Vespel s Parts Shapes Properties

7/21/2019 Vespel s Parts Shapes Properties

http://slidepdf.com/reader/full/vespel-s-parts-shapes-properties 1/18

® Registered trademarks of E.I. du Pont de Nemours and CompanyThe miracles of science ™ is a trademark of E.I. du Pont de Nemours and Company

Curbell Plastics is a proud supplier of DuPontTM Vespel® Polyimide Shapes



VESPEL®: The material for the new age 4– 5

“Today’s sophisticated engineering requires parts

that are smaller, lighter and capable of performing

over a wider temperature range. As designs

become more sophisticated, product performance

more demanding and product warranties longer –

more engineers turn to DuPont’s VESPEL®.”

An outstanding performer 6

“VESPEL® SP polyimide parts offer an outstand-

ing mix of the physical characteristics of metal,

ceramics and plastics, combined with their own

outstanding properties. As a result VESPEL® parts

resist wear, fight creep, and practically never

melt…”

The partnership you can count on 7

“…DuPont and VESPEL® give you something you

simply don’t get from most other materials sup-

pliers – custom-made quality parts combined

with professional assistance. Plus single-source

accountability, from resin development…

to parts concept and design… to finished parts.”

VESPEL® parts can help improve

your bottom line 8–9

“…VESPEL® parts-pay for themselves many times

over by high reliability – and low manufacturing

costs, maintenance costs and warranty claims.”

VESPEL® SP polyimide technical data 10–15

“Unlike most thermoset plastics, VESPEL® parts

are naturally tough and do not require the addi-

tion of abrasive fillers or fibres to enhance part

performance.”

Contents



IntroductionThank you for your interest inDuPont’s VESPEL® polyimideparts. As part of the VESPEL

®

product team, we look forward

to this opportunity to presentour product and services toyou.

DuPont’s VESPEL® team hasevolved to uniquely meet thechanging needs of the world-wide marketplace. We offeryou advanced materials anddedicated professionals:

design engineers, productionengineers well versed in state-of-the-art manufacturing tech-niques for both resin and parts,and others dedicated to ensur-ing that your consistently highquality VESPEL

® parts andshapes get to you on a timelybasis.

We work to make your prod-uct a success – from conceptto design, component analysis,

composition selection, proto-

typing, testing, quality controland on through production of commercial parts.

This VESPEL® brochure is acollection of articles relatingto the use of VESPEL

® polyimide

– some background on itsdevelopment, its applications,demonstrations of its cost

effectiveness, and details onsome of its technical properties.

We hope this publicationstimulates ideas on howVESPEL

® can help you solveyour design challenges. If you

have 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 are custom-made byDuPont from SP polyimide resins

to combine the best characteristicsof plastics, metals and ceramics.They resist wear, fight creep, andthey practically never melt – pro-perties that allow them to survivea broad range of conditions.

For example, VESPEL® parts

provide outstanding wear resist-ance in 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 tempera-tures beyond 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 ma-chined to much tighter tolerances,

are easily machined without spe-cial equipment or procedures.

VESPEL® can bemachined as easilyas brassWhile DuPont can supply finished

machined parts, you can easily doyour own machining using VESPEL®

shapes.

With standard metal-working equip-ment, you can machine VESPEL®

shapes to tolerances once consid-ered too 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 mechanical

strength, stiffness and dimensionalstability at machining temperatures.

For a complete guide to machiningparts from VESPEL® shapes, ask fora copy of the Design Handbook.

2

VESPEL® parts deliver an outstandingcombination of properties

Selector guide – VESPEL® SP for demanding applications

Grades Typical End-Use Applications Polyimide Compositions

SP1 Mechanical and electrical parts at elevated temperatures. Unfilled base resin.Valve seats, seal, insulators. Maximum strength and elongation: lowest modulus and thermal

conductivity: 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 temperature

Grades Typical End-Use Applications Polyimide Compositions

ST2010 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.



