In blown film conversion, POLYBATCH™ Orange 10334 Concentrate Based In LLDPE is metered into the main extruder feed throat for LLDPE and HDPE film structures requiring a saturated orange. Published product-specific pigment loading and carrier melt index for this concentrate are limited; the parameters below therefore follow established process windows for LLDPE-carrier polyolefin colour concentrates and reference standard convertor test methods. Addition rates between 2 wt% and 4 wt% are common for monolayer films of 20 µm to 80 µm, with the lower end used for films thinner than 30 µm to limit pigment-related haze and gel counts. The concentrate is added through a gravimetric dosing unit with an accuracy of ±0.1 wt%; feeder calibration drift beyond 0.2 wt% over an 8 h run produces visible shade variation in printed and unprinted webs. On grooved-feed single-screw extruders with an L/D of 25:1 to 30:1 and a barrier screw fitted with a Maddock mixing section, melt temperatures of 190°C to 230°C are maintained, and a screen pack stack of 60/80/100 mesh removes pigment agglomerates before the die. In HDPE-dominant blown film, the LLDPE carrier contributes lower melt strength than a matched HDPE carrier; at addition rates above 4 wt%, bubble stability can decline, neck height increases, and gauge variation across the web rises above ±3%. When this occurs, the blow-up ratio is reduced from 2.5:1 toward 2.0:1, and frost line height is lowered to 5–7 die diameters to re-stabilise the bubble. Film colour is measured with a spectrophotometer using D65 illumination and 10° observer geometry according to ASTM D2244; optical properties are checked to ASTM D1003 for haze, ASTM D1922 for Elmendorf tear, and ISO 527-3 for tensile properties. Falling dart impact is tested to ISO 7765-1. For food-contact structures, the finished film must meet the overall migration limit of 10 mg/dm² under EU 10/2011 and the colorant requirements of 21 CFR 178.3297; compliance is demonstrated on the finished article, not the concentrate alone.

On cast film lines producing printed and unprinted polyolefin webs at line speeds between 150 m/min and 300 m/min, the LLDPE-carrier orange concentrate is metered into the main resin stream at 2 wt% to 3 wt% for films of 15 µm to 50 µm. The lower melt viscosity of the LLDPE carrier can widen the transition from stable melt curtain to draw resonance in high draw-down cast film; operators control this by holding the die-to-chill-roll air gap to 10–20 mm and setting the chill roll temperature at 18–25°C. Barrel zone temperatures run from 180°C in the feed zone to 240°C at the flat die, while the feed throat is kept below 60°C to prevent pellet blocking and erratic dosing. A screen pack of 100/120 mesh before the die is used to remove undispersed pigment; a rapid increase in filter pressure above 1.0 MPa over a 4 h period indicates pigment agglomeration and requires the processor to evaluate mixing-screw condition or reduce dosage. Cast film properties are verified by ASTM D882 for tensile modulus and elongation at break, ASTM D1003 for total luminous transmittance and haze, ASTM D1922 for tear resistance, and ISO 2813 for 60° gloss. When the concentrate is used in polypropylene cast film, the LLDPE carrier forms a separate phase that can appear as surface streaking and may reduce interlayer adhesion in laminates; therefore, use in PP is outside the intended compatibility envelope and is not recommended without pre-trial dispersion testing. After the run, purging with a low-melt-index LDPE having a melt flow rate of 2 g/10 min at 190°C/2.16 kg per ISO 1133-1 clears residual pigment from the screw and die, reducing carryover contamination in subsequent transparent films.

What Happens When an LLDPE-Based Colour Concentrate Is Let Down into Injection Moulding Grades?

The primary risk in injection moulding is not pigment dispersion but flow-induced colour non-uniformity when the LLDPE carrier has a lower viscosity than the HDPE or LLDPE host resin. Thin-wall containers with a nominal wall thickness of 1.0 mm or less are sensitive to visible knit lines, flow lines, and shade differences between gate and end-of-fill regions. The concentrate is dosed at 2 wt% to 3 wt% through a gravimetric hopper at the feed throat, with barrel zone temperatures from 180°C in the rear zone to 220°C at the nozzle and a melt temperature of 200–230°C. A back pressure of 0.5–1.0 MPa and screw speed of 80–120 rpm improve pigment distribution when the screw is equipped with a mixing tip or fluted mixing section. Mould temperature is maintained at 10–30°C, injection pressure is held at 70–120 MPa, and holding pressure is set to 50–70% of peak injection pressure for 3–6 s. Colour is measured on injection moulded plaques prepared according to ISO 294-3; CIE L*a*b* coordinates are evaluated to ISO 11664-4 or ASTM D2244. A ∆E*ab greater than 1.5 across the part indicates unacceptable colour variation and is typically corrected by raising back pressure within the specified range rather than increasing barrel temperature, because excessive residence time at high temperature can shift the orange shade and create brown degradation products. Hot runner systems above four cavities are run with nozzle temperatures of 210–230°C and are designed to avoid dead spots that contribute to pigment degradation and cross-cavity shade differences. When the host resin is polypropylene, the LLDPE carrier forms discrete domains and can reduce impact strength and create surface defects; this combination is outside the intended compatibility range. Food-contact injection moulded components must comply with the overall migration limit of 10 mg/dm² under EU 10/2011 and the indirect food additive colorant requirements of 21 CFR 178.3297, with migration testing performed on the final moulded article.

