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ContentsVESPEL ® : The material for the new age 4–5“Today’s sophisticated engineering requires partsthat are smaller, lighter and capable of performingover a wider temperature range. As designsbecome more sophisticated, product performancemore demanding and product warranties longer –more engineers turn to DuPont’s VESPEL ® .”An outstanding performer 6“VESPEL ® SP polyimide parts offer an outstandingmix of the physical characteristics of metal,ceramics and plastics, combined with their ownoutstanding properties. As a result VESPEL ® partsresist wear, fight creep, and practically nevermelt…”The partnership you can count on 7“…DuPont and VESPEL ® give you something yousimply don’t get from most other materials suppliers– custom-made quality parts combinedwith professional assistance. Plus single-sourceaccountability, from resin development…to parts concept and design… to finished parts.”VESPEL ® parts can help improveyour bottom line 8–9“…VESPEL ® parts-pay for themselves many timesover by high reliability – and low manufacturingcosts, maintenance costs and warranty claims.”VESPEL ® SP polyimide technical data 10–15“Unlike most thermoset plastics, VESPEL ® partsare naturally tough and do not require the additionof abrasive fillers or fibres to enhance partperformance.”

IntroductionThank you for your interest inDuPont’s VESPEL polyimide®parts. As part of the VESPEL ®product team, we look forwardto this opportunity to presentour product and services toyou.DuPont’s VESPEL ® team hasevolved to uniquely meet thechanging needs of the worldwidemarketplace. We offeryou advanced materials anddedicated professionals:design engineers, productionengineers well versed in stateof-the-artmanufacturing techniquesfor both resin and parts,and others dedicated to ensuringthat your consistently highquality VESPEL ® parts andshapes get to you on a timelybasis.We work to make your producta success – from conceptto design, component analysis,composition selection, prototyping,testing, quality controland on through production ofcommercial parts.This VESPEL ® brochure is acollection of articles relatingto the use of VESPEL ® polyimide– some background on itsdevelopment, its applications,demonstrations of its costeffectiveness, and details onsome of its technical properties.We hope this publicationstimulates ideas on howVESPEL ® can help you solveyour design challenges. If youhave any questions, comments,or need additional information– contact us at one of theoffices listed on the back cover.AllVESPEL ® parts are ISO 9001and QS 9000 certified.1

VESPEL ®parts deliver an outstandingcombination of propertiesVESPEL ® parts are custom-made byDuPont from SP polyimide resinsto combine the best characteristicsof plastics, metals and ceramics.They resist wear, fight creep, andthey practically never melt – propertiesthat allow them to survivea broad range of conditions.For example, VESPEL ® parts● provide outstanding wear resistancein lubricated or unlubricatedenvironments (dry pressurevelocity limits to 12 MPa . m/s,and even higher with lubrication),● can operate continuously fromcryogenic temperatures to 288°C,with short-term use to 482°C andabove,● can withstand loads at temperaturesbeyond the reach of mostother plastics,● have low thermal and electricalconductivity,● offer sealing compliance but resistpermanent deformation. Theyprovide a more reliable seal thanmany metal-to-metal seals machinedto much tighter tolerances,● are easily machined without specialequipment or procedures.VESPEL ®can bemachined as easilyas brassWhile DuPont can supply finishedmachined parts, you can easily doyour own machining using VESPEL ®shapes.With standard metal-working equipment,you can machine VESPEL ®shapes to tolerances once consideredtoo close for plastic materials.In most cases, the techniques usedfor machining metals such as brassare directly applicable. VESPEL ®shapes are relatively easy to machinebecause of their high mechanicalstrength, stiffness and dimensionalstability at machining temperatures.For a complete guide to machiningparts from VESPEL ® shapes, ask fora copy of the Design Handbook.Selector guide – VESPEL ® SP for demanding applicationsGrades Typical End-Use Applications Polyimide CompositionsSP1 Mechanical and electrical parts at elevated temperatures. Unfilled base resin.Valve seats, seal, insulators.Maximum strength and elongation: lowest modulus and thermalconductivity: optimum electrical properties.SP21 For lubricated or non-lubricated, low friction and wear 15% graphite (by weight).applications.Enhances inherent wear resistance, improves long term thermalValve seats, seals, bearings, washers, seal rings.stability.SP22 Applications in which low thermal expansion is more important 40% graphite (by weight).than strength (which is slightly reduced).Gives low coefficient of thermal expansion.Bearings (bushings, washers, etc.).Maximum creep resistance.SP211 For low friction and wear applications in moderate temperature 15% graphite and 10% TEFLON ® fluorocarbon resin (by weight).and PV environments.Lowest static friction.Bearings (bushings, washers, etc.).SP3 For friction and wear applications in vacuum or inert gases. 15% MoS2 (by weight).Bearings, piston rings and seals.Best wear performance in dry environments.SP221 For low wear applications in “non-lube” conditions against soft 40% graphite (by weight) and 15% TEFLON ® fluorocarbon resin.metals like aluminium, brass, bronze.Lowest wear rate in dry service against soft metals.Bearings (bushings, washers, etc.)SP262 Applications in which low thermal expansion and low coefficient 57% graphite (by weight) and 5% carbon fibers.of friction are more important than strength.Lowest coefficient of thermal expansion and highest thermalBushings.conductivity.VESPEL ® ST meets tougher challenges – ST grades for highest toughness, strength and temperatureGrades Typical End-Use Applications Polyimide CompositionsST2010 For lubricated or non-lubricated, low friction and wear Excellent wear and friction properties combined with goodapplications.toughness, strength and insulation properties.Valve seats, seals, bearings, washers, seal rings.Contains 10% graphite. Highest elongation.ST2030 Applications in which low thermal expansion is more important Lower coefficient of thermal expansion, lower elongationthan strength (which is slightly reduced).than ST2010. Contains 30% graphite.Bearings (bushings, washers, etc.).Highest oxidative and thermal stability.2

