Composite Mater& Process
Composite Mater& Process ME 4793
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This 0 page Class Notes was uploaded by Chloe Reilly on Monday November 2, 2015. The Class Notes belongs to ME 4793 at Georgia Institute of Technology - Main Campus taught by Staff in Fall. Since its upload, it has received 33 views. For similar materials see /class/234253/me-4793-georgia-institute-of-technology-main-campus in Mechanical Engineering at Georgia Institute of Technology - Main Campus.
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Date Created: 11/02/15
Glass Fiber Attributes Moderate Density Low Modulus High Strength High Strain Low CTE Isotropic Low Cost Moderate Service Temperature Insulating Good Chemical Resistance Poor Abrasion Resistance Moisture Sensitive Surface GLASS FIBER PROPERTIES PROPERTY Diameter microns Specific Gravity Tensile Modulus GPa msi Tensile Strength GPa ksi Strain to Failure CTE micronsm C Poisson39s Ratio EGLASS 10 254 724 105 35 500 48 5 02 SGLASS 10 249 869 126 43 625 50 29 022 TABLE 21 Typical Properties of Commercial Reinforcing Fibers 3953 Tensile Tensile Strain Coefficient of Typical modulus strength to thermal expansion diameter Specific GPa GPa failure 10quot mm per 390 Poisson39s Fiber urn l gravity 10 psi 103 psi 95 oioo39Cb ratio Glass E glass 10 round 254 724 345 48 5 02 105 500 s glass 10 round 249 869 430 50 29 022 126 625 PANcarbon 39raooc 7 round 176 228 32 14 0 1 to o 5 33 5 470 longitudinal 712 radial 02 ASd 7 round 177 220 31 12 05 to 12 32 4 50 longitudinal 712 radial 39r40 6 round 181 276 565 2 40 820 d N HMS 7 round 185 344 5 2 34 o 58 E 50 340 a 1 11770 3 84 bllobal 196 483 152 038 0 70 220 5 S a Pitchcarbon a P55 10 20 380 190 05 09 g 55 275 longitudinal w Piooc 10 215 690 22 031 16 100 325 longitudinal Kevlar 49f 119 round 145 131 362 28 2 longitudinal 035 v 19 525 59 radial Boron 140 round 27 393 31 079 5 02 57 450 SiC 133 round 308 400 344 084 15 58 485 A130 20 round 395 3793 190 04 83 55 23975 31 ml 0000039 in bi mm per 390 0556 inin per 391 cAmoco dHercules Inc eCelanese fDuPont iI Overview Equipment Process Injection Molding Flow in barrel Flow in cavity ver1 Clamp force Ejection force Design rules ENG 4793 Composite Materials arldProCesses 1 Georgiai ENG 4793 Composite Materials and Processes 39Techl39 Equipment Equipment 2 4 Mold Barrel Georgia ll ENG 4793 Composite Materials and Processes 3 Itch i il 7 ENG 4793 Composite Materials and Processes Equipment Crosssection pellets hopper Clam nozzle barrel throat 0 m m VI heaters motor drive Georgia ENG 4793 Composite Materials and Processes 5 Tbch Georgia ENG 4793 Composite Materials and Processes ijTechi Geargiialjl igy ENG 4793 Composite Materials and Processes 8 it Techlj i ll Process 39 v s 39 quotmange v lt 39 x x I r 39 n H GeorgiaTitre quot5quot 14553 ENG 4793 Composite Materials and Processes 10 GQDrgialI i ifiilf llg fiii a ENG 4793 Composite Materials and Processes 7 iiiiii Techljili ill tjii l3ji Mold runner I W sprue nozzle front ejection side pin Georgialf l quotquotquot ENG 4793 Composite Materials and Processes g Etii39fTechljilr i Process Pellets placed in hopper Pellets fall into barrel through throat Pellets packed to form solid bed air forced out through hopper Pellets melted by mechanical shear between barrel and screw Georgiana ENG 4793 Composite Materials and Processes 11 iiiTiifTEGhUil Process Melted plastic forms shot in front of screw screw moves back as plastic moves fonNard reciprocating screw Geargi l l gyi ENG 4793 Composite Materials and Processes 12 iiciif Techlitigizllzzzz Process Screw moves forward to inject plastic into mold cavity Part cools and solidifies next shot is made Aquot mazw WSW0639 V I J dwsiwmw 39 2amp3 1 Ear4 39 gwxy vmmw W a v A g p w x k Geargi l39quotil iiilquoti14 13 ENG 4793 Composite Materials and Processes 13 iftquotTechlitiiilliiiirfi7 Process Mold opens Ejection pins move fonNard to eject part Mold closes Process starts again Georgial39i i l legit quot1114 39Tjgngg ENG 4793 Composite Materials and Processes 14 23 if Techl iitiizrl lirigiirig Solid bed Pellets crushed together Air ejected Ggargial ifgjzgifyfjgy 1331 ENG 4793 Composite Materials and Processes 15 i39iTechl fi z39l 63525 Melting zone Solid bed melted by mechanical shear e e e screw flight solid bed secondary mixing flow Genrgial39l i si z i f g ENG 4793 Composite Materials and Processes 16 girl Techl rglrjtxl it 31 Homogenization zone Melted polymer is homogenized thermally and colorwise Geprgial 1 gig315 ENG 4793 Composite Materials and Processes 17 iiTeGhl Zaiiii2lJriZri Injection pressure Typically 15000 psi Ranges from 3000 to 40000 psi Hydraulic pressure is about 10x less Gabrgial39l il jgiiV3933 ENG 4793 Composite Materials and Processes 18 23251Techiflcaitsljzziiti315 Process time Pressure history Geo ia 5 1 T29 h plate thickness 3 X 103 m 031315 1 15 30 15 40 45 39nll iii1mm mm TW mold wall temperature 50 C TM melt temperature 250 C TE ejection temperature 100 C Minimum cooling time forthe center line to reach TE is tc 23 sec ENG 4793 Composite Materials and Processes chili Georgia ii i39Techxw AK Open and eject Ciose moid Cycle time pan InjeCtion Mold closed time E Cooling 5 3 5 39 81 E E 5 2 5 23 as a E 2 39E 0 CL w N Pack and hold 5 25 LL 3 gt Pait cooling 8 D 0 0 5 15 33 35 Time s ENG 4793 Composite Materials and Processes 19 ENG 4793 Composite Materials and Processes 20 Temperature history Gates and freezeoff Cooling Gates and Freezeoff 200 c 8 Soiid Melt a 31 3 U m a 8 g Filling 5 100 3 D E 0 m E g E XIi reezeofl39 E Li 3 quot Packing amp Cooling 0 t 0 5 15 33 35 Time s G e grggci i ENG 4793 Composite Materials and Processes 21 1 ENG 4793 Composite Materials and Processes 22 Minimum cooling time to How in screw Cooling Time vs Wall Thickness h2 4 T T E 21n TMTW Understood through simple fluid 057 7r E W 2 m n anaIySIS Example Unroll barrel from screw oc thermal diffusivity 10397 m2s 3 5 rectangulartrough and lid B ENG 4793 Composite Materials and Processes 24 Flow analysis Barrel slides across channel atthe helix angle vZ pumping vX stirring B me 4793 mm Mimi s nmacsss 25 Flow rate vZ shows viscous traction work against exit pressure flow rate fexit pressure vbm u d w I me 4793 mm Mimi s nmacsss 2e Flow analysis Simplify by using Newtonian fluid Separate into drag and pressure flows Add solutions superposition me 4793 mm Mimi s nmacsss 27 Drag flow QD v vO yB QD vO2 wB vim me 4793 mm Mimi s nmacsss 2a Pressure flow 1 y I 2y p p dp Z T lt dz Equilibrium PPdl3 2y 2sz 0 me 4793 mm Mimi s nmacsss 2a Pressure flow p pdpgtlt2y 27dz 0 Newtonian uid T 7 H dv dy me 4793 mm Mimi s nmacsss 3n Pressure flow Total pressure flow Qp Eliminating T B dv id I d A wB3 dp dzyy szwjvgbzfg Integrating and noting yB2v0 pig lily u dz 8 2 Total flow Q Flow rate V23 33 dp Q QD Qp w 2 12 y dz ow 20 I rate fscrew speed fpressure drop output pressure me 4793 mm Mattias me 4793 mm M Flow in mold runner round Flow in round runner 7rr drz irzdp 27r r drT 11 rTdz Neglecting HOT 27139drdp 27rTdr rdTdZ Equilibrium dp ujrrdr 7L39rdrz7r227ErerTdTirTdz i7 me 4793 mm Mattias me 4793 mm M Flow in round runner Tdrrdf d1r dr 2L r A pr Flow in round runner At center I 0 At edge of tube R C max T 2L Georgia 4 1quot 21 iquot ENG 4793 Composite Materials and Processes 37 f i Techv39r liar Flow in round runner du Apr dr 2L y nally A u p r2 R2 4 uL Georgia gt 3 17 sl LU ENG4793 Composite Materials and Processes 39 Techielag A R TmaX p 2L Newtonian uid T u dv dy 1 l7 Vi ENG 4793 Composite Materials and Processes 38 Flow in round runner A u p r2 R2 4 uL R 4 7rA R Q 27171107 2 L O 8 uL i 74 ENG 4793 Composite Materials and Processes 40 Power law viscosity Iognu M mW log n n1 1 Iogf m n are consistency and power law index Viscus39q amaviur ur Palyma Melts Lug Viscosity Log Shear Rate Georgian V jl ENG 4793 