Engineering Polymersfor electric motors ®

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DuPont Engineering Polymers

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Front page:– General purpose motor from FHP Elmotor AB– Window lift motor from Meritor

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Contents

PageIntroduction- Worldwide motor manufacture

and DuPont's global team 4- The total DuPont offering 5- Traditional versus new approach 6-7- Vespel® 8- Automotive window lift motor 9- Significant cost savings 10

Electrical insulation andapproved insulating systemsfrom DuPont

- UL 1446/IEC 85 Electrical Insulation Systems (EIS) 11- Thermoplastic encapsulation 11- Advantages of high temperatureinsulation systems 12

- DuPont family of insulating materials 12

Motor design

- Rotors and stators 14- Overmoulding 14- Commutators 16- End frames 16- Stiffness, strength and creep resistance 18-1- Bearings and bearing housings 20-22- Gears and gear housings 22- Brush holders 22- Motor cooling fans 23- Function integration 24- Assembly features 25- Frame extensions and housings 26- Interconnects 26- Motor design innovations 27- Noise, vibration and harshness 28

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DuPont's Global Motors Team can assist you whenever and wherever you need it

Today's electric motor design teams abeing confronted by more challengesthan ever before. There is a particularneed to develop more cost effectivemotors for an increasingly competitivemarketplace. As a result, a new andbroader range of engineering and insulation materials is changing the way inwhich motors are designed, manufac-tured and assembled.

Global Motors Team

To help you take full advantage of the latest materials and technologywhen you optimize an existing designor develop a new motor, DuPont hasestablished a Worldwide Motors TeamBy drawing on its global experienceand resources, you are assured of propmaterial selection, part design andprocessing. The motors team can helpyou:

• design motor components• with material selection• with processing support

Global technical support

DuPont has R&D, manufacturing,technical service and distribution facili-ties throughout the world. When youpurchase engineering materials forelectric motors, technical support ispart of the offering. You have openedthe door to a world of knowledge thatcan provide you with valuable practicahelp at every stage of your project.

The DuPont technical centres, locatedin strategically selected regions arounthe world, can provide you withinvaluable assistance. And DuPont wilwork with you from concept throughto commercialization.

DuPont's global offering forelectric motors

State-of-the-art insulation technologyprovides motor manufacturers greaterdesign flexibility and the opportunityto reduce costs. DuPont offers you thelargest range of electrical insulationsystems, and each comes with a varieof approvals by testing agencies, including Underwriters' Laboratories, IECand CSA. What's more, engineeringpolymers also provide many benefits in housing, motor bracket and bearingapplications. These materials canreduce finished part costs throughsimplified assembly, parts integration,and lower material costs.

Although this brochure concentrates oengineering polymers used in electricmotors, DuPont's total offering goes fabeyond this. It includes an extremely

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broad range of elastomers, films, fabricated components, fibres, chemicalrefrigerants, advanced structural composites, electronic materials, and finishes.

This brochure illustrates many of theadvantages and options that result froincorporating DuPont's engineeringmaterials in your motor design. Youwill find ideas ranging from plasticbearings to extensions of thermoplastimotor frames, rotor insulation, and protective devices used in motor contro

equipment. Many of the examples useare just re-thinking of an old concept,but in each case new materials havemet the needs of a designer, engineeror end-user.

For more information on DuPont'sfamily of engineering materials, contact your nearest DuPont office (see back page for contact addresses).

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Engineering polymers

Crastin® PBTthermoplastic polyester resinDelrin®

acetal resinHytrel®thermoplastic polyester elastomerMinlon®

mineral reinforced nylon resinRynite® PETthermoplastic polyester resinZenite® LCPliquid crystal polymerZytel®nylon resinZytel® HTN

high temperature nylon resin

Fluoropolymers

Teflon®

fluorocarbon resinsTefzel®fluorocarbon resins

Material for high performance bearings

Vespel® polyimideparts and shapes

Sheet structures for electrical insulation

Nomex® brand sheet structures

Lubrication

Krytox®

fluorinated oil and grease

Films for electrical insulation

Mylar®

polyester filmKapton®

polyimide film

Wire & cable materials

Elvaloy®

Hytrel®thermoplastic polyester resinKapton®

polyimide filmTeflon®

fluorocarbon resinsTefzel®fluoropolymer

® DuPont's registered trademarks.

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The majority of motors produced todayare still manufactured using largenumbers of components in traditionalmaterials such as paper or films forinsulation, thermosets for brush holders,and die-cast metals for end frames. A significant proportion of the cost ofthe finished motor results from labour-intensive assembly.

Traditional universal motor construction

Individual paper or film slot insulators

Field coils secured to laminations by pins or clamps

End frame in metal or thermoset

Paper/tape insulation for stator windings

Paper or film end insulators

Separate connector moulding

De-flashed and machined die-castend frame

Brush holder mouldings

Separate connector mounting plate

Tacho-generator (or encoder) screwedto die-castend frame

Fixing screws for connector

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DuPont engineering polymers offer a better, more cost effective solution.High performance polymers, includingRynite® glass reinforced PETpolyester, aswell as Zytel®nylon, Zytel® HTN hightemperature nylon, Crastin® PBT,Zenite® LCPand Minlon® mineralreinforced nylon, Hytrel® thermoplasticpolyester elastomer and Vespel® poly-imide parts facilitate parts integration.In addition, they provide superiorthermal properties, thin-walled stiffness,processibility and:

• Efficient, reliable wire winding• Free UL and IEC recognition for

materials and insulation systems upto Class R

• No finishing or machining normallynecessary

• Parts integration and reduced assembly costs

• Close part tolerances• Stiffness and dimensional stability• Reliable performance at high

temperatures

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Design utilizing the features of engineering polymers

Overmoulded rotor insulation. The insulation of slots, ends andshaft provides double insulation

Hytrel® overmoulding to reducenoise and vibration

End frame moulded in Rynite® PET,Crastin® PBT, Zytel®, Zytel® HTN withintegral brush holders and integralconnector

High performance lead wireinsulation (e.g. Kapton® or Tefzel®)

Overmoulding acting as both coilformer and stator insulation

Snap-fits for tacho-generator (or encoder)

End frame moulded in Rynite® PET,Crastin® PBT, Zytel®, Zytel® HTN

Vespel® thrust plug (see next page)

Integrated push-fit brush holder

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Vespel®

The search for comfort and safety inthe automotive industry has led toincreased numbers of electric motors

These are now widely used to make driving more pleasant (window lift,sunroof, central locking, air conditioning actuation, seat, mirrors & steeringadjustment), and safer (windscreenwipers, idle and exhaust controls, differential locking).

Increasing regulations and specifica-tions for equipment such as starter-motors and fuel pumps place greaterdemands on mechanical wear andfriction components.

Parts such as bushings, washers andthrust plugs working in electricalmotors have to withstand axial andradial loads coupled with speed.

The wear and friction characteristicsof Vespel® have helped electricalmotor manufacturers to simplify theirdesign while improving performanceand life.

Bushings

Used in all kinds of electrical motors,Vespel® bushings can run with orwithout lubrication, depending on theapplication. A “straight” bushingdesign is adapted to radial loading bua “flanged” design can additionallybear axial loads and therefore elimi-nate the need for a washer.

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Parts can easily be press-fitted into thousing while maintaining very goodcontrol of the inside diameter. In addtion, the high PV capability enablesthe length of the bushing to be reduce

In these types of application, a lowand constant coefficient of friction isrequired, as well as wear and creepresistance.