Direct-formed parts for cost savings on larger quantitiesMachining parts from VESPEL ®shapes is usually the most practicalroute to producing small quantities,prototypes, or parts with highlycomplex geometry.For production quantities of 500or more, VESPEL ® parts can oftenbe most economically fabricatedby the DuPont direct-formingprocess.* Direct forming uses powdermetallurgy techniques to producefinishe or semifinished parts,and minimises material wastes.Machining can often be eliminated.Long production runs also producelabour savings which can be passedalong as lower part prices.The chart below gives an exampleof how part cost varies with quantityfor an uncomplicated polyimidering.Due to the variety of factors thatarise in determining the most economicalfabrication process for anindividual part, you should consultwith a VESPEL ® sales engineer at theearliest stage of part design.* In some cases, depending on part size or complexity,direct-forming may be economical at even lowerquantities.Typical VESPEL ® Part Fabrication EconomicsDirect Forming vs Machining from VESPEL ® Stock ShapePrice per UnitParts Machined from VESPEL® RodDirect-Formed VESPEL® Parts(No Secondary Machining)050010001500Order Quantity2000 250030003

VESPEL ®– the material for the new ageToday’s sophisticated engineeringrequires parts that are smaller, lighterand capable of performing over awider temperature range than everbefore. As designs become moresophisticated, and product warrantieslonger DuPont’s VESPEL ® parts arebeing specified more and more often.The reason is simple. VESPEL ® partsexhibit a superior combination ofproperties in a variety of applicationsrequiring low wear and long life insevere environments.Since 1963, high-strength, lightweightVESPEL ® parts have helpedfoster the revolution in aircraftengine design and performance.Today, many dependable VESPEL ®parts are performing in almost everylet engine made in the Westernworld. Millions more are operatingsuccessfully in automobiles, largeon- and off-road vehicles, farmequipment, business machines,electronic equipment – and whereverelse trouble-free performance isvital to success.Although they originally adoptedVESPEL ® as a “problem solver,”engineers in a variety of fields now“think VESPEL ® ” first – to replacemetal, plastic and ceramic parts.High-performance VESPEL ® polyimideparts include: rotary sealrings, thrust washers and thrustdiscs, bushings, flanged bearings,printer platen bars, plungers, printerwire guides, stripper fingers, splinecouplings, wear strips, locknutinserts, valve seats, check valve balls,thermal and electrical insulators.With plants in the United States,Belgium and Japan, DuPont manufacturesboth SP resin and VESPEL ®parts within a fully integrated globalmanufacturing system.VESPEL ® parts made from DuPontSP polyimide resin are virtuallyin a class by themselves. Availablein five compositions (see TechnicalData, pages 10–13), VESPEL ® partsoffer an outstanding combinationof properties: excellent resistanceto extreme heat, good mechanicalstrength, good solvent resistance,low coefficient of friction, highdielectric strength, excellent dimensionalstability, outstanding wearresistance, sealing compliance, highcompressive strength, outstandingradiation resistance, low outgassingfor vacuum applications and toughness.VESPEL ® quality is worth the investment– providing savings throughsimplified assembly operations,increased reliability, extended componentlife and reduced wear onmating components. Global manufacturingcompanies depend onDuPont and VESPEL ® to deliver.These include Bosch, CaterpillarChrysler, Ford, General Electric,General Dynamics, GeneralMotors, Hitachi, Kodak, RockwellInternational, Toyota and UnitedTechnologies.4

