On shuttle-type extrusion blow moulding lines equipped with 50 mm grooved-barrel single-screw extruders at 25:1 L/D, Borealis MDPE FB2310 is processed with a feed zone set at 180 °C, transition zones at 190–200 °C, metering zone at 205 °C and die head at 200–210 °C. The grade has a nominal density of 0.931 g/cm³ per ISO 1183-1 and an MFR₂ of 0.7 g/10 min at 190 °C/2.16 kg per ISO 1133-1; these values reduce parison sag for shot weights between 45 g and 210 g. A 2 L UN 3H1 Packing Group III agrochemical container is produced from 96 wt% FB2310, 3 wt% UV-stabilised LLDPE masterbatch containing 40 wt% carbon black, and 1 wt% process lubricant masterbatch, yielding a finished wall carbon black content of 2.0–2.5 wt% for outdoor storage. The parison is inflated at 0.6–0.8 MPa through a converging die with a die gap of 1.5–2.0 mm, and the aluminium mould is held at 10–15 °C with closed-loop chiller water. At die head temperatures above 215 °C the parison surface oxidises and gel particles appear in the finished wall; below 185 °C the extruder motor load rises and surface roughness increases. Empty container performance is assessed under the UN Model Regulations Chapter 6.1 for non-removable-head plastics packagings, including drop tests at −18 °C, internal hydraulic pressure tests, and stacking tests appropriate to Packing Group III liquids. The same formulation is used for 750 mL, 1 L and 5 L detergent concentrate containers where ESCR under ASTM D1693 condition B is required to resist stress cracking from non-ionic surfactants; published supplier data for this grade reports F50 values above 1,000 h in 10% Igepal CO-630 at 50 °C, though incoming lot testing is still required.

Compression Moulded Closure Systems and Tamper-Evident Overcaps

Closure systems with wall sections exceeding 1.5 mm and moulded-in hinge geometries are produced on 250–350 t hydraulic injection moulding machines with 28:1 L/D reciprocating screws and 16-cavity cold-runner tools. Barrel temperatures are set from 190 °C at the feed throat to 220 °C at the nozzle, holding pressure is 40–60 MPa, and cooling time is 10–14 s for a 2.0 mm thick overcap. The base resin is mixed with 2.0 wt% HDPE carrier masterbatch containing 4 wt% slip agent and 1.5 wt% white pigment masterbatch; no external mould release agent is added because the medium-density polyethylene shows sufficient mould release at 10–15 °C tool temperature. Borealis MDPE FB2310 has an MFR₂ of 0.7 g/10 min per ISO 1133-1, which is below the 5–10 g/10 min range normally used for thin-wall high-cavitation closure production; published data for such thin-wall configurations is limited, and the grade is not recommended where cycle times below 8 s are mandatory. The bimodal molecular weight distribution provides ESCR behaviour that reduces hinge failure in tamper-evident overcaps subjected to repeated opening. Compliance for food-contact applications is based on EU Regulation No 10/2011 and FDA 21 CFR 177.1520 for olefin polymers, subject to overall migration and specific migration limits specified by the converter. Terminal products are 38 mm and 45 mm overcaps for cosmetic, household chemical and pharmaceutical packages.

For thermoformed packaging produced via sheet extrusion, Borealis MDPE FB2310 is processed on a 75 mm single-screw extruder with 30:1 L/D, a 1,200 mm coat-hanger die, and a three-roll polishing stack. The barrel profile is 180 °C at the feed zone, 190–200 °C in compression, and 205–210 °C at the metering zone; the die temperature is 205–215 °C, and roll temperatures are held at 65–75 °C to produce a 1.0 mm sheet with ≤2% gauge scatter. A formulation for refrigerated dairy packaging uses 90 wt% FB2310, 10 wt% linear low density polyethylene for low-temperature impact, and 0.5 wt% nucleating masterbatch; the blend is dry-mixed before gravimetric feeding. The sheet is thermoformed on a plug-assist machine with sheet surface temperature of 120–130 °C and mould temperature of 20–30 °C; draw ratios above 2.0:1 are avoided because the medium-density resin has lower melt strength than branched LDPE. The finished trays and cups are tested for compression strength according to ISO 12048 and for food-contact migration under EU Regulation No 10/2011. Terminal products are 500 g and 1 kg refrigerated dairy trays, frozen food trays, and snap-on lids.

What Melt Strength Constraints Govern 150 µm Heavy-Duty Liner Film?

A 150 µm black construction film based on FB2310 is produced on a 65 mm blown film line with a 150 mm die, 1.6 mm die gap, and dual-lip air ring. Because the MFR₂ of 0.7 g/10 min per ISO 1133-1 and the bimodal molecular weight distribution give moderate melt strength, the grade is dry-blended with 20–30 wt% linear low density polyethylene to reduce bubble instability and raise dart impact strength. Extruder barrel profile is 180 °C at the feed section, 190–200 °C in the compression section, and 195–205 °C at the die; the blow-up ratio is 2.0:1 to 2.5:1, and the frost line is held at 5–7 die diameters above the air ring to stabilise the 150 µm film. A formulation for outdoor construction film contains 2.5 wt% carbon black masterbatch at 45 wt% carbon black and 0.1 wt% fluoropolymer processing aid; the final film is tested for tensile yield and elongation according to ISO 527-3 and for Elmendorf tear according to ASTM D1922. Published dart impact values for this specific FB2310/LLDPE blend ratio are limited; plant trials are required to establish lot-specific values. Compliance for direct food contact is not applicable for construction film; when used in contact with dry food, EU Regulation No 10/2011 migration testing is required. Terminal products are heavy-duty industrial liners, temporary weather protection membranes, and concrete curing covers.

When Automotive Vent Ducts Need Ductile Failure Below −30 °C

When automotive HVAC ducts with wall thickness of 1.5–2.5 mm and convoluted sections are blow moulded from FB2310, the melt temperature at the die is held at 190–210 °C on accumulator-head machines with 80 mm grooved-barrel extruders and 30:1 L/D. The mould closing pressure is limited to 0.8 MPa to maintain the convoluted geometry without pinching the parison. The resin is compounded with 1.5–2.0 wt% hindered amine light stabilizer masterbatch and 0.5 wt% processing lubricant masterbatch; no plasticizer is added because low-molecular-weight plasticizers would increase VOC emissions and reduce long-term ductility. The finished duct is subjected to multiaxial impact testing at −30 °C according to ISO 6603-2 method A, and to odour and total VOC testing according to VDA 277 for passenger compartment components. Borealis MDPE FB2310 has a nominal density of 0.931 g/cm³ per ISO 1183-1 and a published Vicat A50 near 118 °C per ISO 306; therefore continuous service above 80 °C is not recommended for underhood applications. Terminal products are HVAC air ducts, defroster ducts, and cabin vent conduits.