Materials / Compare

Plastic Polypropylene vs. Plastic POM/Acetal

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

Plastic PolypropyleneBulk polymer (molded or machined)
Plastic POM/AcetalBulk polymer (molded or machined)
MechanicalPlastic PolypropylenePlastic POM/Acetal
Yield strength33MPa169MPa22.09x stronger
Ultimate tensile strengthnot stated (yield given)69MPa2
Compressive strengthnot sourced124MPa2
Flexural strengthnot sourced99MPa2
Elongation at breaknot sourced75%2
Young's modulus (stiffness)1.45GPa12.8GPa21.93x stiffer
Density900kg/m³11.58x lighter1,420kg/m³3
Strength to weight36.7kN·m/kg48.6kN·m/kg33% higher
Stiffness to weight1.61MN·m/kg1.97MN·m/kg22% higher
Poisson's ratiobase material0.4240.352
Shear modulus0.511GPa1.04GPa2.03x stiffer in shear
Bulk modulus3.02GPa3.11GPa3% higher
Speed of sound1,269m/s1,404m/s11% faster
1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic 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 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 PolypropylenePlastic POM/Acetal
Stiffness against densityHigher and further left: stiffer for its weight
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic 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 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 PolypropylenePlastic POM/Acetal
Strength against densityHigher and further left: stronger for its weight
ThermalPlastic PolypropylenePlastic POM/Acetal
Thermal conductivitybase material0.17–0.22W/m·K40.4W/m·K2
Thermal expansionbase material80–100µm/m·K4mean122µm/m·K2
100 mm part over a 50 °C swing450µm growth36% less610µm growth
Specific heatnot sourcedaverage -18 to 100 °C1,465J/kg·K2
Heats up and cools (diffusivity)not sourced0.192mm²/s
Thermal shock resistance28.6W/m52.5W/m1.84x more resistant
Melting pointnot sourced175°C2
Max service temperatureHDT 0.45 MPa90°C1HDT 1.8 MPa125°C2
1k10k0.1110100Density (kg/m³)Thermal conductivity (W/m·K)Plastic PLAPlastic 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 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 PolypropylenePlastic 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 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 PolypropylenePlastic POM/Acetal
Thermal expansion against thermal conductivityLower and further right: warps less when heated
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Sources4 documents: LyondellBasell, DuPont, INEOS Olefins & Polymers USA
Plastic Polypropylene
LyondellBasell Moplen HP501H polypropylene homopolymer (general purpose), typical ISO values
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
    Moplen HP501H Product DataLyondellBasellPlastic Polypropylene · Yield strength: typical, tensile stress at yield ISO 527Plastic Polypropylene · Young's modulus (stiffness): typical, tensile modulus ISO 527Plastic Polypropylene · Density: typical, 23 °C ISO 1183-1Plastic Polypropylene · Max service temperature: HDT 0.45 MPa (ISO 75B), unannealed
  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
    Typical Engineering Properties of PolypropyleneINEOS Olefins & Polymers USAarchived copyPlastic Polypropylene · Poisson's ratio: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)Plastic Polypropylene · Thermal conductivity: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)Plastic Polypropylene · Thermal expansion: base material: polypropylene homopolymer family (INEOS Olefins & Polymers USA, Typical Engineering Properties of Polypropylene)

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.

Questions

Mechanical

Is Plastic Polypropylene stronger than Plastic POM/Acetal?

Plastic POM/Acetal is stronger: its yield strength is 69 MPa against 33 MPa for Plastic Polypropylene (2.09x).

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

Plastic Polypropylene is lighter: 900 kg/m³ against 1,420 kg/m³ for Plastic POM/Acetal.

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

Plastic POM/Acetal is stiffer: Young's modulus 2.8 GPa against 1.45 GPa for Plastic Polypropylene, so the same part in Plastic POM/Acetal deflects less under the same load.

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

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

Part that must bePlastic PolypropylenePlastic POM/Acetal
Stiff rod or tie (tension)22% heavierlighter
Stiff beam (bending)lighter14% heavier
Stiff panel or platelighter27% heavier
Strong rod or tie33% heavierlighter
Strong beam4% heavierlighter
Strong panel or platelighter9% heavier

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).

Thermal

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

Plastic POM/Acetal conducts heat better: 0.4 W/m·K against 0.195 W/m·K for Plastic Polypropylene.

Which expands less with temperature?

Plastic Polypropylene expands less: 90 µm/m·K against 122 µm/m·K for Plastic POM/Acetal.

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