The VESPEL ® parts are custom madewith tiny, debris-free, direct formedholes as specified. They reducewear against the aluminium valvebody and withstand repeatedimpact without permanent deformation.VESPEL ® valve discreduces wear andwithstands impactA precision 0,38 mm diameter holein the VESPEL ® disc of a transmissioncheck valve was required to accuratelycontrol the bleedback of automatictransmission fluid. Metalcould not be economically drilledat the required hole diameter.Customercomplaints declinewith VESPEL ® seatsIn hydraulic pressure relief valveson farm tractors,VESPEL ® seats providea no-leak seal in 135°C hydraulicoil while resisting 25,8 MPawithout creep. The VESPEL ® seatsconform to the balls’ shape andreseal even in the presence of particulatecontaminants. The VESPEL ®seats increase system reliability andreduce customer complaints.Self-lubricating VESPEL ®stemguide extends lifeof pneumatic controlsAVESPEL ® stem-guide allows amaker of pneumatic controls toincrease the upper service temperatureand extend the reliability of itstop-of-the-line valve. The VESPEL ®part performs reliably at 260°C.It remains self-lubricating, exhibitsa low coefficient of friction even atthe high service temperatures of thevalve, and withstands repeatedimpact without deformation.5

An outstanding performerVESPEL ® SP polyimide parts offeran outstanding mix of the physicalcharacteristics of metals, ceramicsand plastics, combined with theirown outstanding properties.VESPEL ®parts resist wear, fight creep, andpractically never melt, allowingthem to operate in the demandingenvironments of engines, transmissionsand high-speed printers.VESPEL ® parts perform reliably undera broad range of conditions, such as:● lubricated or unlubricated environments,at high pressure and /orvelocity, with outstanding wearresistance. VESPEL ® parts performat pressure velocities (PVs) of upto 40 MPa . m/s with lubricationand 12 MPa . m/s without lubrication;● temperatures from cryogenic upto 288°C continuously, with shorttermuse to 482°C;● hydraulic, automotive and manyindustrial fluids and solvents.Of course, PV limits and maximumuse temperatures of any material willvary from application to applicationdepending upon a number of differentfactors. Thorough applicationtesting should be performed todetermine how VESPEL ® parts willperform in your application.VESPEL ® can be superiorto metals in many waysVESPEL ® parts provide reliable sealing,even in contaminated fluids.Because of their compliance, theycan provide a more reliable sealthan many other sealing systemsmachined to much tighter tolerances.VESPEL ® parts can also reduce manufacturingcosts, such as expensivehand lapping or secondary grinding.Further, VESPEL ® parts weigh lessthan metal parts, which can reduceinertia, allowing for faster movementand change of direction whileminimising damage to mating surfacesand providing quieter operation.VESPEL ® parts have a lowcoefficient of friction and resistcorrosion. They have outstandingresistance to fatigue and peeningor repetitive impact deformation.6VESPEL ® parts can be superiorto other plastics in manywaysVESPEL ® parts have an outstandingcontinuous-use temperature range,excellent dimensional stability and,unlike most plastics, are non-flammable.VESPEL ® parts perform withoutmelting or softening and havehigh resistance to creep. VESPEL ®parts resist radiation more effectivelythan most other plastics andpossess outstanding compressivestrength. VESPEL ® parts provide aneffective seal against thin gases andare also compatible with oxygen.VESPEL ® parts exhibit ultra-lowoutgassing even in high vacuums.VESPEL ® parts do not soften, andalmost never melt. They are chemicallycompatible with most fuels,soIvents, lubricants, and hydraulicfluids. Finally, VESPEL ® parts exhibitsuperior wear resistance comparedto most plastics.VESPEL ® parts have threeimportant advantagescompared to ceramicsVESPEL ® parts are more compliantthan ceramics. VESPEL ® parts sealbetter at a lower pressure and areless brittle while exhibiting excellentdimensional and thermal stability.VESPEL ® baffleincreases torch lifeL-Tech was dissatisfied with theperformance of the ceramic bafflein the plasma cutting torches itmanufactures. The electrodes hadto be replaced every eight to tenhours and, each time, the baffleswere also removed and reinserted.Many of the ceramic baffles weredamaged or broken in the process.In their search for a more durablebaffle, engineers tested a varietyof plastics. Only VESPEL ® SP polyimideparts provided the heat resistance,creep resistance and flexibilitynecessary for improved torchoperation. The new VESPEL ® gasswirlbaffles lasted more than sixtimes longer than their predecessors.They could be handled numeroustimes without damage. And themore compliant VESPEL ® polyimideparts can be made with a tighterclearance than the ceramic parts,thus providing a tighter seal againstthe cutting torch’s copper nozzle.By switching to VESPEL ® baffles,L-Tech was able to increase lifeof the baffle from approximately15 to 100 hours.

