MDPE XL
Grade
ASTM D1248 Type II · ISO PE-MD
XL = crosslinkable / crosslinked MDPE
Select when service above 80 °C, creep resistance or full ESCR immunity is needed — hot-water pipe, crosslinked tanks and cable.
Values for the XL condition
Other MDPE grades and fills
MDPE is listed in 7 conditions; see the grade overview at MDPE.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Flame-retardant halogen-free (ATH/MDH filled) MDPE compound | For cable sheathing and enclosures needing V-0 / low-smoke halogen-free performance; heavy mineral loading cuts elongation and toughness. | 11 | 12 | 180 | 62 Shore D |
Rotomoulding grade | Choose for water/chemical tanks, kayaks and containers moulded rotationally, where flow and low-temperature impact matter. | 19 | 23 | 500 | 57 Shore D |
XLThis page Crosslinkable / crosslinked MDPE | Select when service above 80 °C, creep resistance or full ESCR immunity is needed — hot-water pipe, crosslinked tanks and cable. | 19 | 23 | 400 | 57 Shore D |
PE80 pipe grade | Choose for buried gas distribution (yellow/orange) and potable water pipe requiring 50-year MRS 8.0 rating and slow-crack-growth resistance. | 20 | 27 | 800 | 59 Shore D |
UV-stabilized / carbon-black pigmented | Use for any outdoor or buried application — carbon black plus HALS gives decades of weathering life. | 20 | 25 | 650 | 59 Shore D |
Wire & cable jacketing / insulation compound | Black, antioxidant- and CB-stabilised MDPE for telecom and LV cable jackets needing moisture barrier and abrasion resistance. | 20 | 25 | 700 | 59 Shore D |
Injection moulding grade | For thin-wall closures, housewares and caps needing easy fill; trades some ESCR and elongation for flow. | 21 | 22 | 350 | 61 Shore D |
What is MDPE XL?
MDPE XL is MDPE in the XL grade — select when service above 80 °C, creep resistance or full ESCR immunity is needed — hot-water pipe, crosslinked tanks and cable. MDPE XL has a yield strength of 19 MPa (2.76 ksi) and a tensile strength of 23 MPa (3.34 ksi) — weaker than 81% of polymer grades. Elongation at break is 400% and the elastic modulus is 0.72 GPa (0.104 Msi). MDPE XL has a density of 0.94 g/cm³ (0.034 lb/in³), lighter than 76% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).
Advantages
- Low moisture uptake — 0.01%, better than 97% of polymer grades
- Low embodied carbon — 2 kg CO₂/kg, better than 96% of polymer grades
- Conducts heat well — 0.38 W/m·K (0.22 BTU/hr·ft·°F), better than 92% of polymer grades
- Ductile — tolerates forming and impact — 400%, better than 86% of polymer grades
- Good corrosion resistance — 90/100, better than 82% of polymer grades
Limitations
- Difficult to weld — 10/100, worse than 82% of polymer grades
- Hard to polish — 30/100, worse than 82% of polymer grades
- Low strength — 19 MPa (2.76 ksi), worse than 81% of polymer grades
- Degrades in UV without stabilisers — 25/100, worse than 76% of polymer grades
MDPE XL properties
Typical room-temperature values for MDPE XL; 28 are specific to this condition. Other listed values are MDPE reference data and may not represent this condition. Bars are the position among polymer grades.
Physical7
MDPE XL has a density of 0.94 g/cm³ (0.034 lb/in³), lighter than 76% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).
Mechanical16
MDPE XL has a yield strength of 19 MPa (2.76 ksi) and a tensile strength of 23 MPa (3.34 ksi) — weaker than 81% of polymer grades. Elongation at break is 400% and the elastic modulus is 0.72 GPa (0.104 Msi).