Composite Materials and Processes it Techi39 39 11 Clamp force Typically 50 tonsoz of injected material Can be approximated by injection pressure x projected area of part at parting line Georgia i it t j ENG 4793 Composite Materials and Processes 1 Techv rjiii g Ejection force Ejection pins force the part out ofthe mold after the part has cooled and solidified enough The part will shrink onto any cores leading to an interference fit Model as a thin walled cylinder with closed ends plastic part on a rigid core metal mold Georgi ENG 4793 Cumpuslte Materlals arid Processes 43 cf Tech Thinwalled cylinder with closed ends 6139 atzlzj tzal o d aazp zaz 4t 0320263 ENG 4793 Cumpuslte Materials and Precesses 44 Biaxial strain 8 v0392 pd pd 1E E 2tE 4tE 313L1V E 2t 4t 51 2 MT ENG 4793 Cumpuslte Materials and Precesses 45 Ejection force Eam plquot dl v 22 4t Ejection pA EAaAT ENGINES Cumpuslte Materials andPrDEEssEs 46 Gate t es Nomenclature yp Comments 0 A area X thermal mold mingline d core diameter expanson P coef CIent E Young s modulus AT temperature differential p pressure t partthickness v P0lsson s ratio u friction coef cient ENG 4793 Cumpuslte Materials and Precesses 47 Comments dcgaling Georgia 39 39 395 Tech Effects of gate number and location 1quot mm 1 ml ll KITa I J rr39rl l quot elf Lilli if k quotyTwo lll39l gated ll h f r I i r Fun Sinai rlld gained ll Lu 39539 ii 2 a ENG 4793 Composite Materials and Processes 49 Geprgial i r fiiiii 39Techij Fountaining Solidifving layer Advancing 1 Cold wall Geprgial39t ENG 4793 Composite Materials and Processes 50 iiaifTechIr x Fiber orientation and effects Fiber Orientation in Injection Molded Parts Flow direction Mold Modulus vs Fiber Orientation Nylon 66 with 33 glass bers LID 25 Modulus Longitudinal Modulus GPaJ Modulus Transverse 01 02 03 04 05 06 0 Dis 03 1 Planar Orientation Parameter fp ENG 4793 Composite Materials and Processes 51 Geprg ial r t 39Techm Fiber orientation random WW ii39irwlgxii lt M I l 30 it 39 Wt 90 NM it ill Georgial39rI ENG 4793 Composite Materials and Processes 52 EeiJTechviw Weldline development Intrusion by hot core Georgiali ENG 4793 Composite Materials and Processes 53 LL ll 39Techl fl Flash Overfilling of the mold forces mold open inadequate clamp force This leads to flash around the edges of the part at the parting line ENG 4793 Composite Materials and Processes 54 Vacuum Bagging Autoclave Process Sequence High Performance Parts Prepare plies Stack pliesintool Add dry material to absorb excess resin amp remove volatiles 0 Apply vacuum bag amp cure in autoclave Oven postcure for environmental durability Trim Inspect Assemble Ggorgialim ENG 4793 Composite Materials and Processes 2 iigi IL 39TEGhlLfir Vacuum Bag Assembly 4 VACUUM LINE VACUUM VALVE BAGGING FILM BREATHER 39 39 BARRIER SEALANT BLEEDER ENG 4793 Composite Materials and Processes 4 ver1 Georglial39lm LI Tie ENG 4793 Composite Materials and Processes 1 ElliFi TEChl i Gearglial39im Ll 11 ENG 4793 Composite Materials and Processes 3 iciij Techl vir Vacuum bag film Bleeder material V B L Barrierfrelease acuum 39 ay39up Breather material release Ply coatfilm Vacuum valve Sealant Composite laminate Ggorglial39lm U 74752 ENG 4793 Composite Materials and Processes 5 xiiiif39l39echl iz Material on stiffening structure Vacuum bag and fittings attached Ggprgial i m Liiii39TEGhllfjl Alternate Resin Bleed Paths Edge Bleed Georgia NikeEff i quot3quotquot ENG 4793 Composite Materials and Processes 7 if Techi fquot s iii 3 Release Materials Common Materials F berglass Coated with Teflon Coated with Mold Release Nylon Polyester Film Georgiana quot 1 ENG 4793 Composite Materials and Processes 8 iii Tech 1 Eel I Breather Material Common Materials Fiberglass Polyester Felt Cotton Limitations Pressure Temperature Failure Modes Inadequate Testing Georgiaii 33 ENG 4793 Composite Materials and Processes 9 r ifTechl rrLlr Sealant Tape Major Manufacturers Sch neeMorehead General Sealants Limitations Tack Temperature Failure Methods Release Flow Georgiell lil i quotgag ENG 4793 Composite Materials and Processes 10 2 If Tech If all Nylon Films Manufacturing Methods Cast Blown Film Types and Properties Resin Types 6 66 666 Sheets Tubes amp Bags Limitations Failure Methods Becn39gig1quotI ng39fif39iz 11 ENG 4793 Composite Materials and Processes 11 iii quotTechlr Vacuum Bagging Problems Labor Intensive Inconsistent Performance Trapped AirNolatiles Controlling Bleed Poor Heat Transfer Consumes Expensive Materials Wrinkles Loss of Seal Inadequate Pressure Transmission Georgiall Ti Ej l17riirll ENG 4793 Composite Materials and Processes 12 nafTechu1 Won 39 r inwxllkgg mwr will Pad Ggprgiali 13 titty Techllilcitxl 1 Autoclave Genrgial39l ENG 4793 Composite Materials and Processes 14 tillTech1th23132lli lii39igl ifquot Autoclave Flexible vacuum line Thermocouple Menuel Per with vecuum beg GEDrgliall i iiliflill ENG 4793 Composite Materials and Processes 15 2651Techmzisillzgigr Autoclave Features Gases Gas Circulation Air lfT lt 150 C Needed for heat N2 most common tranSfer 302 if p lt 300 psig Velocity 1 to 3 ms e Heating 39 Vacuum Electric if small One outlet per 25 ft3 Indirect gas fired if Of bag area large Trap volatiles may be toxic lntegrally heated tooling recently Control internal bag pressure hard Genrgi llTii il77 f g 3315 ENG 4793 Composite Materials and Processes 16 zilfkrriquotTechiirilrEEillzrii zzgig7 Epoxy Autoclave Cure Cycle Apply vacuum inside bag at 2030 Hg 70100 kPa Apply autoclave pressure at 85 i 5 psi 585 i 35 kPa Heat slowly to 250 1 10 F 120 5 C at 3 to 5 Fmin 2 to 3 Cmin Hold at T and P 60 to 70 min Raise P to 100 i 5 psi 690 i 35 kPa Release vacuum Raise T to 350 1 10 F 177 5 C at 3 to 5 Fmin 2 to 3 Cmin Hold atTandP 12010 min Cool slowly to below 100 F 40 C at 5 Fmin 3 Cmin Release autoclave pressure Gg rgial39ij193lt ftitl ENG 4793 Composite Materials and Processes 17 IfiiilT39E hL itiiUSEiii lfquot Alternative Curve Cycle for V378A m P zoo ismum I x quot00 quotm a 2 Temperature 139 1 a 5 X a r u bupe u u eeI e Pressure 3 quot F K a m b 5047 0 Jo o 0 l 2 3 l 5 8 7 B Timeh E 3 on I I O 2 o I 0 SE S 50E I E 3 gm so gt gt u 395 2 Alternate cure cycle lor V378A Evens sequence apply lull vocm and 586 kPa 85 psi presm he to 80 c 100 391 at 53 C 5 Fymim hold or so C 180 2 for 35 min then vent heal lo mt 350 1 as 53 C 5 Fymim hold 09 I75 C 350 F for 4 h cool at 53 C 5 Fymin to room Worm ll release pressure posrcu rge gt 245 cc 475 F for 4 h 3n will IEE EL Manufacturing Methods Overview Process Goals oControl fiber orientation amp location 0Control per ply thickness Control fiber volume OMinimize voids OReduce internal stresses Minimize costs Evaluation 39Investment 39Materials Processing 39Quality Products Manufacture of Prepreg Materials Advanced Prepreg Procurement Specifications Uncured Physical Properties OFilaments or Tows per unit width 0Volatiles OResin Content OTack oTack retention OFlow Workmanship Cured laminated Mechanical Longitudinal 0 Tensile strength 8 modulus Compression strength amp modulus Flexural strength amp modulus Horizontal shear strength At both room amp service temperature OAIignment oGapsspacing Width OLength OUniformity Storage Properties Transverse 90 Tensile strength ampmodulus Flexural strength ampmodulus Permeation of Dry Fiber Structures PressureP r a5ass ERAquotA lbz lb v u IiilIII 39 I MELT l s e Penetration 1 V 3532 V Velocity 391 I s Apparent Permeability s a rh213 rh hydraulic radius W wetted perimeter S r42 1113 Vi volume traction ber 4quot V12 V tiber radius V 511 412 k Kozeny Constant dt n dz ow coef cient 22 2 5512 u penetration depth tor constant dP 39l PERMEATION EXAMPLE 0 ALIGNED CARBON FIBERS rf 4 pm Vf 08 easy to pack it 18 from experiments Obtain s 00028 0102 dP 100 psi 6895 kPa n 10000 P e 1 kPa s PEEK 400 C 0 100 8 Obtain z 196 pm penetrate 24 bers deep l C E 12 