The partner shipyou can count onTo ensure your success, DuPont andVESPEL ® give you something that yousimply don’t get from most othermatenals suppliers custom-madequality parts combined with professionalassistance and single-sourceaccountability from resin developmentto part concept and design tofinished parts.The process begins with DuPonttechnical consultants. Years of practicalexperience allow our salesengineers to recommend ultra highperformanceVESPEL ® parts that notonly fulfill a particular function,but which can also simplify yourentire assembly. They can help youmake a higher quality, lower costproduct a reality – from designingnew components to troubleshootingexisting ones, and from simplifyingpart design to helping select theright resin composition.The partnership continues withDuPont design and manufacturingprofessionals and tooling experts.Our production facilities in theUnited States, Europe and Japanhave produced hundreds of millionsof custom VESPEL ® parts – tiny tolarge, simple to complex, directformed,secondary-machined, ormachined entirely from standardshapes.We also offer a complete line ofstandard shapes for machining yourown prototype, as well as low-volumeor complex commercial parts.DuPont’s high quality manufactureof SP po yimide resin and VESPEL ®parts includes checkpoints at everystep of the production process toassure consistency. State-of-the-artStatistical Process Control (SPC) isemployed to meet our consistentlyhigh quality standards and therequirements of the world’s mostdemanding original equipmentmanufacturers.For more than 20 years, DuPont’sVESPEL ® Parts Team has beenresponding to the needs of designand materials engineers. Come toDuPont for the quality materials,parts and the “partnership advantage”in designing, prototyping,manufacturing and testing whichwill help you meet your toughestperformance challenges.The inherent lubricity ofVESPEL ® parts simplifiedan entire assemblyThis one-piece VESPEL ® film guidereplaces a complex machined aluminiumroller with press-fit ballbearings. The VESPEL ® part reducesmachining assembly time, and actsas its own self-aligning and selflubricatingbearing.VESPEL ® bearings reduceservice calls and improveproduct performanceThe toner liquid used in a desktopcopier was leaching the oil fromporous bronze bushings, causingincreased wear in the bearing. Theoil was contaminating the tonerand ruining the quality of the copies.VESPEL ® bearings eliminate theneed for lubrication and provideexcellent wear characteristics.7

VESPEL ®parts can helpimprove your profitabilityFor years, designers have turnedto DuPont for VESPEL ® parts whenother materials have failed. Today,they’re turning to VESPEL ® parts foranother critical reason – to cut overallcosts from the start.VESPEL ® parts are custom-made byDuPont to meet the stringent qualityrequirements of the world’s mostdemanding original equipmentmanufacturers – part to part andorder to order. Our Statistical ProcessControl (SPC) procedure makesit possible to produce consistentlyhigh-quality parts at lower costcompared with conventional processcontrol methods. The accuracy ofSPC even permits some customersto eliminate their own inspectionof incoming parts – for a substantialcost savings.Although VESPEL ® parts may havehigher initial costs than some othermaterials, they can save money overtime. Consistent quality, dependableperformance, longer life and reducedwarranty and maintenance costshave proven that VESPEL ® parts arethe most effective solution for manymanufacturers and end users.In nearly everx case, VESPEL ® partspay for themselves many timesover by keeping reliability high –and manufacturing costs, maintenancecosts and warranty claimslow. VESPEL ® parts can make possiblethe following:Parts consolidation. Often, thefunction of two or more existingparts can be combined in a singleVESPEL ® piece, as with flangedbushings.Machining costs elimination.VESPEL ® parts can often be directformedto fit a specific application,eliminating the need for costlymachining.Capital equipment life extension.With their unique combination ofproperties, VESPEL ® parts help preservethe life of critical capitalequipment, such as sophisticatedoffice machines or heavy machinery.In fact VESPEL ® parts provideincreased service life and reliabilityin the transmissions of rigorouslyoperated vehicles such as heavytrucks and buses, as well as in automobiles.Maintenance and warranty claimsminimisation. The ability of VESPEL ®parts to work in critical environmentswithout or with only marginal lubricationcan reduce mamtenance andincrease reliability.8

