MDPE FR
Flame-retardant grade
ASTM D1248 Type II · ISO PE-MD
FR = 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.
Values for the FR 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 |
|---|---|---|---|---|---|
FRThis page 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 |
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 FR?
MDPE FR is MDPE in the FR grade — for cable sheathing and enclosures needing V-0 / low-smoke halogen-free performance; heavy mineral loading cuts elongation and toughness. MDPE FR has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 12 MPa (1.74 ksi) — weaker than 89% of polymer grades. Elongation at break is 180% and the elastic modulus is 1.4 GPa (0.196 Msi). MDPE FR has a density of 1.48 g/cm³ (0.0535 lb/in³), heavier than 87% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).
Advantages
- Conducts heat well — 0.55 W/m·K (0.318 BTU/hr·ft·°F), better than 99% 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
- Low strength — 11 MPa (1.6 ksi), worse than 89% of polymer grades
- Heavy — 1.48 g/cm³ (0.0535 lb/in³), worse than 87% of polymer grades
- Hard to polish — 30/100, worse than 82% of polymer grades
- Difficult to machine — 45/100, worse than 78% of polymer grades
- Limited service temperature — 70°C (158 °F), worse than 77% of polymer grades
MDPE FR properties
Typical room-temperature values for MDPE FR; 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 FR has a density of 1.48 g/cm³ (0.0535 lb/in³), heavier than 87% of polymer grades. Its glass-transition temperature is -110°C (-166 °F).
Mechanical16
MDPE FR has a yield strength of 11 MPa (1.6 ksi) and a tensile strength of 12 MPa (1.74 ksi) — weaker than 89% of polymer grades. Elongation at break is 180% and the elastic modulus is 1.4 GPa (0.196 Msi).
Thermal11
MDPE FR is rated for continuous service to 70°C (158 °F). It conducts heat at 0.55 W/m·K (0.318 BTU/hr·ft·°F), better than 99% of polymer grades. Thermal expansion is 170 µm/m·K (94.4 µin/in·°F).
Electrical7
MDPE FR is an electrical insulator with a dielectric strength of 22 kV/mm (558.8 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (80/100), worse than 52% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of MDPE FR 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 FR's machinability is fair (45/100, worse than 78% of polymer grades); weldability very good (70/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MDPE FR
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 FR — frequently asked
What is MDPE FR used for?
MDPE FR 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 FR?
MDPE FR has a typical yield strength of 11 MPa (1.6 ksi) and a tensile strength of 12 MPa (1.74 ksi) — weaker than 89% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is MDPE FR easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 78% 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 FR be welded?
Yes — weldability is rated very good (70/100). 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 FR?
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 FR 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 FR?
MDPE FR is rated for continuous use to about 70°C (158 °F), and briefly to 90°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.