Materials / Compare

Plastic PLA vs. Plastic POM/Acetal

Compare Plastic PLA vs. Plastic POM/Acetal strength, stiffness, weight and thermal properties.

Plastic PLA3D printed (FDM)
Plastic POM/AcetalBulk polymer (molded or machined)
MechanicalPlastic PLAPlastic POM/Acetal
Yield strength52.5MPa169MPa231% stronger
Ultimate tensile strength52.5MPa169MPa231% stronger
Compressive strengthnot sourced124MPa2
Flexural strength96.8MPa199MPa2
Elongation at break7.8%175%29.62x more ductile
Young's modulus (stiffness)3.25GPa116% stiffer2.8GPa2
Density1,240kg/m³115% lighter1,420kg/m³3
Strength to weight42.3kN·m/kg48.6kN·m/kg15% higher
Stiffness to weight2.62MN·m/kg33% higher1.97MN·m/kg
Poisson's rationot sourced0.352
Shear modulusnot sourced1.04GPa
Bulk modulusnot sourced3.11GPa
Speed of sound1,619m/s15% faster1,404m/s
1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PETGPlastic ABSPlastic TPUPlastic NylonWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin StandardSLA Resin Tough 2000SLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcretePCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Plastic PLAPlastic POM/Acetal
Stiffness against densityHigher and further left: stiffer for its weight
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PETGPlastic ABSPlastic TPUPlastic NylonRubberWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin StandardSLA Resin Tough 2000SLA Resin Elastic 50ASLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelBrickPCB Laminate FR-4SiliconCeramic Alumina 96%Aluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Plastic PLAPlastic POM/Acetal
Strength against densityHigher and further left: stronger for its weight
ThermalPlastic PLAPlastic POM/Acetal
Thermal conductivitybase material0.13W/m·K40.4W/m·K23.08x more heat through a fin
Thermal expansionnot sourcedmean122µm/m·K2
100 mm part over a 50 °C swingnot sourced610µm growth
Specific heatbase material1,200J/kg·K4average -18 to 100 °C1,465J/kg·K222% higher
Heats up and cools (diffusivity)0.0874mm²/s0.192mm²/s2.2x faster
Thermal shock resistancenot sourced52.5W/m
Melting point152°C1175°C223.2 °C higher
Glass transition59.1°C1not sourced
Max service temperatureHDT 0.455 MPa58.8°C1HDT 1.8 MPa125°C2
1k10k0.1110100Density (kg/m³)Thermal conductivity (W/m·K)Plastic PETGPlastic ABSPlastic NylonRubberWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM HIPSSLA Resin StandardDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcreteBrickPCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Plastic PLAPlastic POM/Acetal
Thermal conductivity against densityHigher and further left: spreads more heat for its weight
0.111010010100Thermal conductivity (W/m·K)Thermal expansion (µm/m·K)Plastic PETGPlastic ABSPlastic NylonWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM HIPSSLA Resin StandardDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcreteBrickPlywoodPCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Plastic POM/Acetal
Thermal expansion against thermal conductivityLower and further right: warps less when heated
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Sources4 documents: UltiMaker, DuPont, NatureWorks
Plastic PLA
Ultimaker PLA, 3D-printed specimens, XY (flat) orientation; Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS dated April 20, 2022.
Plastic POM/Acetal
DuPont Delrin 100 acetal homopolymer, Table 2 'Typical Properties of Delrin Acetal Resins' (ASTM methods), Delrin Design Guide Module III hosted on delrin.com
  1. 1
    Ultimaker PLA Technical Data Sheet, v5.00UltiMakerarchived copyPlastic PLA · Yield strength: typicalPlastic PLA · Ultimate tensile strength: typical, peak stress (= stress at yield)Plastic PLA · Flexural strength: typicalPlastic PLA · Elongation at break: typicalPlastic PLA · Young's modulus (stiffness): typicalPlastic PLA · Density: typicalPlastic PLA · Melting point: typicalPlastic PLA · Glass transition: typicalPlastic PLA · Max service temperature: HDT 0.455 MPa (printed specimens)
  2. 2
    Delrin Acetal Resin Design Guide, Module IIIDuPontarchived copyPlastic POM/Acetal · Yield strength: typical (single ASTM D638 tensile strength)Plastic POM/Acetal · Ultimate tensile strength: typicalPlastic POM/Acetal · Compressive strength: compressive stress at 10% deformationPlastic POM/Acetal · Flexural strength: flexural yield strength, typicalPlastic POM/Acetal · Elongation at break: typicalPlastic POM/Acetal · Young's modulus (stiffness): typicalPlastic POM/Acetal · Poisson's ratio: typicalPlastic POM/Acetal · Thermal conductivity: typicalPlastic POM/Acetal · Thermal expansion: mean, 29 to 60 °CPlastic POM/Acetal · Specific heat: average -18 to 100 °C, Delrin acetal resins (not grade-specific)Plastic POM/Acetal · Melting point: crystalline melting pointPlastic POM/Acetal · Max service temperature: HDT 1.8 MPa (annealed)
  3. 3
    Delrin 100 Product Data SheetDuPontPlastic POM/Acetal · Density: typical (DuPont product information for Delrin 100 NC010; 'The data listed here fall within the normal range of product properties')
  4. 4
    Engineering Properties of Ingeo BiopolymerNatureWorksarchived copyPlastic PLA · Thermal conductivity: base material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °CPlastic PLA · Specific heat: base material: NatureWorks Ingeo biopolymer, amorphous sheet, 25 °C

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Plastic PLA is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Mechanical

Is Plastic PLA stronger than Plastic POM/Acetal?

Plastic POM/Acetal is stronger: its yield strength is 69 MPa against 52.5 MPa for Plastic PLA (31%).

Which is lighter, Plastic PLA or Plastic POM/Acetal?

Plastic PLA is lighter: 1,240 kg/m³ against 1,420 kg/m³ for Plastic POM/Acetal.

Which is stiffer, Plastic PLA or Plastic POM/Acetal?

Plastic PLA is stiffer: Young's modulus 3.25 GPa against 2.8 GPa for Plastic POM/Acetal, so the same part in Plastic PLA deflects less under the same load.

Which is lighter for the same job, Plastic PLA or Plastic POM/Acetal?

For the same stiffness or strength: Plastic PLA is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate; Plastic POM/Acetal is lighter for a strong rod or tie, strong beam.

Part that must bePlastic PLAPlastic POM/Acetal
Stiff rod or tie (tension)lighter33% heavier
Stiff beam (bending)lighter23% heavier
Stiff panel or platelighter20% heavier
Strong rod or tie15% heavierlighter
Strong beam5% heavierlighter
Strong panel or plateabout equalabout equal

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Which is more ductile, Plastic PLA or Plastic POM/Acetal?

Plastic POM/Acetal stretches further before it breaks: 75% elongation at break against 7.8% for Plastic PLA.

Thermal

Which conducts heat better, Plastic PLA or Plastic POM/Acetal?

Plastic POM/Acetal conducts heat better: 0.4 W/m·K against 0.13 W/m·K for Plastic PLA.

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