VESPEL ® disc helps savesupermarkets moneywith improvedrefrigeration efficiencyCopeland Corporation spent severalyears looking for a material to meetthe requirements of a new refrigerationcompressor valve system. Manymetals and plastics were tested –none of them had the combinationof creep, fatigue and wear resistanceat high cylinder temperatures whichVESPEL ® provided. Even afterextended service, the VESPEL ® discshowed only the slightest wear,fatigue and creep and the disc surfacewas not abraded by metal ordirt particles. Each VESPEL ® discis expected to last for 15 years. TheVESPEL ® parts allowed Copeland todesign a compressor which will cuta food store’s electrical costs forrefrigeration by 10 to 20 per cent.VESPEL ® seal rings helpreduce manufacturingcosts in many waysToughness and flexibility make themeasier to assemble than cast iron,eliminating the need for specialassembly fixtures. And there is lessbreakage, especially with smallerdiameter seal rings. In addition,sufficient stiffness helps keepVESPEL ® seal rings from bendingout of shape and being cut duringassembly often a problem withrings of PTFE. VESPEL ® parts arecompliant, so mating parts can havewider tolerances and rougher surfaces,thereby reducing machiningcosts. Finally, VESPEL ® can functionas a bearing surface as well asa seal… providing the possibilityof added design economies.VESPEL ® rings savemillions – by stoppingchrome-on-chrome wearCompressor bleed-valve life wasincreased by 50% in a U.S. AirForce programme to replace chromeplatedsteel piston rings with VESPEL ®SP rings. Friction between the metalrings and chrome-plated cylinderswas causing premature failure onJ-57 and TF-33 jet engines. Engineersselected VESPEL ® rings toreplace the chrome piston ringsafter tests showed that they couldwithstand up to 205 000 cycles attemperatures above 315°C withoutfailing. The VESPEL ® rings cost farless than traditional carbon pistonrings. An estimated $ 2.7 millionreduction in maintenance costs isanticipated.VESPEL ® seal rings helpreduce warranty costsby extending service lifeof equipmentVESPEL ® parts can help machinerylast longer in two important ways:by reducing wear and by withstandingthe extreme temperatures createdby the high pressure /velocities(PVs) of severe operating conditionsor marginal lubrication. They outperformmany other materials industy or contaminated environments,and work well in transmission andhydraulic fluids.9

VESPEL ®SP polyimide technical dataSP polyimide, developed by DuPont,has a unique combination of propertieswhich makes it the ideal solutionfor a variety of applications.Please note that all of the propertydata discussed in this brochure arebased upon laboratory tests and / orperformance of VESPEL ® parts inspecific applications. The maximumuse temperature, PV limit and otherperformance parameters of virtuallyall engineering materials will varysomewhat from application to applicationand between laboratory dataand actual applications, dependingupon a number of factors intrinsicto each application. Therefore theonly way to determine how VESPEL ®parts will perform in your applicationis to test them – in yourapplication.Technical discussion ofthe properties of VESPEL ®Dimensional stabilityVESPEL ® parts made from DuPontSP polyimide resin exhibit excellentoverall dimensional stability comparedto other plastics due to acombination of outstanding key properties.Most important is the factthat VESPEL ® parts have no observablesoftening or melting point.Other contributors to VESPEL ® ’sexcellent dimensional stabilityinclude low coefficient of thermalexpansion (some grades are comparableto aluminium), and excellentresistance to creep and repetitiveimpact deformation.This stability allows VESPEL ® partsto be machined to tolerances oncethought to be too tight for plasticsand even allows VESPEL ® to be usedas moulded-in inserts in injectionmouldable thermoplastic parts.This stability also means that yourVESPEL ® parts will maintain theirdimensions and functionality undersome of the harshest operatingconditions.VESPEL ® combines this excellentdimensional stability with a highdegree of toughness not found insome of the more traditional “dimensionallystable” polymers.Temperature resistanceVESPEL ® parts almost never melt,and can operate continuously fromcryogenic temperatures to 288°Cwith excursions to 482°C. Owingto superior thermal stability, VESPEL ®parts maintain consistently highperformance, even when subjectedto high temperatures for extendedperiods.Many physical properties of VESPEL ® ,such as tensile strength, elongation,flexural modulus and compressivestrength, may be comparable tothose of some high-performancepolymers at room temperature. ButVESPEL ® ’s excellent retention ofthese properties at both very highand very low temperatures, evenafter extended service at extremetemperatures, makes VESPEL ® thehigh-performance choice for applicationsinvolving operation at otherthan room temperature.Wear resistanceLike many other plastics, VESPEL ®parts provide corrosion-resistant,gall-resistant, low-wear and lowfrictionsurfaces – even in nonlubricatedenvironments. But thatis where the similarities end.VESPEL ® parts won’t melt or soften– even at 482°C. They have excellentoxidative stability and creepresistance. This helps VESPEL ® partsdeliver consistently superior wearperformance over a broad temperaturerange even when the temperatureat the bearing interface is substantiallyhigher than ambient, dueto the frictional heat generated byoperating at high pressures and /orvelocities.VESPEL ® bearings have performedat up to 12 MPa . m/s, unlubricated,and up to 40 MPa . m/s, lubricated.VESPEL ® parts are naturally toughand don’t require the addition ofabrasive fillers or fibres to enhancepart performance. This reduceswear of the mating surface. Thesuperior oxidative ability of VESPEL ®is also an advantage when comparedwith thermosets.Wear factor and frictioncoefficient for unlubricatedoperation against mildcarbon steelWear Factor, K 10 -6 mm 3 /NmCoefficient of Friction (μ)2,52,01,51,00,670,50,40,30,20,10,0SP211100 200 300 400 500Temperature, °CFrictionSP211SP21SP21100 150 200 300 400 500Temperature, °C10

