PCC Iran supplies HDPE 62107 as an injection-moulding high-density polyethylene with a nominal melt flow rate of 7 g/10 min determined by ASTM D1238 at 190°C/2.16 kg and a nominal density of 0.962 g/cm³ determined by ASTM D1505. The processing window is controlled by a competition between flow length, crystallisation-driven shrinkage, and environmental stress crack resistance. That makes it suited to rigid injection-moulded dairy packaging, closures, open-head industrial pails, logistics crates and pallets, and carrier-resin compounding. The following scenarios treat these applications separately because the failure hierarchy changes with part geometry. Published data for this specific configuration is limited and should be validated against the supplier certificate of analysis and the individual mould.

What Changes When Wall Thickness Falls Below 0.80 mm in High-Speed Dairy Packaging?

Thin-wall dairy packaging converts HDPE 62107 in stackable cups, tubs, and lids with wall sections from 0.60 mm to 1.20 mm, but the critical shift begins below 0.80 mm. At that point, flow length and pressure drop dominate. A flow length-to-wall-thickness ratio of 100:1 to 150:1 requires melt temperature between 215°C and 235°C, injection velocity from 100 mm/s to 180 mm/s, and peak injection pressure from 80 MPa to 120 MPa. Above 235°C the free-flow behaviour creates a false sense of processability; the added fluidity is paid for by surface streaking, gate-stringing, and an increased risk of plate-out on exhaust vents. Dropping below 210°C forces the cavity to freeze before packing, and uncontrolled volumetric shrinkage appears as sink marks at the stacking shoulder and rim distortion. Gate selection follows from the freeze-off condition. Hot-runner valve-gate systems use gate diameters of 0.8 mm to 1.5 mm, with valve-pin delay held below 0.3 s to prevent melt freezing in the gate land. Cold-runner tunnel gates are kept above 1.2 mm; smaller gates freeze in under 1.5 s and block pack pressure from reaching the cavity. The tool is normally maintained at 10°C to 25°C. The lower end of that range shortens cooling time but increases the risk of stress cracking at the rim when the container is later exposed to chilled dairy cream or acidic whey. Targeted cooling time for 0.80 mm wall is 4.5 s to 6.0 s; for 0.60 mm it falls to 2.5 s to 3.5 s, and for 1.00 mm it rises to 8.0 s to 12.0 s. Pack pressure is maintained at 30 MPa to 60 MPa for 0.8 s to 2.5 s. The end product is a stackable dairy pot, lid, or single-serve dessert cup in which the critical release criterion is not tensile yield but drop impact at 0°C to 5°C after filling. Finished-container testing commonly uses ASTM D5276 for free-fall drop and ASTM D2463 for impact damage evaluation. Slip and anti-block levels are masterbatch-controlled and are not fixed by the base resin specification, so the dairy line must qualify the material under EU No 10/2011 and FDA 21 CFR 177.1520(c) before pack-out.

When the Gate Freezes Before Packing Completes in 20 L Open-Head Pails

Open-head pails from 5 L to 25 L are the most structurally demanding application for HDPE 62107 because the useful wall thickness of 2.0 mm to 2.8 mm lies above the thin-wall regime but below the heavy-section regime used in crates. The process conflict is gate freeze time. With a standard cold sprue gate below 3.5 mm diameter, the gate begins to freeze before the pack phase has transmitted 15 MPa to 25 MPa to the far rim, leaving underpacked areas around the handle lugs. The defect may not be visible immediately after ejection; it appears later as environmental stress cracking at the lug root under stacking load or as leakage after a drop test. For a 20 L pail, the gate diameter is kept between 4.0 mm and 5.0 mm, or a hot-runner valve gate is used with a nozzle tip temperature of 220°C to 230°C. Mould fill time is 2.5 s to 4.0 s, pack pressure is 15 MPa to 25 MPa, and hold time is 8 s to 12 s. Cooling time for a 2.0 mm wall is 18 s to 22 s; for a 2.5 mm wall it rises to 28 s to 35 s. Total cycle time on a 650 t hydraulic machine with a single cavity is 40 s to 55 s. The end product is an open-head pail for lubricants, food ingredients, water-based coatings, and industrial chemicals. Mechanical validation is carried out by stacking top-load tests at 40°C and 80% RH for 7 days, with acceptable failure load above 250 kg per column depending on wall thickness and rim design. Low-temperature drop testing follows ASTM D5276 after conditioning at -18°C for 24 h; the drop height is 1.2 m. The weak feature is rarely the flat wall; it is the weld line around the handle bridge. With a single gate, weld-line tensile strength retention in HDPE is only 50% to 70% of the bulk value, so gate position is biased to move the weld line away from the handle attachment zone and into the base corner. ESCR testing under ASTM D1693 Condition B in 10% Igepal at 50°C is used to screen for stress crack resistance; in this geometry, F50 values below 100 h are considered inadequate for lubricant and detergent pails. Regrind reincorporation is capped at 20 wt% to 25 wt%, because higher ratios reduce ESCR and low-temperature impact disproportionately compared with melt flow index. Shrinkage in a pail with this wall thickness is measurable but manageable: 1.5% to 1.8% in flow and 0.8% to 1.1% cross-flow. The mould designer compensates by increasing the rim diameter and maintaining uniform cooling between the bottom and the rim. If the bottom is cooled faster than the rim, the pail becomes oval and the lid seal fails.

