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HDPE HMW (High molecular weight HDPE)

Grade

ASTM D1248 Type III · ISO PE-HD · also Hostalen, Lupolen

Higher-Mw ram-extruded sheet for chute liners, tanks and wear parts; much better impact and ESCR than standard HDPE, slightly lower stiffness.

Values for the HMW condition

Other HDPE grades and fills

HDPE is listed in 12 conditions; see the grade overview at HDPE.

Compare all 12 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
FR V-0
Use where UL 94 V-0 or low-smoke behaviour is required in cable ducts, mine liners and enclosures; heavily filled, so strength and ductility drop sharply.15163068 Shore D
Antistatic / conductive carbon-black compound
Specify for fuel-handling parts, powder chutes and electronics handling where charge build-up must be dissipated.22246067 Shore D
Post-consumer recycled HDPE
Recycled bottle/crate regrind for non-critical mouldings, pipes and lumber; property spread is wide and colour is limited to dark shades.2223200
HMWThis page
High molecular weight HDPE
Higher-Mw ram-extruded sheet for chute liners, tanks and wear parts; much better impact and ESCR than standard HDPE, slightly lower stiffness.232480063 Shore D
40% talc/calcium-carbonate mineral filled
Low-cost stiffened compound for crates, pipe fittings and automotive parts; higher modulus and HDT, lower impact and higher density.232420
Blow moulding grade
Low-flow bimodal resin for bottles, drums and IBCs where melt strength and stress-crack resistance dominate.242670063 Shore D
Bimodal black pressure-pipe grade
Use for buried gas/water pressure pipe and fittings needing 50-year MRS 10 MPa rating and slow-crack-growth resistance.2425700
natural, unreinforced HDPE
Standard natural/white HDPE resin, sheet or machined part where chemical resistance and toughness matter more than stiffness.262860065 Shore D
Injection moulding grade
High-flow, lower-molecular-weight resin for thin-wall caps, crates and housings; fast cycles but lower ESCR and impact.282930066 Shore D
20% Glass Fiber
HDPE compound with 20% coupled short glass fiber — roughly triples stiffness and doubles heat-deflection temperature versus unfilled HDPE, at the cost of ductility.5055370 Shore D
30% glass fiber reinforced HDPE
Coupled glass-filled compound for structural housings and pallets needing 4–5× stiffness and much lower creep/shrinkage; loses ductility and weldability.55372 Shore D
40% Glass Fiber
Highly reinforced HDPE with 40% coupled short glass fiber — maximum stiffness, strength and dimensional stability in the PE family, used for structural and under-hood-type mouldings.7880273 Shore D

What is HDPE HMW?

HDPE HMW is HDPE in the HMW grade — higher-Mw ram-extruded sheet for chute liners, tanks and wear parts; much better impact and ESCR than standard HDPE, slightly lower stiffness. HDPE HMW has a yield strength of 23 MPa (3.34 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 77% of polymer grades. Elongation at break is 800% and the elastic modulus is 1.1 GPa (0.16 Msi). HDPE HMW has a density of 0.95 g/cm³ (0.0342 lb/in³), lighter than 75% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).

Advantages

  • Ductile — tolerates forming and impact — 800%, better than 100% of polymer grades
  • Readily welded — 95/100, better than 99% of polymer grades
  • Conducts heat well — 0.48 W/m·K (0.277 BTU/hr·ft·°F), better than 97% of polymer grades
  • Low moisture uptake — 0.01%, better than 97% of polymer grades
  • Low embodied carbon — 2 kg CO₂/kg, better than 96% of polymer grades

Limitations

  • Hard to polish — 30/100, worse than 82% of polymer grades
  • High mold shrinkage — 2%, worse than 81% of polymer grades
  • Low strength — 23 MPa (3.34 ksi), worse than 77% of polymer grades
  • Degrades in UV without stabilisers — 25/100, worse than 76% of polymer grades

HDPE HMW properties

Typical room-temperature values for HDPE HMW; 10 are specific to this condition. Other listed values are HDPE reference data and may not represent this condition. Bars are the position among polymer grades.

