Materials

PlywoodDescriptionThe Material

CompositionCellulose/Hemicellulose/Lignin/12%H2O/AdhesiveImage

Caption

General propertiesDensity 43.7 - 49.94 lb/ft^3Price 0.2565 - 0.4275 USD/lbMechanical propertiesYoung's Modulus 1.001 - 1.885 10^6 psiShear Modulus * 0.07252 - 0.2901 10^6 psiBulk modulus * 0.2321 - 0.3626 10^6 psiPoisson's Ratio 0.22 - 0.3Hardness - Vickers 3 - 9 HVElastic Limit * 1.305 - 4.351 ksiTensile Strength 1.45 - 6.382 ksiCompressive Strength 1.16 - 3.626 ksiElongation 2.4 - 3 %Endurance Limit * 1.015 - 2.321 ksiFracture Toughness * 0.91 - 1.638 ksi.in^1/2Loss Coefficient * 8.00E-03 - 0.11Thermal propertiesThermal conductor or insulator? Good insulatorThermal Conductivity 0.1733 - 0.2889 BTU.ft/h.ft^2.FThermal Expansion 3.333 - 4.444 µstrain/°FSpecific Heat 0.3965 - 0.4084 BTU/lb.FGlass Temperature 248 - 284 °FMaximum Service Temperature * 212 - 266 °FMinimum Service Temperature * -148 - -94 °FElectrical propertiesElectrical conductor or insulator? Poor insulatorResistivity 6.00E+13 - 2.00E+14 µohm.cmDielectric Constant 6 - 8

Plywood is laminated wood, the layers glued together such that the grain in successive layers are at right angles, giving stiffness and strength in both directions. The number of layers varies, but is always odd (3, 5, 7…) to give symmetry about the core ply - if it is unsymmetric it warps when wet or hot. Those with few plies (3,5) are significantly stronger and stiffer in the direction of the outermost layers; with increasing number of plies the properties become more uniform. High quality plywood is bonded with synthetic resin. The data listed below describe the in-plane properties of a typical 5-ply.

Plywood dominates the market for both wood and steel stud construction. It is widely used, too, for furniture and fittings, boat building and packaging.

Power Factor * 0.08 - 0.11Breakdown Potential * 10.16 - 15.24 V/milOptical propertiesTransparency OpaqueEco propertiesProduction Energy 2708 - 3142 kcal/lbCO2 creation -0.9 - -0.7 kg/kgRecycle 0Downcycle 1Biodegrade 1Incinerate 1Landfill 1A renewable resource? 1Impact on the environmentWood is a renewable resource, absorbing CO2 as it grows. Present day consumption for engineering purposes can readily be met by controlled planting and harvesting, making wood a truly sustainable material.Processability (Scale 1 = impractical to 5 = excellent)Mouldability 3 - 4Machinability 5 DurabilityFlammability PoorFresh Water AverageSea Water AverageWeak Acid AverageStrong Acid Very PoorWeak Alkalis GoodStrong Alkalis PoorOrganic Solvents GoodUV GoodOxidation at 500C Very PoorSupporting informationDesign guidelinesPlywoods offers high strength at low weight. Those for general construction are made from softwood plys, but the way in which plywood is made allows for great flexibility. For aesthetic purposes, hardwoods can be used for the outermost plys, giving "paneling plywoods" faced with walnut, mahogany or other expensive woods on a core of softwood. Those for ultra-light design have hardwood outer plys on a core of balsa. Metal-faced plywoods can be riveted. Curved moldings for furniture such as chairs are made by laying-up the unbonded plys in a shaped mould and curing the adhesive under pressure using an airbag or matching mould. Singly curved shapes are straightforward; double curvatures should be minimized or avoided.Technical notesLow cost plywoods are bonded with starch or animal glues and are not water resistant -- they are used for boxes and internal construction. Waterproof and marine plywoods are bonded with synthetic resin -- they are used for external paneling and general construction.Typical usesFurniture, building and construction, marine and boat building, packaging, transport and vehicles, musical instruments, aircraft, modeling.LinksReferenceProcessUniverseProducers

Plywood is laminated wood, the layers glued together such that the grain in successive layers are at right angles, giving stiffness and strength in both directions. The number of layers varies, but is always odd (3, 5, 7…) to give symmetry about the core ply - if it is unsymmetric it warps when wet or hot. Those with few plies (3,5) are significantly stronger and stiffer in the direction of the outermost layers; with increasing number of plies the properties become more uniform. High quality plywood is bonded with synthetic resin. The data listed below describe the in-plane properties of a typical 5-ply.

Plywood dominates the market for both wood and steel stud construction. It is widely used, too, for furniture and fittings,

Wood is a renewable resource, absorbing CO2 as it grows. Present day consumption for engineering purposes can readily be met by controlled planting and harvesting, making wood a truly sustainable material.

Plywoods offers high strength at low weight. Those for general construction are made from softwood plys, but the way in which plywood is made allows for great flexibility. For aesthetic purposes, hardwoods can be used for the outermost plys, giving "paneling plywoods" faced with walnut, mahogany or other expensive woods on a core of softwood. Those for ultra-light design have hardwood outer plys on a core of balsa. Metal-faced plywoods can be riveted. Curved moldings for furniture such as chairs are made by laying-up the unbonded plys in a shaped mould and curing the adhesive under pressure using an airbag or matching mould. Singly curved shapes are straightforward; double curvatures should be minimized or avoided.

Low cost plywoods are bonded with starch or animal glues and are not water resistant -- they are used for boxes and internal construction. Waterproof and marine plywoods are bonded with synthetic resin -- they are used for external paneling and general construction.

Furniture, building and construction, marine and boat building, packaging, transport and vehicles, musical instruments, aircraft, modeling.


Low cost plywoods are bonded with starch or animal glues and are not water resistant -- they are used for boxes and internal construction. Waterproof and marine plywoods are bonded with synthetic resin -- they are used for external paneling and general construction.





Softwood: pine, across grainDescriptionThe MaterialSoftwoods come from coniferous, mostly evergreen, trees such as spruce, pine, fir and redwood. Wood must be seasoned before it is used. Seasoning is the process of drying the natural moisture out of the raw timber to make it dimensionally stable, allowing its use without shrinking or warping. In air-seasoning the wood is dried naturally in covered but open-sided structure. In kiln-drying the wood is artificially dried in an oven or kiln. Modern kilns are so designed that an accurate control of moisture is achieved. Wood has been used for construction and to make products since the earliest recorded time. The ancient Egyptians used it for furniture, sculpture and coffins before 2500 BC. The Greeks at the peak of their empire (700 BC) and the Romans at the peak of theirs (around 0 AD) made elaborate buildings, bridges, boats, chariots and weapons of wood, and established the craft of furniture making that is still with us today. More diversity of use appeared in Mediaeval times, with the use of wood for large-scale building, and mechanisms such as pumps, windmills, even clocks, so that, right up to end of the 17th century, wood was the principal material of engineering. Since then cast iron, steel and concrete have displaced it in some of its uses, but timber continues to be used on a massive scale, particularly in housing and small commercial buildings.CompositionCellulose/Hemicellulose/Lignin/12%H2OImage

CaptionWood remains one of the world's major structural materials, as well finding application in more delicate objects like furniture and musical instruments. General propertiesDensity 27.47 - 37.46 lb/ft^3Price 0.2565 - 0.6841 USD/lbMechanical propertiesYoung's Modulus 0.08702 - 0.1305 10^6 psiShear Mod* 0.05076 - 0.05802 10^6 psiBulk modulus 0.05366 - 0.05947 10^6 psiPoisson's R* 0.02 - 0.04Hardness - Vickers 2.6 - 3.2 HVElastic Limi* 0.2466 - 0.3771 ksiTensile Strength 0.4641 - 0.5656 ksiCompressiv* 0.4351 - 1.305 ksiElongation 1 - 1.5 %Endurance * 0.1392 - 0.174 ksiFracture T * 0.364 - 0.455 ksi.in^1/2Loss Coeffi * 0.028 - 0.036Thermal propertiesThermal coGood insulatorThermal Conductivity 0.04622 - 0.08089 BTU.ft/h.ft^2.FThermal Ex* 14.44 - 20 µstrain/°FSpecific Heat 0.3965 - 0.4084 BTU/lb.FGlass Temperature 170.6 - 215.6 °FMaximum Service Tem 248 - 284 °FMinimum S* -148 - -94 °FElectrical propertiesElectrical Poor insulatorResistivity * 2.10E+14 - 7.00E+14 µohm.cmDielectric * 5 - 6.2Power Fact* 0.05 - 0.07Breakdown * 25.4 - 50.8 V/milOptical propertiesTransparenOpaqueEco propertiesProduction Energy 1560 - 1723 kcal/lbCO2 creation -1.16 - -1.05 kg/kgRecycle 0Downcycle 1Biodegrad 1

