MF3713 (PCC Iran) is processed as an HDPE injection-moulding grade with a nominal melt flow index of 13 g/10 min measured to ISO 1133-1:2022 at 190 °C under 2.16 kg load and a typical density near 0.947 g/cm³ determined by ISO 1183-1. The melt rheology places the material in the moderate-flow HDPE class, suitable for medium-flow-length injection tools but not for very long thin-wall flow paths requiring melt flow indices above 30 g/10 min.

Industrial open-top pails and UN-certified transport jerricans are injection-moulded from MF3713 using thick-wall tooling with nominal wall sections of 2.5–4.5 mm. A general-purpose screw with L/D 20:1–24:1 and compression ratio 2.5:1–3.0:1 is used. Melt temperature is maintained at 200–240 °C, mould temperature at 15–40 °C, injection pressure at 80–120 MPa, hold pressure at 50–70 MPa, and back pressure at 0.5–1.5 MPa. Cooling time is set between 12–20 s depending on handle section thickness and mould cooling layout. Clean in-house regrind from sprues, runners, and rejected pails is incorporated at 10–15 wt%; for UN-certified packages, the regrind fraction must be traceable and the finished pail must pass drop testing after conditioning at -18 °C and stack testing under the applicable UN modal requirements. Heavy-metal concentration is controlled to a total of <100 ppm for lead, cadmium, mercury, and hexavalent chromium under EU Packaging and Packaging Waste Directive 94/62/EC. Terminal products are 5–25 L open-top pails for paints, lubricants, adhesives, and non-food industrial compounds.

How Does MF3713 Behave in High-Cavitation Thin-Wall Dairy Packaging?

Thin-wall dairy cups and tubs require a balance of flow length, demoulding stiffness, and drop impact at refrigerated temperature. For this segment, MF3713 is processed at melt temperatures of 220–250 °C and mould temperatures of 10–25 °C. Injection velocity is set between 200–400 mm/s with fill times of 0.08–0.35 s on accumulator-assisted machines of 100–250 t clamp force. Hot-runner valve gates with diameters of 0.6–1.0 mm are used across 4–16 cavities. Warpage is controlled by keeping mould temperature differential across the cavity and core within ±5 °C because HDPE solidification shrinkage of 1.5–2.5% combined with asymmetric cooling produces sidewall ovality. Low-density polyethylene or linear low-density polyethylene is added at 5–10 wt% to improve environmental stress crack resistance in the presence of dairy fat; a nucleating agent at 0.05–0.10 wt% raises crystallization temperature and shortens demoulding time, while slip/antiblock masterbatch at 0.05–0.15 wt% contributes to denesting behaviour after stacking. Food-contact compliance is assessed to EU 10/2011 with an overall migration limit of 10 mg/dm² and to FDA 21 CFR 177.1520(c) for olefin polymers. Organoleptic acceptance for dairy contact is verified by sensory evaluation according to ISO 13302. Finished articles include 150–200 mL yogurt pots, margarine tubs, and frozen dessert containers.

In high-cavitation closure manufacturing, MF3713 is processed on injection moulding machines of 100–300 t clamp force with hydraulic accumulator assist. Production tools typically contain 48–128 cavities with valve-gated hot runners and gate diameters of 0.4–1.2 mm. Melt temperature is held at 220–260 °C, mould temperature at 10–25 °C, and total cycle time at 4–8 s. Unscrewing or collapsing cores are used to demould tamper-evident bands without tearing. Slip masterbatch based on erucamide or oleamide is compounded at 1.5–3.0 wt% to control cap-on and cap-off torque; LLDPE is added at 2–4 wt% to improve band stretch and impact resistance at refrigerated distribution temperatures. For food-contact closures, compliance is verified against FDA 21 CFR 177.1520, EU 1935/2004, and EU 10/2011. MF3713 is not recommended for carbonated soft drink closures because HDPE exhibits lower top-load retention and higher creep under carbon dioxide pressure than polypropylene impact copolymers, particularly after pasteurisation. Terminal parts are 28 mm and 38 mm tamper-evident closures for still water, dairy beverages, household cleaners, and motor oil containers.

