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Manufacturing Processes

Mountain bike example Manufacturing process definition Deformation processes Casting processes Sheet metalworking Polymer processing http://www.stanford.edu/group/AIM/HETM/index.html http://www.sme.org/cgi-bin/getgmnpage.pl?/html/fmp.htm&&SME&

How would we manufacture a mountain bike ?

TopTube

SaddleSeatP t

Handle Bar

Front BrakeRear Brake

Post

DownTube

Fork

RearDerailleur

Pedal

(Courtesy of Trek Bicycle, 2002)

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Manufacturing process decisions

Specific manufacturing processes? How do the selected materials influence the choice of How do the selected materials influence the choice of

manufacturing processes? Does product function or performance issues

influence our choice of mfg. processes? What criteria should we use to select processes? Which criteria are more important? Who will make the final decisions?

Parts undergo sequence of processes

Primary - alter the (“raw”) material’s basic shape or form. Sand casting

Changes?

RollingForgingSheet metalworking

Secondary - add or remove geometric features from the basic forms Machining of a brake drum casting (flat surfaces)Drilling/punching of refrigerator housings (sheet metal)T i i f i j ti ld d t fl hTrimming of injection molded part flash

Tertiary - surface treatments PolishingPaintingHeat-treatingJoining

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Types of manufacturing processes

ManufacturingProcesses

How is the input material changed?

ExtrusionForging

Deformation

CentrifugalDie casting

Casting

BendingBlanking

SheetMetal

Blow moldingCasting

PolymerProcesses

BoringDrilling

Machining

AnodizingHoning

Finishing

AutomatedBonding

Assembly

RollingBar drawingWire drawing

InvestmentPermanent moldSand casting

DrawingPunchingShearingSpinning

Compression moldingExtrusionInjection MoldingThermoformingTransfer molding

FacingGrindingMillingPlaningTurningSawingECM, EDM

PaintingPlatingPolishing

BrazingManualRivetingSolderingWelding

Manufacturing Process Considerations

1. Production Volume2 Part Size (overall)2. Part Size (overall)3. Shape Capability (features)

boss/depression 1Dboss/depression >1Dholesundercuts (int./ext.)uniform wallsuniform wallscross sections - uniform/regularrotational symmetrycaptured cavities

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Deformation processes

Rolling Rolling Extrusion Drawing Forging

Rolling (of ductile materials)

Rollers in compression

thick slab

thin sheet

Plastic deformation

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Rolling

l b

bloom

hcoil

structural

ingot

slab

billet

sheetcoil

bar rod

Extrusion

Extrusion

Ram

Crosssections

die

Billet

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Drawing

D i di

Pulling

Crosssections

Drawing die

forceBillet

Forging (closed-die)

Blockedpreform

Ram pressure

Flash

Gutter

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Casting Processes

Sand casting Sand casting Die casting Investment casting

Sand casting (closed-mold)

Core Riser

SprueFlask

Cope

Runner

Drag Gate

Partingline

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Die casting

Moving die

Stationary die

Plunger Ejector pins

Moltenmetal

Parting line

Sprue

Investment casting

Wa pattern

Ceramic mold(hardened slurry)4-part pattern tree

Wax patternis cast

Wax removedby melting

Molten metal solidifies in cast

Ceramic mold is removed

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Sheet Metalworking

Bending Bending Blanking Drawing Punching Shearing Spinning

Punch ram

Sheet metal drawing

Clamp

Blank holder

Punch

BlankDrawn part

Clamp forceDie

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Example sheet metal parts

Types of manufacturing processes

ManufacturingProcesses

ExtrusionForgingR lli

Deformation

CentrifugalDie castingI t t

Casting

BendingBlankingD i

SheetMetal

Blow moldingCastingC i ldi

PolymerProcesses

BoringDrillingF i

Machining

AnodizingHoningP i ti

Finishing

AutomatedBondingB i

Assembly

RollingBar drawingWire drawing

InvestmentPermanent moldSand casting

DrawingPunchingShearingSpinning

Compression moldingExtrusionInjection MoldingThermoformingTransfer molding

FacingGrindingMillingPlaningTurningSawingECM, EDM

PaintingPlatingPolishing

BrazingManualRivetingSolderingWelding

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Polymer Processes

Compression molding Compression molding Transfer Molding Blow molding Injection molding

Compression molding

Charge

Heated mold Ram Pressure

Part

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Transfer molding

Ram pressure

Ram

Heatedmold

Sprue

p

ChargePart

Blow molding

Part is

Airblown into

Mold halves

Molten parison is

Extruderair injector

parison

Part isremoved

into parison

halvesclose

parison is extruded

parison

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Injection molding

Cavity half Core halfof mold of mold

Ejector pins

Feed hopper

Barrel

Pellets

Shear-heating

Moving

Sprue

Fixed

Mold closure directionParting

plane/surface

Example of a box …with no undercuts

partingejector

core

partingline

ejector pins

cavitymold closure

directionplastic

injection

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Internal undercuts

partingejector

core

p glinepins

cavityclosuredirection

plasticinjection

External undercuts

partingejector

core

partingline

ejector pins

cavity

plasticinjection

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Solidification processes summary

Casting ProcessesSand Casting

Polymer ProcessesInjection Molding

solid Part molten material freezing

Sand CastingDie CastingInvestment CastingCentrifugal

Injection MoldingBlow MoldingThermoFormingCompression Molding

Flow (voids, flash)Cooling time (cycle time)Temperature

ld l iMold complexity Warpage Post processing Costs (materials, tooling, processing)

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