Incinerate 1Landfill 1A renewabl 1Impact on the environmentWood is a renewable resource, absorbing CO2 as it grows. Present day consumption for engineering purposes can readily be met by controlled planting and harvesting, making wood a truly sustainable material.Processability (Scale 1 = impractical to 5 = excellent)Mouldability 2 - 3Machinability 5 DurabilityFlammabiliPoorFresh WateAverageSea Water AverageWeak Acid AverageStrong Aci Very PoorWeak AlkalGoodStrong AlkaPoorOrganic So GoodUV GoodOxidation Very PoorSupporting informationDesign guidelinesWood offers a remarkable combination of properties. It is light, and, parallel to the grain, it is stiff, strong and tough - as good, per unit weight, as any man-made material except CFRP. It is cheap, it is renewable, and the fossil-fuel energy needed to cultivate and harvest it is outweighed by the energy it captures from the sun during growth. It is easily machined, carved and joined, and - when laminated - it can be molded to complex shapes. And it is aesthetically pleasing, warm both in color and feel, and with associations of craftsmanship and quality. Technical notesThe values for the mechanical properties given for woods require explanation. Wood-science laboratories measure the mean properties of high-quality "clear" wood samples: small specimens with no knots or other defects; the data for woods in the Level 3 CES database is of this type. This is not, however, the data needed for design. All engineering materials have some variability in quality and properties. To allow for this design handbooks list "allowables" - property values that will be met or exceeded by, say, 99% of all samples (meaning the mean value minus 2.33 standard deviations). Natural materials like wood show greater variability than man-made materials like steel, with the result that the allowable values for mechanical properties may be only 50% of the mean. There is a second problem: structures made of wood are much larger than the wood-science test samples. They contain knots, shakes and sloping grain, all of which degrade properties. To deal with this the wood is "stress-graded" by visual inspection or by automated methods, assigning each piece a stress grading G between 0 and 100: a grading of G means that properties are further knocked down by the factor G/100. Finally, in building construction, there is the usual requirement of sound practice - an overall safety factor, typically 2.25. The result is that the permitted stress for design may be as low as 20% of the value quoted in wood-science tabulations.The data in this record is for Scots pine of medium density, and lists wood-science ranges for the properties of clear wood samples.Typical usesFlooring; furniture; containers; cooperage; sleepers (when treated); building construction; boxes; crates and palettes; planing-mill products; sub-flooring; sheathing and as the feedstock for plywood, particleboard and hardboard.LinksReferenceProcessUniverseProducers

Softwoods come from coniferous, mostly evergreen, trees such as spruce, pine, fir and redwood. Wood must be seasoned before it is used. Seasoning is the process of drying the natural moisture out of the raw timber to make it dimensionally stable, allowing its use without shrinking or warping. In air-seasoning the wood is dried naturally in covered but open-sided structure. In kiln-drying the wood is artificially dried in an oven or kiln. Modern kilns are so designed that an accurate control of moisture is achieved. Wood has been used for construction and to make products since the earliest recorded time. The ancient Egyptians used it for furniture, sculpture and coffins before 2500 BC. The Greeks at the peak of their empire (700 BC) and the Romans at the peak of theirs (around 0 AD) made elaborate buildings, bridges, boats, chariots and weapons of wood, and established the craft of furniture making that is still with us today. More diversity of use appeared in Mediaeval times, with the use of wood for large-scale building, and mechanisms such as pumps, windmills, even clocks, so that, right up to end of the 17th century, wood was the principal material of engineering. Since then cast iron, steel and concrete have displaced it in some of its uses, but timber continues to be used on a massive scale, particularly in housing and small commercial buildings.

Wood remains one of the world's major structural materials, as well finding application in more delicate objects like furniture and musical instruments.


Wood offers a remarkable combination of properties. It is light, and, parallel to the grain, it is stiff, strong and tough - as good, per unit weight, as any man-made material except CFRP. It is cheap, it is renewable, and the fossil-fuel energy needed to cultivate and harvest it is outweighed by the energy it captures from the sun during growth. It is easily machined, carved and joined, and - when laminated - it can be molded to complex shapes. And it is aesthetically pleasing, warm both in color and feel, and with associations of craftsmanship and quality.

The values for the mechanical properties given for woods require explanation. Wood-science laboratories measure the mean properties of high-quality "clear" wood samples: small specimens with no knots or other defects; the data for woods in the Level 3 CES database is of this type. This is not, however, the data needed for design. All engineering materials have some variability in quality and properties. To allow for this design handbooks list "allowables" - property values that will be met or exceeded by, say, 99% of all samples (meaning the mean value minus 2.33 standard deviations). Natural materials like wood show greater variability than man-made materials like steel, with the result that the allowable values for mechanical properties may be only 50% of the mean. There is a second problem: structures made of wood are much larger than the wood-science test samples. They contain knots, shakes and sloping grain, all of which degrade properties. To deal with this the wood is "stress-graded" by visual inspection or by automated methods, assigning each piece a stress grading G between 0 and 100: a grading of G means that properties are further knocked down by the factor G/100. Finally, in building construction, there is the usual requirement of sound practice - an overall safety factor, typically 2.25. The result is that the permitted stress for design may be as low as 20% of the value quoted in wood-science tabulations.The data in this record is for Scots pine of medium density, and lists wood-science ranges for the properties of clear wood samples.

Flooring; furniture; containers; cooperage; sleepers (when treated); building construction; boxes; crates and palettes; planing-mill products; sub-flooring; sheathing and as the feedstock for plywood, particleboard and hardboard.

































Softwood: pine, along grainDescriptionThe MaterialSoftwoods come from coniferous, mostly evergreen, trees such as spruce, pine, fir and redwood. Wood must be seasoned before it is used. Seasoning is the process of drying the natural moisture out of the raw timber to make it dimensionally stable, allowing its use without shrinking or warping. In air-seasoning the wood is dried naturally in covered but open-sided structure. In kiln-drying the wood is artificially dried in an oven or kiln. Modern kilns are so designed that an accurate control of moisture is achieved. Wood has been used for construction and to make products since the earliest recorded time. The ancient Egyptians used it for furniture, sculpture and coffins before 2500 BC. The Greeks at the peak of their empire (700 BC) and the Romans at the peak of theirs (around 0 AD) made elaborate buildings, bridges, boats, chariots and weapons of wood, and established the craft of furniture making that is still with us today. More diversity of use appeared in Mediaeval times, with the use of wood for large-scale building, and mechanisms such as pumps, windmills, even clocks, so that, right up to end of the 17th century, wood was the principal material of engineering. Since then cast iron, steel and concrete have displaced it in some of its uses, but timber continues to be used on a massive scale, particularly in housing and small commercial buildings.CompositionCellulose/Hemicellulose/Lignin/12%H2OImage

