HDPE vs mLLDPE
Polymer · grade comparison
HDPE and mLLDPE are both polymer grades. HDPE is the stronger of the two: yield strength 26 MPa (3.77 ksi) against 10 MPa (1.45 ksi) for mLLDPE, about 160% more. In exchange, mLLDPE is the more ductile: elongation 750% versus 600% for HDPE, and HDPE is harder (65 Shore D vs 48 Shore D). MLLDPE is lighter (0.92 g/cm³ vs 0.96 g/cm³ for HDPE) and HDPE is stiffer (1.1 GPa vs 0.25 GPa). On the shop floor, HDPE machines more easily (very good vs fair) and HDPE sits in a lower cost tier (budget, $) than mLLDPE (standard, $$).
HDPEChoose it when strength drives the design, or when the part is machined in volume.
mLLDPEChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
HDPE vs mLLDPE: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell R
Hardness, Shore A
Same in both: Fracture Toughness (K_IC) 2 MPa·√m1.8 ksi·√in
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Same in both: Water Absorption (24 h) 0.01%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Limiting Oxygen Index 18%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Polishability 30 / 100 · Mold Shrinkage 2%
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 2 kg CO₂/kg
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | HDPE | mLLDPE |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| Default condition | FDA Compliant | — |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Chrome Plating (Plastic) | Yes | — |
| EMI Shielding Coating | Yes | — |
| Painting | Yes | — |
| Soft Touch Coating | Yes | — |
| Spray Painting | Yes | — |
| UV Coating | Yes | — |
HDPE vs mLLDPE — frequently asked
Is HDPE stronger than mLLDPE?
Yes. HDPE has a typical yield strength of 26 MPa (3.77 ksi) against 10 MPa (1.45 ksi) for mLLDPE — about 160% more. Tensile strength is 28 MPa (4.06 ksi) vs 30 MPa (4.35 ksi).
Which is cheaper, HDPE or mLLDPE?
HDPE is the lower-cost material: it sits in the budget tier ($) while mLLDPE is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, HDPE or mLLDPE?
HDPE. Its machinability rates very good (75/100) against fair (50/100) for mLLDPE; for welding the order is HDPE first (excellent, 95/100) then mLLDPE (excellent, 90/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in HDPE and mLLDPE side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.