| HS Code | 782217 |
| Grade | HD-6081 |
| Polymer Type | High Density Polyethylene (HDPE) |
| Density | 0.960 g/cm³ (typical) |
| Melt Flow Rate | 0.8 g/10 min (190°C/2.16 kg, typical) |
| Tensile Strength At Yield | 30 MPa (typical) |
| Tensile Strength At Break | 35 MPa (typical) |
| Elongation At Break | >600% (typical) |
| Flexural Modulus | 1200 MPa (typical) |
| Notched Izod Impact Strength | 20 kJ/m² (typical) |
| Shore D Hardness | 65 (typical) |
| Vicat Softening Temperature | 125°C (typical) |
| Heat Deflection Temperature | 70°C at 0.45 MPa (typical) |
| Environmental Stress Crack Resistance | >1000 h (typical) |
| Water Absorption | <0.01% (typical) |
| Coefficient Of Linear Thermal Expansion | 1.2×10⁻⁴ /°C (typical) |
| Dielectric Constant | 2.3 at 1 MHz (typical) |
As an accredited High Density Polyethylene HDPE HD-6081 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | High Density Polyethylene HDPE HD-6081 is supplied in 25 kg polyethylene bags, palletized and shrink-wrapped for safe transport and storage. |
| Container Loading (20′ FCL) | High Density Polyethylene HDPE HD-6081 in 25 kg bags loaded into a 20′ FCL container, palletized, secured for dry ocean transport. |
| Shipping | High Density Polyethylene HDPE HD-6081 is shipped as solid pellets in 25 kg bags, 500–1,000 kg bulk bags, or bulk trucks. Keep packages dry, closed, and away from heat and direct sunlight. It is not classified as dangerous goods for transport; follow standard handling and local regulations. |
| Storage | Store HDPE HD-6081 in a cool, dry, well-ventilated area, away from direct sunlight, heat, flames, and strong oxidizers. Keep containers sealed and labeled; prevent moisture, dust, and contamination. Avoid prolonged storage near incompatible materials. Use suitable PPE and follow the supplier’s SDS and local regulations. Maintain good housekeeping and spill containment. Ensure adequate ventilation and avoid damaging containers. |
| Shelf Life | High Density Polyethylene HDPE HD-6081 has a shelf life of approximately 24 months when stored cool, dry, and protected from direct sunlight. |
In HDPE HD-6081 conversion to extrusion blow-moulded jerrycans intended for UN 1H2/Y liquid transport, the resin is processed on accumulator-head machines with clamp force between 300 kN and 1,800 kN depending on container volume. Density measured under ISO 1183-1:2019 falls in the high-density range 0.950–0.962 g/cm³, and melt flow rate under ISO 1133-1:2022 at 190°C and 2.16 kg remains within the blow-moulding window of 0.7–0.9 g/10 min. The melt is conditioned at 180°C–210°C through a barrier screw with L/D ratio not lower than 24:1; the accumulator head uses a spiral mandrel and diverging die, with land length held between 18 mm and 24 mm to control parison swell. HD-6081 belongs to the high-molecular-weight blow-moulding HDPE class in which the melt strength is sufficient to limit sag of a 1,200 mm parison below 12% total length extension during 4 s open-mould time. Axial parison programming is applied at 30–100 points, and radial die eccentricity is maintained below 0.2 mm total indicated runout because wall thickness at chime and pinch-off weld zones must remain above 1.2 mm. Blow air enters at 0.6–0.8 MPa, mould cooling water is held at 8°C–15°C, and demoulding is initiated when the pinch-off web reaches 55°C–65°C. Release criteria include drop impact at -18°C according to ASTM D2463-15 method B, hydrostatic stacking at 40°C for 28 days under ADR 6.1.5.3, and environmental stress-crack resistance under ASTM D1693-15 condition B with F50 above 150 h. Because jerrycan compliance is tied to wall distribution, processors reject parisons when the top-load closure boss shows wall thinning greater than 20% relative to sidewall nominal thickness.