Hot Melt Solution SlurryEmulsion Dry Powder Fiber Commingling39 Film Surface Polymerization MMWFMW Plastic cum lilm Tuneup roll Gm 00 Metering Dry fiber creel Fig I Typical tawpreg molactwing procns rolls Solventresin C illed bath r quot Winding bank Electrostatic Fluidized Bed Powder Fusion Coating Process Leon Phase W W W I 6 V3 Q L quot39 Mr Dullnu Dane n Hole Elcdl39lc I otenllll new Aeromb Oven m3 Winder Spreadet 939 Tension uidized Pull Control Bed Rollers Thermoplastic Processing Techniques ver1 Gigurgialii Elsi ENG 47 93 Composite Materials and Processes Ii39iiii Techijiii i What is different No reactions hopefully Saves time easy storage High viscosity Not tacky stiff highert T and P Fracture toughness Low interfacial bonding Remelting Correct defects thermoforming Costs Currently higher ultimately lower Gggrgiali ENG 4793 Composite Materials and Processes Techlit22itngigis39 Roll Forming Shaping Halli Twpint Laminltid Simian Shoat ilnpul I t L A i I I r ll V r r Gggrgialjl gli fig fligfji ENG 47 93 Composite Materials and Processes 3 tiltTechl i illii i iiii Rollformed Part PHUTOC IRFLFH 0F FORMED AND HNFDRMED SHAPES Gg rgial39i ENG 4793 Composite Materials and Processes Techi Weld points 300mm wide prepreg tape 1200mm wide prepreg broad goods Fig I 8 Simple buttwelding of thermoplastic tape Feed roll x Weld point 39 r 39 w quot o 39 f adeto order plies by GED rgtlallhissing 1M4 19331 Flg BUquot weld39quotg o m fiziii Techi iiiElicia spiral winding onto adjustable mandrels 5 Matched Die Forming sample and holder weights I 1 39 I I I I 39m9nl r i 1 not rats I Egargiali ENG 4793 Composite Materials and Processes i iilf39TEGhljiirEEljiiiiijEfs39 a quotmquot adjustment bolts t not quot 7 Matched Die Formed Part Defects Press Forming of LDF long discontinuous fibers Transfer into Clamp and Formed component Heat material heated dies thermoform after trimming 7 gt1 oooooooooooo ii MW 000000000005 r a Georgians ENG 4793 Composite Materials and Processes 8 255Techlrflzjgzrquot39 Fiber Buckling Interply slippage Fiber buckling No fiber buckling Adjacent reverse Free edge bends Interply slip No slip at free edge Fiber Breaking Fig I 0 lnterply slippage Georgial39 quot739 I ENG 4793 Composite Materials and Processes 7 ifiiiiTEGhiIii PET 3 r if Fiber r 1iquotiii139 Giass 1 Fiber wetla Conversiyon Porous Sheetmgl Convection Sheet StaCkl ng Heating Parts F Base Coat Fabrication Co tstgrgggign Clear Coat With IMC Molding ENG 4793 Composite Materials and Processes 9 Compression Molding Sequence SEAL 8 COMPRESSION INMOLD OVEN PREHEAT CHARGE MOLD EVACUATE FORM COATING To Mold 2000 3000 psi 1 0 C Vacuum Seal Vacuum Rapid Transit W 1 rf H b r Bottom Mold 160 C Mat39l Charge 39 Shear Ed 0 g Coating 5080 Coverage GEOrgiai39lfiiE 7 l ENG 4793 Composite Materials and Processes 10 iat Techies Hood Cost vs Production Volume All hoods except steel are one piece construction 80 7 60 50 i 75 SRIM o o j 3 smc u 40 4 J O 3 Thermoplastic 30 Composite Thermoplastic Composite 1o 1Ib premium for weight savings o 100 i 200 300 Production Volume M vehiclesyr ENG 4793 Composite Materials and Processes 1 1 Gapirfgial 39 i39 iri Techij Hydroforming M Press ram W Hydrostatic reservoir Flexible L diaphragm Hot blank I N r Shaping tool Bottom platen Fig I I Hydroforming Ggprgial i ii ENG 4793 Composite Materials and Processes 12 rgiat39Techlit A NONMATCHED MOLDS Diaphragm Forming I lt RUBBER PAD l Hyd roformlng L i Etiipl i lSST39C LAMINATE METAL MOLD PRESS B MATCHED MOLDS PRESS I I THERMOPLASTIC COMPOSITE LAMINATE METAL MOLD PRESS ENG 4793 Composite Materias and Processes Geargia ll ENG 4793 Composite Materials and Processes fiTechlj FIGURE 7 Photograp i ml f If si f39 model analysis 0139 a diaphragm termed at u slainquot7quot i3 i39n339fr3939 r39al u mg Fcirrrlrisj ENG 4793 Composite Materials and Processes qr Etuljt IEIF r d li t highlight rig ENG 4793 Composite Materials and Processes l Vacuum Forming in Autoclave Stretch Forming Pressure vessel l autoclave Radiant heaters Plastic film diaphragms Vacuum manifold Pressure connection j x 72334 39 72127 h 2122N Vacuum connection Vacuum forming Mold rig u I o Flg I 7 Vacuum forming fixture desugn for use in autoclaves ENG 4793 Composite Materials and Processes E irglal iii ENG 4793 Composite Materials and Processes echlf Stretch Forming Sequence 1 1 L A A A A L L LIA f 3 2 3 14 35 i6 Ggprgiali Exit ENG 4793 Composite Materials and Processes 19 iii quot TEGhlt jizl Fiber Position 90 in Stretch Formed Part INITIAL Tape Laying Feed drum Cold lnIine pressure nondestructive testing consolidation roller Focused heat X ra C scan v energy AX AI s 39 r Consolidated E substrate P 39 cold a Flg I 2 Automated tapelaying process Georgian ENG 4793 Composite Materials and Processes 21 21175 39i quotTBGhil iquot391711l iIfitfrIiIf39g ngirgial39ljiggi giii 313 Elli ENG 4793 Composite Materials and Processes 20 zziiw i 39ITechi F eed reel Crossaxis consolidation roller Focused heat energy Fig I 3 Thermoplastic filament winding with con tinuous consolidation G rgi li i i 3 ENG 4793 Composite Materials and Processes 22 I quot3quot 7 Z TEEhi if ii iii g f g I H J Thermoplastics Processing Comparison quot39 Relative m ReIatweblt Performance t III Pmcess39 39 39 y StrengthStiffness z 0 lt 0 2 m a i 2 0 a DJ II DI CL lt I Melt Flow Random LDF Continuous Oriented Chopped System Fiber Injection Strands System Molding SMC 4 COMPOSITE MATERIAL SYSTEMS gt Gg ctrgiali ENG 4793 Composite Materials and Processes 23 Tecihi ti Thermoplastics vs Thermosets Processing Comparison Process Comments Prepreg Harder melt commingle powder Manual LayUp Need heat and pressure SprayUp not done Vacuum bag Less material higher temperature T Autoclave More T and P less time t Matched Die More T and P less time t RTM not commercial Pultrusion More T and P should be faster Filament Winding More T and P currently slower Geargiial fiaE aai 139 ENG 47 93 Composite Materials and Processes 24 Techi Injection Molding The Processing Window The Molding Area Diagram The Processing Window Background The Molding Area Diagram MAD is a simple and economical method to quantitatively analyze several characteristics of the injection molding process The MAD was originally developed to measure the robustness of an injection molding process in the early stages of mold debugging so as to assist technicians in identifying problems and determining the effects of process and tool changes in a quantitative and objective manner The procedure consists of determining the molding pressure latitudes ranges at two orthree different melt temperature levels and charting the results Unfortunately this technique cannot be accomplished with some ofthe newer velocitycontrolled machines since a molding latitude requires determining the process limits by changing the injection pressure while holding the injection time fixed Many newer injection molding machines do not have a quotmanualquot option to allow this approach The basic MAD plot shown in Figure 1 depicts a typical graphic analysis ofthe entire processing range forthe moldmachine combination It is typically a tilted geometric figure having four boundaries two related to temperature and two related to pressure These boundaries are gross attribute failures points beyond which the process cannot exist Four process characteristics become quantifiable when these boundaries are reached the range of the molding latitude the area tilt and rate of decay ofthe MAD Typically Pressure ngaQI Pre ssura l3 anHeetsd h m lNCDMPLETE occasionle EJECTION may 1000 500 900 EDD 700 Bill Pressure PSI Figure 1 Structure of the MoldingArea Diagram The nature of the process failure at the Iow and highpressure limits of the molding latitude is the key for process improvement Molding latitude limits are primarily the httpwww4speorgd23windowhttn1 82801 In echon Moldmg