Physical6

HDPE HMW has a density of 0.95 g/cm³ (0.0342 lb/in³), lighter than 75% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).

Density0.95 g/cm³0.03 lb/in³
Melting Temperature (Tm)132°C270 °F
Glass Transition (Tg)-110°C-166 °F
Water Absorption (24 h)0.01%
Water Absorption (Saturation)0.05%
Refractive Index1.54

Mechanical16

HDPE HMW has a yield strength of 23 MPa (3.34 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 77% of polymer grades. Elongation at break is 800% and the elastic modulus is 1.1 GPa (0.16 Msi).

Elastic (Young's) Modulus1.1 GPa0.16 Msi
Shear Modulus0.4 GPa0.06 Msi
Bulk Modulus3 GPa0.44 Msi
Poisson's Ratio0.44
Tensile Strength (Ultimate)24 MPa3.5 ksi
Yield Strength (0.2% offset)23 MPa3.3 ksi
Elongation at Break800%
Compressive Strength22 MPa3.2 ksi
Compressive Modulus0.9 GPa0.13 Msi
Flexural Strength27 MPa3.9 ksi
Flexural Modulus1 GPa0.15 Msi
Shear Strength20 MPa2.9 ksi
Fracture Toughness (K_IC)2 MPa·√m1.8 ksi·√in
Izod Impact, Notched250 J/m4.7 ft·lbf/in
Hardness, Shore D63 Shore D
Hardness, Rockwell R55 HRR

Thermal11

HDPE HMW is rated for continuous service to 80°C (176 °F). It conducts heat at 0.48 W/m·K (0.277 BTU/hr·ft·°F), better than 97% of polymer grades. Thermal expansion is 150 µm/m·K (83.3 µin/in·°F).

Thermal Conductivity0.48 W/m·K0.28 BTU/hr·ft·°F
Specific Heat Capacity1,900 J/kg·K0.45 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)150 µm/m·K83.3 µin/in·°F
Max Service Temperature (continuous)80°C176 °F
Min Service Temperature-80°C-112 °F
Heat Deflection Temp. @ 0.45 MPa76°C169 °F
Heat Deflection Temp. @ 1.8 MPa47°C117 °F
Vicat Softening Point (B50)76°C169 °F
Flammability (UL 94)HB (burns slowly, drips); no self-extinguishing rating without FR package
Limiting Oxygen Index18%
Max Service Temperature (short-term)110°C230 °F

Electrical7

HDPE HMW is an electrical insulator with a dielectric strength of 24 kV/mm (609.6 V/mil) and a resistivity of 1×10¹⁴ Ω·m.

Electrical Resistivity1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
Dielectric Strength24 kV/mm610 V/mil
Dielectric Constant (1 MHz)2.35
Dissipation Factor (1 MHz)3×10⁻⁴
Volume Resistivity1×10¹⁶ Ω·cm
Surface Resistivity1×10¹⁵ Ω
Comparative Tracking Index (CTI)600 V

Chemical & Environmental3

Corrosion resistance is excellent (90/100), better than 82% of polymer grades. UV resistance is poor.

Corrosion ResistanceExcellent90/100
UV / Weathering ResistancePoor25/100
Chemical Resistance SummaryExcellent against water, brine, acids, alkalis, alcohols, most salts and aqueous solutions; poor against strong oxidizers (fuming HNO3, halogens); swells in hydrocarbons/chlorinated solvents above ~60 °C; susceptible to environmental stress cracking with surfactants under load.

Sustainability4

Producing a kilogram of HDPE HMW takes about 78 MJ of energy and emits 2 kg of CO₂ — less than 88% of polymer grades. Typical recycled content is 10%.

Embodied Energy (primary production)78 MJ/kg33,534 BTU/lb
Embodied Carbon (primary production)2 kg CO₂/kg
Embodied Water90 L/kg10.8 gal/lb
Typical Recycled Content10%

Manufacturability8

HDPE HMW's machinability is very good (78/100, better than 81% of polymer grades); weldability excellent (95/100); formability very good (70/100).