| Release test | Standard | Condition | Acceptance criterion |
|---|---|---|---|
| Drop impact | ASTM D2463-15 method B | -18°C | no crack at seams |
| Hydrostatic stack | ADR 6.1.5.3 | 40°C, 28 days | no leakage |
| ESCR | ASTM D1693-15 condition B | 10 vol% Igepal, 50°C | F50 > 150 h |
| Oxidative induction | ISO 11357-6:2018 | 210°C | OIT > 20 min |
Coextruded automotive fuel tanks assign HDPE HD-6081 to outer and inner layers, with maleic anhydride grafted tie layers surrounding a central ethylene vinyl alcohol barrier and a post-industrial regrind layer. Published data for HD-6081 in this exact six-layer configuration is limited; layer-ratio qualification is therefore run on the target line rather than copied from generic high-density polyethylene datasheets. Typical total wall thickness ranges from 4 mm to 8 mm, with HDPE layers contributing 35–45%, regrind 40–50%, tie layers 2–3% each, and EVOH 1.5–3%. The HDPE extruder is typically a 90 mm grooved-barrel machine with 24:1 L/D, the regrind layer uses a 60 mm vented extruder, and the EVOH layer is processed at melt temperature not exceeding 220°C to avoid thermal decomposition of the barrier polymer. Coextrusion die temperature is held at 205°C–220°C because viscosity mismatch between HDPE HD-6081 and EVOH causes interfacial instability below 200°C. Axial wall-thickness programming must maintain the barrier layer uniformly across the pinch-off, because EVOH thinning below 0.5% of total wall thickness produces local permeation spikes exceeding 2 g/m²/day in SHED testing under EPA 40 CFR 86.1813-08. Weld-line integrity after pinch-off is tested by burst pressure above 0.4 MPa and drop impact at -40°C following ECE R34 procedures. Amine-based tie resins are not used in this construction because residual free amines can accelerate oxidative crosslinking of HDPE at coextrusion temperatures above 180°C.
On shuttle blow-moulding lines with 12-station web transfer and clamp force per mould of 150–250 kN, coolant expansion reservoirs from HDPE HD-6081 are formed at melt temperature 190°C–205°C. The part is deliberately moulded with a top weld-line across the upper tank shell, and this weld is the primary failure site in production audits after thermal cycling in 50 vol% ethylene glycol at 120°C for 1,000 h. A low-temperature impact test at -30°C according to ISO 179-1/1eA is applied to notched specimens taken across the weld; industrial release values for HDPE blow-moulding grades remain above 8 kJ/m² only when the pinch-off temperature is held above 145°C at closing. The mould cooling circuit is zoned: reservoir base inserts run at 10°C while the weld zone runs at 35°C to delay freeze-off and allow molecular diffusion across the pinch boundary. Coolant reservoirs exposed to long-term glycol ageing are additionally checked for oxidative induction time under ISO 11357-6:2018, with OIT values above 20 min at 210°C accepted only when the antioxidant package of the incoming HD-6081 lot is confirmed by lot certificate. The terminal component is a 1.0–1.5 mm nominal wall expansion tank with hose-barb bosses formed in the same cycle; boss ovality above 0.3 mm is a dimensional reject because it prevents interference fit sealing with EPDM hose connections.
Three-layer agrochemical bottle coextrusion uses HDPE HD-6081 as the outer structural layer, with post-industrial regrind ratio programmed against parison length and outer-layer melt temperature. Containers for organophosphate emulsifiable concentrates are blow-moulded on shuttle or wheel machines at cycle times between 8 s and 14 s, with outer layer HDPE at 190°C–210°C, tie layer at 200°C–210°C, and barrier layer at 205°C–215°C. Because HD-6081 has a high molecular weight tail, shear viscosity at 100 s⁻¹ remains above 1,000 Pa·s, and the introduction of more than 25% regrind lowers die pressure below 8 MPa, causing layer interface waviness. The layer stack is controlled by a three-layer annular die with layer distribution error below ±1%; outer HDPE layer is held at 35–40% of wall thickness, tie at 2–3%, and barrier at 3–5%, with the remainder regrind. Environmental stress-crack resistance is tested with 10 vol% Igepal CO-630 at 50°C according to ASTM D1693-15 condition B; bottles entering agrochemical service must show F50 above 100 h after 30 days of contact with a xylene-in-water emulsion. Terminal bottle drop testing uses 1.2 m flat drops with closures fitted and fill level 90%; any wall separation at the pinch-off or layer delamination is an automatic batch rejection.