Sealing complianceVESPEL ® valve seats, poppets andballs provide sealing compliancewhile resisting permanent deformation.This means that VESPEL ®parts can provide positive sealseven in fluids containing particulatecontaminants. And they can providemore reliable seals than metal-tometalseals machined to much tightertolerances – a feature which canreduce manufacturing costs byeliminating the need for expensivehand-lapping of the mating surface.VESPEL ® parts are tough. Duringan application test of valve seatsdesigned to test the failure limit ofvalve components, the pressure ona carbide ball in a VESPEL ® seat wasincreased to levels far beyond normaloperating conditions, until theball was finally forced through theVESPEL ® seat. However, in subsequenttesting on that same VESPEL ®valve seat, the seat had recoveredsufficiently to still provide a positiveseal at normal operating pressuresfor that system.Radiation resistanceVESPEL ® parts perform well in radioactiveenvironments, even at relativelyhigh dosage rates. At exposurelevels up to and including 1 × 10 8rads of gamma radiation, VESPEL ®bars displayed less than 1,0% weightloss*. At exposure levels up to andincluding 1 × 10 8 rads of electronbeam radiation, VESPEL ® bars displayedless than 2,0% weight loss*.Low outgassingWeight loss in vacuum at high temperaturesis low for VESPEL ® parts.In tests run by NASA in high vacuum,VESPEL ® samples, which werefirst dried at 93°C to remove water,had a weight loss rate of less than10 –10 grammes / cm 2 / s at temperaturesbelow 260°C.Fabricating VESPEL ®MachiningVESPEL ® shapes are relatively easyto machine because of their inherentmecanical strength, stiffness anddimensional stability at machiningtemperatures. In addition, they canbe machined with standard metalworkingequipment to produce partsto tolerances once considered tooclose for plastic materials. In mostcases, the techniques used in machiningbrass are directly applicable.Direct-formed VESPEL ® partsWhile VESPEL ® shapes are easy tomachine, direct forming is often themost economical process by whichto produce parts, especially if yourequire more than 500 to 1000VESPEL ® parts per year.* This represents the mean of a group of treated samplescompared to bars receiving no radiation exposure.11

Summary of typical properties SP polyimide resins (SI units)MECHANICALWEAR AND FRICTIONTHERMALTemp. ASTM SP1 SP21 SP22 SP211 SP3Property °C method Units M DF M DF M DF M DF MTensile strength 23 D-1708 MPa 86,2 72,4 65,5 62,0 51,7 48,3 44,8 51,7 58,5260 or E8† 41,4 36,5 37,9 30,3 23,4 26,2 24,1 24,1Strain at break 23 D-1708 % 7,5 7,5 4,5 5,5 3,0 2,5 3,5 5,5 4,0260 or E8† 6,0 7,0 3,0 5,2 2,0 2,0 3,0 5,3Flexural strength 23 D-790 MPa 110,3 82,7 110,3 82,7 89,6 62,1 68,9 68,9 75,8260 62,1 44,8 62,0 48,3 44,8 37,9 34,5 34,5 39,9Flexural modulus 23 D-790 MPa 3102 2482 3792 3171 4826 4826 3102 2758 3275260 1724 1448 2551 1792 2758 2758 1379 1379 1862Compressive stress 23 D-695 MPaat ,1% strain 24,8 24,1* 29,0 22,8* 31,7 24,1* 20,7 14,5* 34,5at ,10% strain 133,1 112,4* 133,1 104,8* 112,4 93,8* 102,0 75,8* 127,6at 0,1% strain 51,0 33,1* 45,5 33,8* 41,4 25,5* 37,2 27,6*Compressive modulus 23 D-695 MPa 2413 2413* 2895 2275* 3275 2654* 2068 1379* 2413Axial fatigue, endurance limitat 10 3 cycles 23 MPa 55,8 46,2260 26,2 22,8at 10 7 cycles 23 42,1 32,4260 16,5 16,5Flexural fatigue, endurance limitat 10 3 cycles 23 MPa 65,5 65,5at 10 7 cycles 23 44,8 44,8Shear strength 23 D-732 MPa 89,6 77,2Izod notched impact strength 23 D-256 J/m 42,7 42,7 21,3Izo, unnotched impact strength 23 D-256 J/m 747 320 112Poisson’s ratio 23 0,41 0,41Wear rate†† m/s ×10 –10 17–85 17–85 6,30 6,30 4,20 4,20 4,90 4,90 17–23Friction coefficient**PV = 0,875 MPa.m/s 0,29 0,29 0,24 0,24 0,30 0,30 0,12 0,12 0,25PV = 3,5 MPa.m/s 0,12 0,12 0,09 0,09 0,08 0,08 0,17In vacuum 0,03Static in air 0,35 0,30 0,27 0,20Coefficient of linear expansion 23 to 260 D-696 μm/m/°C 54 50 49 41 38 27 54 41 52–62 to +23 45 34Thermal conductivity 40 W/m.°C 0,35 0,29* 0,87 0,46* 1,73 0,89* 0,76 0,42* 0,47Specific heat J/kg/°C 1130Deformation under 14 MPa load 50 D-621 % 0,14 0,20 0,10 0,17 0,08 0,14 0,13 0,29 0,12Deflection temperature at 2 MPa D-648 °C ~360 ~360All the above information is subject to the disclaimer printed on the back page of this document.12