The various Vespel® graphite filledgrades provide cost effective solutions

Washers

Washers take the axial load in electrical motors, which means that whileproviding wear and friction resistanceas bushings do, they also have towithstand impact.

Due to the small loading area of suchcomponents, both pressure and velocconditions can be high, generatingexcessive frictional heat.

The creep resistance and the PV capbility of Vespel® washers guaranteelong and reliable life of the equipment

Noise, often generated by metallicparts running against each other, iseliminated.

Thrusused autom

Thrust plugs

Specifically used in windscreenwipers, window lift, sunroof, seatadjusting, differential lock motors,etc., thrust plugs are parts that aredirectly fitted into the rotor shaft witha slight interference.

Like washers, these parts have to takeaxial loads, and resist creep and wear

Depending on the application, a lowor relatively high coefficient of fric-tion may be required, and unfilled SP 1or SP 21 filled with graphite are theusual preferred choices.

During very severe use, Vespel® thrustplugs will not melt, and thereforeguarantee the function.

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t plugs made out of Vespel® SP 1 arein ITT’s powerful, reliable and economicotive rear windscreen wiper motor.

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Automotive window lift motor using DuPont engineering polymers

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DuPont engineering polymers andmany other DuPont resins are ideallysuited for automotive motor applica-tions, as they greatly contribute tooverall cost reduction by providingfunctional integration and weightreduction for most of the motor com-ponents. The window lift motor is agood example as illustrated in thisdrawing, but similar application possbilities can also be extended to othermotors such as wiper motors, seatmotors, sunroof motors, and many othe some 80 different motors we findin modern cars.

Gear - Delrin®

Connector seal- Hytrel®

pel® thrust plug

Insulation spiders- Zytel® nylon

Almost all window lift gear housingstoday are in nylon such as Zytel® 70G30,for polyester PBT and PETresins likeCrastin® PBT SK605 and LW9030 andRynite® PET940. Die-cast metals arestill being used in some other motors,which are graduallybeing replaced byZytel®, Crastin® PBT, and if highermechanical strength at elevated tem-peratures is required, by Rynite® PETor Zytel® HTN.

Delrin® 100 and Delrin® 100P with itsunique combination of toughness,stiffness and superb friction and weaproperties, has long been the classicgear material for automotive motorgears.

Acetal

Connect- Zytel® H- Crastin- Rynite®

Hytrel® is an excellent candidate forseals and hard/soft combinations.

Vespel® is the ideal material for thrustplugs due to its excellent low wearperformance. Insulation spiders can be moulded in Zytel®, Rynite® PETorZytel® HTN. External parts such asconnectors can be moulded in Zytel®,Crastin® PBT or Rynite® PETand inte-grated into the main body.

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Vespel® thrust plug

Cushion- Neoprene

Gear housing- Zytel®- Crastin® PBT- Rynite® PET- Zytel® HTN

or sealTN

® PBTPET

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Significant savings

Engineering polymers offer significantsavings in electric motors. The higherraw material cost is normally morethan offset by the production benefits,combined with a reduction in the num-ber of components and lower assembcosts.

Fig. 1, for example, shows some of thkey areas where cost savings can begenerated, using a motor end frame inRynite® PET, Crastin® PBT, Zytel® orZytel® HTN, rather than thermoset ordie-cast metal.

Additionally, these products provide althe design and assembly advantagesassociated with engineering polymersresulting in further cost savings and abetter product.

For further assistance in making adetailed comparative cost estimate foryour application, including materials,processing, finishing, assembly andproduction suitable for your operation,contact your local DuPont office (seeback page).

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Versus thermosets Rynite® PET, Crastin®PBT,Zytel®, Zytel® HTN offer:

• Superior mechanical propertiesallowing volume reduction of part

• Higher production rates

• Easier handling during processingand assembly due to superiortoughness

• Advantage of using regrind to min-imize scrap

• No de-flashing

• Parts integration

• Minimal breakage problems withfinished products during handlingand shipping

• Environmental friendliness due torecyclability

Versus metalsRynite® PET, Crastin®PBT,Zytel®, Zytel® HTN offer:

• Reduced part weight (also leads tolower transportation costs)

• No de-flashing

• No machining

• Parts integration

• 4 to 5 times the mould life for similar toolmaking costs

• Integrated colour, avoiding theneed for painting

• Ability to provide double insulation

• Attenuation of noise and vibration

Electrical insulation and approved insulating systems from DuPont

The electrical insulation system of amotor consists of a number of majorand minor components:

Major

• Ground insulation(e.g. slot and edge insulators)

• Magnet wire• Dipping varnish• Phase separators

Minor

• Insulating tapes• Lead wire• Wire end sleeving• Tie cord• Wedges and other related parts

UL 1446/IEC 85 ElectricalInsulation Systems (EIS)

A fundamental requirement for manymotors is that they meet either UL 1446or IEC 85 (EIS) requirements, or both(see Fig. 3). To meet this need, wehave gained both UL 1446/IEC 85recognitions for our engineering poly-mer resins in temperature classes from130ºC to 220ºC. The DuPont EISavailable to customers contain a widerange of tapes, sleeving materials,magnet wires and varnishes and arelisted in the UL “Yellow Cards” (see Fig. 4 and Fig. 6) under “PlasticMaterials and Electrical InsulationSystems (OBEU2) for UL 1446 andunder “Insulation System Components

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electrical, evaluated in accordance withIEC publications (OCTU2)” for IEC 85.We continue to expand our number of recognized EIS, and as additional systems receive recognitions, they willbe listed. We have also published anextensive brochure on EIS which isentitled: “Thermoplastics for UL/IECElectrical Insulation Systems:Transformers, Motors, Coils, Relays andEncapsulation”available to customersfrom DuPont as publication H-74531.

What are electrical insulationsystems (EIS)?

When designing a motor, for example,you have two basic ways of selectingthe materials going into your product:you can pick the wires, tapes and thethermoplastics used either by the indi-vidual material thermal and perfor-mance recognitions, e.g. the UL rela-tive thermal indices of each material byitself, or by the collective systemrecognition, which is a measure of howthe group of materials selected behavetogether in a common environment.

As an example, consider a simple coilform moulded in Zytel® 132F nylonused in a shaded pole motor. Both thewire and thermoplastic may be sepa-rately qualified in the thermal classrequired for this application. However,UL 1446/IEC 85 recognition of a sys-tem containing all the materials testedtogether helps build confidence the EISused will produce a quality product forthe global marketplace.

Fig. 2 - Rotor end-insulatRynite® PETFR530 used b

Other motor components that may besubject to EIS requirements includemoulded thermoplastic spiders (seeFig. 2) used in armatures, overmouldedstator insulation, and separate statorcomponents.

Thermoplastic encapsulation

Motors are beginning to see the use ofthermoplastic encapsulation, particularlyin stator insulation. Being replaced arethe tapes, films, etc. that are used inconventional motor insulation, as wellas the epoxy potting used in some constructions. Complexity of encapsu-lation can vary from small stator coils tolarger and more intricate motors suchas the Pacific Scientific encapsulatedstators (see photo H, page 15). Usingthe steel laminate covers as an insert,the stator is made in a one-step over-moulding operation. Encapsulationprovides slot and end insulation, termi-nation holders, contour supports, andguide posts for windings – all in a single moulding step.

Additional information on thermoplasticencapsulation can be found in“Electrical/Electronic ThermoplasticEncapsulation” available from DuPontas publication H-58633.