CaptionWood remains one of the world's major structural materials, as well finding application in more delicate objects like furniture and musical instruments. General propertiesDensity 27.47 - 37.46 lb/ft^3Price 0.2565 - 0.6841 USD/lbMechanical propertiesYoung's Modulus 1.218 - 1.494 10^6 psiShear Mod* 0.08992 - 0.1102 10^6 psiBulk modulus 0.05366 - 0.05947 10^6 psiPoisson's R* 0.35 - 0.4Hardness - * 3 - 4 HVElastic Limi* 5.076 - 6.527 ksiTensile Str * 8.702 - 14.5 ksiCompressiv* 5.076 - 6.237 ksiElongation * 1.99 - 2.43 %Endurance * 2.756 - 3.336 ksiFracture T * 3.094 - 3.731 ksi.in^1/2Loss Coeffi * 7.00E-03 - 0.01Thermal propertiesThermal coGood insulatorThermal Co* 0.1271 - 0.1733 BTU.ft/h.ft^2.FThermal Ex* 1.389 - 5 µstrain/°FSpecific Heat 0.3965 - 0.4084 BTU/lb.FGlass Temperature 170.6 - 215.6 °FMaximum Service Tem 248 - 284 °FMinimum S* -148 - 338 °FElectrical propertiesElectrical Poor insulatorResistivity * 6.00E+13 - 2.00E+14 µohm.cmDielectric * 5 - 6.2Power Fact* 0.05 - 0.1Breakdown * 10.16 - 15.24 V/milOptical propertiesTransparenOpaqueEco propertiesProduction Energy 1560 - 1723 kcal/lbCO2 creation -1.16 - -1.05 kg/kgRecycle 0Downcycle 1Biodegrad 1

Incinerate 1Landfill 1A renewabl 1Impact on the environmentWood is a renewable resource, absorbing CO2 as it grows. Present day consumption for engineering purposes can readily be met by controlled planting and harvesting, making wood a truly sustainable material.Processability (Scale 1 = impractical to 5 = excellent)Mouldability 2 - 3Machinability 5 DurabilityFlammabiliPoorFresh WateAverageSea Water AverageWeak Acid AverageStrong Aci Very PoorWeak AlkalGoodStrong AlkaPoorOrganic So GoodUV GoodOxidation Very PoorSupporting informationDesign guidelinesWood offers a remarkable combination of properties. It is light, and, parallel to the grain, it is stiff, strong and tough - as good, per unit weight, as any man-made material except CFRP. It is cheap, it is renewable, and the fossil-fuel energy needed to cultivate and harvest it is outweighed by the energy it captures from the sun during growth. It is easily machined, carved and joined, and - when laminated - it can be molded to complex shapes. And it is aesthetically pleasing, warm both in color and feel, and with associations of craftsmanship and quality. Technical notesThe values for the mechanical properties given for woods require explanation. Wood-science laboratories measure the mean properties of high-quality "clear" wood samples: small specimens with no knots or other defects; the data for woods in the Level 3 CES database is of this type. This is not, however, the data needed for design. All engineering materials have some variability in quality and properties. To allow for this design handbooks list "allowables" - property values that will be met or exceeded by, say, 99% of all samples (meaning the mean value minus 2.33 standard deviations). Natural materials like wood show greater variability than man-made materials like steel, with the result that the allowable values for mechanical properties may be only 50% of the mean. There is a second problem: structures made of wood are much larger than the wood-science test samples. They contain knots, shakes and sloping grain, all of which degrade properties. To deal with this the wood is "stress-graded" by visual inspection or by automated methods, assigning each piece a stress grading G between 0 and 100: a grading of G means that properties are further knocked down by the factor G/100. Finally, in building construction, there is the usual requirement of sound practice - an overall safety factor, typically 2.25. The result is that the permitted stress for design may be as low as 20% of the value quoted in wood-science tabulations.The data in this record is for Scots pine of medium density, and lists wood-science ranges for the properties of clear wood samples.Typical usesFlooring; furniture; containers; cooperage; sleepers (when treated); building construction; boxes; crates and palettes; planing-mill products; sub-flooring; sheathing and as the feedstock for plywood, particleboard and hardboard.LinksReferenceProcessUniverseProducers


Wood remains one of the world's major structural materials, as well finding application in more delicate objects like furniture and musical instruments.





































Flexible Polymer Foam (LD) DescriptionThe MaterialPolymer foams are made by the controlled expansion and solidification of a liquid or melt through a blowing agent; physical, chemical or mechanical blowing agents are possible. The resulting cellular material has a lower density, stiffness and strength than the parent material, by an amount that depends on its relative density - the volume-fraction of solid in the foam. Flexible foams can be soft and compliant, the material of cushions, mattresses, and padded clothing. Most are made from polyurethane, although latex (natural rubber) and most other elastomers can be foamed.CompositionHydrocarbonImage

CaptionFlexible latex foams are used for cushions, mattresses and packaging.General propertiesDensity 2.372 - 4.37 lb/ft^3Price 0.5985 - 4.874 USD/lbMechanical propertiesYoung's Modulus 1.45E-04 - 4.35E-04 10^6 psiShear Modulus 5.80E-05 - 2.90E-04 10^6 psiBulk modulus 1.45E-04 - 4.35E-04 10^6 psiPoisson's Ratio 0.23 - 0.33Hardness - Vickers 2.00E-03 - 0.03 HVElastic Limit 2.90E-03 - 0.04351 ksiTensile Strength 0.03481 - 0.3408 ksiCompressive Strength 2.90E-03 - 0.04351 ksiElongation 10 - 175 %Endurance * 0.02901 - 0.2901 ksiFracture T * 0.01365 - 0.0455 ksi.in^1/2Loss Coeffi * 0.1 - 0.5Thermal propertiesThermal coGood insulatorThermal Conductivity 0.02311 - 0.03409 BTU.ft/h.ft^2.FThermal Expansion 63.89 - 122.2 µstrain/°FSpecific Heat 0.418 - 0.5398 BTU/lb.FMelting Point 233.3 - 350.3 °FGlass Temperature -171.7 - 8.33 °FMaximum Service Tem 181.1 - 233.3 °FMinimum Service Tem -99.67 - -9.67 °FElectrical propertiesElectrical Good insulatorResistivity 1.00E+20 - 1.00E+23 µohm.cmDielectric Constant 1.05 - 1.3Power Factor 1.00E-04 - 6.00E-04Breakdown Potential 101.6 - 177.8 V/milOptical propertiesTransparenOpaqueEco propertiesProduction* 1.22E+04 - 1.35E+04 kcal/lbCO2 creati * 4.78 - 5.28 kg/kgRecycle 0Downcycle 1

Biodegrad 0Incinerate 1Landfill 1A renewabl 0Impact on the environmentFoaming of insulation with CFCs has a damaging effect on the ozone layer - it is now abandoned. Monomers and foaming agents pose hazards; good practice overcomes these. For cushioning, the requirements are comfort and long life; polyurethane foams have been commonly used, but concerns about flammability and durability limit their use in furniture.Processability (Scale 1 = impractical to 5 = excellent)Castability 3 - 5Mouldability 1 - 4Machinability 3 - 4Weldability 1 DurabilityFlammabiliVery PoorFresh WateVery GoodSea Water Very GoodWeak Acid Very GoodStrong Aci GoodWeak AlkalVery GoodStrong AlkaAverageOrganic So GoodUV AverageOxidation Very PoorSupporting informationDesign guidelinesFlexible foams have characteristics that suit them for cushioning and packaging of delicate objects. They are shaped by injecting or pouring a mix of polymer, catalyst and foaming agent into a mould where the agent evolves gas, expanding the foam. Expanding in a cold mould gives a solid surface skin. Closed cell foams float in water; open cell foams absorb liquids and act as sponges.Technical notesThe properties of foams depend, most directly, on the material of which they are made and on the relative density (the fraction of the foam that is solid). Most commercial foams have a relative density between 1% and 30%. To a lesser extent, the properties depend on the size and the shape of the cells. Low density, closed cell, foams have exceptional low thermal conductivity. Skinned rigid foams have good bending stiffness and strength of low weight.Typical usesPackaging, buoyancy, cushioning, sleeping mats, soft furnishings, artificial skin, sponges, carriers for inks and dyes. LinksReferenceProcessUniverseProducers

Polymer foams are made by the controlled expansion and solidification of a liquid or melt through a blowing agent; physical, chemical or mechanical blowing agents are possible. The resulting cellular material has a lower density, stiffness and strength than the parent material, by an amount that depends on its relative density - the volume-fraction of solid in the foam. Flexible foams can be soft and compliant, the material of cushions, mattresses, and padded clothing. Most are made from polyurethane, although latex (natural rubber) and most other elastomers can be foamed.

