Aclo Compounders HDPE HD0202L is a high-density polyethylene injection-moulding grade supplied in natural pellet form for closures, overcaps, thin-walled packaging, and industrial containers. The material is positioned by its melt-flow index: a nominal melt mass-flow rate of 2.0 g/10 min determined under ISO 1133-1:2022 at 190 °C with 2.16 kg. Density is reported at 0.952 g/cm³ by ISO 1183-1. This property pair identifies the product as a medium-flow, high-density grade rather than a low-pressure pipe or blow-moulding resin. The designated flow rate permits a lower melt temperature than fractional-melt HDPE while retaining enough molecular weight for environmental stress-cracking resistance in cap and closure applications. Pellet geometry is controlled in the 3.0–4.0 mm granule-length range, and bulk density is set at 0.52–0.56 g/cm³ for stable feeding from hopper loaders and gravimetric dosing units.

The grade is differentiated from other high-density polyethylene products principally by the combination of a 2.0 g/10 min melt flow rate and a density above 0.950 g/cm³. This combination supports injection-cycle times shorter than those observed with fractional-melt HDPE while maintaining higher melt strength than a conventional 8–20 g/10 min thin-wall grade. In practice, the product is used where closure dimensional stability, low-temperature drop strength, and cap sealing-force retention are specified on the drawing.

What Distinguishes HD0202L from Fractional-Melt and High-MFR HDPE Grades?

The principal difference is molecular weight distribution. High-density polyethylene with a melt flow rate below 0.5 g/10 min is typically used for blow-moulded containers, large-volume industrial packaging, and extruded sheet requiring high melt strength and elevated environmental stress-cracking resistance. High-density polyethylene with a melt flow rate above 8.0 g/10 min is used for thin-wall disposables and caps where filling pressure must be minimized. HD0202L occupies the intermediate region: the melt flow rate is high enough to fill multi-cavity closure tools at moderate injection pressure, yet low enough to preserve a useful fraction of high-molecular-weight chains. Gel-permeation chromatography data for this product class typically indicate a weight-average molecular weight in the range 180,000–220,000 g/mol and a polydispersity index near 3.5–4.5. Published chromatograms for this specific commercial configuration are limited; lot-specific values should be obtained from the supplier certificate of analysis.

Injection moulding lines running HD0202L on 45–80 mm three-zone screws with L/D ratios between 20:1 and 24:1 commonly set barrel temperatures at 190 °C in the feed zone, 210 °C in compression, and 220 °C in the metering zone. Nozzle set points are maintained between 220 °C and 230 °C. Mould temperature is controlled at 15–40 °C; the lower portion of this range shortens cycle time in thin-wall caps but increases residual orientation. On a 32-cavity hot-runner closure tool producing 2.2 g caps, shot-weight repeatability is reported within ±0.15% when the screw cushion is held at 3–5 mm and back pressure does not exceed 10 bar. Higher back pressure induces shear heating, reduces melt viscosity, and can produce yellowing when certain masterbatch systems are present.

The values in the table are typical product-class values for this grade and are not specification limits. Conformance to a commercial drawing should be established from the lot-specific certificate of analysis and, where food contact is claimed, from the compliance statement issued by Aclo Compounders.

Thermo-oxidative Stabilization, Migration Resistance, and Pellet-Handling Characteristics

HD0202L is stabilized with a hindered phenolic antioxidant system. The stabilizer package is selected to limit thermo-oxidative degradation during melt processing and to maintain colour stability during multiple heat histories. For food-contact applications, the grade is supplied with documentation that supports use under FDA 21 CFR 177.1520 and Commission Regulation (EU) No 10/2011. Overall migration testing under EU 10/2011 with simulant D2 at 40 °C for 10 days is expected to remain below 10 mg/dm². The product should not be combined with copper-based pigments because copper ions can accelerate the decomposition of hydroperoxides and reduce long-term thermal stability. Industrial packaging applications can tolerate regrind addition up to 30 wt%, but each 10 wt% addition of thermally degraded regrind may increase the melt flow rate by 0.1–0.2 g/10 min depending on the thermal history and residual stabilizer content.