Machining 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 pow-der metallurgy techniques to pro-duce finishe or semifinished parts,and minimises material wastes.

Machining can often be eliminated.Long production runs also producelabour savings which can be passed

along as lower part prices.

The chart below gives an exampleof how part cost varies with quanti-ty for an uncomplicated polyimidering.

Due to the variety of factors that arise in determining the most eco-nomical fabrication process for an

individual part, you should consult with a V ESPEL® 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.

3

Direct-formed parts for cost savings on larger quantities

Order Quantity

P r i c e p e r U n i t

30002000 2500150010005000

Typical VESPEL® Part Fabrication Economics

Direct Forming vs Machining from VESPEL® Stock Shape

Parts Machined from VESPEL® Rod

Direct-Formed VESPEL® Parts(No Secondary Machining)



Today’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 of properties in a variety of applicationsrequiring low wear and long life insevere environments.

Since 1963, high-strength, light-weight VESPEL® parts have helped

foster 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 replace

metal, plastic and ceramic parts.High-performance VESPEL® poly-imide parts 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 manu-factures both 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 dimen-

sional stability, outstanding wearresistance, sealing compliance, highcompressive strength, outstandingradiation resistance, low outgassingfor vacuum applications and toughness.

VESPEL® quality is worth the invest-ment – providing savings throughsimplified assembly operations,increased reliability, extended com-ponent life and reduced wear onmating components. Global manu-facturing companies depend on

DuPont and VESPEL® to deliver.These include Bosch, CaterpillarChrysler, Ford, General Electric,General Dynamics, GeneralMotors, Hitachi, Kodak, RockwellInternational, Toyota and UnitedTechnologies.

4

VESPEL® – the material for the new age



VESPEL® valve disc

reduces wear andwithstands impact

A precision 0,38 mm diameter holein theVESPEL® disc of a transmissioncheck valve was required to accur-ately control the bleedback of auto-matic transmission fluid. Metal

could not be economically drilledat the required hole diameter.

The VESPEL® parts are custom madewith tiny, debris-free, direct formedholes as specified. They reducewear against the aluminium valvebody and withstand repeatedimpact without permanent defor-mation.

Customercomplaints declinewith VESPEL

® seatsIn hydraulic pressure relief valveson farm tractors,VESPEL® seats pro-vide a no-leak seal in135°C hydrau-lic oil while resisting 25,8 MPawithout creep. The VESPEL® seats

conform to the balls’ shape andreseal even in the presence of par-ticulate contaminants. The VESPEL®

seats increase system reliability andreduce customer complaints.

Self-lubricating VESPEL®

stemguide extends lifeof pneumatic controlsA VESPEL® stem-guide allows amaker of pneumatic controls to

increase the upper service tempera-ture and 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



VESPEL® 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, transmis-sions and high-speed printers.VESPEL® parts perform reliably undera broad range of conditions, such as: lubricated or unlubricated environ-

ments, at high pressure and/orvelocity, with outstanding wearresistance. VESPEL® parts perform

at pressure velocities (PVs) of upto 40 MPa . m/s with lubricationand 12 MPa . m/s without lubri-cation;

temperatures from cryogenic upto 288°C continuously, with short-term use to 482°C;

hydraulic, automotive and manyindustrial fluids and solvents.

Of course, PV limits and maximumuse temperatures of any material will

vary from application to applicationdepending upon a number of differ-ent factors. Thorough applicationtesting should be performed todetermine how VESPEL® parts willperform in your application.

VESPEL® can be superiorto metals in many ways

VESPEL® parts provide reliable seal-ing, even in contaminated fluids.Because of their compliance, they

can provide a more reliable sealthan many other sealing systemsmachined to much tighter tolerances.VESPEL® parts can also reduce manu-facturing costs, such as expensivehand lapping or secondary grinding.Further, VESPEL® parts weigh lessthan metal parts, which can reduceinertia, allowing for faster move-ment and change of direction whileminimising damage to mating sur-faces and providing quieter opera-tion. VESPEL® parts have a lowcoefficient of friction and resistcorrosion. They have outstandingresistance to fatigue and peeningor repetitive impact deformation.