For rotomoulded LLDPE tanks, enclosures, and safety barriers, the orange concentrate is ground or micro-pulverized to a particle size compatible with 35 mesh polyethylene powder before dry blending, because pellet-sized carrier particles do not fuse at the same rate as powder and create surface porosity. The concentrate is mixed in high-speed dry blenders for 15–20 min at an addition rate of 1 wt% to 2 wt%, lower than extrusion processes because the wall thickness of 3–10 mm and long oven residence time develop full colour strength. Oven temperatures are set between 260°C and 300°C, with peak internal air temperature between 190°C and 210°C; cycle times of 20–35 min require a pigment with sufficient thermal stability under slow, air-exposed heating. Oxidative stability is monitored by oxidative induction time using ASTM D3895 or ISO 11357-6; a significant drop in OIT relative to uncoloured powder indicates degradation and requires a lower peak internal air temperature or nitrogen purge. When addition rates exceed 2 wt%, surface pinholes and internal voids can increase because LLDPE carrier particles may not fully coalesce with HDPE or MDPE powder at the same rate. A biaxial rotation speed ratio in the range of 3:1 to 4:1 and cooling rates below 10°C/min in the mould are typical to control warpage and colour variation. Impact strength is evaluated by instrumented puncture testing according to ISO 6603-2 at -20°C for outdoor applications. For UV-exposed parts, accelerated weathering is performed to ISO 4892-2 with a xenon-arc source, 340 nm irradiance of 0.51 W/m², and colour retention reported as ∆E*ab after 1000 h. Published specific data for this concentrate in rotational moulding is limited; pre-production trials are required to confirm dispersion, surface finish, and oxidative stability on the target machine.

When Replacing Wax-Based Colourants in Polyethylene Conduit Extrusion

In non-pressure polyethylene conduit extrusion, the substitution of an LLDPE-carrier orange concentrate for wax-based dispersions alters screw feed behaviour and dispersion stability because the carrier contributes melt viscosity rather than lubricating the system. The concentrate is dry blended with HDPE or MDPE pipe grade having a melt flow rate of 0.2–0.7 g/10 min at 190°C/5 kg per ISO 1133-1 and metered at 2 wt% to 4 wt% for orange non-pressure duct. A single-screw extruder with an L/D of 30:1 and a screw equipped with a Pineapple mixing section disperses the pigment without exceeding a melt temperature of 230°C. Barrel zone temperatures range from 180°C to 230°C, the die head is maintained at 210–220°C, and a melt filter pack with 200 µm mesh protects the calibration sleeve from pigment agglomerates. Pressure drop across the breaker plate is recorded at the start of each run; an increase greater than 5% per hour indicates filter loading from undispersed pigment and requires a review of screw mixing condition or a reduction in dosage. The final conduit is tested for ring stiffness according to ISO 9969 or EN 61386-24 for non-flame-propagating conduits. Because an LLDPE carrier at 4 wt% can reduce modulus relative to uncoloured HDPE, elongation at break is measured to ISO 6259-1 and Vicat softening temperature to ISO 306 method A50 for buried duct applications. Colour coding for orange telecom and power ducts is frequently specified as RAL 2004; colour matching is performed with a spectrophotometer using D65/10° geometry and ASTM D2244. Replacing wax-based colourants eliminates die-lip plate-out; plate-out is assessed gravimetrically after 8 h runs by weighing residue collected from the die lip. The LLDPE carrier requires stable feed-throat cooling below 60°C to prevent pellet bridging.

Maintaining Melt Curtain Stability in Extrusion Coating

Extrusion coating of paper, paperboard, and aluminum foil with orange-tinted LLDPE layers uses melt temperatures from 280°C to 320°C to promote substrate adhesion and reduce melt curtain breaks. The concentrate is metered at 2 wt% to 6 wt% depending on coat weight and colour saturation; for coat weights of 15–30 g/m², the lower end of the range limits neck-in and edge bead thickness variation. Neck-in is measured as the difference between die width and coated web width; values above 10–12% of die width indicate excessive low-viscosity carrier dilution and require either a narrower die slot, a reduction in concentrate dosage, or blending with an LDPE resin of higher melt strength. The flat die gap is set between 0.5 mm and 0.8 mm, the air gap is maintained at 100–150 mm, and chill roll temperature is held at 12–20°C. Adhesion is evaluated by T-peel testing according to ASTM D1876; a minimum of 1.5 N/15 mm is commonly specified for paperboard, but the target varies with substrate and coating weight. Fume generation at 280–320°C is controlled by limiting melt residence time to 15 min and by using a low-shear screw with a compression ratio of 2.5:1 to 3.0:1; excessive residence time produces odour and shifts the orange shade, measurable as a decrease in b* greater than 1.0. For food packaging laminates, the final structure must comply with EU 10/2011 and FDA 21 CFR 176.170 for components in contact with aqueous and fatty foods, with migration testing conducted on the finished laminate rather than the coated web alone. When coating aluminium foil, melt temperature above 290°C improves adhesion, but volatile residues from the colour concentrate can deposit on the pressure roll; the pressure roll is cleaned after each 4–6 h run to prevent transfer defects.