Returnable Crates, Pallets, and Logistics Equipment

Returnable logistics products such as ventilated produce crates, distribution totes, and rackable pallet boxes are moulded with MF3713 at wall thicknesses of 3.0–6.0 mm. Flow length in 600 × 400 mm or 1200 × 1000 mm tools is managed through multiple hot drops and sequential valve gating to prevent weld-line weakness at the base. Melt temperature is set at 200–240 °C, mould temperature at 15–35 °C, injection pressure at 70–100 MPa, and hold pressure at 40–60 MPa. Cooling time of 25–40 s is common for thick ribs and handle sections. Post-industrial regrind from the logistics stream is incorporated at 10–30 wt%; if the regrind fraction exceeds 20 wt%, notched Charpy impact strength to ISO 179-1/1eA and environmental stress crack resistance to ISO 22088-2 must be revalidated on the production tool. Mechanical handling performance is assessed to ISO 8611-1 for pallets and ASTM D4169 for distribution simulation. The primary operational limitation is low-temperature impact: MF3713, as an injection-moulding grade, may not retain sufficient impact at -20 °C for freezer warehouse pallet use unless the regrind fraction is reduced and the design eliminates sharp notches at rib intersections. Finished applications include ventilated agricultural crates, dairy distribution totes, and rackable pallet boxes for closed-loop retail logistics.

For household storage modules and garden furniture components, MF3713 is injected at lower melt temperatures of 190–230 °C and mould temperatures of 15–35 °C. Wall thickness is normally 1.5–3.0 mm, injection pressure 60–100 MPa, hold pressure 35–55 MPa, and cooling time 10–25 s. Colour masterbatch is added at 1–3 wt%. Outdoor grades require UV stabiliser masterbatch at 1–3 wt% or carbon black at 0.5–1.0 wt% to delay surface chalking and embrittlement under sunlight. Flow marks and gloss variation are controlled by holding melt temperature uniformity within ±5 °C and by texturing the cavity surface. Regulatory assessment includes REACH 1907/2006 and RoHS 2011/65/EU; if the article is marketed as children’s storage furniture, the applicable element migration limits of EN 71-3 also apply. Terminal products are modular storage bins, stackable crates, drawer units, and garden side-table shells.

When Post-Consumer HDPE Regrind Is Added to MF3713 at 25 wt%

When post-consumer HDPE regrind is added to MF3713 at 25 wt%, the processing window narrows because post-consumer flake typically has a melt flow index of 0.5–1.5 g/10 min, creating viscosity heterogeneity with the virgin fraction. The blend is prepared on a co-rotating twin-screw extruder with L/D 40:1–48:1, screw speed 300–500 rpm, and melt temperature 200–230 °C, followed by strand pelletising. Antioxidant masterbatch is added at 0.05–0.10 wt% and acid scavenger at 0.03–0.06 wt% to stabilise residual hydroperoxides and acidic species from the recycled stream. Tensile yield stress measured to ISO 527-2/1A typically remains above 85% of the virgin MF3713 value when washed flake with melt flow index above 0.8 g/10 min is used. Notched Charpy impact to ISO 179-1/1eA may decrease by 10–20% at 23 °C. Published data for this specific configuration is limited; tool-specific validation is required for each crate or pallet design. Polypropylene contamination must be kept below 2 wt% because incompatible PP domains concentrate at weld lines and produce delamination under drop loading. The resulting compound is used for non-food returnable transit containers, refuse container bodies, and automotive service parts where food-contact approval is not required.

As a melt-compoundable carrier resin for polyolefin masterbatches, MF3713 is run in co-rotating twin-screw extruders with L/D 40:1–48:1, screw speed 400–800 rpm, and temperature profile 180–240 °C. Die-face air or water-ring pelletising is used. Pigment loadings of 20–60 wt% are dispersed with waxes at 5–15 wt% and antioxidant at 0.1–0.3 wt%, the balance being carrier resin. The melt viscosity associated with a melt flow index of 13 g/10 min permits wetting of high-surface-area organic pigments without excessive screw torque. Residence time is maintained below 60 s to limit thermal degradation of phthalocyanine and disazo pigments. For masterbatches intended for food-contact packaging, the final fabricated article must satisfy EU 10/2011 and FDA 21 CFR 177.1520; RoHS 2011/65/EU restricts lead, mercury, and hexavalent chromium to 0.1 wt% each and cadmium to 0.01 wt%. End products are colour and additive masterbatches for HDPE blow film, injection-moulded crates, and closure moulding.