LLDPE vs MDPE
Polymer · grade comparison
LLDPE and MDPE are both polymer grades. MDPE is the stronger of the two: yield strength 19 MPa (2.76 ksi) against 11 MPa (1.6 ksi) for LLDPE, about 73% more. MDPE is harder — 58 Shore D against 50 Shore D for LLDPE — which matters for wear surfaces and threads. MDPE is stiffer (0.75 GPa vs 0.25 GPa) and LLDPE runs hotter in service (80°C vs 65°C continuous). On the shop floor, LLDPE forms better (excellent vs very good).
LLDPEChoose it when the part sees heat.
MDPEChoose it when strength drives the design, or when surface hardness matters.
LLDPE vs MDPE: 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
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore A
Hardness, Shore D
Hardness, Rockwell R
Same in both: Bulk Modulus 2 GPa0.29 Msi · Elongation at Break 700%
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Water Absorption (Saturation)
Refractive Index
Light Transmission
Same in both: Glass Transition (Tg) -110°C-166 °F · 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)
Limiting Oxygen Index
Max Service Temperature (short-term)
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Volume Resistivity
Same in both: Dielectric Constant (1 MHz) 2.3 · Dissipation Factor (1 MHz) 3×10⁻⁴ · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 90 / 100 · UV / Weathering Resistance 25 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Melt Flow Rate
Same in both: Machinability 55 / 100 · Polishability 30 / 100 · Mold Shrinkage 2% · Processing Melt Temperature (typ.) 210°C410 °F · Mold Temperature (typ.) 40°C104 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · 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
Same in both: Thermal Diffusivity 0.2 mm²/s · 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 | LLDPE | MDPE |
|---|---|---|
| Default condition | — | — |
| Relative cost | $ Budget | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
LLDPE vs MDPE — frequently asked
Is MDPE stronger than LLDPE?
Yes. MDPE has a typical yield strength of 19 MPa (2.76 ksi) against 11 MPa (1.6 ksi) for LLDPE — about 73% more. Tensile strength is 24 MPa (3.48 ksi) vs 25 MPa (3.63 ksi).
Which is cheaper, LLDPE or MDPE?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, LLDPE or MDPE?
MDPE. Its weldability rates excellent (95/100) against excellent (90/100) for LLDPE.
Ready to make it?
Upload a CAD file and FabDigit prices the part in LLDPE and MDPE 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.