Agricultural silage cover film is one of the first downstream applications for BiologiQ ESR-PE EcoStarch mLLDPE Blend because the starch phase contributes incremental bio-based content without removing the puncture and tear requirements set by ASTM D5748 and ISO 527-3. On production extruders, the compound is usually dry-blended with neat mLLDPE at the hopper to bring the starch-derived portion to 10 wt% to 18 wt% of the melt. Blown film lines fitted with grooved feed sections and 25:1 to 30:1 L/D single screws maintain stable throughput at this addition level. The melt temperature at the die lip is held between 170°C and 185°C. Pre-drying in a desiccant hopper dryer at 65°C for 3 h is required when the resin has been stored at relative humidity above 60%. Film downgauging to 25 µm is permissible only after verification of dart impact resistance using ASTM D1709, because starch domains act as stress concentrators at high stretch ratios. The final silage cover must resist punctures from chopped corn stalks and maintain oxygen permeability below the crop respiration threshold. The mLLDPE phase contributes the elastomeric recovery required for stretched film retention on pit walls. Film tear resistance is checked by ASTM D1922 in both machine and transverse directions. The starch phase is not intended to render the silage film compostable, and the mLLDPE matrix remains non-hydrolyzable under ISO 14855-1 conditions. Grade-specific published data for the ESR-PE blend is limited, so plant validation is required before final gauge selection.

What Limits Starch Loading in Collation Shrink Film on High-Speed Wrappers?

Collation shrink film produced from BiologiQ ESR-PE EcoStarch mLLDPE Blend is constrained by two competing requirements: the low shrink-initiation temperature required for multi-pack beverages and the thermal sensitivity of the starch phase. The recommended starch-derived fraction in the final melt is 8 wt% to 12 wt%. At this concentration, transverse direction shrinkage at 150°C in a hot-air tunnel remains measurable by ASTM D2732, though published data for the ESR-PE grade is limited. The extruder profile is set lower than a conventional mLLDPE shrink line: feed zone 145°C, compression zone 160°C, metering zone 170°C, and die 175°C. Screw speed is reduced by 10% to 15% relative to a neat mLLDPE reference to avoid local shear heating. The die gap is opened to 1.2 mm to reduce melt pressure and starch-phase friction. Bubble stability is maintained with a blow-up ratio of 2.0:1 to 2.4:1. Frost line height is set at 5 die diameters. Plant trials on multi-pack bottle collation have identified web tear at the shrink tunnel exit when film temperature exceeds 165°C; infrared tunnel zoning must therefore avoid radiant overshoot. The finished film is not compostable unless an additional degradable masterbatch is added, because the mLLDPE matrix remains non-hydrolyzable. Shrink force is monitored through ISO 14616, and seal strength through ASTM F88. At starch fractions above 12 wt%, the shrink force can fall below the threshold required to hold bottle arrays under vibration.

Across heavy-duty shipping sack extrusion, BiologiQ ESR-PE EcoStarch mLLDPE Blend is used as a let-down resin in multi-layer coextruded structures rather than as the sole skin layer. A typical structure places the blend in a core layer at 15% to 25% by mass. The outer skins remain neat mLLDPE or LDPE. This layer sequence preserves the high coefficient-of-friction surfaces demanded by automated sack filling lines, while the core starch phase absorbs part of the dart impact load. Coextrusion blown film lines with 3 to 5 layers are suitable. The die temperature is capped at 190°C because starch degradation onset approaches 200°C. Layer melt pumps must be calibrated independently. The starch-containing core shows higher melt viscosity at low shear than the mLLDPE skin, so the core extruder typically runs 5°C to 8°C cooler. Burst strength after filling is measured using ISO 2758 for sacks with paper-like failure modes or ASTM D3786 for film. At equivalent gauge, a 20% loss in burst pressure relative to neat mLLDPE is observed in some field trials when the starch phase exceeds 20 wt%. The core layer addition reduces the fossil-carbon fraction of the sack without altering the mechanical handling behaviour of the skin layers. No anti-blocking agent is added to the core because the starch phase itself provides limited interlayer separation. The final sack must pass ISO 7965-2 drop testing after filling with the intended product.