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Fig. 4

Maximumtemperatureat hottest

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UL 1446temperature

classes

IEC85temperature

classes

Maximumtemperatureat hottest

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---

130°C155°C180°C200°C220°C240°C

>240°C

---BFHNRS

>240°C

YAEBFH

200220250*

90°C105°C120°C130°C155°C180°C200°C220°C250°C

*

*Above 250, each class is a temperature of 25°C higher than the preceding one: i.e. 275, 300, etc.

ULClass

Temperaturerating

Mouldedengineering

polymers

Films

A

B

F

HNR

105°C

130°C

155°C

180°C200°C220°C

Rynite® PET,Zytel® nylon

Rynite® PET,Zytel® nylonCrastin® PBT

Rynite® PETCrastin® PBTZytel® nylonZytel® HTN

Rynite® PETRynite® PETZenite® LCP

Mylar®, Nomex®,Kapton®

Mylar®, Nomex®,Kapton®

Mylar®, Nomex®,Kapton®

Nomex®, Kapton®

Nomex®, Kapton®

Nomex®, Kapton®

Advantages of hightemperature insulation systems

By designing a motor to operate athigh temperatures, one of two benefitcan be gained: reduced size for a givpower output, or increased power ouput for a given size.

With the ability of Rynite® PETto per-form in insulation systems up to ClasN, it is normally possible to use it toupgrade the rating of a motor at littleor no additional cost.

The DuPont family of insulating materials

DuPont offers you an extremely widerange of insulating materials.

Crastin® PBT

These thermoplastic polyester resinsfeature excellent processibility, tough-ness, and good electrical properties.They are used in connectors, coilforms, and other electrical componen

Rynite® PET

Rynite® PETthermoplastic polyesterresins offer an excellent combination of thermal stability, electrical propertiesdimensional stability, and stiffness fortoday’s small, more complex electricaand electronic components. Rynite® PETis widely used in coil forms and encasulation.

Zytel®, Zytel® HTN

Over half of all coil forms used world-wide are in unreinforced and glass-reinforced nylon. Zytel® HTN (HighTemperature Nylon) resins are hightemperature nylon copolymers with a300°C melting point and a 125°Cglass transition temperature (dry).Zytel® HTN is used in applicationsrequiring high strength and high tem-perature capabilities.

Zenite® LCP Liquid CrystalPolymer

Zenite® LCP resins are aromatic poly-ester resins with high (335-352°C)melting points. Features includeexcellent dimensional stability andcreep resistance, even at very hightemperatures. Their processibilitymakes moulding surface-mount coilforms with 0.25 mm thick flanges acommercial reality.

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Nomex® brand sheet structures

These sheet structures offer high temperature resistance, superior dielectricproperties and high tensile strength,combined with excellent flexibility andresilience. Available in strip and sheetform, Nomex® provides superior layerand phase insulation between coil layeand around coil formers.

Mylar®

This exceptionally strong polyesterfilm offers an unusual balance ofchemical, electrical, physical and thermal properties. Well suited for manyelectric, electronic and industrial usesMylar® provides superior interwindingbarrier and phase insulation in wire ancable coils.

Kapton®

An ultra-tough polyimide film capableof withstanding extreme temperatures(400°C) and pressure, it is imperviousto most chemicals. As an insulator,Kapton® has unmatched dielectricproperties and remarkable tensilestrength, which permit thinner wallconstruction for increased performanceand cost efficiency.

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Fig. 6. - Examples of a pre-approvedClass F (155°C) insulation systemsbased on Rynite® PET and Zytel®.

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Heat deflection temperature at 264 psi, °C

200 ¡C

Rynite® PET

Crastin® PBT Zytel® PA66

Zytel® HTN

Zenite® LCP

100 ¡C

150 ¡C

200 ¡C

250 ¡C

250 ¡C

Fig. 5 - RTI versus HDT of DuPont Engineering Polymers (30-35% glass-reinforced)

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Motor design

Rotors and stators

Engineering polymers such as Rynite® PET, Crastin® PBT, Zytel®, Zytel® HTN and Zenite® LCPare wellsuited to motor insulation, as shown ithe preceding section.

These moulded insulators make motoassembly easier, and reduce labourcosts. Several examples of applicatioare shown here.

Overmoulding

There is a cost efficient technique forinsulating rotors and stators which hanot been discussed, and that is over-moulding – where the lamination stac(preferably pre-heated) is inserted intoa mould and selectively coated withplastic.

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Overmoulding is normally used toavoid the need for separate insulatormouldings and/or pieces of insulatingfilm.

Consequently, this technique can offefurther cost savings and productionadvantages.

The thickness of thermoplasticrequired, particularly in the case ofovermoulded slot insulation, is verysmall (typically <1 mm). As a result,one of the most important considerationwhen designing such insulation is theability to fill the plastic part completelyduring the moulding operation.Complete filling is critical to eliminateany possibility of dielectric failurewhen the part is operational.

Therefore, material selection is veryimportant. Grades of Rynite® PETandZenite® LCP offer particularly low meltviscosities (high flow), and Rynite® PEToffers excellent insulation performance(up to Class N = 200°C) and Zenite® LCP(Class R = 220°C).

It is sometimes useful to employ flowleaders to aid in material flow. Thesecan be holes a few millimetres indiameter through the rotor or statorlamination stack. These leaders aid thflow of thermoplastic and promotecomplete filling of thin sections.

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A. Grundfos (Denmark) stator insulatormoulded in Rynite®.

B. Multi-functional armature insulators,also known as spiders, in Zytel® HTN,for windshield wiper motors from ITT.

C. Motor stator insulation in Zytel® 70G30 for Elco (Italy).

D. Mycalex (UK) shaded pole motorswith coil bobbins and terminal blockmoulded in Rynite® PETFR530.

E. Sanyo (Japan), overmoulded statobobbins in Rynite® PETFR530 andFR515 for permanent magnet steppinmotors.

F. Miele (Germany) stator insulationmade of Zytel® 101L.

G. Stator encapsulation of 25-W shadepole AC induction motor for ElectricMotors and Specialties, Inc. (USA).

H. Encapsulation of motor windinginsulation, end frame and connectorhousing in Rynite® PETfor PacificScientific (USA).

I. Asynchronous motor shaft over-moulding for SEL (Germany), Rynite® PET(Class H).

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Commutators

Commutators require insulationbetween the bars as well as at the eA traditional way of providing thisinsulation is with mica sheet, as showin Fig. 7.

However, as with rotors and stators,the insulation can often be providedmore cost effectively by engineeringpolymers. A material with good flowcharacteristics – to completely fill thinpart sections in the mould – and goohigh temperature insulation performanis normally required. Rynite® PETmeetsboth of these requirements.

For larger commutator applicationswhere the requirements for high flowdimensional stability and high tempeature resistance are even moredemanding, Zenite® LCP provide anexcellent balance of properties.

End frames

It is well recognized that most motorend frames are demanding engineering applications. The air gap betweerotor and stator is usually less than1 mm, so rotor alignment is critical.

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Traditionally, materials such asstamped steel, die-cast aluminium orzinc alloys, and thermosets have beenused for motor frames. However, thesmaterials have limitations in terms ofweight, function integration, environ-mental friendliness, assembly, noiseand vibration.

Engineering thermoplastics not onlyoffer the required mechanical proper-ties, but also permit weight savings,functional integration and eliminatethe shortcomings of metals and thermosets. This capability results in areduction of the number of componentsand consequently in lower finished parcost.

Naturally, when an end cap, a motorbracket, or even a complete housing isbeing designed, the same question isoften raised: “Does a thermoplastichave sufficient stiffness and dimen-sional stability for this application?”