VESPEL® parts can be superiorto other plastics in manyways

VESPEL® parts have an outstandingcontinuous-use temperature range,excellent dimensional stability and,unlike most plastics, are non-flam-mable.VESPEL® parts perform with-out melting or softening and havehigh resistance to creep. VESPEL®

parts resist radiation more effective-ly than most other plastics andpossess outstanding compressivestrength. VESPEL® parts provide aneffective seal against thin gases and

are also compatible with oxygen.VESPEL® parts exhibit ultra-lowoutgassing even in high vacuums.VESPEL® parts do not soften, andalmost never melt. They are chemi-cally compatible with most fuels,soIvents, lubricants, and hydraulicfluids. Finally,VESPEL® parts exhibitsuperior wear resistance comparedto most plastics.

VESPEL® parts have threeimportant advantagescompared to ceramics

VESPEL® 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 had

to 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 poly-imide parts provided the heat resis-tance, creep resistance and flexibil-ity necessary for improved torch

operation. The new VESPEL®

gas-swirl baffles 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.

6

An outstanding performer



The partner shipyou can count on

To ensure your success, DuPont andVESPEL® give you something that yousimply don’t get from most othermatenals suppliers custom-madequality parts combined with profes-sional assistance and single-sourceaccountability from resin develop-ment to part concept and design tofinished parts.

The process begins with DuPonttechnical consultants. Years of prac-tical experience allow our sales

engineers to recommend ultra high-performanceVESPEL® 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, direct-formed, secondary-machined, ormachined entirely from standardshapes.

We also offer a complete line of standard shapes for machining yourown prototype, as well as low-vol-ume or 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 been

responding to the needs of designand materials engineers. Come toDuPont for the quality materials,parts and the “partnership advan-tage” in designing, prototyping,manufacturing and testing whichwill help you meet your toughestperformance challenges.

The inherent lubricity ofVESPEL® parts simplifiedan entire assembly

This one-piece VESPEL® film guidereplaces a complex machined alu-minium roller with press-fit ballbearings. The VESPEL® part reduces

machining assembly time, and actsas its own self-aligning and self-lubricating bearing.

VESPEL® bearings reduceservice calls and improveproduct performance

The 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



For years, designers have turnedto DuPont for VESPEL® parts when

other materials have failed. Today,they’re turning to VESPEL® parts foranother critical reason – to cut over-all costs from the start.

In nearly everx case, VESPEL® partspay for themselves many timesover by keeping reliability high –and manufacturing costs, mainte-nance costs and warranty claimslow. VESPEL® parts can make pos-sible the following:

Parts consolidation. Often, thefunction of two or more existing

parts can be combined in a singleVESPEL® piece, as with flangedbushings.

Machining costs elimination.VESPEL® parts can often be direct-formed to fit a specific application,eliminating the need for costlymachining.

Capital equipment life extension.With their unique combination of properties, VESPEL® parts help pre-serve the life of critical capitalequipment, such as sophisticatedoffice machines or heavy machin-ery. In fact VESPEL® parts provideincreased service life and reliabilityin the transmissions of rigorouslyoperated vehicles such as heavytrucks and buses, as well as in auto-mobiles.

Maintenance and warranty claimsminimisation. The ability of VESPEL®

parts to work in critical environmentswithout or with only marginal lubri-cation can reduce mamtenance andincrease reliability.

VESPEL® parts are custom-made byDuPont to meet the stringent quality

requirements of the world’s mostdemanding original equipmentmanufacturers – part to part andorder to order. Our Statistical Pro-cess Control (SPC) procedure makesit possible to produce consistentlyhigh-quality parts at lower costcompared with conventional processcontrol methods. The accuracy of SPC 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 are

the most effective solution for manymanufacturers and end users.