r The Processing Wmdow W on man r In rnumeavny rn m mmur dr erenees m ow paths temperature and galmgmeu ugma e ecls Tne n n m an m h M r n 1 each y In 3 1y uuvlubm m a m u srrnnartu the eavmy mung sequence pa em Example Frgure 2 snuws the resuus and anaxysrs cf a srrnme 48 eavny hut mnner ma d usmg mgh densrty pa yelhy ene HDFE Spema MAD charadenzahun memos deve up w M M u a Mad A hen n m n and V sCDdECBY standard campulerspreadsheel 43 CAVITY PRODUCTION MOLD 50 T j m kquot nausea I a ri am PM aw 45 151 r W A acme 2sa sI r 450 9 0 50 13950 1250 73 0 V150 55 550 noun a es Frgure 2 Example oftyprcal MAD wrm analysrs MOLDING LATITUDE ans s the pressure range wnnrn the allnbule boundary hrrHIs unne process Furlms examp e the range 31450quotFs150 PSI at 500quotF m rs h pwww45peoxgd23wmdowh ml 82801 Injection Molding The Processing Window Page 3 of 5 250 PSI and at 550 F it is 350 PSI A typical minimum range fora production process is 100 PSI In this case all three temperature ranges are acceptable For the final selection the highest temperature was felt to be simply too hot and might cause some operating problems The lowest temperature is at a point where the product performance might be affected due to excessive orientation levels causing cracking in normal use This was a thinwalled part having a thickness of slightly over 1 mm Experience had shown that molded parts with thickness in this range and below were quite susceptible to high levels of retained molded in orientation which significantly reduced useful impact resistance The middle temperature was the final selection for the production process MAD AREA This is the area within the boundaries of the trapezoid To calculate this value the formula for area as well as the formulas for the other two characteristics should be set up using a typical computer spreadsheet This way a plot can be generated at the same time The process is simple enough though and manual calculating and plotting can be easily accomplished The resulting area is an excellent comparison metric for materials evaluation studies and mold quality rating A typical use of this calculation would be to compare quotidenticalquot molds for robustness or as a reference for the same mold when major tool changes have been incorporated in the mold Material evaluations and comparisons can now be accomplished in an unambiguous and objective manner through the use of this parameter VISCOSENSITIVITY The tilt of the figure yields another useful value to help the molder characterize both the robustness and potential problems with his process This characteristic value is the slope of the line joining the midpoints of the molding latitudes that compose the high and low temperature boundaries This value provides us with a sensitivity index related to the viscosity of the molten polymer It reflects the combination of the effect of the material viscosity and the geometry of the mold This factor has significant bearing on the robustness of the process the lower the tilt the less sensitive the process will be to viscosity changes caused by temperature and material variations The slope of the tilt for this example is 25 PSI F This is within the normal range of observed values for this characteristic It will always tilt to the left yielding a negative slope although occasionally very robust processes have been observed with practically no tilt over the temperature range evaluated Processes having tilt values in excess of 10 PSI F usually exhibit very difficult operating histories VISCODECAY A notable aspect of the typical MAD plot is the shrinkage of the molding latitude as the melt temperature decreases If the MAD geometry is considered as an inverted truncated pyramid the rate of decrease of the molding latitude can be estimated by a simple linear calculation There may be some curvature in these boundaries but in a typical molding process these molding latitude boundaries are fuzzy and can be assumed to be linear for all practical purposes For this example the decay rate is 20 PSI F This value is another indicator of processing stability and robustness Its value is typical of many products and may approach zero on some very robust products The molding area diagrams shown in httpWWW4speorgd23windowhtml 82801 Injection Molding The Processing Window Page 4 of 5 textbooks usually show a decrease in width as the temperature increases but these are usually not based on practical production molds Textbook examples are usually generated from simple single cavity molds and are run in machines with excess clamp tonnage available With most production molds melttemperature problems such as poor ejection or excessive runner curling occur long before such a zone is encountered An interesting byproduct of the Viscodecay value is the ability to calculate the temperature at which the process will vanish For this example the molding latitude at 450 F is 150 PSI Using the calculated decay rate the molding latitude will become zero at 375 F At this point the molded part will simultaneously exhibit both incomplete and flash attributes Procedure MOLDING LATITUDES The machine holding pressure should be at a low level such that the screw is stable at the injecthold transition and does not allow any filling of the cavity to take place The overall machine cycle should be the normal production time When adjusting the injection pressure to develop the attribute failure limits the limit selected should be just inside the failure point If parts are incomplete or ejecting poorly etc the limits have been exceeded and the data is unusable Limits tend to be quotfuzzyquot due to slight normal variations in the process Back off from the extremes slightly when determining the limit A few PSI does not make a significant difference in the final result TEMPERATURE The minimum difference between the high and low temperatures needed to develop useful process information is about 25 F A temperature difference of 50 F is quite adequate and usually achievable Selection of the maximum and minimum temperatures is the first step in the process of developing a molding area diagram The difficulty with this step is that determining these temperatures is a subjective process particularly in the selection of the low temperature limit and depends greatly on the judgement and experience of the technician The hightemperature limit is usually and easily determined by process problems The lowtemperature limit is typically characterized by excessive injection pressures andor physical property degradation Every technician has his own opinion on what is considered a quotcomfortablequot maximum injection pressure The physical property response of the polymer to melt temperature is another characteristic that should be strongly considered Many processes have sufficient processing latitude to allow parts to be molded far below the temperature at which sufficient physical properties are developed The most common property failure is poor impact strength Molding at too low a melt temperature yields parts with excessive levels of retained orientation which results in poor impact performance An example of this is HIPS High Impact Polystyrene When polymer temperatures are at or below 450 F the practical impact strength is at an unacceptably low value often barely above crystal polystyrene The hightemperature limit is typically characterized by material degradation or molding problems due to unreliable part or runner ejection from the mold These failure modes are easily identified httpWWW4speorgd23windowhtml 82801 G rgial quot 2222 TEGI I 1 Fl 7521 liiiii Economics SMC molding ver 1 ENG 4793 Composite Materials and Processes Important factors Material Labor Capital Energy 1 71 5 11 7 l39 121 325 51 quotquot Techl lazizzl tics ENG 4793 Composite Materials and Processes Cost model Formulation specification