Vertical accumulator water storage tanks in 500 L to 1,500 L capacities are blown from HDPE HD-6081 on single-station vertical machines with shot capacity up to 100 kg and clamp force up to 3,000 kN. The parison is dropped over a fixed blow pin; wall programming is adjusted so base sidewall thickness reaches 4–6 mm while the upper shoulder remains at 2–3 mm. Cycle times on tanks above 1,000 L are typically 360–540 s because internal blow air is maintained at 0.5–0.6 MPa until the inner wall at the base boss falls below 65°C. For outdoor service, natural HD-6081 is compounded with a carbon black masterbatch to achieve 2.0–2.5 wt% carbon black; dispersion is assessed by ISO 18553:2002 and pressure-aging at 60°C for 500 h. With adequate compounding, tensile elongation after 2,000 h of artificial weathering under ISO 4892-2:2013 cycle 1 remains above 400%; without carbon black, surface microcracking appears below 500 h. Creep in the base cone is assessed by applying a static head of 1.1 times nominal volume at 23°C for 42 days, and the vertical deflection of the top rim must remain under 5 mm. When drinking-water contact is required, olefin polymer compliance is verified under FDA 21 CFR 177.1520 olefin polymers provisions for food-contact use.
After extrusion blow moulding of monolayer IBC liners from HDPE HD-6081, fluorine gas is injected into the blow air to reduce solvent permeation. The mould cavity is designed for a 1,000 L liner with nominal wall thickness 2.5–3.5 mm and sidewall ribs at 18° draft angle. During fluorination, fluorine is introduced into the parison interior at concentrations below 1 vol% in nitrogen for 15–60 s inside the closed mould, creating a fluorinated surface layer of 5–30 nm. Permeation for hydrocarbons is measured by gravimetric loss according to ASTM D2684-15; fluorinated HD-6081 liners generally show weight loss below 0.5% over 28 days at 40°C with 50% xylene/50% isooctane, whereas untreated HDPE falls above 1.0%. The pinch-off weld at the liner base is the limiting location for fluorination uniformity; scanning electron microscopy of cryo-fractured sections must show continuous fluorine coverage across the weld line, and incomplete coverage triggers a batch hold. Parting-line flash must be trimmed before fluorination because fluorinated flash surface is incompatible with subsequent butt-welding of the outer steel cage attachments; this operational boundary is specific to in-mould fluorination equipment with closed-loop fluorine monitoring. Published data for fluorinated HD-6081 in returnable IBC service is limited to internal converter qualification reports rather than open literature, so incoming resin lots are qualified by permeation coupon testing before production release.
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HD-6081 is a high-density polyethylene grade supplied as pelletized ethylene polymer with a nominal density of 0.959 g/cm³ to 0.961 g/cm³ when measured by ISO 1183-1 and a melt flow index of 7.5 g/10 min to 8.5 g/10 min at 190°C under a 2.16 kg load in accordance with ISO 1133-1:2022. The grade is used in high-speed injection molding of thin-wall rigid articles, overcaps, and containers where rapid solidification, part-weight stability, and low warpage are controlling variables. Published data for this specific configuration is limited for some specialized end uses; the values presented below derive from supplier technical bulletins and representative high-flow HDPE grades with comparable density. The resin is not intended for pressure-pipe service or blown film, where fractional-melt flow indices and higher molecular weight fractions are required for long-term hydrostatic strength and bubble stability.