Temp. ASTM SP1 SP21 SP22 SP211 SP3Property °C method Units M DF M DF M DF M DF MELECTRICALOTHER PROPERTIESDielectric constant 23 D150at 10 2 Hz 3,62 13,53at 10 4 Hz 3,64 13,28at 10 6 Hz 3,55 13,41Dissipation factor 23 D150at 10 2 Hz 0,0018 0,0053at 10 4 Hz 0,0036 0,0067at 10 6 Hz 0,0034 0,0106Dielectric strengthshort time 2 mm thick D149 MV/m 22 9,84Volume resistivity 23 D257 Ω.m 10 14 -10 15 10 12 -10 13Surface resistivity 23 D257 Ω 10 15 -10 16Water absorption D570 %24 h 23 0,24 0,19 0,14 0,21 0,2348 h 50 0,72 0,57 0,42 0,49 0,65Equilibrium, 50% RH 1,0-1,3 1,0-1,3 0,8-1,1 0,8-1,1Specific gravity D792 1,43 1,34 1,51 1,42 1,65 1,56 1,55 1,46 1,60Oxygen index D2863 % 53 49† Machined tensile specimens made per D1708 and direct-formed specimens made per figure 19 of E-8(standard bar for powdered metallurgy products); specimens tested by D638.* Direct-formed (DF) properties marked with asterisk were measured parallel to the forming direction.All other direct-formed properties were measured perpendicular to the forming direction. Machined (M)properties are non-directional.†† Unlubricated in air (PV 0,875 MPa.m/s).** Steady state, unlubricated in air.Remark:M: Parts machined out of shapes material.DF: Parts obtained by «Direct Forming» process.All the above information is subject to the disclaimer printed on the back page of this document.13

Preliminary properties of new SP polyimide resinsMECHANICALWEAR AND FRICTIONTHERMALTemp. ASTM SP221 SP262Property °C Method Units DF DFTensile strength 23 D638 MPa 38,6 37,9260 or E8 19,3Strain at break 23 D638 % 3,5 1260 or E8 0,7Flexural strength 23 D790 MPa 55,1260 31Flexural modulus 23 D790 MPa 3445260 2205Tensile modulus 23 D638 MPa 8410260 or E8 3720Compressive stress D695 MPaUltimate 23 111,7 100Ultimate 260 57 59at 1% strain 23 14,5 40at 1% strain 260 21,4at 10% strain 23 78,6at 10% strain 260 46,5Compressive modulus 23 D695 MPa 1412 2860260 790 1790Specific gravity D732 1,6 1,74PV limit MPa . m/s 10,5 10,5Coefficient of frictionPV = 0,875 MPa.m/s 0,10-0,14PV = 3,5 MPa.m/s 0,05-0,08Wear factorPV = 0,875 MPa.m/s mm 3 /Nm 0,44PV = 3,5 MPa.m/s × 10 –6 0,66Wear and friction against 6061 Wrought AluminiumPV = 0,875 MPa . m/s Coefficient of friction 0,21PV = 0,875 MPa . m/s Wear rate VESPEL ® / Metal mm/s 10 –6 2,3/0Wear and friction against ADC 12 Diecast AluminiumPV = 0,5 MPa . m/s Coefficient of friction 0,15PV = 0,5 MPa . m/s Wear rate VESPEL ® / Metal mm/s 10 –6 1,2/0PV = 4,7 MPa . m/s Coefficient of friction 0,12PV = 4,7 MPa . m/s Wear rate VESPEL ® / Metal mm/s 10 –6 3,7/0,3Coefficient of lineal thermal expansion D696 μm/m .°CPerpendicular 23-300 29 13,1Parallel 23-300 48,9Thermal conductivity 23 W/m .K 2,46200 1,98Specific heat 23 J/kg.K 79240 837Note: SP221 and SP262 Stock Shapes are not yet available.All the above information is subject to the disclaimer printed on the back page of this document.14