MachinabilityVery good78/100
WeldabilityExcellent95/100
Formability (cold)Very good70/100
PolishabilityPoor30/100
Mold Shrinkage2%
Melt Flow Rate0.06 g/10 min
Processing Melt Temperature (typ.)230°C446 °F
Mold Temperature (typ.)40°C104 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with HDPE HMW

Is HDPE easy to machine?

Cuts easily with sharp, high-rake, polished tools and high speed/low feed; use air blast and generous support since heat build-up and low modulus cause gumming, burrs and part distortion.

Can HDPE be welded?

Excellent hot-plate, butt-fusion, electrofusion, hot-gas and extrusion welding (DVS 2207); adhesive bonding requires corona, flame or plasma pre-treatment.

Can HDPE be formed, bent or molded?

Injection, blow, rotational and profile extrusion all standard; melt 200–260 °C, mould 20–60 °C, allow 1.5–3% shrinkage with strong anisotropy and post-mould shrink over 24 h.

What surface finishes work on HDPE?

Cannot be plated or anodized and holds paint poorly; use in-resin colour, laser marking, hot stamping or corona-treated printing, and flame-polish or scrape edges for smooth finishes.

HDPE chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
1-butene / 1-hexene comonomershort-chain branching to tune density and ESCR0 – 20.5
antioxidant / process stabilizerhindered phenol + phosphite0.05 – 0.50.2
carbon black2.0–2.5% only in UV-stabilized / pipe grades0 – 2.50
ethylene (polyethylene chain)linear homopolymer backbone≥ 97 (balance)

HDPE HMW — frequently asked

What is HDPE HMW used for?

HDPE HMW is typically used for cutting boards and food-contact surfaces, PE100 pressure pipe and fittings, chemical and water storage tanks, blow-moulded bottles and jerricans, playground equipment panels and conveyor wear strips and guides. In short: chemical resistant; budget.

What is the yield strength of HDPE HMW?

HDPE HMW has a typical yield strength of 23 MPa (3.34 ksi) and a tensile strength of 24 MPa (3.48 ksi) — weaker than 77% of polymer grades. Strength varies by condition: see the 12 listed tempers.

Is HDPE HMW easy to machine?

Yes — machinability is rated very good (78/100, better than 81% of polymer grades). Cuts easily with sharp, high-rake, polished tools and high speed/low feed; use air blast and generous support since heat build-up and low modulus cause gumming, burrs and part distortion.

Can HDPE HMW be welded?

Yes — weldability is rated excellent (95/100). Excellent hot-plate, butt-fusion, electrofusion, hot-gas and extrusion welding (DVS 2207); adhesive bonding requires corona, flame or plasma pre-treatment.

What surface finishes work on HDPE HMW?

Cannot be plated or anodized and holds paint poorly; use in-resin colour, laser marking, hot stamping or corona-treated printing, and flame-polish or scrape edges for smooth finishes.

Can HDPE HMW be formed, bent or molded?

Injection, blow, rotational and profile extrusion all standard; melt 200–260 °C, mould 20–60 °C, allow 1.5–3% shrinkage with strong anisotropy and post-mould shrink over 24 h.

What is the maximum service temperature of HDPE HMW?

HDPE HMW is rated for continuous use to about 80°C (176 °F), and briefly to 110°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Can FabDigit make parts in HDPE HMW?

Yes — HDPE HMW is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASTM D4976 — Standard Specification for Polyethylene Plastics Molding and Extrusion Materials — ASTM International (2020)
  2. ISO 1872-1/-2 — Plastics: Polyethylene (PE) moulding and extrusion materials — ISO (2015)
  3. Engineered Materials Handbook Vol. 2 — Engineering Plastics — ASM International (1988)
  4. CAMPUS Plastics — HDPE datasheets (ISO 10350 property set) — CAMPUS Consortium (2024)
  5. Hostalen / Lupolen HDPE grade datasheets — LyondellBasell (2023)
  6. Sclair HDPE resin datasheets — NOVA Chemicals (2023)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.