The designation “HD” identifies high density, while the numeric suffix distinguishes the melt flow range and additive package within a producer’s grade slate. Different producers may assign similar numbering without identical specifications; direct substitution should be verified by first-article inspection. In polymer architecture, HD-6081 belongs to the class of high-density resins with a low to moderate comonomer content and a narrow to medium molecular weight distribution. This design lowers melt viscosity at high shear rates and permits shorter injection hold times, but it also reduces environmental stress crack resistance relative to blow-molding and film-grade HDPE. The density range places the product near the upper end of the HDPE family; higher density generally increases flexural modulus and surface hardness while decreasing impact toughness and environmental stress crack resistance.
On a reciprocating-screw injection molding machine with a screw L/D ratio of 20:1 to 24:1 and compression ratio of 2.5:1 to 3.0:1, the practical melt temperature envelope for HD-6081 is 200°C to 240°C. Mold temperature is commonly maintained between 15°C and 40°C for thin-wall food packaging. At the upper end of the melt temperature range, viscosity decreases sufficiently to fill wall sections of 0.6 mm to 0.8 mm, but residence time should remain below 5 min to limit oxidative chain scission. At the lower end, hot-runner pressure demand increases; with gate diameters below 0.8 mm, injection pressure can exceed 100 MPa to sustain shear heating at the gate. Clamp force estimation for HDPE thin-wall production generally falls between 4.0 kN/cm² and 5.0 kN/cm² of projected area.
Batch-to-batch melt flow variation of ±0.3 g/10 min has been observed in multi-cavity tools and can alter fill time by 0.2 s to 0.5 s at constant transfer pressure. In a 40 mm screw with L/D 22:1 at 120 rpm, screw recovery time may fall between 2.0 s and 2.8 s; if recovery time exceeds cooling time, frictional heat history increases and gel formation can occur in transparent or light-colored parts. Hot-runner systems should be designed with streamlined melt channels and no dead spots, because stagnation at 240°C can generate oxidized gel particles.
Pre-drying is not usually required because HDPE is non-hygroscopic. When pellets are transferred from cold storage at relative humidity above 60%, surface condensation can produce splay; 80°C for 2 h in a desiccant or hot-air dryer is sufficient. Melt temperatures above 250°C increase the risk of chain scission and low-molecular-weight degradation products. Regrind blends containing more than 2 wt% polypropylene should be avoided in applications requiring weld-line strength or cap hinge durability.
Rheological characterization by capillary rheometry at 190°C shows shear-thinning behavior typical of linear polyethylene. For a representative high-flow HDPE with melt flow index 8 g/10 min, apparent shear viscosity decreases from approximately 900 Pa·s at 100 s⁻¹ to 180 Pa·s at 1000 s⁻¹. This viscosity reduction assists filling in thin-wall tools but reduces melt strength; gas-counterpressure or sequential valve gating may be required when flow length/wall thickness ratios exceed 150:1. In thin-wall containers, hesitation at flow-front velocities below 100 mm/s can generate surface flow marks.
Gate design modifies pressure loss and surface quality. With a direct pin gate below 0.8 mm, calculated shear rates can exceed 10,000 s⁻¹, producing local melt temperature rise of 5°C to 10°C. This rise may reduce filling pressure but can also create gate blush. Edge gates or tab gates with land lengths of 1.0 mm to 1.5 mm reduce jetting and improve weld-line strength. In multi-cavity tools, runner balance should be maintained within ±2% of flow path length to keep part weight variation below 0.5%.
Failure modes observed on production lines include gate-stringing from hot runners due to low melt strength at high temperature, intermittent short shots from insufficient decompression, and flaking at gate lands caused by rough surfaces or excessive holding pressure. Decompression settings of 3 mm to 5 mm screw retraction after recovery prevent drool into open tool halves. Holding pressure is typically set at 60% to 80% of peak injection pressure and held for 0.5 s to 1.5 s for thin-wall parts; longer hold times increase cycle time without improving dimensional stability once gate freeze has occurred.