Foaming of insulation with CFCs has a damaging effect on the ozone layer - it is now abandoned. Monomers and foaming agents pose hazards; good practice overcomes these. For cushioning, the requirements are comfort and long life; polyurethane foams have been commonly used, but concerns about flammability and durability limit their use in furniture.

Flexible foams have characteristics that suit them for cushioning and packaging of delicate objects. They are shaped by injecting or pouring a mix of polymer, catalyst and foaming agent into a mould where the agent evolves gas, expanding the foam. Expanding in a cold mould gives a solid surface skin. Closed cell foams float in water; open cell foams absorb liquids and act as sponges.

The properties of foams depend, most directly, on the material of which they are made and on the relative density (the fraction of the foam that is solid). Most commercial foams have a relative density between 1% and 30%. To a lesser extent, the properties depend on the size and the shape of the cells. Low density, closed cell, foams have exceptional low thermal conductivity. Skinned rigid foams have good bending stiffness and strength of low weight.

Packaging, buoyancy, cushioning, sleeping mats, soft furnishings, artificial skin, sponges, carriers for inks and dyes.












Rigid Polymer Foam (LD) DescriptionThe MaterialPolymer foams are made by the controlled expansion and solidification of a liquid or melt through a blowing agent; physical, chemical or mechanical blowing agents are possible. The resulting cellular material has a lower density, stiffness and strength than the parent material, by an amount that depends on its relative density - the volume-fraction of solid in the foam. Rigid foams are made from polystyrene, phenolic, polyethylene, polypropylene or derivatives of polymethylmethacrylate. They are light and stiff, and have mechanical properties the make them attractive for energy management and packaging, and for lightweight structural use. Open-cell foams can be used as filters, closed cell foams as flotation. Self-skinning foams, called 'structural' or 'syntactic', have a dense surface skin made by foaming in a cold mould. Rigid polymer foams are widely used as cores of sandwich panels.CompositionHydrocarbonImage

CaptionRigid polymer foam is used as the core of the GFRP sandwich shell for ultra-light weight designs such as this glider.General propertiesDensity 2.247 - 4.37 lb/ft^3Price 1.026 - 51.3 USD/lbMechanical propertiesYoung's Modulus 3.34E-03 - 0.0116 10^6 psiShear Modulus 1.16E-03 - 5.08E-03 10^6 psiBulk modulus 3.34E-03 - 0.0116 10^6 psiPoisson's Ratio 0.25 - 0.33Hardness - Vickers 0.037 - 0.17 HVElastic Limit 0.04351 - 0.2466 ksiTensile Strength 0.06527 - 0.3263 ksiCompressive Strength 0.05366 - 0.2466 ksiElongation 2 - 5 %Endurance * 0.04293 - 0.1973 ksiFracture Toughness 1.91E-03 - 0.0182 ksi.in^1/2Loss Coeffi * 5.00E-03 - 0.3Thermal propertiesThermal coGood insulatorThermal Conductivity 0.01329 - 0.02311 BTU.ft/h.ft^2.FThermal Expansion 11.11 - 44.44 µstrain/°FSpecific Heat 0.2675 - 0.4562 BTU/lb.FGlass Temperature 152.3 - 339.5 °FMaximum Service Tem 152.3 - 296.3 °FMinimum Service Tem -351.7 - -99.67 °FElectrical propertiesElectrical Good insulatorResistivity 1.00E+17 - 1.00E+21 µohm.cmDielectric Constant 1.04 - 1.448Power Factor 8.00E-05 - 5.10E-03Breakdown Potential 48.26 - 153.4 V/milOptical propertiesTransparenOpaqueEco propertiesProduction* 1.50E+04 - 1.66E+04 kcal/lbCO2 creati * 6.59 - 7.28 kg/kgRecycle 1Downcycle 1Biodegrad 0

Incinerate 1Landfill 1A renewabl 0Impact on the environmentFoaming of insulation with CFCs has a damaging effect on the ozone layer - it is now abandoned. Monomers and foaming agents pose hazards; good practice overcomes these. Processability (Scale 1 = impractical to 5 = excellent)Castability 1 - 3Mouldability 3 - 4Machinability 3 - 4Weldability 1 - 2DurabilityFlammabiliAverageFresh WateVery GoodSea Water Very GoodWeak Acid Very GoodStrong Aci AverageWeak AlkalVery GoodStrong AlkaGoodOrganic So GoodUV GoodOxidation Very PoorSupporting informationDesign guidelinesEnergy management and packaging requires the ability to absorb energy at a constant, controlled crushing stress; here polyurethane, polypropylene and polystyrene foams are used. Acoustic control requires the ability to absorb sound and damp vibration; polyurethane, polystyrene and polyethylene foams are all used. Thermal insulation requires long life; polyurethane foams were common but are now replaced by phenolics and polystyrenes. When fire-protection is needed phenolic foams are used. Foams are usually shaped by injecting or pouring a mix of polymer and foaming agent into a mould where the agent evolves gas, expanding the foam. The mix can be pelletised, and the mould part-filled with solid pellets before foaming (see "Expanded foam molding" in this database). Expanding in a cold mould gives a solid surface skin, creating a sandwich-like structure with attractive mechanical properties.Technical notesThe properties of foams depend, most directly, on the material of which they are made and on the relative density (the fraction of the foam that is solid). Most commercial foams have a relative density between 1% and 30%. To a lesser extent, the properties depend on the size and the shape of the cells. Low density, closed cell, foams have exceptional low thermal conductivity. Skinned rigid foams have good bending stiffness and strength of low weight.Typical usesThermal insulation, Cores for sandwich structures, Panels, Partitions, Refrigeration, Energy Absorption, Packaging, Buoyancy, Floatation.LinksReferenceProcessUniverseProducers

Polymer foams are made by the controlled expansion and solidification of a liquid or melt through a blowing agent; physical, chemical or mechanical blowing agents are possible. The resulting cellular material has a lower density, stiffness and strength than the parent material, by an amount that depends on its relative density - the volume-fraction of solid in the foam. Rigid foams are made from polystyrene, phenolic, polyethylene, polypropylene or derivatives of polymethylmethacrylate. They are light and stiff, and have mechanical properties the make them attractive for energy management and packaging, and for lightweight structural use. Open-cell foams can be used as filters, closed cell foams as flotation. Self-skinning foams, called 'structural' or 'syntactic', have a dense surface skin made by foaming in a cold mould. Rigid polymer foams are widely used as cores of sandwich panels.

Rigid polymer foam is used as the core of the GFRP sandwich shell for ultra-light weight designs such as this glider.

Foaming of insulation with CFCs has a damaging effect on the ozone layer - it is now abandoned. Monomers and foaming agents pose hazards; good practice overcomes these.

Energy management and packaging requires the ability to absorb energy at a constant, controlled crushing stress; here polyurethane, polypropylene and polystyrene foams are used. Acoustic control requires the ability to absorb sound and damp vibration; polyurethane, polystyrene and polyethylene foams are all used. Thermal insulation requires long life; polyurethane foams were common but are now replaced by phenolics and polystyrenes. When fire-protection is needed phenolic foams are used. Foams are usually shaped by injecting or pouring a mix of polymer and foaming agent into a mould where the agent evolves gas, expanding the foam. The mix can be pelletised, and the mould part-filled with solid pellets before foaming (see "Expanded foam molding" in this database). Expanding in a cold mould gives a solid surface skin, creating a sandwich-like structure with attractive mechanical properties.


Thermal insulation, Cores for sandwich structures, Panels, Partitions, Refrigeration, Energy Absorption, Packaging, Buoyancy, Floatation.



