The answer is normally yes, providedthat the right engineering polymer isselected for the task, and that correctdesign and ribbing techniques areemployed.

MicaMicainsulationbetweenbars

Back V ring withmica inner and outerrings for insulation

Iron shell

Commutatorbars

Front V ring

Commutatorbars

Mica V ring

Tightening nut

Iron ring

Fig. 7

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A. Vacuum cleaner motor end framein Rynite® PET and Crastin® PBT fromElectrolux (U.K.).

B. Commutator plates moulded inZytel® nylon for Maxon motor(Switzerland).

C. Fiat rear screen wiper motorframe in Rynite® PETFR530.

D. Zanussi dish washer pump motorframe in Rynite® PETFR 530 fromSole (Italy).

E. Thrige-Titan (Denmark) forklifttruck motor end frame in Rynite® PET530.

F. Rexon (Taiwan) mitre saw motorframe/housing in flame-retardant,glass-reinforced Zytel®.

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Fig. 8 - Stiffness/strength combination of materials.

Fig. 9 - Beams of equivalent stiffness.

Rynite® PET 545 Zytel® 70G30Zytel® HTN 51G35

Zenite® LCP 6130

Zinc-Al

MgDelrin®

Zytel® 101

1 2 2.51.5

h1

8h1

h 2

8h 2

3h 2

Crastin® PBT SK605

Thickness (mm)

Metal Plastic

Fle

xura

l mod

ulus

MP

a

Flexural modulus GPa

Tens

ile s

tren

gth

MP

a

100

200

300

400

500

1 5 10 50 100

Zn

AlMg

Zenite® LCP

Rynite® PET 555

PA66PA612

PA11PP

ABS

Delrin® (POM)PC

Rynite® PET 530Crastin® PBT SK 605

30% GR PCZytel® 70G30 HSL

Zytel® HTN 51G35

PBT

Reinforced thermoplastics

Die-cast materials

Unreinforced thermoplastics

Thermosets moulding

compounds

Examples of finite element analysisfor a motor frame:Top photo shows deflection in a Y direction in mm.Bottom photo shows stress in N/mm2.

The stiffness and stability of thermo-plastics have now been confirmed byexperience in commercial applica-tions. However, when a new motorframe is being developed, a finiteelement analysis (FEA) is oftenvaluable in optimizing the design.

As shown in Fig. 8 and Fig. 9, glass-reinforced engineering polymers areparticularly well suited to motorframe applications. Rynite® PETabsorbsonly extremely small quantities ofwater following moulding,giving itexcellent dimensional stability. Italso has a high heat deflection tem-perature. In addition, these resins canbe modified with mineral additives tofurther increasedimensional accuracyfor very demanding applications.

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eal.

Creep resistance

Deformation under load with time iscalled creep. The amount of creepdepends on material composition(polymer type, reinforcement, etc.),time, temperature and the appliedstress level.

The data shown in Fig. 10 indicatethat glass-reinforced engineeringpolymershave particularly good resistance to creep, even at high temperatures and stress levels.

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

01 10 1

Fig.10 - Long-term creep data (at 27

For comparis23°C/20 MPa

Str

ain

(%)

* It is critical to note that for Zytel® 70 G30 HS

Times (hou

Components of automotive motorssuch as the windowlift motor shownon this page or windshield wipermotors and seat motors can be subjeed to considerable stresses which ovetime will cause creep. For example, thgear housings of these motors have towithstand external and rotor shaftforces over thousands of cycles.Coupled with relatively high tempera-tures even in the interior of a car, thesforces can lead to creep of the materiGlass reinforced grades of Zytel®,Crastin® PBT, Rynite® PETand Zytel®HTN have good creep resistance towithstand this.

00 1000 10000

125¡C

125¡C

125¡C

23¡C23¡C

23¡C

60¡C

Rynite® PET 530

Rynite® PET 530

Rynite® PET 530* Zytel® 70 G30 HSLR

* Zytel® 70 G30 HSLR

Rynite® PET 555

Rynite® PET FR 530

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.6 MPa stress)

on Zytel® 101F stress

LR: 23°C = 50% RH, 125°C = DAM

rs)

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Fig. 11

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Bearings and bearing housings

In micromotors, the end cap itself,frequently made of thermoplastic,often also acts as the bearing.Thermoplastic bearings can offer anumber of advantages over bearingsin metal, including:• Ability to operate with minimal or no lubrication

• Longer wear life• No corrosion by chemicals andlubricants

• Noise dampening and reduced vibration

Plastics commonly used in thesetypes of bearings are Zytel® andMinlon® nylon resins, and Delrin®

acetal resins.

As plastics do not conduct heat reaily from the frictional source, heatdissipation is a major considerationin the design of thermoplastic bear-ings. For an initial evaluation ofwhether a plastic bearing will performin a specific application, the PVconcept (Pressure x Velocity) ratingcan be used.

The PV value is defined in the follow-ing way (see Fig. 11):Specific bearing load:

p =

Peripheral speed:

v =

PV value:

PV = pv (MPa – m/s)

d x ̧ x n1000

Fd x l

(MPa)

(m/s)

20Maxon m

-

For bearings which require very lowcoefficients of friction and higherPV values, standard engineeringpolymers can be modified with, orreplaced by, Teflon® and Tefzel®.

Full details of these PV calculations,together with advice on designingbearings in Zytel® and Delrin®, areavailable within separate designbrochures. If you need assistance,please contact your nearest DuPonoffice (see last page).

d = Shaft diameter mml = Length of bearing mmV = Peripheral speed m/sF = Overall load Nn = Revolutions per s

otor with bearings/end-caps in Minlon®

The benefits of thermoplastic bearingscan sometimes be brought to largermotors, but traditionally these motorsemploy metal bearings press-fittedinto a metal frame (see Fig. 12). Thisarrangement gives a good interferencfit over the full range of operatingtemperatures, as the bearing and bearing seat have similar coefficientsof thermal expansion.

gn,y-t

t

-

Metal frame

• High E-modulus

• Small increase in interferencegives large increase in specific pressure on external ball bearing cage

• Dynamic interference required= 0.08%= 0.02 mm;resulting specific pressure =18.8 MPa

• Low permitted interferencemeans tight tolerances required

• Machining of bearing tolerance

Engineering polymers(glass-reinforced frame)

• Lower E-modulus

• Large increase in interferencegives small increase in specificpressure on ball bearing cage

• Interference for equivalent specificpressure = approx. 1%

= 0.26 mm

• Even with 1% interference, there isa safety margin since elongation tobreak of glass-reinforced engineer-ing polymers is around 2.5-3%

• Precision moulding total toleranceachievable for 26 mm = 0.1 mm

When a thermoplastic motor frame isused with a metal bearing, attentionmust be paid to the bearing seat desias the thermal expansion of most polmers is considerably greater than thaof metals.

However, for most motors, attention todimensions and proper interference fifor the plastic will provide good bear-ing alignment over the required rangeof operating temperatures. Thermo-plastics also allow easier parts assembly, including the use of snap-fits.

A number of new designs for thermo-plastic bearing seats have also beendeveloped for use with conventionalbearings (see Fig.13).

21

Fig. 12

seat needed • Required bearing seat tolerances

can be achieved by moulding

• Machining of bearing seat avoided

• Lower temperature of the bearing,due to low heat conductivity of thepolymer frame, gives longer life-time

Fig. 13

Finger spring washer Spring washer (slotted or not)

Spring ring

Olive bearing Ball bearing

Elastomer part(self alignment vibration and

noise reduction)

Housing Housing (snap-fit)Housing

b

g

s

r

s

fC

For the most demanding applications,additional techniques have beendeveloped. One of these, patented SKF, involves the overmoulding of ametal coil. As the coil has a rate ofthermal expansion similar to that ofthe bearing itself, it keeps the playbetween bearing and housing to a mini-mum. This is achieved by preventingfree expansion of the bearing housinwith temperature variations.