8

VESPEL® parts can helpimprove your profitability



VESPEL® disc helps savesupermarkets moneywith improvedrefrigeration efficiency

Copeland Corporation spent severalyears looking for a material to meetthe requirements of a new refrigera-

tion compressor 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 sur-

face was 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 ways

Toughness 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 sur-faces, 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 wear

Compressor bleed-valve life wasincreased by 50% in a U.S. AirForce programme to replace chrome-plated steel piston rings with VESPEL®

SP rings. Friction between the metalrings and chrome-plated cylinders

was causing premature failure onJ-57 and TF-33 jet engines. Engi-neers selected VESPEL® rings toreplace the chrome piston ringsafter tests showed that they couldwithstand up to 205000 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 equipment

VESPEL® parts can help machinerylast longer in two important ways:by reducing wear and by withstand-ing the extreme temperatures creat-ed by the high pressure /velocities(PVs) of severe operating conditionsor marginal lubrication. They out-perform many other materials industy or contaminated environments,and work well in transmission andhydraulic fluids.

9



SP polyimide, developed by DuPont,has a unique combination of prop-erties which makes it the ideal solu-tion for 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 appli-cation and between laboratory dataand actual applications, depending

upon a number of factors intrinsicto each application. Therefore theonly way to determine how VESPEL®

parts will perform in your appli-cation is to test them – in yourapplication.

Technical discussion ofthe properties of VESPEL®

Dimensional stabilityVESPEL® parts made from DuPontSP polyimide resin exhibit excellentoverall dimensional stability com-pared to other plastics due to acombination of outstanding key pro-perties. Most important is the factthat VESPEL® parts have no observ-able softening or melting point.Other contributors to VESPEL®’sexcellent dimensional stabilityinclude low coefficient of thermal

expansion (some grades are compar-able to 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 “dimen-

sionally stable” polymers.

Temperature resistance

VESPEL® 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 of these properties at both very highand very low temperatures, evenafter extended service at extremetemperatures, makes VESPEL® the

high-performance choice for appli-cations involving operation at otherthan room temperature.

Wear resistance

Like many other plastics, VESPEL®

parts provide corrosion-resistant,gall-resistant, low-wear and low-friction surfaces – even in non-lubricated environments. But thatis where the similarities end.

VESPEL®

parts won’t melt or soften – even at 482° C. They have excel-lent oxidative stability and creepresistance. This helps VESPEL® partsdeliver consistently superior wearperformance over a broad tempera-ture range even when the tempera-ture at the bearing interface is sub-stantially higher 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 of abrasive fillers or fibres to enhance

part 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 steel

10

VESPEL® SP polyimide technical data

100 200 300 400 500

0,5

1,0

1,5

2,0

2,5

W e a r F a c t o r , K 1 0 - 6

m m 3 / N m

Temperature, °C

0,67

SP211

SP21

Friction

0,0

0,1

0,2

0,3

0,4

C o e f f i c i e n t o f F r i c t i o n ( µ )

SP211SP21

100 200 300 400 500

Temperature, °C

150



Sealing compliance

VESPEL® valve seats, poppets andballs provide sealing compliancewhile resisting permanent deform-ation. This means that VESPEL®

parts can provide positive seals

even in fluids containing particulatecontaminants. And they can providemore reliable seals than metal-to-metal seals 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 of valve components, the pressure on

a carbide ball in aVESPEL®

seat wasincreased to levels far beyond nor-mal operating conditions, until theball was finally forced through theVESPEL® seat. However, in subse-quent testing on that same VESPEL®

valve seat, the seat had recoveredsufficiently to still provide a positiveseal at normal operating pressuresfor that system.

Radiation resistance

VESPEL

®

parts perform well in radio-active environments, even at rela-tively high dosage rates. At exposurelevels up to and including 1 × 108

rads of gamma radiation, VESPEL®

bars displayed less than 1,0% weightloss*. At exposure levels up to andincluding 1 × 108 rads of electronbeam radiation, VESPEL® bars dis-played less than 2,0% weight loss*.