Regrind levels up to 30 wt% are generally accepted for non-food applications, provided the regrind is free of dust and fines below 150 µm. Beyond 30 wt%, cumulative thermal history can reduce notched Izod impact by more than 15% and increase gel count. For food-contact articles, closed-loop regrind from the same production line may be used under FDA 21 CFR § 177.1520(c) conditions if the material is handled in compliance with good manufacturing practices; the converter must document that the recycled feedstock is not contaminated. In Europe, use of recycled HDPE in food packaging must meet Commission Regulation (EG) No 282/2008 and national provisions.
Because published specification limits for HD-6081 vary among producers, the following values are typical ranges rather than lot-release limits. Specimens are injection molded and conditioned at 23°C and 50% relative humidity for 48 h before testing according to the referenced methods.
| Property | Test Method | Typical Range | Measurement Condition |
|---|---|---|---|
| Density | ISO 1183-1 / ASTM D1505 | 0.959–0.961 g/cm³ | 23°C |
| Melt Flow Index | ISO 1133-1:2022 | 7.5–8.5 g/10 min | 190°C, 2.16 kg |
| Tensile Yield Strength | ISO 527-2 / ASTM D638-14 | 27–30 MPa | 50 mm/min, type 1A |
| Elongation at Break | ISO 527-2 / ASTM D638-14 | 200–600% | 50 mm/min, type 1A |
| Flexural Modulus | ISO 178 / ASTM D790 | 1,300–1,500 MPa | 2 mm/min |
| Notched Izod Impact | ISO 180/A | 3.0–5.0 kJ/m² | 23°C |
| Shore D Hardness | ISO 868 | 63–65 | 15 s |
| Vicat Softening Temperature | ISO 306/A50 | 126–129°C | 10 N |
| Heat Deflection Temperature | ISO 75-2/A | 48–52°C | 1.8 MPa |
| Environmental Stress Crack Resistance | ASTM D1693, condition B | 4–10 h | 100% Igepal CO-630, F50 |
The moderate environmental stress crack resistance value reflects the lower molecular weight and low comonomer content required for high flow. Closure hinge performance and seal retention should be validated by application-specific testing rather than inferred from single-point mechanical data.
The distinction between HD-6081 and other HDPE products is controlled by molecular weight, molecular weight distribution, and comonomer selection. A lower melt flow index corresponds to higher average molecular weight and generally higher environmental stress crack resistance, but also higher melt pressure demand and slower fill. A broader molecular weight distribution improves die swell and melt strength for blown film and blow molding, while a narrower distribution gives more predictable injection molded dimensions.
| Criterion | HD-6081 | Fractional-Melt Blow Molding | HMW Film | PE100 Pipe |
|---|---|---|---|---|
| Melt Flow Index | 7.5–8.5 g/10 min | 0.2–0.35 g/10 min | 0.05–0.1 g/10 min | 0.2–0.5 g/10 min |
| Density | 0.959–0.961 g/cm³ | 0.953–0.956 g/cm³ | 0.949–0.952 g/cm³ | 0.959–0.961 g/cm³ |
| Molecular Weight Distribution | narrow–medium | broad | broad/bimodal | bimodal |
| Comonomer | low | moderate hexene/butene | moderate hexene | hexene/butene |
| Primary Conversion | injection molding | extrusion blow molding | blown film | pipe extrusion |
| ESCR | low–moderate | high | high | very high |
| Typical Service Failure Mode | stress cracking at hinge or closure | hoop stress crack | film tear or puncture | slow crack growth |
Compared with low-density polyethylene and linear low-density polyethylene, HD-6081 has lower elongation at break and lower dart impact strength but greater flexural modulus and surface hardness. Tensile yield strength is 27–30 MPa for HD-6081, whereas typical LLDPE extrusion grades exhibit 15–20 MPa. This makes HD-6081 suitable for rigid packaging and closures, but it is not a substitute for LLDPE film in puncture-prone or frozen-food packaging where low-temperature toughness below −30°C is required. These comparisons are class-level and not product-specific declarations for every supplier. The selection of HD-6081 is appropriate only when high flow and rapid cycle time outweigh long-term slow crack growth resistance and high-ESCR service.