Experience has shown that this over-moulded insert is particularly usefulfor those applications where therange of operating temperatures isvery wide.

DuPont also offers materials such aVespel® SP polyimide for very highperformance bearings.

Gears and gear housings

Automotive motors, such as windowlift motors and wiper motors, usegears and gear housings (see A and B).

Engineering polymers are increas-ingly being established as the mostsuitable material for these applica-tions. For example, Delrin® 100 iswidely used in gear applications.Depending on the dimensional sta-bility and thermal requirements, geahousings can be moulded in Zytel®,Crastin® PBT, Rynite® PETor Zytel® HTN(see Fig. 14).

A

22

y

Brush holders

With a metal motor frame, it is normallynecessary to have separate plasticmouldings to insulate the brushes andbrush holders from the frame. A typicaexample is shown in photo E.

Engineering plastics have the requiredelectrical and thermal properties toperform well in such applications.Tracking resistance (CTI) is particularlyimportant.

However, another advantage of thermoplastic motor frames is that theyavoid the need for these separatemouldings. The brush holder supportscan be moulded as integralparts of theend frame, allowing thebrush holdersto be directly push-fitted into theframe (see page 7). This clearlyreduces component and assemblycosts.

During motor operation, the brushesbecome hot, but plastics are goodthermal as well as electrical insu-lators. In some small motors, thetemperature rise is not significant,and the brushes can be locateddirectly in the moulded motor frame, ashown in photo H.

However, many motors require metalbrush holders. These are often made obrass and can be similarly push-fitteddirectly into the plastic frame.

In some larger motors, the brushescan rise significantly in temperatureduring operation. Here, it is impor-tant to design the area of the plasticbracket acting as the brush holdersupport for maximum ventilation.This can be done easily.

In some applications, it is necessaryto insulate the exposed end of thebrush holder. A simple plastic covercan be designed to snap onto themotor frame to provide this insulation.This snap fit may be designed as permanent, or recoverable – to permitmaintenance or replacement of thebrushes.

Once again, a design which permitsmaximum ventilation of the brushes isrecommended.

l

-

B

I

I

.

Motor cooling fans

Many motors incorporate their owncooling fans, to increase air flow and reduce operating temperaturesTraditionally these fans have beenmade of metal, but they can also becost effectively moulded from engi-neering polymers.

Normally, materials used for theseapplications are often the same asthose used to mould the motor'sinsulation, or end frame.

Fig. 14 - Deformation comparison of engineering polymersWiper motor gear housing – concept study (45%-50% GR)

Def. (mm)Zytel® data at 23°C at 50%RH

D E

F

G

0

Zytel® HTN 51G45

Rynite® PET 545

Crastin® PBT SK609

Zytel® 70G50

Zytel® 73G50

100¡C

23¡C

0,05 0,1 0,15 0,2

C. Cut-away view of plastic motorframe using the overmoulded SKFinsert.

D. Thrige-Titan forklift truck motorframe in Rynite® PET530 using theovermoulded SKF insert.

E. Brushes fitted directly into motorframe of Zytel®.

F. Paris-Rhône (France) automotive alternator, using fan, brush holderand diode support plate moulded inRynite® PET 545.

G. Snap-fit bearing design used byStebel (Italy) for their horn compres-sor motor in glass-reinforced Zytel®.

H. Snap-fit bearing design used witha motor frame in Rynite® PET for aZanussi dish washer pump from Sole(Italy).

I. Flame retardant Rynite® PET wasselected for this cooling fan fromJapan Servo because of its gooddimensional stability and heat resis-tance. Temperatures in photocopymachines can often reach 150°C.

23

H

o

-

.

Function integration

Function integration and minimizingassembly costs are becomingincreasingly important in today'scompetitive market. However, motorframes have traditionally been multi-component assemblies.

A major advantage of redesigningmotor frames in thermoplastic is theease with which one component canbe designed to perform the functionsmany.

The integration of some functions,such as brush holders, has alreadybeen discussed. This section concentrates on other features which canalso be incorporated into motorframes.

24

f

A. Traditional motor assembly.

B. Motor design based on engineeringpolymers, showing function integration

C. Multi-functional motor frame inZytel® FR51 from Braun (Spain).

D. Easy-assembly motor bracket inMinlon® 11C140 from Maxon(Switzerland).

E. Braun selected Zytel® for themotor end-frames of a recent hand-mixer because of its long termtemperature resistance, excellentdimension stability and overallmechanical performance.

A

C

Assembly features

Motor frames are normally assembledto each other, or to the stator lami-nations, using bolts or metal clips,but this is a relatively expensivemethod of assembly.

Thermoplastic end frames lend them-selves to more efficient assemblytechniques, such as snap-fits, inter-ference-fits or ultrasonic welding.Some examples of these assemblytechniques are illustrated in Fig. 15and Fig. 16. They are particularlysuited to smaller motors which havesmall applied loads, where they canoffer valuable cost advantages.

25

Fig.15 - Plastic motor frame assembly using ultrasonic welding.

Fig. 16 - Plastic motor frame assembly using snap-fit.

B

D E

-

-

d

A

A

Frame extensions and housings

Motor frames can often be readilyextended to fulfil additional func-tions. The availability of a wide rangeof DuPont engineering polymerswith suitable properties for multi-functional parts means that motorsystems can be designed to makeproducts much more competitive inthe marketplace.

Minlon® can give high-speed fansused in vacuum cleaners the flatnessrequired to generate a constant air-flow, and the impact resistance needed to prevent breakage by incomingobjects. Its warp-free mouldabilityand excellent dimensional stabilityalso allow it to be used for multi-functional parts in the same appli-ances, reducing costs in componentsand labour.

The heat buildup of fully enclosedmotors requires the use of high tem-perature class polymers. Rynite® PET,Crastin® PBT, Zytel® HTN can meetthese demands reliably, acting asboth motor insulation and housing.

Glass-reinforced Zytel® gives design-ers high strength, stiffness, very highdeflection temperatures, rigidity, ten-sile strength, dimensionalstability andimpact strength. Just what they needto combine a motor frame and housinginto a single unit.

Here are some examples of commercial applications.

26

Interconnects

Materials such as those recommendefor motor frames, e.g. Rynite® PET,Crastin® PBT and Zytel® polyamide, arewidely used for connector applications

By moulding the electrical connector asan integral part of the motor frame, anumber of separate connectors areusually eliminated. These mayinclude a metal mounting plate, theseparate connector moulding, andtwo or more assembly screws.

B

.

A. Myson (U.K.) uses Rynite® as bothhousing and insulation for this pumpmotor.

B. Milwaukee (U.S.) power tool hasmotor frame and housing incorporatedinto a single moulding of glass-reinforced Zytel®.

e

h

se

e

ud

edd

ce-g

ntdnt

to-a

s

C

Motor design innovations

Fisher & Paykel Co, of Auckland,New Zealand, the country’s leadingappliance manufacturer, has developea radically new type of power drivefor washing machines. This new“Smart Drive” incorporates multi-functional components made ofDuPont Rynite® PET thermoplasticpolyester resin, and is used in thecompany’s top-loading automaticwashers.