Thin-Wall Injection Molding of Dairy Tubs and Lids

Injection molding of thin-wall dairy tubs and lids from BiologiQ ESR-PE EcoStarch mLLDPE Blend is limited to starch fractions below 15 wt%. Higher concentrations generate flow hesitation and weld-line parting at the base of the tub. The feedstock must be dried to 0.03 wt% moisture or lower, using a dehumidifying dryer at 75°C for 4 h. Barrel temperatures are set in the range 160°C to 195°C, with the nozzle at 190°C. Injection speed is reduced by 20% versus a neat mLLDPE reference to prevent jetting and starch-phase orientation streaks. Mold temperature is held at 15°C to 30°C. Clamp force per square centimeter of projected area follows the machine manufacturer’s recommendation, typically 0.6 tons/cm² to 0.8 tons/cm² for thin-wall mLLDPE grades. The starch phase lowers notched Izod impact strength measured by ASTM D256; when starch fraction rises from 0 wt% to 15 wt%, a reduction of 25% to 35% is typical in starch-filled polyolefin systems, though grade-specific ESR-PE data is limited. The final tubs are printable with UV inks after corona treatment at 42 dyn/cm. Dimensional stability is checked by ISO 294-3. The injection gate land length is increased by 0.5 mm compared with neat mLLDPE tooling practice to reduce starch-phase orientation at the gate. No post-mold annealing is required below 15 wt% starch.

When Extrusion Coating onto Kraft Paper Replaces Neat LDPE in Industrial Liners

Extrusion coating of BiologiQ ESR-PE EcoStarch mLLDPE Blend onto paper substrates for industrial liners is feasible only with starch fractions at the lower end of the specification, typically 5 wt% to 10 wt%. The melt curtain must remain stable at line speeds exceeding 120 m/min. The presence of starch reduces draw resonance resistance. The coating die is positioned at a distance of 150 mm to 200 mm from the chill roll. Melt temperature at the slot die is held at 175°C. Air-gap cooling is avoided because the starch phase increases extensional viscosity and promotes filament breakage. The chill roll temperature is set at 10°C to 15°C. Adhesion to kraft is measured using a 180° peel test per ISO 8510-2; values above 2 N/cm are generally required for industrial liner release. The starch component may increase water-vapor transmission rate compared with neat LDPE at equal coating weight, so barrier performance must be confirmed using ISO 15106-2 at 23°C and 85% RH. If the liner is intended for food contact, migration testing under FDA 21 CFR 177.1520 and EU 10/2011 must be repeated for the specific blend, because starch-based additives can alter overall migration under oil simulants. Coating weight is controlled gravimetrically and verified by ISO 4593. The starch phase may also reduce the heat-seal strength against ionomer skins, so the final laminate is sealed at 130°C to 145°C with residence time extended by 0.3 s compared with neat LDPE.

Retail produce bags on roll-stock converting lines are produced from BiologiQ ESR-PE EcoStarch mLLDPE Blend blended with reprocessed mLLDPE at a 1:1 ratio. Extrusion is performed on conventional LDPE blown film lines with die diameters between 50 mm and 80 mm. The starch phase creates micro-haze that is acceptable for produce display, but gloss measured by ASTM D2457 at 60° falls by 10% to 20% when starch content exceeds 10 wt%. Bag seal strength is measured by ASTM F88, with minimum seal initiation at 120°C. The final film must resist elongation under discrete load, so the mLLDPE phase value is verified by ISO 527-3. No additional slip agent is required below 15 wt% starch, but above that level the coefficient of friction can rise above 0.4, as checked by ASTM D1894. Screen packs of 80 mesh are installed upstream of the die to remove starch agglomerates larger than 50 µm. The bubble is quenched at a frost line height of 3 die diameters to limit starch migration to the film surface. The resulting bags are not certified compostable and must not be labelled as such without completing ASTM D6400 or EN 13432 testing.