Sheet line calculations Sheet molding inputs Molding cost estimate Gggrgial quot Ti 5L 39l Tech ENG 4793 Composite Materials and Processes Formulation specification General purpose Low profile 2 nonstructural Class A non Class A ribs Low profile 1 High strength Class A structural no ribs no hick sections Ggprgial quot in 13 L1 139 2 Tech Mill 1 ENG 4793 Composite Materials and Processes 4 Generic SMC lComponent 33592 Function Reactive monomers that provide a Styrene 13394 cross linking structure Reactive monomers that provide a POlyeSter 10395 cross linkind structure Glass fiber 300 Reinforcement Calcium Filler increases bulk volume and 400 carbonate reduces part cost Low profile 3 45 Controls part shrinkage a agent IPA 39 thermoplastic additive nitiator 1 00 Provides free radicals to initiate 39 polvmerization Magnesium hvdroxide 070 Increases wscos y kinc stearate 100 Lubricant mold release agent 2 ENG 4793 Composite Materials and Processes High Strength SMC A Formulation c PHR Percent Fomum o Numbquot SMC 13 39 n 1 5030 Resin 60 solids 100 2732 Source Rapp R S 39 High Strength Molding Compounds Oct 2 Zinc Stearate 3 032 1976 SPI RPCI Thermostat Press Molding Committee meeting 3 tButyl Perbenzoate 1 027 4 MgO Dispersion 6 164 Type compound High Strength SMC 5 Glass 1quot PFC518 256 6995 6 Total Compound 366 10000 B Compound Properties c Typical Physical Properties 1 Fl lSt th 61000 1 Masterbatch VlSCOSll y 600800 cps 2 5431511535 Psi 250 2 lhour Thickened Viscosity 8001400 cps 3 Tensile Su sm Psi 39 00 4 T 391 Mod 1 106 39 240 3 Tune to 20 X 10 Viscosuy 4872 hrs 5 13 llfnpactun gtched if lein a 215 6 12 dlm ctU t h an new 286 4 SheetWexght mesft 7 51322 e m 1 quot zjgl 39Z7ie ENG 4793 Composite Materials and Processes 6 Sheet line calculations Sheet cost materials me 4793 mm Mimi s nmacsss 7 Material cost MC MC weight price 1 scrap me 4793 mm Mimi s nmacsss a Labor cost LC cycle time wage laborers prd cav wage direct labor wages including direct bene ts laborers number of direct laborers per molding press prd productivity productive time available time cav number of cavities mold me 4793 mm Mimi s nmacsss a Capital cost Fixed recovery period 5 years Fixed interest rate 12 Annual capital recovery payment distributed over annual production yields capital cost per pound of SMC me 4793 mm Mimi s nmacsss lEI Cost breakdown for producing low profile SMC me 4793 mm Mimi s nmacsss ll Molding cost estimates Material cost seen above Labor cost seen above Main machine cost M MC see next slide me 4793 mm Mimi s nmacsss 12 FIBER REINFORCEMENTS Features Sought High Strength Wide Service Temperature High Modulus 39 Compatibility Low Density Low Cost Uniform Easy PrOcessing Continuous FIBER REINFORCEMENTS QuestionsIssues Why Fibers Why Small diameters Why Anisotropic Why low compression strength Why low thermal expansion Why expensive Why not high strength m high modulus Tensile properties of Fiber Reinforced Polymers Plastics Stress A G of 4 J Fiber Composite 6 lt c Matrix I O39m 39 L f Strain 8 Rule of Mixtures OcCfoCmvm EcEfoEmvm Polymer Matn39x gt Transfers loads gt Protects Fibers Sample Calculation 0 Carbon Fiber Hercules AS 4 Ef 32 msi 32 x 106 psi 220 GPa Ofu 450 ksi 450000 psi 31 GPa Efu 0012 0 Epoxy Matrix Em 350 ksi Gmu 12 ksi emu 0034 0 Composite Vf 060 unidirectional EC 32 06 035 04 193 msi 99 ber Sfu 0012 O39m 350 0012 42 ksi cc 450 06 42 04 272 ksi 99 ber Need High Aspect Ratio to reach Ultimate Strength of Fibers Assume stress transfer by shear Assume constant interfacial shear stress 0 Fiber section near end of ber diameter d and length dx Ti lt Gf e gt gt ofdof 4 Ti interfacial shear stress 0 Force balance of dO39f 1 124 0f1c d24 4i 1rd dx 0 1 iii or 6f 4Iis dx d 39 d 0 Critical length IC 2 xc when Of Gfu lcd so critical aspect ratio or so 5213 392 Ti 0 Sample calculation Carbon ber AS 4 Gfu 450 ksi d 8 gm Epoxy matrix assume ti gm 6 ksi 2 sc59375 39 26 193758um300ptm03mm118milsr OGoals 250sc 13 gm where omy is the marix yield strength 2 mm 5214 re amnka xaemav aspecfmtq M ferf cEz 59621 52229 12 A c7g 2745 5 E V m A422 539 5 4 Z gt c 5 2 37 M 5L w I quot W M SMALL DIAMETER FIBERS HAVE SMALLER STRESS CONCENTRATIONS Thus 39 Tensile strength increases Modulus not altered Grif thErwin Crack Growth Model c2 EG Y1v2ac o Failure Stress E Modulus G Work of Fracture Strain Energy Release Rate Y Geometric Factor v Poisson39s Ratio ac Critical Crack Length at Failure Reinforcement Matrix Interactions SIZING CLASSES BEE Emma EXAMPLE Filmforming Protect Fiber Polyvinyl Alcohol PVA organicspolymers Adhesion Promoter Strength Moisture Silanes Resist Interlayers Toughness Elastomers Chemical Modi ers Protect Fibers SiC on Boron Chemically 92mg d c f j mmo KS ew2 57078 1470 C X A 3 1 M CW 70AM A a A If EX 7 LO lb K f sg 5 quot y W l if V f a x r l J z p 522 XM l 39 Compression Molding ver2 Georgialiitgiltquotlining ENG 4793 Composite Materials and Processes quot t m gm Compression Molding Process Thermnset or Gg r gliallTl iiifil flitil31 ENG 4793 Composite Materials and Processes 2 ii iiif39TEEIiilrifE3ElEif V quot quot 339 Ernrr rgtl1nln n r 39i 53 yr 3911quot rt nnns39nnm nlru lnrt lnm nrnr n39il39h 391r1 Imllnu r39rlr39il urncu GeargialI i z ilf lgigging ENG 4793 Composite Materials and Processes EECiL Techl I39EETIllif ii lEf Schematic of a Compression Molding Press MOVABLE PLATEN 1U U Movable Mold Half Fixed Mold Half Shear edge Charge 1 Ejector pin l I l l i 39 I I l l Georgialjl te X quotmquot 4 ili i39jTealmuggy rm 5 11 Schematic of a compression molding process 535L131 095114 6 g i qugialljtti Lowe Linux 5 zafl camm Ram Shear Edge Part Chafge Placement Mold Closed Part Ejected r ByPass 39 Cavity GEOrgialll lg z39ill lliftErie ENG 47 93 Composite Materials and Processes 6 iiii ifTechIiill1iiiiiiti lgji Typical products Front and rear end automobile panels Hoods Roofs Scoops Fenders Spoilers Air deflectors Lift gates Battery trays Georgiai 531 711 uquot ENG 4793 Composite Materials and Processes 7 ri Tech wall Lightweight Durable Aerodynamic styling SMC Components 1 Alrlnmk Gnilu 006 gt100 SMC parts 450 lbtruck 114 million lb 1996 Georgia 39 quot571 1 Techi iquot w Car parts by SMC Prowler Advantages and disadvantages Advantages Short cycle time typically 16 minutes High volume production Class A high quality surfaces Disadvantages High initial capital investment Labor intensive Secondary operations are sometimes required Georgi V 1 ENG 4793 Composite Materials and Processes 10 Three Thermoset Material Types Preform Molding Shaped dry reinforcement Binder Matrix as liquid or powder BMC Bulk Molding Compound Molding Fibers lt 30 and lt1 inch Resin about 25 Filler about 40 Log or rope form SMC Molding Fibers 3050 by weight Fibers 13 inches to continuous Resin about 25 Filler 2545 Thin flat Sheet Molding Qompound Georgia 391 li 4 ENG 4793 Composite Materials and Processes 11 E Tech 391 Thermoplastic SMC Azdel PP matrix glass fiber mat 3040 by weight continuous chopped directionalized Geprgia l ENG 4793 Composite Materials and Processes 12 1 Tech a A It to m in the it rest it it in E r t E I IITH wt Hi 539 trip it HE t JF 39lt h dashboard rm ding toutweight structural strength and high E Et g absorption Partfem ures molded in texture and a Stifftouch paint system Pu intact kneebahtm with naldecider texture to pruuide Class A interior sutfh co 39 39 ENG 4793 Composite Materials and Processes 14 SMC manufacture using a configuration that can make choppedfiber SMCR continuous fiber SMCC or continuous random SMCCR material L r Continuous strand roving Chopper Continuous Resinliitier strand roving paste Carrier film Chain link compaction belt nesinmuer iiio i paste 39 Carriettiim Takeapron 39 39 SMC manufacture using a configuration that can make choppedfiber SMCR continuous fiber SMCC or 1 continuous random SMCCIR material A 16 39 E E39J