The Fisher & Paykel design replacesthe conventional U.S. washingmachine’s combination of a fixed-speed a.c. motor and a 40- or 50-piecgear case with a system using an electronically controlled brushless d.c.motor that drives the agitator and spinbowl directly through a patentedclutch.

The washing machine’s motor designis most unusual. Windings are locatedon the stator rather than on the rotor,and the rotor turns around the outsideof a centrally mounted stator ratherthan inside it. This approach allows adirect mechanical link between therotor and a common shaft to drive botspin and agitator movements.

The stator’s entire support structure, itground insulation and coil supports arproduced of Rynite® PETin a singleinjection-moulding step. A ring-shapedstack of specially profiled stampedsteel laminations is placed in a mouldand then injection overmoulded withthe polyester resin.

d

-

The wheel-shaped part that comes oof the mould needs only windings anterminations to become a fully finishstator. It measures 25 cm across, anhas 42 integrally moulded windingpoles spaced around its circumferenas well as moulded-in wire ways, terminal holders and holes for mountinbolts and drainage. A three-phasewinding is applied in a separate, fullyautomated step.

The rotor is a dish-shaped compone27 cm in diameter. Integrally mouldeteeth at its hub serve for spline mouing on the end of the shaft that spinsthe washer tub and moves the agitaSpaced around the rotor’s circumference are 56 rare-earth permanent mnets, which are bonded to a ring-shaped stack of steel laminates.

The rotor is made by placing the laminate stack and attached non-magnetized rare-earth strips in themould, and then overmoulding withRynite® PET, leaving the magnet stripexposed. These are subsequently activated by placing the rotor over ahigh-energy magnetising head.

C

C

C. An innovative machine motor reester for both insuin the wheel-shapdish-shaped rotor

Assembly of the rotor and stator issimplicity itself. The stator is first bolt-ed onto the washer’s outer bowl, whichis accurately located over a bearingsupporting the spin basket and agitatorshaft. The rotor is then placed over thespline near the end of the drive shaft,and pulled down into position with asecuring nut. At this stage, the motor isready for electrical connection to thewashing machine’s electronic controls.

The Rynite® PETresins selected byFisher & Paykel meet a rigorous com-bination of structural, dielectric andmanufacturing requirements. Thedimensional stability of Rynite® PETallows both the rotor and the stator tobe moulded without the need for fur-ther machine processes.

The rotor withstands dynamic torsionaland radial loading as it oscillates atvariable speeds within a 200-degreearc during agitation cycles, and itwhirls at speeds up to 1 100 rpm dur-ing spin cycles. These requirements armet with Rynite® PET545 and FR543for the rotor and stator, respectively.Rynite® PETFR543 is recognized byUnderwriters Laboratories as UL 94 V-0 at 0,8 mm and 5-V at 1,6 mm.

t

,

-

r.

g-

27

brushless d.c. washinglies on Rynite® poly-lation and structureed stator and the.

Noise, vibration and harshness

Two increasingly important factorsin the design and marketing of motorsare vibration and noise, particularly fosuch applications as office equipmentand household appliances.

Although product design has a majorinfluence on the noise of a motor,there are a number of areas wherematerials selection can also play animportant role.

For example, the use of thermoplastibearings wherever possible can reducevibration and help to dampen noise.

28

r

c

The right material choice for themotor frame is also important. Anapplication where Rynite® PETreplaced a die-cast motor frame,allowing both cost savings and quieterperformance, is shown in photo B.

Further noise reduction is possibleby isolating the motor frame from itsnormal mounting points, thus pre-venting the transmission of vibra-tion. This can be achieved by usingmounts moulded from a thermoplasticelastomer, such as Hytrel®. Severaldesign concepts suitable for suchapplications as office equipment fansare shown in Fig. 17 and Fig. 18.

Transmission of vibration can also bereduced by modifying gears. In theFrench food processor shown in photo A, a small gear moulded inHytrel® has reduced the operatingnoise level of the appliance by 15 dB.The part in Hytrel® replaces a gear inacetal.

A

When dealing with noise problems ofplastic components, it is important tounderstand the source of the noise, i.e.what is causing the part to vibrate, aswell as to understand how the partitself is resonating before a solution ispossible.

The DuPont NVH laboratory was setup to deal with the noise problems ofplastic components. It has portableNVH test equipment, making it possi-ble to analyze a component in situ. Fora more detailed analysis, samples aretaken back to the NVH laboratory andexcited using a relevant test rig. Thecomponents response to the excitationcan then be measured by using tech-niques such as acoustic or laser holog-raphy. This testing helps to identifyhow the part needs to be modified soas to reduce the noise problem. Samplecomponents can then be modified in-house and supplied to customers fortesting. The facility can test vibrationand noise properties of electricalmotors using various materials for thehousing. A whole system can also beanalyzed, such as the door mechanismon which a window-lift motor has beenmounted.

B

A. Gear of flexible Hytrel® reducesnoise by 15 dB in this appliance fromSEB (France).

B. Torin (UK) fan housing and bearing (overmoulded PCB) inRynite® PETFR530.

C. Hytrel® is used for blower mountingsto provide quieter computer storagesub-systems. It offers excellent sounddeadening properties, can absorb andisolate impact shocks, as well as beingeasy to overmould onto steel.

Fig. 17

Fig. 18

C

29

Ventilator mounting for vibration isolation

Ventilator housing

Sheet-iron

Steel sheet

Ventilator

Product guide and properties for electricmotors

DuPont Engineering Polymers

®

® DuPont registered trademark

2

CTI UL 746 A CTI-MIEC PLC level IEC

Crastin® PBT S600F10, S600F20, S620F20 >600 2 350ST820 >600 >600SK601 300 2 200SK602 350 2 200SK603 400 2 200SK605 450 1 200SK608 475 200SK609 500 1 200LW9130 400 2 200LW9020, LW9030 550 1 175T805 500 1 200SO653 300 2 200SO655 250 2 200HTI619 >600 0 200S650 FR 225 2 175S680 FR 250 175T850 FR >600 275SK641 FR 225 2 175SK642 FR, SK 645 FR 250 2 175SK643 FR 250 3 175CE7931 250 2 150SK673 GW 250 175LW9020 FR 350 2 175LW9020 FR GY 325 2LW9030 FR 375 2 175LW9320 FR 350 2LW9330 FR 375 1LW9330 FR GYB 350 1T841 FR 250 3 175T843 FR 275T845 FR 325HTI681 FR >600 0 450HTI668 FR >600 0 200HTI688 FR 475 1 250

Delrin® acetal 100, 107 >600 0 >600100 P >600 0500, 507 >600 0500 P, 900 P 600 0100 ST, 100 T, 500 T, 570 600 0 600500 CL, 500 AF >600 0

Rynite® PET 520 250 3530 250 2 200545 250 2 250555 200 3935 3251) 2FR515 275 3FR530 L 250 2 125FR543 250 2 125FR943 225 2 100

Test performance ratings of DuPont Engineering Polymers

Tracking Resistance, IEC 112 / UL 746 A V (volt) thickness of specimens: >3 mm

3

CTI UL 746 A CTI-MIEC PLC level IEC

Zytel® PA66 E101 L >600 0 375 (325)unreinforced 101 F >600 0 575 (475)

E103 HSL 525 (425) 0 400 (350)E103 HSL BK-80 525 400105 F BK-10 0114 L BK-97 575 (525) 0135 F 600 0 475E42 A 0450 600 (590) 0 525 (475)490 >600 0 475ST801 NC-010, NC-010 A >600 0 600