Low outgassing

Weight loss in vacuum at high tem-peratures is low for VESPEL® parts.In tests run by NASA in high vacu-um, VESPEL® samples, which werefirst dried at 93°C to remove water,

had a weight loss rate of less than10 –10 grammes/cm2/ s at tempera-tures below 260°C.

Fabricating VESPEL®

Machining

VESPEL® shapes are relatively easy

to machine because of their inherentmecanical strength, stiffness anddimensional stability at machiningtemperatures. In addition, they canbe machined with standard metal-working equipment to produce partsto tolerances once considered tooclose for plastic materials. In mostcases, the techniques used in ma-chining brass are directly applicable.

Direct-formed VESPEL® parts

While VESPEL® shapes are easy tomachine, direct forming is often themost economical process by whichto produce parts, especially if yourequire more than 500 to 1000

VESPEL®

parts per year.* This represents the mean of a group of treated samples

compared to bars receiving no radiation exposure.

11



12

Summary of typical properties SP polyimide resins (SI units)

M E C H A N I C A L

W E A R

A N D F R I C T I O N

T H E R M A L

Temp. ASTM SP1 SP21 SP22 SP211 SP3

Property °C method Units M DF M DF M DF M DF M

Tensile strength 23 D-1708 MPa 86,2 72,4 65,5 62,0 51,7 48,3 44,8 51,7 58,5

260 or E8† 41,4 36,5 37,9 30,3 23,4 26,2 24,1 24,1

Strain at break 23 D-1708 % 7,5 7,5 4,5 5,5 3,0 2,5 3,5 5,5 4,0

260 or E8† 6,0 7,0 3,0 5,2 2,0 2,0 3,0 5,3

Flexural strength 23 D-790 MPa 110,3 82,7 110,3 82,7 89,6 62,1 68,9 68,9 75,8

260 62,1 44,8 62,0 48,3 44,8 37,9 34,5 34,5 39,9

Flexural modulus 23 D-790 MPa 3102 2482 3792 3171 4826 4826 3102 2758 3275

260 1724 1448 2551 1792 2758 2758 1379 1379 1862

Compressive stress 23 D-695 MPa

at ,1% strain 24,8 24,1* 29,0 22,8* 31,7 24,1* 20,7 14,5* 34,5

at ,10% strain 133,1 112,4* 133,1 104,8* 112,4 93,8* 102,0 75,8* 127,6

at 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* 2413

Axial fatigue, endurance limit

at 103 cycles 23 MPa 55,8 46,2

260 26,2 22,8

at 107 cycles 23 42,1 32,4

260 16,5 16,5

Flexural fatigue, endurance limit

at 103 cycles 23 MPa 65,5 65,5

at 107 cycles 23 44,8 44,8

Shear strength 23 D-732 MPa 89,6 77,2

Izod notched impact strength 23 D-256 J/m 42,7 42,7 21,3

Izo, unnotched impact strength 23 D-256 J/m 747 320 112

Poisson’s ratio 23 0,41 0,41

Wear rate†† m/s ×

10–10 17–85 17–85 6,30 6,30 4,20 4,20 4,90 4,90 17–23

Friction coefficient**

PV = 0,875 MPa .m/s 0,29 0,29 0,24 0,24 0,30 0,30 0,12 0,12 0,25

PV = 3,5 MPa .m/s 0,12 0,12 0,09 0,09 0,08 0,08 0,17

In vacuum 0,03

Static in air 0,35 0,30 0,27 0,20

Coefficient of linear expansion 23 to 260 D-696 µm/m/°C 54 50 49 41 38 27 54 41 52

–62 to +23 45 34

Thermal conductivity 40 W/m .°C 0,35 0,29* 0,87 0,46* 1,73 0,89* 0,76 0,42* 0,47

Specific heat J/kg/°C 1130

Deformation under 14 MPa load 50 D-621 % 0,14 0,20 0,10 0,17 0,08 0,14 0,13 0,29 0,12

Deflection temperature at 2 MPa D-648 °C ~360 ~360

All the above information is subject to the disclaimer printed on the back page of this document.