quot 39 Ixquot 3939 quotAll tropism fty GEWQi lfl 39i ii ilf i39fjgiTEE ENG 4793 Composite Materials and Processes 13 zitiztiquot echnlit i s lquot iquot3 lEi39 it An tomotiwe serif he titt wt tits I t nicttttesses 57335 than 2 mm Elli tvutt ts titreE recycled for reuse Gemgiall 39igi39il j ligl ENG 4793 Composite Materials and Processes 15 n aiquotTechllit i031 Wei ht IComponent 9 Function Percent Reactive monomers that rovide a Styrene 134 p cross linking structure Reactive monomers that rovide a Polyester 105 p cross linking structure Glass fiber 300 Reinforcement Calcium Filler increases bulk volumeand 400 carbonate reduces part cost Low profile 3 45 Controls part shrinkage a adent LPA 39 therm0plastic additive Provides free radicals to initiate lnItIator 100 bolvmerlzatlon IMa nesium g 070 Increases wscos y hvd rQXIde Zinc stearate 100 Lubricant mold release aoent GEM QEE l39 jtgi ill f39llitigigi ENG 4793 Composite Materials and Processes 17 if i ilj TEEhl lE El i HE High Strength SMC A Formulation Formulation Number SMC13 PHR Percent 1 8030 Resin 60 solids 100 2732 Source Rapp R 8 High Strength Molding Compounds Oct 2 Zinc siearate 3 032 1976 SPI RPCI Thennostat Press Molding Committee meeting 3 tButyl Perbenzoate 1 027 quot 4 MgO Dispersion 6 39 164 Type compound 1311 Strength SMC 5 Glass 1quot PPS518 256 6995 6 Total Compound 366 10000 B Compound Properties c Typical Physical Properties 1 Flex a1 Stren th 39 61000 1 Masterbatch VISCOSll y 600800 cps 2 119331 01515 Psi 250 2 lhour Thickened Viscosity 8001400 cps 3 Tensile Strength Psi 3039000 4 T 391 Mod 1 106 39 240 3 Time to 20 X 106 Viscosuy 4872 hrs 5 1215 llrenpactun ched 1 lein 215 39 612 dlm ctU t h dftlbl39 286 4 Sheet Weight 7 ozsq ft 7 Sf nkagz e m 1 GEpt rfgi l mega HT1114721332 ENG 4793 Composite Materials and Processes 18 zftia39nfTechMinotit jnglgit Polyester Polyesters can be thermosets or thermoplastics Thermoset polyesters such as those used in compression molding are formed from linear unsaturated thermoplastic polyesters which are crosslinked during a cure reaction Special features of polyester resins Does not emit gases byproducts during cure Most common ENG 4793 campesiie Materials arid Prueesses ig Epoxy Do not emit gases during cure Compared to polyesters Higher mechanical properties Longer cycle times Less desirable surface appearance ENG 4793 campesiie Materials arid Processes 20 Other resins Phenolic Urea Melamine All three of these emit gases condensation products during cure Gas emission can lead to voids in the final product an obvious disadvantage Georgi ENG 4793 CDmpDSltE Materials and PVUEESSES 21 39gi Tec Molding process Campressmn load llllllllllllllll gaming Mold eavily Initial charge ENG 4793 campesiie Materials arid Processes 22 SMC cycle charge placed eyei begins r P we erases Press apens Material ows 7 Cure and holding Coultng l s g T I 150 a 4 i E a 150 a E 2 3 g i 2 E g 140 r E a n i l 135 n o 10 20 an an so so 73 an Time 5 ENG 4793 CumpusltE Materials arid Processes 23 Geometry factors Wall thickness of part Charge area vs mold area Charge placement location Single or multiple charges ENG 4793 campesiie Materials arid Processes 24 Manufacturing Factors Mold wall heating Closing rate Maximum clamping force Gel time Mold filling should be complete before the resin gels Demolding time Time to attain a sufficient degree of cure to demold the part Geprgialiii ENG 4793 Composite Materials and Processes 25 32le Techl f l 1 Curing Time vs Mold Temperature for SMC sheets 10 3 CURE 64 Thickness TIME cm MIN 4 20 2 V10 025 0 1 A A 130 140 150 160 175 MOLD TEMPERATURE C FIG 5 13 Curing time versus mold temperature for SMC sheets Note that the shaded area represents undesirable molding conditions due to the exo exceeding 20039C After Ref 12 Viscosity variation of an SMC before and during the compression molding operation BefOre During Resin Molding Molding Viscosity Increasing MgO 39 Flow Thickening L days A seconds Gap FIG 5 14 Viscosity variation of an SMC before and during the compression 27 55537 molding operation Flow of various layers of an SMC charge during compression molding INITIAL CHARGE 7 LAYERS A FAST MOLD CLOSING SPEED B Stow MOLD CLOSING SPEED e i 39 a ll ll FIG 5 15 Flow of various layers of an SMC charge during Weston I molding at a high moldclosing speeds and b slow moldclash speeds C After Ref 15 Fiber orientation Planar twodimensional fiber orientation Fibers aggregate to form bundles Compaction of bundles to produce quotswirlingquot Principal direction changes throughout plaque because flow direction varies Most affected by amount of flow GeorgialIrut332g1343 133511 ENG 4793 Composite Materials and Processes 29 ii TEGhIl if l 1z Fiber orientation 1 mm quot Compression Winding Ggprgial lrf l39 i quot i if ENG 4793 Composite Materials and Processes 30 ziiii Tech r it l CARBON FIBER ATTRIBUTES 0 Moderate Density 0 Moderate to High Service Temperature 0 High Modulus gt Different Fibers 0 High Strength 0 Low to Moderate Strain 0 Conducting 0 Negative CT E 0 Anisotropic High Cost 91 Dram gure 1 The symmetrical timedimensional diamond lattice 0 Good Chemical Resistance 0 Poor Abrasion Resistance Inert Surface m 3 Figure 2 Closrpacked sheets of graphite Tensile Strength and stmnesa de on m quotmac mm m covalent bonds m the TheOry GPa Practice Range at bres 511000 600 230 700 5235 mat100 39SSStninUit 250350 56 10 20 3 35 239 15 03 Fibre em 1quot 39 Van der wants bonds Twist ed Less entered tore between eroticquot planes cryetelllte 0mm quotaquot Figure 3 The structure at carbon bre v 1 6 II 2 05 Figure 5 Graphitic plates lining aws in carbon bre from an micrographs Plates at a large angle to the fibre axis at A B H CH H CH1 EH2 CH CH c t ll Pel mlommle N N Nc Inert tyclusntlen 04 CH CH CH tIci 1 N N N N Olluttenlcyrhutten Corbemlgruw39iu Figure 6 PAN39DSSEU carbon bre Spatial puma Flgurc 8 Typical morphology of carbon films quot an 30 l 20 quot 39quot39 3 g C 10 39oro Skin Fl1lu 0 1000 2000 3000 390 Flgurc 4 The crystal orientalion angle 9 plotted against the lompcrcluro T L m IF rm GPal r5 J l 100 10 10 01 Gauge longquot an Flgura 9 The ms plotted against the gauge length of single bres showing an increase in strangth with a decrease in gauge length 12 0 rm 0 lamnun D menuser 3900 quot a mm A anonaw Amn1s m up 0 OM gums u o memo 800quot 13000 A quotIn A36 L M M 400 500 CW no can STRENGTH K3 Figure 80 Properties of Available Carbon Fiber 1 l l l l 1 34 KEVLAR 49 FIBER ATTRIBUTES 9 Moderate Density SG 145 Moderate Modulus E 19 msi High Strength 039 525 ksi Moderate Strain e 28 Negative CTE 2 pmm C Anisotropic Moderate Cost 201b Low Service Temperature 0 Insulating Good Chemical Resistance except water Moderate Abrasion Resistance Inert Surface requires activation Fig 4 Fibrillar structure of Kevlar aromd b a Loop break b Tensile failure Stress Tenmn k gdenier Strain 10 Dilute solution Higher concentration m t a random cailsl l i i ii a 3 2 1 2 9 L I c I o 7 7 L 5 I Comoressmn 20T gt m C a a n 39 I b 9 Paraade stressstrain behaviarintensii K b Cid Wanton mm 5352235321133quot g 3 pm m m M cm organic characterized by chain folds mis alignment and crystalline and amorphous regions Fi 2 Polymer states in solution a Flexible mal b Paraammod characterized by long straigh terrains 939 ecules lb Rigid molecules without folds parallel co the fiber axis crystalline Tooling ver1 Ggorgiall j ENG 4793 Composite Materials and Processes 1 e 1 Tech I 3 l Tool Design Options Cast Layup Machined Sprayedcast Electroformed GeorgiaH i7 ENG 4793 Composite Materials and Processes up i v TechLe keg Georgian l 1 3 ENG 4793 Composite Materials and Processes 3 2 Techirc ENG 4793 Composite Materials and Processes Georgian it A w l 39 Techiv it Mold Machining Georgiana 3 V1 Lil ENG 4793 Composite Materials and Processes 5 r Techiulrug Tool Considerations Physicals