Zytel® PA66 FR70G28 V1 300 2glass reinforced, flame retardant FR70G25 V0 325 2 150Zytel® PA66 79G13 L 475 1glass reinforced 70G20 HSL, 70G25 HSL 400 (325)

70G30 HSL 400 (325) 1 35074G33E HSL BK-354 450

Zytel® PA66 FR70M30 V0 325 2 2501)mineral reinforced, flame retardantMinlon® PA66 10B140 575 250 (200)mineral reinforced 11C140 550 (475) 1 300 (250)

Zytel® PA66/6 FR7200 V0F 575 0unreinforced, flame retardant

Zytel® PA66/6 FR72G25 V0 325 3 150glass reinforced, flame retardant FR72G25 V0 BK 275 150

Zytel® PA66/6 72G30 L 1glass reinforced

Zytel® PA6 FR73GM60 V0F >600 0glass-mineral reinforced, flame retardant FR73GM60E V0F >600 0

FR73GM50 GWF >600

Zytel® HTN HTN 51G35 HSL NC-010 >600 0 300 (250)high temperature HTN 51G45 HSL NC-010 >600 0 250nylon HTN FR51G35 L NC-010 500 1 225

Hytrel® thermoplastic polyester 5556 >600 0elastomer 7246 >600 0 575

Zenite® LCP 6130 WT-010 150 4 100liquid crystal polymer 7130 WT-010 150 4 100

6330 NC-010 150 4 100

Vespel® SP-1, SP-21 3polyimide resins

1) KC, KB values. * Only available in black.

Caution: Colours often significantly affect tracking values in one or the other way.

Further information on this is available on request.

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

4

UL rating at minimum thickness (mm)

HB V-2 V-1 V-0 5VA

Crastin® PBT S600 F10, S600 F20, S620 F20 1,5ST820** 1,5SK601, SK602, SK603 0,8SK605, SK608**, SK609 0,8LW9130 0,8LW9020, LW9030 1,5T805 0,8SO653, SO655 1,5HTI619 1,5S650 FR, S680 FR 0,8T850 FR 1,5SK641 FR, SK642 FR 1,5SK643 FR, SK645 FR 0,8CE7931 1,5SK673 GW** 1,5LW9020 FR. LW9030 FR 1,5T841 FR, T843 FR, T845 FR 1,5HTI681 FR 0,8HTI668 FR, HTI688 FR 1,5

Delrin® acetal 100, 107 0,8500, 507 0,8500 CL, 500T 0,8570 0,8

Rynite® PET 520, 415 HP, 935 0,8530, 545, 555, 408 0,8FR515 0,86 1,5FR530 L, FR943 0,35 1,5FR543 0,81 1,59082 F**, 9085 F** 0,82)

Zytel® PA66 unreinforced E101 L, 101 F, E103 HSL 0,84)

105 F BK-10 0,84)

114 L BK-97 0,8135 F 0,84)

408, 450, 490 0,8ST801 0,8

Zytel® PA66 glass reinforced, flame retardant FR70G28 V1 1,47

FR70G25 V0 0,5

Zytel® PA66 glass reinforced 79G13 L, 70G20 HSL, 70G25 HSL 0,870G30 HSL, 70G30 PSR 0,870G35 HSL 0,8

Zytel® PA66 glass-bead reinforced 70GB40 HSL 0,75

Zytel® PA66 mineral reinforced, flame retardant FR70M30 V0 1,5 1,5

Flammability classification, UL 94

5

UL rating at minimum thickness (mm)

HB V-2 V-1 V-0 5VA

Minlon® PA66 mineral reinforced 10B140** 0,83)

11C140 0,81)

Zytel® PA66/6 unreinforced, flame retardant FR7200 V0F 0,5

Zytel® PA66/6 glass reinforced, flame retardant FR72G25 V1 0,75 1,50

FR72G25 V0 0,5

Zytel® PA66/6 glass reinforced 72G15 L, 72G30 L 0,872G40 HSL BK* 0,8

Zytel® PA6 unreinforced 7335 F 1,5

Zytel® PA6 glass reinforced 73G15, 73G20, 73G30, 73G50 1,5

Zytel® PA6 mineral and glass reinforced, FR73GM60 V0F, FR73GM60E V0F 1,5flame retardant, halogen and phosphorus free FR73GM50 GWF** 1,5

Minlon® PA 6 mineral reinforced 73M30 0,85

Zytel® HTN high temperature nylon HTN 51G35 HSL NC-010 0,8HTN 51G45 HSL NC-010 0,8HTN FR51G35 L NC-010 0,8

Zenite® LCP liquid crystal polymer 6130 WT-010 0,417130 WT-010 0,86330 NC-010 1,5

Hytrel® thermoplastic polyester 4056 1,47elastomer 5556 1,47

7246 1,47

Vespel® polyimide resins SP-1 0,8 1,7SP-21 0,8 1,6

1) UL yellow cards are available. ** Only available in black.

2) DuPont test results using ISO 9290. ** Only available in natural colour.

3) NC, BK.

4) All colours. Table for information only. For actual classification, please consult the most recent UL Yellow Cards.

5) NC, BK, GY. For products or grades that do not appear on this table, please contact your DuPont representative

for more information.

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

6

1 mm 2 mm 3 mm 6,4 mm

Crastin® PBT S600, S620 750ST820 700 700SK602, SK603, SK605 750SK608, SK609 750LW9130 750LW9020, LW9030 650T805 750SO653, SO655, HTI619 750S650 FR, S680 FR T850 FR 960 960SK641 FR, SK642 FR 960SK643 FR, SK645 FR 960 960CE7931, SK673 GW 960LW9020 FR, LW9030 FR 960 960T841 FR, T843 FR, T845 FR 960 960HTI681 FR, HTI668 FR, HTI688 FR 960 960

Delrin® acetal 100, 107, 100 P 550 550 550500, 507 550 550 550500 P, 900 P 550 550 550100ST, 100T, 500T 550 550 550500 CL 550500 AF, 570 600

Rynite® PET 520 650 650 750530 960

650 750 750545 960

750 750 850FR530 L 960 960 960 960

(0,8 mm) (2,2 mm) (3,2 mm) (1,2 mm)FR 543 NC-010, FR 943 NC-010 960RE 5211 S 750

(3,2 mm)RE 5213 S 750

(0,8 mm)9082 F 850 960 960 960

(0,8 mm)

Zytel® PA66 unreinforced E101 L 850 960 960(1,6 mm)

101 F 750 960 960E103 HSL 850 960 960105 F BK-10 960* 960* 960*114 L BK-97 650 650 650135 F 850 850 960408 650* 650* 650*450 675* 650* 650*490 700* 700* 700*XA480 750ST801 650 650

Zytel® PA66 glass reinforced, FR70G25 V0 850 960flame retardant (1,6 mm)

FR70G28 V1 960

Glow Wire Flammability Index: “GWFI” °C

7

1 mm 2 mm 3 mm 6,4 mm

Zytel® PA66 glass reinforced 79G13 L 650 (2,5 mm)

70G20 HSL 650* 650* 75070G25 HSL 650 650 75070G30 HSL 650* 650* 750*70G60 HSL BK** 700 700 850

Zytel® PA66 glass-bead reinforced 70GB40 HSL

Zytel® PA66 mineral reinforced, FR70M30 V0 960flame retardant (at 1,2, 1,5 and 2,5 mm)

960 (at 1,2 mm)

Minlon® PA66 mineral reinforced 10B140 750 (3,2 mm)

11C140 650 (3,1 mm)

Zytel® PA66/6 unreinforced, FR7200 V0F 960 flame retardant (at 0,8, 1,6 and 3,2 mm)