Closure production changes the failure hierarchy from drop impact to stress-crack growth at the thread root and torque loss during repeated resealing. HDPE 62107 is used for beverage, sauce, and pharmaceutical closures with thread diameters from 24 mm to 48 mm. In a 38 mm carbonated soft drink cap, the thread root wall is 0.6 mm to 1.0 mm, and the bridge dimensions of the tamper-evident band are 0.25 mm to 0.45 mm. The mould is typically a 32-cavity hot-runner tool with point gates of 0.6 mm to 0.9 mm. Filling takes 0.5 s to 1.2 s, packing takes 0.5 s to 1.5 s, and cooling takes 2.5 s to 4.5 s. Total cycle time is 6.0 s to 9.0 s. The cap must combine low removal torque with high burst resistance. Erucamide slip is added by masterbatch at 0.05 wt% to 0.15 wt%; above that range the removal torque drops but the outer surface develops haze and the cap may scuff during high-speed capping. Taste and odour are controlled by limiting degradation during extrusion and moulding, but the grade itself is not a barrier polymer; oxygen ingress through the cap gasket should be managed by the liner or valve design, not by the cap body. Carbonated soft drink closure performance is verified on a PET bottle by pressurisation to 5.5 bar at 30°C, and leakage is assessed under ASTM D4991. For pharmaceutical and chemical closures, the restriction is chemical resistance and stress cracking. A 10% Igepal solution at 50°C is used with ASTM D1693 Condition B; the criterion is F50 above 150 h for aggressive surfactant-based products. White cap applications often use titanium dioxide masterbatch at 2 wt% to 5 wt% to increase opacity. The food-contact status is established through EU No 10/2011 overall migration testing and FDA 21 CFR 177.1520(c). The table below summarises the compliance matrix for closure and rigid packaging end-uses.

Heavy-Duty Crate Weld-Line Placement under 700 t Clamp Force

Logistics crates and modular pallets represent the upper shot-weight boundary for this grade. HDPE 62107 can fill a 15 kg to 25 kg shot when the projected area is supported by a clamp force of 700 t to 1,200 t, depending on the number of cavities. Wall thickness in load-bearing side walls is 4 mm to 6 mm, and the floor ribs are 5 mm to 8 mm. The dominant moulding problem is not fill but weld-line placement and differential shrinkage. Injection time is 6 s to 12 s, pack pressure is 30 MPa to 50 MPa, and total cycle time is 60 s to 120 s. Barrel temperatures are lower than in thin-wall moulding: 200°C to 220°C, because longer residence time at high temperature causes yellowing and brittleness at the weld line. The tool temperature is 10°C to 20°C; turbulent cooling with Reynolds numbers above 10,000 prevents hot spots in thick bosses. Weld lines in crates should be moved out of the corner columns and handle apertures. If the weld line is forced into a high-stress corner, the part fails at 50% to 70% of the un-welded tensile strength. The finished crate is usually validated by cold chain drop tests at -20°C after 24 h conditioning; the acceptance criterion is no fracture in 10 drops from 0.5 m to 1.0 m depending on the market. Long-term load is evaluated according to ISO 8611-2 for pallet racking stiffness and creep. With high-density crystallinity, shrinkage is 1.6% to 2.0% in flow and 0.8% to 1.2% transverse. Unbalanced cooling of the floor and side walls creates corner lift above 3 mm per 500 mm side length, which causes pallet instability. For outdoor logistics crates, UV stabilization is necessary; unstabilized HDPE loses surface gloss and impact strength after 1000 h of ASTM G154 weatherometer testing, and the stabilizer masterbatch is incorporated at 1 wt% to 3 wt%.

Masterbatch production uses the same melt flow index as a carrier because the 7 g/10 min flow wetting allows pigment loading from 30 wt% to 50 wt% on a co-rotating twin-screw extruder. Barrel temperature is kept between 160°C and 210°C, die pressure is 3 MPa to 8 MPa, and the extruder is operated at L/D 40:1 with specific energy input 0.15 kWh/kg to 0.25 kWh/kg. Underwater pelletizing at 20°C to 35°C produces uniform pellets for letdown ratios of 1% to 4% in HDPE and PP conversion lines. Above 50 wt% loading, dispersion uniformity becomes dependent on additive surface treatment and rheology; published data for this specific configuration is limited, and a higher MFI carrier is used in practice.

General housewares and storage boxes produced from the same grade follow the thin-wall packaging profile; no separate processing window is required beyond a clamp force of 0.4 kN/mm² to 0.6 kN/mm² projected area and a mould temperature of 15°C to 30°C.