pressure temperature time operators Economics cost quality production rate useful service life Part Design configuration material tolerance size Process filament winding layup compression molding etc Georgia C ENG 4793 Composite Materials and Processes A Tech 7 Cast Composite Tool Fabrication closed mold for RTM 1 Create Master Pattern 8 3quot Mom Half a mum step process 9 Invert and Remove Parting Plate 10 Apply PVA Release 11 Apply Surface Coat 2 Define Parting Plane 3 Fabricate Parting Plate 4 Setup Pattern and Parting Plate 12 Cast Mold Half 5 Fabricate Containment 13 Separate MOId HalVeS Box 14 Remove Master 6 Apply PVA Release Pattern 7 Apply Surface Coat 15 Release and Season Mold Georgianal3511 ENG 4793 Composite Materials and Processes 7 Iil Tech r1131flail RTM Process SCHEMATIC DIAGRAM CLAMPING PRESS U RESININJECTION MOLD PART MACHINE RES N 3 2 AIR OUT 0 D MOLD I T 1 CLAMPING PRESS wov39EN FIBER PLACED IN MOLD PRIOR TO INJECTION Eli2 ENG 4793 Composite Materials and Processes 8 l 39 Tech l l39 Master Pattern Options Solids Model Plaster Plastic Faced Plaster PFP Polymer Styling Compounds Tooling Boards Castable Polymers Monolithic Graphite Wood Georgial l3 L331 17 rTECI39IJ39U E391lJI ENG 4793 Composite Materials and Processes 9 Plaster Plastic Faced Plaster PFP m N MODEL PLASTIC SPLASH FACED PLASTER PFP TOOL COMPOSITE PART Figure 513 Composite tool fabrication Georg ial I if quot all 39 EN G 47 93 Comp os ite Materials an d Pro cesses 10 Master Pattern Considerations Physicals durability impact resistance CTE mismatch Economics cost material labor Part Design detail tolerance size Process machinability hand work Geargiallrll3r1 quotElf24 ENG 4793 Composite Materials and Processes 1 1 131 71 I TEChf I311 15 Relative Tooling Costs Type Cost Index EpoxyGypsum Prototype Temporary Tools 03 Low Mass Laminated Tools Room Temperature 35 Polyester Epoxy High Mass Laminated Tools Temperature 58 Controlled Polyester Epoxy Mass Cast Tools Temperature Controlled Acrylic 58 Low Profile Polyester Epoxy Net Cast Aluminum 69 Electroformed Nickel Steel 12 15 Machined Steel 2050 Open Mold 10 V seman DH quotMethod of Mast Casting Molds for RTMquot Paper 3C 50th Annual Conference Composites Institute SPI February 1995 Georg ial li i 35 ENG 4793 Composite Materials and Processes 12 galaTechl lllr P u ltru s I o n ver1 Georgiai39im ENG 4793 Composite Materials and Processes 1 zEiiLiTechu t F1 i anquot an E Typical Pultrusion Process MAT nemroncsusur guy 1 Typical Pultrusion Process 1 Maten at Guides I n posite Materials and Processes Resin impregnatio Puller ultrusion Equipment Continuous Fiber Reinforcement Gantinmus fiber relntereement in mat earlier tabris terms are drawn thre h a resin hath ta neat eaeh fiberquot with a specially emulated Basin mixture The mated filters are assembled by farming guides and then drawn threugh a heated rile Cure at themesettieg resin is initiated by heat in the die and natal st in the rg n mix The rate at reaatien is matmiled by heating and me me tenets In t la The resulting high strength pretiie is eut in length ready tar use as it leaves the puitrusien machine Georgielilaquotquotquotquot quot3312 ENG 4793 Composite Materials and Processes 4 xiiiquotTeal life Hollow Structure PultruSIon Process 30quotquot um um i continuous an wuss muons 7 4 I uq 5 nmommwaom lt i3 5 nssm um o e r nurse on a OONTI UOUI an GEOFQi ici ENG 4793 Composite Materials and Processes 6 zisi Techi RIM ReactionInjected Molded Pultrusion Exploded View of Putruded Composite TANK 1A A o 39 Rm PULTRUSION 39 sunracmo an mx no 39 HEATED DIE conrmuouo ammo an 2 39 7 rfo i39o39o i i u u 39 i I CONVINUOUS STRAND I PULLERS 5M9 ovmo ONTINUOUI 81 5quot IA UBFAGINO HAT FIBERS Figure 6 Exploded View of Pultruded Composite 1 31 w ReactionIr acted Pultrusion ENG 4793 Composite Materials and Processes 8 Reinforcements Resms Rovings Thermoset continuous Polyester bulk Epoxy VIny ester Continuous strand mat ThermoplaStICS Chopped strand mat many Surface veils Georgjahm ENG 4793 Composite Materials and Processes 9 Georgiana ENG 4793 comPOSite Materials and Processes 10 tilt Techlmii ifTeamail Standard Structures Pultruded Products From small rod and flat sheet to huge lbeams pultruded structurals are available through construction materials 7 distributors throughout the country Composite structurals with 1 t 111 H strengths that allow substitution for steel structurals fill the I l 22 r demand for all types of fabricated building structures in most Em 39 i nd ustri es Georgial lm ENG 4793 Composite Materials and Processes 1 1 Georgiana ENG 4793 Composite Materials and Processes 12 ZEiiiifTechI tii 3331Tealmil y 1151 I Lu 39 r twisting External llange lentilie or Pultruded Bridges Pultruded 39 1 1 and s Ibeam I rrl lally ble to 1 quotesting ed by lemon I lipany f guide j in has Creek a ad for le 36 lcairier in the 1p and red red 1 lbs 1011 St or Fni tafil heavier tow Strongwell39s puiirudid doubletrained rippling by internallrsilanged 35inch cnrnnusire beam 33 3 fabrics 1W lll tilp laies carbon fiber in the i011 and 1 000001 anges Geurgiall ENG 4793 Composite Materials and Processes 14 iritif iTechilriiznling H 3 139Ic39339h quotIn Geargiall ENG 4793 Composite Materials and Processes 13 iiilfiTechlliiiiiill iir3r Uses of Pultruded Shapes Applications for Pultruded Shapes ConsumerRecreational Construction Corrosron Resrstant F h d E39eCtr39Ca39 Portableworkplatforms Bridgesand platforms S mgro S TianSformera39rdUCtSPacer Sign posts Floor gratings 83 battens St39CkS Lamp posts Handrails TentpOIGS Pole line hardware Rooftrim Europe Laddercages CB antennas Ladders Gutters Pipe supports Skate boards BUS barsupports Glazrngsystems Europe Stairs Toolhandles Motortop Sticks Green house structures Structural su orts pp SKIPOIGS Cable supporttrays Building panel sections Pipes and tubes H k t k Sign supportposts Weirplates OC eySIC S U39Shaped mOtorStOUter Signs Slideguides 39 Fence Posts wedges Highwaydelineatormarkers Suckerrods foroil wells Bike ags semcetrUCk booms Transportation Internaltanksupports Paddle shafts Switch actuators Lading bars in trucks and railcars 39 DemiSter blades BOWS and arrOWS FUSGtUbeS Kick plates 39 Sthturalsmpes Crossbows Trailerjampposts Wetscrubbersforpowerrndustry Golfshafts Cablesu orttras Subwaycontactrarl covers I pp y Flagpoles Bus luggage racks 39 Miscellaneous Pole vault poles Seating Heat shreldson Xerox copiers Flatsheetsforrefrigeratedtrucks Slatsforhog pens Xylophone bars Leafsprings Farm wagons umbrella Shafts te Materials and Processes 16 Pallets in food processing plants Snowmobile track stiffeners Mechanical Properties of Pultruded E glassPolyester Comparative Properties of Structural Materials Sheets Total fiber content content 70 60 50 40 d 30 Structural Property Pultruded Rod amp Bar Stainless Steel Low Carbon Steel weight percent 388 288 188 18 8 161 Glass COHtCHt bV weight 70 Mat content Flexural Strength psi 100 000 30 00035 000 28 000 weight percent 31 2 31 2 312 20 8 139 Flexural Modulus psi X 105 60 280 300 R Vm8 mat 3 0 1 24 03992 0 63 0 90 13916 Tensile Strength psi 100 000 30 00035 000 27 00033 000 Rovmgendcount 79 58 38 29 33 Tensile Modulus psi x 105 60 280 300 N 39 mt 13 quot 3 3 3 3 3 Impact Strength ftlbin 49 8511 Mat Weight 1quot 1395 1 5 15 15 1 Thermal Conductivity 5 96185 260460 T gjsgewh39 BTUhrsq ftOFin Longitudinal 3731 3324 2821 2655 2172 Speci c Heat BTUlbOF 024 012 010011 391 48392 3 395 31 s Rockwell Hardness scale 80H 90B 72B 222 32 332 322 332 Dlelectecsmnsh gt400 Tensile modulus VOltSm GPa Mei Speci c Gravity 250C 210 792 79 WWW if 3322 1333 1218 1334 Dens1tV 1bcu in 0072 029 029 Transverse 834 931 855 7 1 524 Thermal cooef oment Of 6 3 910 68 121 1 35 124 103 076 Expansmn 1nlnOF X 10 Flexural strength MPa ks longitudinal 4124 3759 3255 3386 1807 598 545 472 491 262 Gg rgiai39l