Aluminium alloysDescriptionThe MaterialAluminum was once so rare and precious that the Emperor Napoleon III of France had a set of cutlery made from it that cost him more than silver. But that was 1860; today, nearly 150 years later, aluminum spoons are things you throw away - a testament to our ability to be both technically creative and wasteful. Aluminum, the first of the 'light alloys' (with magnesium and titanium), is the third most abundant metal in the earth's crust (after iron and silicon) but extracting it costs much energy. It has grown to be the second most important metal in the economy (steel comes first), and the mainstay of the aerospace industry.CompositionAl + alloying elements, e.g. Mg, Mn, Cr, Cu, Zn, Zr, LiImage

CaptionAluminum can formed both by casting and by deformation.General propertiesDensity 156.1 - 181 lb/ft^3Price 0.6453 - 1.046 USD/lbMechanical propertiesYoung's Modulus 9.863 - 11.89 10^6 psiShear Modulus 3.626 - 4.496 10^6 psiBulk modulus 9.282 - 10.3 10^6 psiPoisson's Ratio 0.32 - 0.36Hardness - Vickers 12 - 150.5 HVElastic Limit 4.351 - 72.52 ksiTensile Strength 8.412 - 79.77 ksiCompressive Strength 4.351 - 72.52 ksiElongation 1 - 44 %Endurance Limit 3.133 - 22.77 ksiFracture Toughness 20.02 - 31.85 ksi.in^1/2Loss Coefficient 1.00E-04 - 2.00E-03Thermal propertiesThermal coGood conductorThermal Conductivity 43.91 - 135.8 BTU.ft/h.ft^2.FThermal Expansion 11.67 - 13.33 µstrain/°FSpecific Heat 0.2047 - 0.2365 BTU/lb.FMelting Point 886.7 - 1250 °FMaximum Service Tem 248 - 410 °FMinimum Service Tem -459.7 °FElectrical propertiesElectrical Good conductorResistivity 2.5 - 6.5 µohm.cmOptical propertiesTransparenOpaqueEco propertiesProduction Energy 1.99E+04 - 2.20E+04 kcal/lbCO2 creation 11.6 - 12.8 kg/kgRecycle 1Downcycle 1Biodegrad 0Incinerate 0Landfill 1A renewabl 0

Impact on the environmentAluminum ore is abundant. It takes a lot of energy to extract aluminum, but it is easily recycled at low energy cost.Processability (Scale 1 = impractical to 5 = excellent)Castability 4 - 5Formability 3 - 4Machinability 4 - 5Weldability 3 - 4Solder/Brazability 2 - 3DurabilityFlammabiliGoodFresh WateVery GoodSea Water GoodWeak Acid Very GoodStrong Aci Very GoodWeak AlkalGoodStrong AlkaPoorOrganic So Very GoodUV Very GoodOxidation Very PoorSupporting informationDesign guidelinesAluminum alloys are light, can be strong, and are easily worked. Pure aluminum has outstanding electrical and thermal conductivity (copper is the only competition here) and is relatively cheap - though still more than twice the price of steel. It is a reactive metal - in powder form it can explode - but in bulk an oxide film (Al2O3) forms on its surface, protecting it from corrosion in water and acids (but not strong alkalis). Aluminum alloys are not good for sliding surfaces - they scuff - and the fatigue strength of the high-strength alloys is poor. Nearly pure aluminum (1000 series alloys) is used for small appliances and siding; high strength alloys are used in aerospace (2000 and 7000 series), and extrudable, medium strength alloys are used in the automotive and general engineering sectors (6000 series). Technical notesUntil 1970, designations of wrought aluminum alloys were a mess; in many countries, they were simply numbered in the order of their development. The International Alloy Designation System (IADS), now widely accepted, gives each wrought alloy a 4-digit number. The first digit indicates the major alloying element or elements. Thus the series 1xxx describe unalloyed aluminum; the 2xxx series contain copper as the major alloying element, and so forth. The third and fourth digits are significant in the 1xxx series but not in the others; in 1xxx series they describe the minimum purity of the aluminum; thus 1145 has a minimum purity of 99.45%; 1200 has a minimum purity of 99.00%. In all other series, the third and fourth digits are simply serial numbers; thus 5082 and 5083 are two distinct aluminum-magnesium alloys. The second digit has a curious function: it indicates a close relationship: thus 5352 is closely related to 5052 and 5252; and 7075 and 7475 differ only slightly in composition. To these serial numbers are added a suffix indicating the state of hardening or heat treatment. The suffix F means 'as fabricated'. Suffix O means 'annealed wrought products'. The suffix H means that the material is 'cold worked'. The suffix T means that it has been 'heat treated'. No classification system for cast aluminum alloys has international acceptance. In the most widely used (the AAUS system), the first digit indicates the alloy group. In the 1xx.x group, the second two digits indicate the minimum percentage of aluminum; thus 150.x indicates a composition containing a minimum of 99.5% aluminum. The digit to the right of the decimal point indicates the product form: 0 means 'castings' and 1 means 'ingot'. In the 2xx.x to 9xx.x groups, the second two digits are simply serial numbers. The digit to the right of the decimal point again indicates product form. More information on designations and equivalent grades can be found in the Users section of the Granta Design website, www.grantadesign.comTypical usesAerospace engineering; automotive engineering - pistons, clutch housings, exhaust manifolds; die cast chassis for household and electronic products; siding for buildings; foil for containers and packaging; beverage cans; electrical and thermal conductors. LinksReferenceProcessUniverseProducers

Aluminum was once so rare and precious that the Emperor Napoleon III of France had a set of cutlery made from it that cost him more than silver. But that was 1860; today, nearly 150 years later, aluminum spoons are things you throw away - a testament to our ability to be both technically creative and wasteful. Aluminum, the first of the 'light alloys' (with magnesium and titanium), is the third most abundant metal in the earth's crust (after iron and silicon) but extracting it costs much energy. It has grown to be the second most important metal in the economy (steel comes first), and the mainstay of the aerospace industry.

Aluminum ore is abundant. It takes a lot of energy to extract aluminum, but it is easily recycled at low energy cost.

Aluminum alloys are light, can be strong, and are easily worked. Pure aluminum has outstanding electrical and thermal conductivity (copper is the only competition here) and is relatively cheap - though still more than twice the price of steel. It is a reactive metal - in powder form it can explode - but in bulk an oxide film (Al2O3) forms on its surface, protecting it from corrosion in water and acids (but not strong alkalis). Aluminum alloys are not good for sliding surfaces - they scuff - and the fatigue strength of the high-strength alloys is poor. Nearly pure aluminum (1000 series alloys) is used for small appliances and siding; high strength alloys are used in aerospace (2000 and 7000 series), and extrudable, medium strength alloys are used in the automotive and general engineering sectors (6000 series).

Until 1970, designations of wrought aluminum alloys were a mess; in many countries, they were simply numbered in the order of their development. The International Alloy Designation System (IADS), now widely accepted, gives each wrought alloy a 4-digit number. The first digit indicates the major alloying element or elements. Thus the series 1xxx describe unalloyed aluminum; the 2xxx series contain copper as the major alloying element, and so forth. The third and fourth digits are significant in the 1xxx series but not in the others; in 1xxx series they describe the minimum purity of the aluminum; thus 1145 has a minimum purity of 99.45%; 1200 has a minimum purity of 99.00%. In all other series, the third and fourth digits are simply serial numbers; thus 5082 and 5083 are two distinct aluminum-magnesium alloys. The second digit has a curious function: it indicates a close relationship: thus 5352 is closely related to 5052 and 5252; and 7075 and 7475 differ only slightly in composition. To these serial numbers are added a suffix indicating the state of hardening or heat treatment. The suffix F means 'as fabricated'. Suffix O means 'annealed wrought products'. The suffix H means that the material is 'cold worked'. The suffix T means that it has been 'heat treated'. No classification system for cast aluminum alloys has international acceptance. In the most widely used (the AAUS system), the first digit indicates the alloy group. In the 1xx.x group, the second two digits indicate the minimum percentage of aluminum; thus 150.x indicates a composition containing a minimum of 99.5% aluminum. The digit to the right of the decimal point indicates the product form: 0 means 'castings' and 1 means 'ingot'. In the 2xx.x to 9xx.x groups, the second two digits are simply serial numbers. The digit to the right of the decimal point again indicates product form. More information on designations and equivalent grades can be found in the Users section of the Granta Design website, www.grantadesign.com

Aerospace engineering; automotive engineering - pistons, clutch housings, exhaust manifolds; die cast chassis for household and electronic products; siding for buildings; foil for containers and packaging; beverage cans; electrical and thermal conductors.