Thermal11
MDPE XL is rated for continuous service to 95°C (203 °F). It conducts heat at 0.38 W/m·K (0.22 BTU/hr·ft·°F), better than 92% of polymer grades. Thermal expansion is 170 µm/m·K (94.4 µin/in·°F).
Electrical7
MDPE XL is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 82% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of MDPE XL takes about 78 MJ of energy and emits 2 kg of CO₂ — less than 88% of polymer grades. Typical recycled content is 5%.
Manufacturability8
MDPE XL's machinability is good (55/100, worse than 64% of polymer grades); weldability not recommended (10/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MDPE XL
Is MDPE easy to machine?
Machines easily but gummy and low-modulus — use sharp high-rake tools, high speed, low feed, coolant/air blast and generous fixturing to avoid part deflection and springback.
Can MDPE be welded?
Ideal for butt fusion, electrofusion, hot-plate, hot-gas and extrusion welding; joints reach near parent-material strength — adhesive bonding requires corona/flame or plasma pretreatment.
Can MDPE be formed, bent or molded?
Processes on standard PE screws at 180–240 °C melt with 20–60 °C tools; allow 1.5–3 % shrinkage with anisotropy, and thermoform or cold-bend sheet with allowance for large elastic recovery.
What surface finishes work on MDPE?
No paint, plating or anodising possible without surface activation; pigment in the melt, use in-mould texture, laser marking or corona-treated print/label systems.
MDPE 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| 1-butene / 1-hexene comonomershort-chain branching sets density 0.926–0.940 | 0.5 – 4 | 2 |
| antioxidant / process stabiliserhindered phenol + phosphite | 0.05 – 0.5 | 0.2 |
| carbon black2.0–2.5 % in UV/pipe/cable grades only | 0 – 2.5 | 0 |
| HALS UV stabiliserweatherable grades | 0 – 0.5 | 0 |
| ethylene (repeat unit)polymer backbone | ≥ 95 (balance) | — |
MDPE XL — frequently asked
What is MDPE XL used for?
MDPE XL is typically used for gas pipe and fittings, shrink film, screw closures, carrier bags and sacks. In short: gas-pipe grade polyethylene; between LDPE and HDPE; good stress-crack resistance.
What is the yield strength of MDPE XL?
MDPE XL has a typical yield strength of 19 MPa (2.76 ksi) and a tensile strength of 23 MPa (3.34 ksi) — weaker than 81% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is MDPE XL easy to machine?
Reasonably — machinability is rated good (55/100, worse than 64% of polymer grades). Machines easily but gummy and low-modulus — use sharp high-rake tools, high speed, low feed, coolant/air blast and generous fixturing to avoid part deflection and springback.
Can MDPE XL be welded?
Not readily — weldability is rated not recommended (10/100). Ideal for butt fusion, electrofusion, hot-plate, hot-gas and extrusion welding; joints reach near parent-material strength — adhesive bonding requires corona/flame or plasma pretreatment.
What surface finishes work on MDPE XL?
No paint, plating or anodising possible without surface activation; pigment in the melt, use in-mould texture, laser marking or corona-treated print/label systems.
Can MDPE XL be formed, bent or molded?
Processes on standard PE screws at 180–240 °C melt with 20–60 °C tools; allow 1.5–3 % shrinkage with anisotropy, and thermoform or cold-bend sheet with allowance for large elastic recovery.
What is the maximum service temperature of MDPE XL?
MDPE XL is rated for continuous use to about 95°C (203 °F), and briefly to 120°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D1248 — Polyethylene Plastics Extrusion Materials — ASTM International (2016)
- ISO 4437 — Plastics piping systems for the supply of gaseous fuels — Polyethylene (PE) — ISO (2014)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- CAMPUS / UL Prospector polyethylene datasheet set — CWFG / UL Solutions (2024)
- Polyethylene MDPE pipe, film and rotomoulding grade datasheets — Borealis / SABIC / Dow / Sinopec (2024)
- (PE resin spot pricing) (2026)
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.