13

E L E C T R I C A L

O T H E R P R O P E R T I E S

Temp. ASTM SP1 SP21 SP22 SP211 SP3

Property °C method Units M DF M DF M DF M DF M

Dielectric constant 23 D150

at 102 Hz 3,62 13,53

at 104 Hz 3,64 13,28

at 106 Hz 3,55 13,41

Dissipation factor 23 D150

at 102 Hz 0,0018 0,0053

at 104 Hz 0,0036 0,0067

at 106 Hz 0,0034 0,0106

Dielectric strength

short time 2 mm thick D149 MV/m 22 9,84

Volume resistivity 23 D257 Ω .m 1014-1015 1012-1013

Surface resistivity 23 D257 Ω 1015-1016

Water absorption D570 %

24 h 23 0,24 0,19 0,14 0,21 0,23

48 h 50 0,72 0,57 0,42 0,49 0,65

Equilibrium, 50% RH 1,0-1,3 1,0-1,3 0,8-1,1 0,8-1,1

Specific gravity D792 1,43 1,34 1,51 1,42 1,65 1,56 1,55 1,46 1,60

Oxygen 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.




1414


Preliminary properties of new SP polyimide resins

Temp. ASTM SP221 SP262

Property °C Method Units DF DF

Tensile strength 23 D638 MPa 38,6 37,9

260 or E8 19,3

Strain at break 23 D638 % 3,5 1

260 or E8 0,7

Flexural strength 23 D790 MPa 55,1

260 31

Flexural modulus 23 D790 MPa 3445

260 2205

Tensile modulus 23 D638 MPa 8410

260 or E8 3720Compressive stress D695 MPa

Ultimate 23 111,7 100

Ultimate 260 57 59

at 1% strain 23 14,5 40

at 1% strain 260 21,4

at 10% strain 23 78,6

at 10% strain 260 46,5

Compressive modulus 23 D695 MPa 1412 2860

260 790 1790

Specific gravity D732 1,6 1,74

PV limit MPa . m/s 10,5 10,5

Coefficient of friction

PV = 0,875 MPa .m/s 0,10-0,14

PV = 3,5 MPa .m/s 0,05-0,08

Wear factor

PV = 0,875 MPa .m/s mm3 /Nm 0,44

PV = 3,5 MPa .m/s × 10–6 0,66

Wear and friction against 6061 Wrought Aluminium

PV = 0,875 MPa . m/s Coefficient of friction 0,21

PV = 0,875 MPa . m/s Wear rate VESPEL® / Metal mm/s 10–6 2,3/0

Wear and friction against ADC 12 Diecast Aluminium


PV = 0,5 MPa . m/s Wear rate VESPEL® / Metal mm/s 10–6 1,2/0


PV = 4,7 MPa . m/s Wear rate VESPEL® / Metal mm/s 10–6 3,7/0,3

Coefficient of lineal thermal expansion D696 µm/m .°C

Perpendicular 23-300 29 13,1

Parallel 23-300 48,9

Thermal conductivity 23 W/m .K 2,46

200 1,98

Specific heat 23 J/kg .K 79240 837

Note: SP221 and SP262 Stock Shapes are not yet available.