Aerospace engineering; automotive engineering - pistons, clutch housings, exhaust manifolds; die cast chassis for household and electronic products; siding for buildings; foil for containers and packaging; beverage cans; electrical and thermal conductors.





























Polyamides (Nylons, PA)DescriptionThe MaterialBack in 1945, the war in Europe just ended, the two most prized luxuries were cigarettes and nylons. Nylon (PA) can be drawn to fibers as fine as silk, and was widely used as a substitute for it. Today, newer fibers have eroded its dominance in garment design, but nylon-fiber ropes, and nylon as reinforcement for rubber (in car tires) and other polymers (PTFE, for roofs) remains important. It is used in product design for tough casings, frames and handles, and - reinforced with glass - as bearings gears and other load-bearing parts. There are many grades (Nylon 6, Nylon 66, Nylon 11….) each with slightly different properties.Composition(NH(CH2)5C0)nImage

CaptionPolyamides are tough, and easily colored.General propertiesDensity 69.92 - 71.17 lb/ft^3Price 1.645 - 1.81 USD/lbMechanical propertiesYoung's Modulus 0.38 - 0.4641 10^6 psiShear Mod* 0.1407 - 0.1719 10^6 psiBulk modulus 0.5366 - 0.5656 10^6 psiPoisson's Ratio 0.34 - 0.36Hardness - Vickers 25.8 - 28.4 HVElastic Limit 7.252 - 13.75 ksiTensile Strength 13.05 - 23.93 ksiCompressive Strength 7.977 - 15.12 ksiElongation 30 - 100 %Endurance * 5.221 - 9.572 ksiFracture T * 2.019 - 5.111 ksi.in^1/2Loss Coeffi * 0.0125 - 0.01527Thermal propertiesThermal coGood insulatorThermal Conductivity 0.1346 - 0.1462 BTU.ft/h.ft^2.FThermal Expansion 80 - 83 µstrain/°FSpecific He* 0.3823 - 0.3976 BTU/lb.FMelting Point 409.7 - 427.7 °FGlass Temperature 110.9 - 132.5 °FMaximum Service Tem 163.1 - 188.3 °FMinimum S* -189.7 - -99.67 °FElectrical propertiesElectrical Good insulatorResistivity * 1.50E+19 - 1.40E+20 µohm.cmDielectric Constant 3.7 - 3.9Power Fact* 0.014 - 0.06Breakdown Potential 383.5 - 416.6 V/milOptical propertiesTransparenTranslucentRefractive Index 1.52 - 1.53Eco propertiesProduction* 1.11E+04 - 1.22E+04 kcal/lbCO2 creation 3.99 - 4.41 kg/kgRecycle 1

Downcycle 1Biodegrad 0Incinerate 1Landfill 1A renewabl 0Recycle mark

Impact on the environmentNylons have no known toxic effects, although they are not entirely inert biologically. Nylons are oil-derivatives, but this will not disadvantage them in the near future. With refinements in polyolefin catalysis, nylons face stiff competition from less expensive polymers.Processability (Scale 1 = impractical to 5 = excellent)Castability 1 - 2Mouldability 4 - 5Machinability 3 - 4Weldability 5 DurabilityFlammabiliAverageFresh WateVery GoodSea Water Very GoodWeak Acid GoodStrong Aci PoorWeak AlkalVery GoodStrong AlkaGoodOrganic So AverageUV AverageOxidation Very PoorSupporting informationDesign guidelinesNylons are tough, strong and have a low coefficient of friction, with useful properties over a wide range of temperature (-80 to +120 C). They are easy to injection mould, machine and finish, can be thermally or ultrasonically bonded, or joined with epoxy, phenol-formaldehyde or polyester adhesives. Certain grades of nylon can be electroplated allowing metallisation, and most accept print well. A blend of PPO/Nylon is used in fenders, exterior body parts. Nylon fibers are strong, tough, elastic and glossy, easily spun into yarns or blended with other materials. Nylons absorb up to 4% water; to prevent dimensional changes, they must be conditioned before molding, allowing them to establishing equilibrium with normal atmospheric humidity. Nylons have poor resistance to strong acids, oxidizing agents and solvents, particularly in transparent grades.Technical notesThe density, stiffness, strength, ductility and toughness of Nylons all lie near the average for unreinforced polymers. Their thermal conductivities and thermal expansion are a little lower than average. Reinforcement with mineral, glass powder or glass fiber increases the modulus, strength and density. Semi-crystalline nylon is distinguished by a numeric code for the material class indicating the number of carbon atoms between two nitrogen atoms in the molecular chain. The amorphous material is transparent; the semi-crystalline material is opal white. Typical usesLight duty gears, bushings, sprockets and bearings; electrical equipment housings, lenses, containers, tanks, tubing, furniture casters, plumbing connections, bicycle wheel covers, ketchup bottles, chairs, toothbrush bristles, handles, bearings, food packaging. Nylons are used as hot-melt adhesives for book bindings; as fibers - ropes, fishing line, carpeting, car upholstery and stockings; as aramid fibers - cables, ropes, protective clothing, air filtration bags and electrical insulation.TradenamesAdell, Akulon, Albis, Amilan, Ashlene, Capron, Celanese, Chemlon, Durethan, Gapex, Grilon, Grivory, Hylon, Kopa, Latamid, Lubrilon, Magnacomp, Maranyl, Minlon, NSC, Nivionplast, Novamid, Nydur, Nylamid, Nylene, Nypel, Orgamide, Radilon, Schulamid, Selar, Sniamid, Star-C, Star-L, Staramide, Texalon, Ultramid, Vestamid, Wellamid, ZytelLinksReferenceProcessUniverseProducers

Back in 1945, the war in Europe just ended, the two most prized luxuries were cigarettes and nylons. Nylon (PA) can be drawn to fibers as fine as silk, and was widely used as a substitute for it. Today, newer fibers have eroded its dominance in garment design, but nylon-fiber ropes, and nylon as reinforcement for rubber (in car tires) and other polymers (PTFE, for roofs) remains important. It is used in product design for tough casings, frames and handles, and - reinforced with glass - as bearings gears and other load-bearing parts. There are many grades (Nylon 6, Nylon 66, Nylon 11….) each with slightly different properties.

Nylons have no known toxic effects, although they are not entirely inert biologically. Nylons are oil-derivatives, but this will not disadvantage them in the near future. With refinements in polyolefin catalysis, nylons face stiff competition from less expensive polymers.

Nylons are tough, strong and have a low coefficient of friction, with useful properties over a wide range of temperature (-80 to +120 C). They are easy to injection mould, machine and finish, can be thermally or ultrasonically bonded, or joined with epoxy, phenol-formaldehyde or polyester adhesives. Certain grades of nylon can be electroplated allowing metallisation, and most accept print well. A blend of PPO/Nylon is used in fenders, exterior body parts. Nylon fibers are strong, tough, elastic and glossy, easily spun into yarns or blended with other materials. Nylons absorb up to 4% water; to prevent dimensional changes, they must be conditioned before molding, allowing them to establishing equilibrium with normal atmospheric humidity. Nylons have poor resistance to strong acids, oxidizing agents and solvents, particularly in transparent grades.

The density, stiffness, strength, ductility and toughness of Nylons all lie near the average for unreinforced polymers. Their thermal conductivities and thermal expansion are a little lower than average. Reinforcement with mineral, glass powder or glass fiber increases the modulus, strength and density. Semi-crystalline nylon is distinguished by a numeric code for the material class indicating the number of carbon atoms between two nitrogen atoms in the molecular chain. The amorphous material is transparent; the semi-crystalline material is opal white.

Light duty gears, bushings, sprockets and bearings; electrical equipment housings, lenses, containers, tanks, tubing, furniture casters, plumbing connections, bicycle wheel covers, ketchup bottles, chairs, toothbrush bristles, handles, bearings, food packaging. Nylons are used as hot-melt adhesives for book bindings; as fibers - ropes, fishing line, carpeting, car upholstery and stockings; as aramid fibers - cables, ropes, protective clothing, air filtration bags and electrical insulation.