Transvem 2041 3 1993 2200 1814 169 17 Ggargiai l ENG 4793 Composite Materials and Processes 18 girlTechliiinu 296 289 319 263 245 0301iTechlriliiizll Viscosity change of a thermosetting resin in a pultrusion die quotKFIBERRESIN 0 TEMPERATURE oov 390 s we 1 i i a TEMPERATURE 7 l 3 J P 2 J j 2 ll 3 o E l 0 K is VISCOSITY 5 331 E gci o 05 z lt D E 0 6 12 18 24 30 36 Temperature distribution along the length of a pultrusion die l i 24 400 39 39 7 m l a 300 i g t 30 iii PULLIMG SPEED 33 200 35 IllMIN 100 l l I39 I I I 7 I I D 6 1 2 18 2 4 30 36 42 48 54 PGSITIDN Ill THE DIE UH FIG 522 Temperamra distribution along the length of a Mansion die 20 After Ref 22 POSITION INCHES 19 Te FIG 5 21 Viscosity change of a thermosetttng resin in a pultrusion die Pull Force vs Time 1200 G 065 phr RSM 537 1000 e B130phrRSM537 800 Pull Force lb 600 quot quot quot39 quot E 200 i i i l 0 to 20 30 40 St Time from initiation of Pultrusmn Run minutes Figure 12 Pull Force vs Time for EPONW Resin 93109360 10033 Acceletated with Two Concentrations oi EPON CURING AGENT 9 RSM 537 I Georgial39i ENG 4793 Composite Materials and Processes 21 LE 1 if Teculfjsg L Pull Wind Process Anticleck wiee helicellywound inner layer Finished tube Axial inner layer Clockwise helicelly wound outer layer GQOI QEBi IT T ENG 4793 Composite Materials and Processes 22 xiigirl 39Techifi 34 qurgial i IiiL 39Techljii Pull Wind Process ENG 4793 Composite Materials and Processes 23 Problems Fiber wet out Fiber breakage Inadequate cure Too much heat burning decomposition Die jamming cure to the die ENG 4793 Composite Materials and Processes 24 Georgians 9511I Techijil MACHINE DRIVE RESIN BATH FILAMENT FEED quot HOOP WINDINGS MANDFIEL HELICAL WINDINGS t Filament Winding 39 3 M l 4 FILAMENT ver 1 CARRIAGE FIBER SPOOLS ENG 4793 Composite Materials and Processes 2 2 amp 1F2042 ENG 4793 Composite Materials and Processes 1 Georgialll Georgialim 1 LiiquotTechu1rz zt tiiitTecImu grzx GT s machine Filament winding machines ENG 4793 Composite Materials and Processes 3 Georgialjif quot m quot 13933 ENG 4793 Com H Georgialvin r q I i5iquotTechljLrE zi iziifTecther Creel tensioners Integral head resin wetout bath i u 7 l I mm TECHNULCIGV wc ENG 4793 Composite Materials and Processes 6 Geprgialiut ENG 4793 Composite Materials and Processes 5 Georg aljuL Ei TEGthir l 39 quot x za39ifTechu Lre Simulated tapered box beam wound on sixaxis computercontrolled filament winder Actual machine motion indicated by arrows Fi a lo Simulated tapered box beam wound on sixmi amtucotmollndl Elam winder Adqu machim indieull39d by rm Wet winding boxlike structures Gemgiant ENG 4793 Composite Materials and Processes 8 LitTechlili Layout of a computercontrolled filamentwinding machine Pivoting payout eye Rovnng creel and lensioners a 9 layout of a computercontrolled filamentwinding Mine 39 Workpiece Geometry G 39 39 39 9 mu 3 1l39v Spherical pressure I h Wt 7 ligan 6 Filamentqu spherical premm mack Ggorgialif 193 ENG 4793 Composite Materials and Processes 11 t 39TechuL BEFORE ROUND E3 STRAND PRESSURE VESSEL it 10 Gas ta n ks Georgial39ri 397 ENG 4793 Composite Materials and Processes 12 xiiHijiTechUita Aerospace Hydrospace and Military Applications Rocket motor cases Rocket motor insulators Solid propellent motor liners Nose cones for space fairings Rocket nose cones Rocket nozzle liners Jato motor APU turbine cases Highpressure bottles gas or liquid Vacuum cylinders Torpedo launching tubes Rocket launcher tubes Flame thrower tubes Missile landing spikes Deep space satellite structures Radomes lg niter baskets Wing dip tanks Helicopter rotor blades Thermistors Liquid rocket thrust chamber rocket exit cones Chemical rockets Chemical tanks Sounding rocket tubes Tactical bombardment rockets Tent poles Heat shields Artillery shell shipping grommet Artillery roundprotective cones Submarine uid pipes Submarine tanks and containers Submarine ventilation pipes Submarine hulls Underwater buoys Cryogenic vessels Electronic packages Submarine fainNaters Sonar domes Engine cowlings Patriot missile Soviet missile Georgiall ENG 4793 Composite Materials and Processes I 2l echlflil Georgialjl ENG 4793 Composite Materials and Processes 13 illiTechlr Commercial Applications Highvoltage switch irrigation pipes gear Oil well tubes Electrlcal contalners Ladders Decoratlve bqulngs Structural tubing supports Electrlcal condUIt Valves Water hea lng tanks Boat masts nghway stanchlons Lamp poles Prlnted CerUItforms Race track ralllng CerUIt breaker housmg Dnve Shafts Hi h volta e insulators Air brake cylinder 9 Antennadlshes Heatlng ducts Motor housmg Pontoons Georgiall ENG 4793 Composite Materials and Processes 15 alfTechlJL Sporting goods ENG 4793 Composite Materials and Processes 16 Glass epoxy filamentwound 9 footdiameter by 55foot long assembled railway tank car Large tanks Run 5 GI epoxy lunentowound 94me by 554mm tumbled nilvny tank cu Geor iall HT 9 l echti l ENG 4793 Composite Materials and Processes 17 ENG 4793 Composite Materials and Processes 18 Pipe machine and cure oven Gg rgiialii i f 39i wijtijzige ENG 4793 Composite Materials and Processes 19 tatTeammatea ight pole JAEv GEDr gli lI39 l ifiil i ilEggs ENG 4793 Composite Materials and Processes 20 CielTechno Typical Tools amp Geometry Produced MANDRELS mm w PLASTER LEACHABLE r4 4 H J COLLAPSIBLE RUBBER WW W 7 Wm Fv m m rewimr l 4 it 8W C97 7 NONREUSEABLE FOAM I r yyy rr H yi 39 quot quV r39 39x k xu ivi ka LIX J 903139 mkwowgiw AIRCRAFT WING FLAP 1F2044 lei 1985 BRIGHAM YOUNG UNIVERSITY n o u rutnurt ht C CUHCh ENG 4793 Composite Materials and Processes 21 Large selfdriven mandrel Gg irgljallm 17in ENG 4793 Composite Materials and Processes 22 iiiif Team11st A Delta IV Rocket Faring Mandrel Georgialiiti 39 1114 ENG 4793 Composite Materials and Processes 23 ierTechies 39 Framework for Plaster Mandrel Plaster shell Machined framework Heavywall tube Plaster support screen 0 6625 Fla 8 Framework for plaster mandrel 24 IJiiiiLquot E ILL Process Needs Prepreg High viscosity Latent curatives Advantages no mixing or QC at plant potential for high speed automated processing Disadvantages more costly compaction needed ENG 4793 Composite Materials and Processes 25 Wet Wind Low viscosity Long pot life Resin should gel Toxicity Advantages cheap one step no compaction Disadvantages poor resin control mixing at plant QC needed at plant GET Drgiial i 7T ifti74i 21 Techi iiif iiii Thermoset Resins Plus Minus small molecules react to brittle form larger ones after Part cure takes time and energy windingeasy processing may crack under thermal tight crosslinking provides cycling strong chemically hard and thermally resistant glass type of polymerization may cause volatiles which hurt Very easy to mOdifY by performance blending mixing tweaking and thumping old well known technology Ggargiial i ii at 39Iiuira 11 TE hl irfiltiii ENG 4793 Composite Materials and Processes 26 Thermoplastic resins Plus Minus molecule in fully reacted only heat and pressure neec39ed to fuse creeps or ows under remeltableflows and stress and heat heals defects no wet windonly new emerging technology for winding possibility forfully PREPREG form automated rapid manufacturing Gg rgiiali ENG 4793 Composite Materials and Processes 27 iiarijTechijgiiiizrllcziiti315 Conditions for Slipping or Bridging I 9 ns r Potantigi m w I am Mil I uni In Wind afiqu 39 Ge rgiial i ii i iiiiiiiiquotTechiiiitiZiLliaiiiigigjif l t 51mph conical 39 discontinuity 39Fig 7 Cardamhr awn bridging ENG 4793 Composite Materials and Processes 28 Winding pins for low angle winding GE r giialiT39T39i isifiiquotEli ENG 4793 Composite Materials and Processes 29 iifai39ii TEGhl l Special Filament Winding Methods qurgial i ii if zriizri Techi it iiif1 A lNTERNAL RIBS 7A SESS ERE INFLATABLE es 30 B PRESSURE FORMING
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