Rigid overcaps, dairy containers, and thin-wall storage boxes produced from HD-6081 are commonly processed in stack molds or hot-runner systems with cycle times of 6 s to 9 s in a 12-cavity tool. The main production bottleneck is not pellet melt quality but gate-stringing and ovality caused by differential shrinkage at wall-thickness transitions. Spiral flow length of 45 cm to 55 cm at 220°C and 80 MPa injection pressure, measured in a spiral mold per ASTM D3123, is representative for high-flow HDPE of this density. At wall sections below 0.4 mm, flow hesitation can create visible knit lines and reduce burst strength in container sidewalls; processors using high-speed injection should verify short-shot weight stability with a balance resolution of 0.01 g.
In caps and closures, HD-6081 is compared against polypropylene random copolymer for hinge durability and seal force retention. For HDPE, mold shrinkage measured per ISO 294-4 typically falls between 1.5% and 2.5%, whereas polypropylene random copolymer exhibits 1.2% to 2.0%. HDPE has lower flexural modulus and better freezer-temperature impact, but it has a lower continuous use temperature, typically 65°C to 80°C in air. Linerless closures exposed to hot-fill conditions above 85°C may exhibit stress relaxation at the seal; torque retention should be evaluated per ASTM D3474, and hinge-life testing should follow ASTM D5419 or equivalent protocols before production approval.
Chemical resistance follows the nonpolar behavior of high-density polyethylene. HD-6081 withstands dilute aqueous acids, alkalis, and most polar solvents at temperatures up to 40°C. Aromatic hydrocarbons, chlorinated solvents, and turpentine can swell the polymer and reduce tensile strength by more than 20% after sustained contact. Strong oxidizing agents such as 98% sulfuric acid and sodium hypochlorite solutions above 10% active chlorine can initiate surface oxidation at elevated temperatures; immersion testing per ISO 175 is required before chemical storage or cleaning-in-place conditions are approved.
HD-6081 is not recommended for outdoor service without UV stabilization. Natural HDPE degrades under ultraviolet exposure; tensile elongation can fall below 50% after 500 h to 1,000 h of accelerated weathering in QUV per ISO 4892-3 unless carbon black or hindered amine light stabilizers are added. Carbon black at 2.0 wt% to 2.5 wt% is standard for outdoor-grade HDPE; however, black pigmentation is not suitable for many packaging applications.
Food-contact status for HD-6081 as an olefin polymer is generally supported by FDA 21 CFR § 177.1520(c), subject to extraction limits and end-use conditions. In the European Union, the base resin may be compliant with Commission Regulation (EU) No 10/2011 Annex III, but finished-article migration testing under Annex V is required because converting conditions, pigments, and recycled content can alter overall migration. Under REACH, suppliers must provide safety data sheets and communicate SVHC above 0.1% w/w per Article 33. RoHS Directive 2011/65/EU does not apply to general packaging, but HDPE components in electrical and electronic equipment must be assessed against restricted substance limits for lead, mercury, cadmium, hexavalent chromium, PBB, and PBDE.
Pellets should be stored in original sealed containers at temperatures below 50°C and out of direct sunlight. During thermal processing at 200°C to 240°C, low levels of volatile organic compounds are generated; local exhaust ventilation should be engineered to maintain airborne particulates and decomposition products below national occupational exposure limits. Incompatibilities include strong oxidizing agents, halogenated solvents, and certain mineral oils that can promote environmental stress cracking in molded parts under residual stress. No post-annealing is required for most thin-wall applications, but parts molded with high injection speed and low mold temperature may retain frozen-in stress; annealing at 70°C for 30 min can reduce warpage in dimensional-control applications.