Adell, Akulon, Albis, Amilan, Ashlene, Capron, Celanese, Chemlon, Durethan, Gapex, Grilon, Grivory, Hylon, Kopa, Latamid, Lubrilon, Magnacomp, Maranyl, Minlon, NSC, Nivionplast, Novamid, Nydur, Nylamid, Nylene, Nypel, Orgamide, Radilon, Schulamid, Selar, Sniamid, Star-C, Star-L, Staramide, Texalon, Ultramid, Vestamid, Wellamid, Zytel


Nylons have no known toxic effects, although they are not entirely inert biologically. Nylons are oil-derivatives, but this will not disadvantage them in the near future. With refinements in polyolefin catalysis, nylons face stiff competition from less expensive polymers.





















Polyoxymethylene (Acetal, POM) DescriptionThe MaterialPOM was first marketed by DuPont in 1959 as Delrin. It is similar to nylon but is stiffer, and has better fatigue and water resistance - nylons, however, have better impact and abrasion resistance. It is rarely used without modifications: most often filled with glass fiber, flame retardant additives or blended with PTFE or PU. The last, POM/PU blend, has good toughness. POM is used where requirements for good moldability, fatigue resistance and stiffness justify its high price relative to mass polymers, like polyethylene, which are polymerized from cheaper raw materials using lower energy input.Composition(CH2-O)nImage

General propertiesDensity 86.77 - 89.27 lb/ft^3Price 1.599 - 2.394 USD/lbMechanical propertiesYoung's Modulus 0.3626 - 0.7252 10^6 psiShear Modulus 0.1218 - 0.3296 10^6 psiBulk modulus 0.6382 - 0.6672 10^6 psiPoisson's Ratio 0.33 - 0.4066Hardness - Vickers 14.6 - 24.8 HVElastic Limit 7.049 - 10.5 ksiTensile Strength 8.702 - 13 ksiCompressive Strength 10.86 - 17.98 ksiElongation 10 - 75 %Endurance * 3.18 - 4.965 ksiFracture Toughness 1.555 - 3.822 ksi.in^1/2Loss Coeffi * 6.38E-03 - 0.01702Thermal propertiesThermal coGood insulatorThermal Conductivity 0.1277 - 0.2025 BTU.ft/h.ft^2.FThermal Expansion 42.05 - 112 µstrain/°FSpecific Heat 0.3258 - 0.3422 BTU/lb.FMelting Point 319.7 - 362.9 °FGlass Temperature -0.6704 - 17.33 °FMaximum Service Tem 170.3 - 206.3 °FMinimum Service Tem -189.7 - -99.67 °FElectrical propertiesElectrical Good insulatorResistivity 3.30E+20 - 3.00E+21 µohm.cmDielectric Constant 3.6 - 4Power Factor 9.50E-04 - 5.00E-03Breakdown Potential 383.5 - 520.7 V/milOptical propertiesTransparenOpaqueEco propertiesProduction* 1.08E+04 - 1.19E+04 kcal/lbCO2 creati * 3.8 - 4.2 kg/kgRecycle 1Downcycle 1Biodegrad 0Incinerate 1

Landfill 1A renewabl 0Recycle mark

Impact on the environmentAcetal, like most thermoplastics, is an oil derivative, but this poses no immediate threat to its use.Processability (Scale 1 = impractical to 5 = excellent)Castability 1 - 2Mouldability 4 - 5Machinability 3 - 4Weldability 4 - 5DurabilityFlammabiliPoorFresh WateVery GoodSea Water Very GoodWeak Acid GoodStrong Aci PoorWeak AlkalGoodStrong AlkaGoodOrganic So GoodUV AverageOxidation Very PoorSupporting informationDesign guidelinesPOM is easy to mould by blow molding, injection molding or sheet molding, but shrinkage on cooling limits the minimum recommended wall thickness for injection molding to 0.1mm. As manufactured, POM is gray but it can be colored. It can be extruded to produce shapes of constant cross section such as fibers and pipes. The high crystallinity leads to increased shrinkage upon cooling. It must be processed in the temperature range 190-230 C and may require drying before forming because it is hygroscopic. Joining can be done using ultrasonic welding, but POM's low coefficient of friction requires welding methods that use high energy and long ultrasonic exposure; adhesive bonding is an alternative. POM is a good electrical insulator. Without coPolymerization or the addition of blocking groups, POM degrades easily.Technical notesThe repeating unit of POM is - (CH2O)n and the resulting molecule is linear and highly crystalline. Consequently, POM is easily moldable, has good fatigue resistance and stiffness, and is water resistant. In its pure form, POM degrades easily by dePolymerization from the ends of the polymer chain by a process called 'unzipping'. The addition of 'blocking groups' at the ends of the polymer chains or coPolymerization with cyclic ethers such as ethylene oxide prevents unzipping and hence degradation. Typical usesPOM is more expensive than commodity polymers such as PE, so is limited to high performance applications in which its natural lubricity is exploited. It is found in fuel-system; seat-belt components; steering columns; window-support brackets and handles; shower heads, ballcocks, faucet cartridges, and various fittings; quality toys; garden sprayers; stereo cassette parts; butane lighter bodies; zippers; telephone components; couplings; pump impellers; conveyor plates; gears; sprockets; springs; gears; cams; bushings; clips; lugs; door handles; window cranks; housings; seat-belt components; watch gears; conveyor links; aerosols; mechanical pen and pencil parts; milk pumps; coffee spigots; filter housings; food conveyors; cams; gears; TV tuner arms; automotive underhood components.TradenamesAcetron, Delrin, Fulton, Latan, Lupital, Plaslube, Tenac, Thermocomp, UltraformLinksReferenceProcessUniverseProducers

POM was first marketed by DuPont in 1959 as Delrin. It is similar to nylon but is stiffer, and has better fatigue and water resistance - nylons, however, have better impact and abrasion resistance. It is rarely used without modifications: most often filled with glass fiber, flame retardant additives or blended with PTFE or PU. The last, POM/PU blend, has good toughness. POM is used where requirements for good moldability, fatigue resistance and stiffness justify its high price relative to mass polymers, like polyethylene, which are polymerized from cheaper raw materials using lower energy input.

POM is easy to mould by blow molding, injection molding or sheet molding, but shrinkage on cooling limits the minimum recommended wall thickness for injection molding to 0.1mm. As manufactured, POM is gray but it can be colored. It can be extruded to produce shapes of constant cross section such as fibers and pipes. The high crystallinity leads to increased shrinkage upon cooling. It must be processed in the temperature range 190-230 C and may require drying before forming because it is hygroscopic. Joining can be done using ultrasonic welding, but POM's low coefficient of friction requires welding methods that use high energy and long ultrasonic exposure; adhesive bonding is an alternative. POM is a good electrical insulator. Without coPolymerization or the addition of blocking groups, POM degrades easily.

The repeating unit of POM is - (CH2O)n and the resulting molecule is linear and highly crystalline. Consequently, POM is easily moldable, has good fatigue resistance and stiffness, and is water resistant. In its pure form, POM degrades easily by dePolymerization from the ends of the polymer chain by a process called 'unzipping'. The addition of 'blocking groups' at the ends of the polymer chains or coPolymerization with cyclic ethers such as ethylene oxide prevents unzipping and hence degradation.

POM is more expensive than commodity polymers such as PE, so is limited to high performance applications in which its natural lubricity is exploited. It is found in fuel-system; seat-belt components; steering columns; window-support brackets and handles; shower heads, ballcocks, faucet cartridges, and various fittings; quality toys; garden sprayers; stereo cassette parts; butane lighter bodies; zippers; telephone components; couplings; pump impellers; conveyor plates; gears; sprockets; springs; gears; cams; bushings; clips; lugs; door handles; window cranks; housings; seat-belt components; watch gears; conveyor links; aerosols; mechanical pen and pencil parts; milk pumps; coffee spigots; filter housings; food conveyors; cams; gears; TV tuner arms; automotive underhood components.






