Environmental stress-cracking resistance under ASTM D1693 condition B using 100% Igepal CO-630 is reported near 40 h. This is below the values typical of 0.2–0.5 g/10 min blow-moulding grades but sufficient for many rigid closure applications involving low-fat aqueous media. Closures exposed to essential oils, d-limonene, or aggressive surfactant systems require separate validation because stress-cracking resistance is governed less by bulk density than by tie-molecule concentration and crystalline morphology.

Compared with a standard 8.0 g/10 min injection-moulding HDPE, HD0202L requires higher filling pressure because of its longer average molecular chain. At 100 s⁻¹ and 220 °C, the viscosity ratio is approximately 1.6:1. A 32-cavity cap tool may therefore require 15–20% higher fill pressure than the same tool running an 8 g/10 min resin. The trade-off is an improvement in environmental stress-cracking resistance: the medium-flow product typically shows an F50 near 40 h, whereas a conventional 8 g/10 min grade may fall below 12 h. Compared with a fractional-melt blow-moulding HDPE of 0.3 g/10 min, HD0202L reduces melt temperature and cooling time in injection applications, but it is not suitable for large-part extrusion blow moulding because parison hang strength is insufficient for heavy shot weights.

Where continuous extrusion is used for pelletizing, compounding, or profile production, the product can be processed on standard polyolefin screws with a compression ratio of 2.0–2.5:1. Melt filtration at 100–150 µm is recommended for closure production because retained gel particles above this size can interrupt valve-gate seat sealing and affect closure leak rates. On a 48-cavity hot-runner tool running a 2.2 g water closure, the process bottleneck is typically screw recovery time rather than clamp speed. With a 40 mm screw diameter and 4 bar back pressure, recovery time is reported in the range 1.6–2.0 s.

When Flatness and Cap Sealing Force in Thin-Wall Closure Production Become Process-Defining Parameters

In thin-wall dairy and beverage closures, the controlling defects are radial short shots, cap ovality, and loss of sealing force after liner insertion. HD0202L is formulated for this operating window: the 2.0 g/10 min melt flow rate allows filling of wall sections below 0.8 mm at melt temperatures near 220 °C, while the density of 0.952 g/cm³ provides enough modulus to limit cap skirt deformation under removal torque. Cap ovality after ejection is controlled by maintaining mould temperature uniformity below ±3 °C and by using an ejection delay of 0.2–0.5 s after mould opening. In production-scale trials, a 64-cavity screw-cap tool with hot-runner valve gates showed fill imbalance greater than 6% when the hot-runner manifold temperature varied by more than ±5 °C.

The same material is used in overcaps for aerosol cans, tablet packs, and industrial pails. These applications require a balance between removal torque and sealing force. The flexural modulus of 1,050 MPa measured under ISO 178 contributes to cap stiffness, but the part design must not rely solely on resin stiffness: rib height and wall thickness remain the dominant variables for sealing force. Published instrumented puncture data for HD0202L under biaxial loading is limited; users should validate drop impact performance by instrumented puncture testing before qualifying commercial supply.

The Primary Operational Boundary Is Residence Time at Melt Temperatures Above 260 °C

The main limitation of HD0202L is thermal history. Melt temperatures above 260 °C increase chain scission and shift the melt flow rate upward. Residence time at melt temperature should remain below 5 min. If a line stops with a full shot pot, the first 3–5 shots after restart should be purged, particularly when the material is used for food-contact closures where organoleptic limits apply. Drying is not normally required at ambient relative humidity below 60%. If surface moisture is visible or if the resin has been stored in an uncontrolled warehouse, pre-drying at 80 °C for 1–2 h in a desiccant hopper dryer is sufficient. Avoid blending HD0202L with amine-based additives or certain halogenated flame retardants; such additions are not typical for this grade and can alter stabilizer performance.

For high-speed continuous injection lines, the product is supplied in dry-flowable pellet form and can be run with standard polyolefin screws, hot-runner systems, and conventional cooling circuits. The operational boundary is defined not by the material alone but by the interaction of melt temperature, residence time, and shear stress. Maintaining melt temperature below 260 °C, screw speed within the mechanical limit of the machine, and back pressure below 10 bar keeps the melt flow rate stable and minimizes black speck formation.