Typical properties of Direct-Formed VESPEL ST parts®MECHANICALELECTRICALMISCELLANEOUSTemp. ASTM ST2010 ST2030Property °C Method Units DF DFTensile strength 23 D638 MPa 68 57150 49260 32300 26Strain at break 23 D638 % 10,0 4,9150 10,0260 9,8300 9,7Tensile modulus 23 D638 MPa 2758 3930Izod notched impact strength 23 D256 J/m 53Compressive strength D695 MPa1% strain 23 1510% strain 82ultimate 269 155Compressive modulus 23 D695 MPa 1827 1207Dielectric strength 23 D149 kV/mm 10,4Dielectric constant 23 D150100 Hz 4,80 30010 kHz 4,78 1101 MHz 4,70 40,6Dissipation factor 23 D150100 Hz 0,0014 6,9010 kHz 0,0023 0,651 MHz 0,0075 0,30Volume resistivity 23 D257 ohm.cm 3,2 × 10 16 4,8 × 10 7Surface resistivity 23 D257 ohm 2,0 × 10 16 2,6 × 10 6Thermal conductivity[W . cm/cm 2 . °C]23 F433 × 10 –3 5,0 9,7Coefficient of linear thermal expansion 23–260 D696 μ/m/°C 48 32Water absorption % change (weight),24 h 23 D570 1,3 0,548 h 3,1 1,3Deformation under 14 MPa load 23 D621 % 0,1850 0,38Specific gravity 23 D272 1,38 1,44Note: ST Stock Shapes are not yet available.All the above information is subject to the disclaimer printed on the back page of this document.15

Curbell Plastics is a proud supplierof DuPont TM Vespel ® Polyimide ShapesNationwide1.888.CURBELLwww.curbellplastics.comFor further information on Engineering Polymers contact:Internet location: http://dupont.com/vespelEUROPEBelgique / BelgiëDu Pont de Nemours (Belgium)BVBA-SPRLAntoon Spinoystraat 6B-2800 MechelenTel. (015) 44 15 27Telefax (015) 44 14 08DeutschlandDu Pont de Nemours(Deutschland) GmbHDuPont Straße 1D-61343 Bad HomburgTel. (06172) 87 0Telefax (06172) 87 27 01EspañaDu Pont Ibérica S.A.Edificio L’IllaAvda. Diagonal 561E-08029 BarcelonaTel. (3) 227 60 00Telefax (3) 227 62 00FranceDu Pont de Nemours (France) S.A.137, rue de l’UniversitéF-75334 Paris Cedex 07Tel. (01) 45 50 65 50Telefax (01) 47 53 09 67ItaliaDu Pont de Nemours Italiana S.r.L.Via Volta, 16I-20093 Cologno MonzeseTel. (02) 25 30 21Telefax (02) 25 30 23 06ÖsterreichBiesterfeld Interowa GmbH & Co. KGBräuhausgasse 3-5P.O. Box 19AT-1051 WienTel. (01) 512 35 71-0Telefax (01) 512 35 71-31e-mail : info@interowa.atinternet: www.interowa.atSchweiz / Suisse / SvizzeraDolder AGImmengasse 9Postfach 14695CH-4004 BaselTel. (061) 326 66 00Telefax (061) 322 47 81Internet: www.dolder.comUnited KingdomDu Pont (U.K.) LimitedMaylands AvenueGB-Hemel HempsteadHerts. HP2 7DPTel. (01442) 34 65 00Telefax (01442) 24 94 63ASIA-PACIFICJapanDuPont K.K.Arco Tower8-1, Shimomeguro 1-chomeMeguro-ku, Tokyo 153-0064Tel. 03-5434-6989Telefax 03-5434-6982Taiwan /ChinaDuPont Taiwan Limited13th Floor, Hung Kuo Building167, Tun Hwa North RoadTaipei, Taiwan 105Tel. 02-719-1999Telefax 02-712-0460UNITED STATESDuPont Engineering PolymersPencader SiteNewark, DE 19714-6100Tel. 800-222-VESPTelefax (302) 733-8137The information provided in this documentation corresponds to our knowledge on the subject at the date of its publication. This information may be subjectto revision as new knowledge and experience becomes available. The data provided fall within the normal range of product properties and relate only to thespecific material designated; these data may not be valid for such material used in combination with any other materials or additives or in any process, unlessexpressly indicated otherwise. The data provided should not be used to establish specification limits nor used alone as the basis of design; they are not intendedto substitute for any testing you may need to conduct to determine for yourself the suitability of a specific material for your particular purposes. Since DuPontcannot anticipate all variations in actual end-use conditions DuPont makes no warranties and assumes no liability in connection with any use of this information.Nothing in this publication is to be considered as a license to operate under or a recommendation to infringe any patent rights.Caution: Do not use this product in medical applications involving permanent implantation in the human body. For other medical applications see “DuPontMedical Caution Statement”.H-34480 06.02 ® Registered trademarks of E.I. du Pont de Nemours and Company Printed in Switzerland