Stainless steelDescriptionThe MaterialStainless steels are alloys of iron with chromium, nickel, and - often - four of five other elements. The alloying transmutes plain carbon steel that rusts and is prone to brittleness below room temperature into a material that does neither. Indeed, most stainless steels resist corrosion in most normal environments, and they remain ductile to the lowest of temperatures. CompositionFe/<0.25C/16 - 30Cr/3.5 - 37Ni/<10Mn + Si,P,S (+N for 200 series)

Image

CaptionOne the left: Siemens toaster in brushed austenitic stainless steel (by Porsche Design). On the right, scissors in ferritic stainless steel; it is magnetic, austenitic stainless is not.General propertiesDensity 474.5 - 505.7 lb/ft^3Price 1.283 - 5.13 USD/lbMechanical propertiesYoung's Modulus 27.41 - 30.46 10^6 psiShear Modulus 10.73 - 12.18 10^6 psiBulk modulus 19.44 - 21.9 10^6 psiPoisson's Ratio 0.265 - 0.275Hardness - Vickers 130 - 570 HVElastic Limit 24.66 - 145 ksiTensile Strength 69.62 - 324.9 ksiCompressive Strength 24.66 - 145 ksiElongation 5 - 70 %Endurance * 25.38 - 109.2 ksiFracture Toughness 56.42 - 136.5 ksi.in^1/2Loss Coeffi * 2.90E-04 - 1.48E-03Thermal propertiesThermal coPoor conductorThermal Conductivity 6.933 - 13.87 BTU.ft/h.ft^2.FThermal Expansion 7.222 - 11.11 µstrain/°FSpecific Heat 0.1075 - 0.1266 BTU/lb.FMelting Point 2507 - 2642 °FMaximum Service Tem 1202 - 1652 °FMinimum Service Tem -457.9 - -456.1 °FElectrical propertiesElectrical Good conductorResistivity 64 - 107 µohm.cmOptical propertiesTransparenOpaqueEco propertiesProduction* 8364 - 9241 kcal/lbCO2 creati * 4.86 - 5.37 kg/kgRecycle 1Downcycle 1Biodegrad 0Incinerate 0Landfill 1

A renewabl 0Impact on the environmentStainless steels are FDA approved -- indeed, they are so inert that they can be implanted in the body, and are widely used in food processing equipment. All can be recycled.Processability (Scale 1 = impractical to 5 = excellent)Castability 3 - 4Formability 2 - 3Machinability 2 - 3Weldability 5 Solder/Brazability 5 DurabilityFlammabiliVery GoodFresh WateVery GoodSea Water Very GoodWeak Acid Very GoodStrong Aci GoodWeak AlkalVery GoodStrong AlkaVery GoodOrganic So Very GoodUV Very GoodOxidation Very GoodSupporting informationDesign guidelinesStainless steel must be used efficiently to justify its higher costs, exploiting its high strength and corrosion resistance. Economic design uses thin, rolled gauge, simple sections, concealed welds to eliminate refinishing, and grades that are suitable to manufacturing (such as free machining grades when machining is necessary). Surface finish can be controlled by rolling, polishing or blasting. Stainless steels are selected, first, for their corrosion resistance, second, for their strength and third, for their ease of fabrication. Most stainless steels are difficult to bend, draw and cut, requiring slow cutting speeds and special tool geometry. They are available in sheet, strip, plate, bar, wire, tubing and pipe, and can be readily soldered and braised. Welding stainless steel is possible but the filler metal must be selected to ensure an equivalent composition to maintain corrosion resistance. The 300 series are the most weldable; the 400 series are less weldable. Technical notesStainless steels are classified into four categories: the 200and 300 series austenitic (Fe-Cr-Ni-Mn) alloys, the 400 series ferritic (Fe-Cr) alloys, the martensitic (Fe-Cr-C) alloys that also form part of the 400 series, and precipitation hardening or PH (Fe-Cr-Ni-Cu-Nb) alloys with designations starting with S. Typical of the austenitic grades of stainless steel is the grade 304: 74% iron, 18% chromium and 8 % nickel. Here the chromium protects by creating a protective Cr2O3 film on all exposed surfaces, and the nickel stabilizes face-centered cubic austenite, giving ductility and strength both at high and low temperatures; they are non-magnetic (a way of identifying them). The combination of austenitic and ferritic structures (the duplex stainless steels) provide considerably slower growth of stress-induced cracks, they can be hot-rolled or cast and are often heat treated as well. Austenitic stainless steel with high molybdenum content and copper has excellent resistance to pitting and corrosion. High nitrogen content austenitic stainless steel gives higher strength. Superferrites (over 30% chromium) are very resistant to corrosion, even in water containing chlorine. More information on designations and equivalent grades can be found in the Users section of the Granta Design website, www.grantadesign.comTypical usesRailway cars, trucks, trailers, food-processing equipment, sinks, stoves, cooking utensils, cutlery, flatware, architectural metalwork, laundry equipment, chemical-processing equipment, jet-engine parts, surgical tools, furnace and boiler components, oil-burner parts, petroleum-processing equipment, dairy equipment, heat-treating equipment, automotive trim. Structural uses in corrosive environments, e.g. nuclear plants, ships, offshore oil installations, underwater cables and pipes.LinksReferenceProcessUniverseProducers

Stainless steels are alloys of iron with chromium, nickel, and - often - four of five other elements. The alloying transmutes plain carbon steel that rusts and is prone to brittleness below room temperature into a material that does neither. Indeed, most stainless steels resist corrosion in most normal environments, and they remain ductile to the lowest of temperatures.

One the left: Siemens toaster in brushed austenitic stainless steel (by Porsche Design). On the right, scissors in ferritic stainless steel; it is magnetic, austenitic stainless is not.

Stainless steels are FDA approved -- indeed, they are so inert that they can be implanted in the body, and are widely used in food processing equipment. All can be recycled.

Stainless steel must be used efficiently to justify its higher costs, exploiting its high strength and corrosion resistance. Economic design uses thin, rolled gauge, simple sections, concealed welds to eliminate refinishing, and grades that are suitable to manufacturing (such as free machining grades when machining is necessary). Surface finish can be controlled by rolling, polishing or blasting. Stainless steels are selected, first, for their corrosion resistance, second, for their strength and third, for their ease of fabrication. Most stainless steels are difficult to bend, draw and cut, requiring slow cutting speeds and special tool geometry. They are available in sheet, strip, plate, bar, wire, tubing and pipe, and can be readily soldered and braised. Welding stainless steel is possible but the filler metal must be selected to ensure an equivalent composition to maintain corrosion resistance. The 300 series are the most weldable; the 400 series are less weldable.

Stainless steels are classified into four categories: the 200and 300 series austenitic (Fe-Cr-Ni-Mn) alloys, the 400 series ferritic (Fe-Cr) alloys, the martensitic (Fe-Cr-C) alloys that also form part of the 400 series, and precipitation hardening or PH (Fe-Cr-Ni-Cu-Nb) alloys with designations starting with S. Typical of the austenitic grades of stainless steel is the grade 304: 74% iron, 18% chromium and 8 % nickel. Here the chromium protects by creating a protective Cr2O3 film on all exposed surfaces, and the nickel stabilizes face-centered cubic austenite, giving ductility and strength both at high and low temperatures; they are non-magnetic (a way of identifying them). The combination of austenitic and ferritic structures (the duplex stainless steels) provide considerably slower growth of stress-induced cracks, they can be hot-rolled or cast and are often heat treated as well. Austenitic stainless steel with high molybdenum content and copper has excellent resistance to pitting and corrosion. High nitrogen content austenitic stainless steel gives higher strength. Superferrites (over 30% chromium) are very resistant to corrosion, even in water containing chlorine. More information on designations and equivalent grades can be found in the Users section of the Granta Design website, www.grantadesign.com

Railway cars, trucks, trailers, food-processing equipment, sinks, stoves, cooking utensils, cutlery, flatware, architectural metalwork, laundry equipment, chemical-processing equipment, jet-engine parts, surgical tools, furnace and boiler components, oil-burner parts, petroleum-processing equipment, dairy equipment, heat-treating equipment, automotive trim. Structural uses in corrosive environments, e.g. nuclear plants, ships, offshore oil installations, underwater cables and pipes.


























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