M E C H A N I C A L

W E A R A N D F R I C T I O N

T H E R M A L



15

Temp. ASTM ST2010 ST2030

Property °C Method Units DF DF

Tensile strength 23 D638 MPa 68 57

150 49

260 32

300 26

Strain at break 23 D638 % 10,0 4,9

150 10,0

260 9,8

300 9,7

Tensile modulus 23 D638 MPa 2758 3930

Izod notched impact strength 23 D256 J/m 53

Compressive strength D695 MPa

1% strain 23 15

10% strain 82

ultimate 269 155

Compressive modulus 23 D695 MPa 1827 1207

Dielectric strength 23 D149 kV/mm 10,4

Dielectric constant 23 D150

100 Hz 4,80 300

10 kHz 4,78 110

1 MHz 4,70 40,6

Dissipation factor 23 D150

100 Hz 0,0014 6,90

10 kHz 0,0023 0,65

1 MHz 0,0075 0,30

Volume resistivity 23 D257 ohm .cm 3,2 ×1016 4,8 ×107

Surface resistivity 23 D257 ohm 2,0 ×1016 2,6 ×106

Thermal conductivity [W . cm/cm2 . °C]

23 F433 × 10–3 5,0 9,7

Coefficient of linear thermal expansion 23–260 D696 µ/m/°C 48 32

Water absorption % change (weight),24 h 23 D570 1,3 0,5

48 h 3,1 1,3

Deformation under 14 MPa load 23 D621 % 0,18

50 0,38

Specific gravity 23 D272 1,38 1,44

Note: ST Stock Shapes are not yet available.


M E C H A N I C A L

E L E C T R I C

A L

M I S C E L L A N E

O U S

Typical properties of Direct-Formed VESPEL® ST parts



The 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 informa-tion. 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”.

For further information on Engineering Polymers contact:Internet location: http://dupont.com/vespel

EUROPEBelgique/BelgiëDu Pont de Nemours (Belgium)BVBA-SPRLAntoon Spinoystraat 6B-2800 MechelenTel. (015) 44 15 27Telefax (015) 44 14 08

DeutschlandDu Pont de Nemours(Deutschland) GmbHDuPont Straße 1D-61343 Bad HomburgTel. (06172) 87 0

Telefax (06172) 87 27 01

EspañaDu Pont Ibérica S.A.Edificio L’IllaAvda. Diagonal 561E-08029 BarcelonaTel. (3) 227 60 00Telefax (3) 227 62 00

FranceDu Pont de Nemours (France) S.A.137, rue de l’UniversitéF-75334 Paris Cedex 07Tel. (01) 45 50 65 50Telefax (01) 47 53 09 67

ItaliaDu Pont de Nemours Italiana S.r.L.Via Volta, 16I-20093 Cologno MonzeseTel. (02) 25 30 21Telefax (02) 25 30 23 06

ÖsterreichBiesterfeld Interowa GmbH & Co. KGBräuhausgasse 3-5P.O. Box 19AT-1051 WienTel. (01) 512 35 71-0Telefax (01) 512 35 71-31e-mail : [email protected]

internet: www.interowa.atSchweiz/Suisse/SvizzeraDolder AGImmengasse 9Postfach 14695CH-4004 BaselTel. (061) 326 66 00Telefax (061) 322 47 81Internet: www.dolder.com

United KingdomDu Pont (U.K.) LimitedMaylands AvenueGB-Hemel HempsteadHerts. HP2 7DPTel. (01442) 34 65 00

Telefax (01442) 24 94 63

ASIA-PACIFICJapanDuPont K.K.Arco Tower8-1, Shimomeguro 1-chomeMeguro-ku, Tokyo 153-0064Tel. 03-5434-6989Telefax 03-5434-6982

Taiwan/ChinaDuPont Taiwan Limited13th Floor, Hung Kuo Building167, Tun Hwa North RoadTaipei, Taiwan 105Tel. 02-719-1999

Telefax 02-712-0460

UNITED STATESDuPont Engineering PolymersPencader SiteNewark, DE 19714-6100Tel. 800-222-VESPTelefax (302) 733-8137

Curbell Plastics is a proud supplier

of DuPontTM Vespel® Polyimide Shapes

Nationwide

1.888.CURBELL www.curbellplastics.com

Documents

Vespel s Parts Shapes Properties