4. Mold-filling simulation should therefore use a compressible, semi-crystalline rheology model with measured crystallization half-times rather than a generic amorphous model.

For film or sheet extrusion of LLDPE class materials, the die design differs from LDPE because linear chains have limited melt extension. A die gap of 1.5–2.5 mm, a blow-up ratio below 3:1, and a reduced draw distance are typical class-level starting points; the green concentrate may produce visible die lines if the screen pack is too coarse. If Icorene 3560 G GRN 6107 is evaluated for film, tensile properties should be measured in both machine and transverse directions according to ISO 527-3, and tear resistance according to ISO 6383-2. The producer’s application designation should be confirmed before using this grade in high-speed packaging film, because the pigment may alter coefficient of friction and heat-seal initiation temperature relative to the natural base resin.

Comparative Classification Against LDPE, HDPE, and Metallocene LLDPE

Compared with high-pressure low-density polyethylene, linear low-density polyethylene has a short-chain-branched linear backbone without long-chain branching. The same density range can be achieved with different comonomer types; 1-butene, 1-hexene, and 1-octene copolymers differ in tear strength, dart impact, and seal performance. LLDPE generally offers higher tensile yield and elongation at break measured by ISO 527-2, higher environmental stress-crack resistance measured by ASTM D1693, and higher puncture resistance than LDPE at equal density. Against HDPE, the density window from 0.915 g/cm³ to 0.940 g/cm³ lowers crystallinity, flexural modulus measured by ISO 178, and Vicat softening temperature measured by ISO 306. Against metallocene LLDPE, conventional Ziegler-Natta LLDPE often exhibits broader molecular weight distribution, higher extractables, and lower hot-tack strength. The catalyst technology for Icorene 3560 G is not explicitly disclosed in the public grade designation; therefore, direct comparison requires producer molecular architecture data. The green pigment adds a further variable because it can mask optical clarity, raise ash content, and alter thermal nucleation.

On a hydraulic injection molding machine with clamp force between 800 kN and 3500 kN, the material is processed with a flat barrel profile and medium injection velocity. Pack pressure should be maintained until gate freeze; for LLDPE the gate freeze time can be estimated from part squared thickness divided by thermal diffusivity. Pigmented grades can alter ultrasonic weld transmission relative to natural polyethylene; if welding is specified, weld strength must be validated to ISO 527-2 at the production amplitude and duration. For parts requiring regulatory documentation, the color concentrate must be disclosed in the material declaration.

Although Green Colorants Are Non-Migratory, Extraction Testing Still Governs Compliance

For food-contact and toy applications, the final article must be tested in the intended condition of use. The base LLDPE may fall under 21 CFR 177.1520 for olefin polymers; however, the green pigment system must independently satisfy 21 CFR 178.3297 or other applicable colorant requirements. Overall migration into food simulants is evaluated according to EN 1186; the general EU limit under EU Regulation No 10/2011 is 10 mg/dm², commonly expressed as 60 mg/kg when corrected for surface-to-volume ratio. Compliance is not automatic from the base resin classification. Industrial purchasers commonly require a REACH SVHC declaration under EC No 1907/2006 and a RoHS screening under 2011/65/EU for lead, cadmium, mercury, and hexavalent chromium in the pigment package. The material should be kept away from strong oxidizing agents, aromatic solvents, and high-oxidizing acids; these agents can degrade polyethylene and organic pigments even at temperatures above 40 °C under sustained contact.

Color-dependent optical parameters such as L*a*b* values, lightfastness, and weathering retention are not part of the base polyethylene specification and must be controlled by the color concentrate supplier. Outdoor exposure of green LLDPE parts may produce chalking and color shift; UV stabilization should be specified separately and tested by ISO 4892-2 xenon-arc exposure with a defined irradiance and black-standard temperature. Published data for this specific configuration is limited, particularly for color retention beyond 1000 h of accelerated weathering.