Zytel® PA66/6 glass reinforced, FR72G25 V1 960 flame retardant (1,5 mm)

FR72G25 V0 960 (1,6 and 3,2 mm)

Zytel® PA6 unreinforced 7300, 7335 F 800 850(1,6 mm)

Zytel® PA6 glass reinforced 73G1573G30 HSL BK 700 700 70073G40, 73G50

Zytel® PA6 mineral and FR73GM60 V0F, FR73GM60E V0F 960glass reinforced, flame retardant, halogen and phosphorus free FR73GM50 GWF 960

Zytel® HTN high temperature nylon HTN 51G35 HSL NC-010 750HTN 51G45 HSL NC-010 750HTN FR51G35 L NC-010 960

Hytrel® thermoplastic polyester 4056 775 750 750elastomer

Zenite® LCP liquid crystal polymer 6130 WT-010, 7130 WT-010 9606330 NC-010 960

Vespel® polyimide resins SP-1, SP-21

* DuPont Laboratory test results. ** Only available in black. *** Only available in natural colour

For products or grades that do not appear on this table, please contact your DuPont representative for more information.

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

8

0,45 MPa 1,8 MPaDAM DAM

Crastin® PBT S600, S620 160 60ST820 105 48SK601 215 185SK603 220 204SK605 220 205SK609 222 215LW9130 202 180LW9020 215 172LW9030 215 182T805 205 190SO653 185 70SO655 212 99HTI619 220 200S650 FR 160 65S680 FR 175 64T850 FR 167 60SK642 FR 218 203SK643 FR 220 205SK645 FR 220 210CE7931 221 210SK673 GW 220 205LW9020 FR 215 175LW9030 FR 220 190T841 FR 200 183T843 FR 204 188T845 FR 205 192HTI681 FR 194 88HTI668 FR 200 185HTI688 FR 205 190

Delrin® acetal 100, 107, 500, 507 170 115100 ST 145 70500T 165 90500 CL 170 105500 AF 168 105570 174 158

Rynite® PET 520 220530 224545 226555 229935 200FR515 200FR530 L, FR543 224FR943 220RE5211 S 227RE5213 S 2039082 F 251 232

Deflection temperature under flexural load, ASTM D 648, DIN 53461, ISO 75 °C

9

0,45 MPa 1,8 MPaDAM DAM

Zytel® PA66 unreinforced E101 L, 101 F, E103 HSL 235 80105 F BK-10 240 90114 L BK-97 235 77135 F 240 88408 230 69450, 490 225 65ST801 219 66

Zytel® PA66 glass reinforced, FR70G28 V1 243flame retardant FR70G25 V0 244

Zytel® PA66 glass reinforced 79G13 L 24270G20 HSL, 70G25 HSL 25470G30 HSL, 70G35 HSL 254

Zytel® PA66 mineral reinforced, flame retardant FR70M30 V0 238 203

Minlon® PA66 mineral 10B140 240 210reinforced 11C140 220 147

Zytel® PA66/6 unreinforced, FR7200 V0F 75flame retardant

Zytel® PA66/6 glass FR72G25 V1 240 226reinforced, flame retardant FR72G25 V0 215

Zytel® PA66/6 glass 72G15 L 215reinforced 72G30 L 222

72G40 HSL BK* 224

Zytel® PA6 mineral and glass FR73GM50 GWF – 200reinforced, flame retardant

Zytel® HTN HTN 51G35 HSL 276 264high temperature nylon HTN 51G45 HSL 276 264

HTN FR51G35 L 270 255

Hytrel® thermoplastic polyester 7246 130 52elastomer

Zenite® LCP liquid crystal 6130 WT-010 277 265polymer 7130 WT-010 – 295

6330 WT-010 – 245

Vespel® polyimide resins SP-1, SP-21 360

* Only available in black.

For products or grades that do not appear on this table, please contact your DuPont representative for more information.

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

10

Electrical Mechanical Mechanical with impact ºC without impact ºC

Crastin® PBT S600, S620 130 115 120SK601 130 115 120SK603 130 130 130SK605 130 130 130SK609 130 125 130LW9130 140 125 140LW9020 130 125 130LW9030 130 125 130T805 130 130 130SO653 120 115 120SO655 120 120 120HTI619 130 125 130S650 FR 130 130 130SK642 FR 140 130 140SK643 FR 140 130 140SK645 FR 140 125 140CE7931 130 130 140LW9020 FR 140 115 120LW9030 FR 140 125 130T841 FR 130 120 130T843 FR 130 120 130T845 FR 140 130 140HTI681 FR 140 130 140HTI668 FR 125 125 125HTI688 FR 125 125 130

Delrin® acetal 100*, 107*, 500*, 507* 50 50 50100 ST* 50 50 50500T* 50 50 50500 CL* 50 50 50500 AF* 50 50 50570* 50 50 50

Rynite® PET 520 140 140 140530 140 140 140545 140 140 140555 140 140 140935 140 140 140FR515 140 140 140FR530 L 150 150 150FR543, FR943 155 155 155RE5211 S 140 140 140RE5213 S 75 75 75

Thermal Index - UL 746B measured at 0,8 mm

11

Electrical Mechanical Mechanical with impact ºC without impact ºC

Zytel® PA66 unreinforced E101 L, 101 F 130 75 85E103 HSL 140 95 115105F BK-10 125 65 65135 F 135 75 85450, 490 65 65 65ST801 125 75 85

Zytel® PA66 glass reinforced 79G13 L 105 65 10570G20 HSL, 70G25 HSL 105 65 10570G30 HSL, 70G35 HSL 140 125 140

Zytel® PA66 mineral reinforced, flame retardant FR70M30 V0 105 95 105

Zytel® PA66/6 unreinforced, FR7200 V0F 130 105 130flame retardant

Zytel® PA66/6 glass reinforced, FR72G25 V1 115 95 95flame retardant FR72G25 V0 140 120 140

Zytel® PA66/6 glass reinforced 72G30 L 105 65 105

Minlon® PA6 mineral 73M30 65 65 65reinforced

Zytel® HTN HTN 51G35 HSL 150 125 130high temperature nylon HTN 51G45 HSL 150 125 130

HTN FR51G35 L 140 120 130

Hytrel® thermoplastic polyester 5556 85elastomer

Zenite® LCD liquid crystal 6130 WT-010 240 240 240Polymer (1,5mm) 7130 WT-010 240 210 240

6330 WT-010 130 130 130

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

* All Delrin ® grades are measured at 1,5 mm.

12/98 Printed in SwitzerlandH-11740 part II ® DuPont registered trademark

Start withDuPont EngineeringPolymers

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Requests for further information from countries not listed aboveshould be sent to:

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For further information on Engineering Polymers contact:

The information provided in this documentation corresponds to our knowledge on the subject at the dateof its publication. This information may be subject to revision as new knowledge and experience becomesavailable. The data provided fall within the normal range of product properties and relate only to the spe-cific material designated; these data may not be valid for such material used in combination with any othermaterials or additives or in any process, unless expressly indicated otherwise. The data provided shouldnot 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 spe-cific material for your particular purposes. Since DuPont cannot anticipate all variations in actual end-use conditions DuPont makes no warranties and assumes no liability in connection with any use of thisinformation. Nothing in this publication is to be considered as a license to operate under or a recom-mendation to infringe any patent rights.Caution: Do not use this product in medical applications involving permanent implantation in the humanbody. For other medical applications see “DuPont Medical Caution Statement”, H-50102.

DuPont Engineering Polymers

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