injection injection manufacturing process producing parts material mould injection performed host materials including metals process called glasses commonly material fed heated barrel mixed forced mould cavity configuration cavity product designed usually industrial designer engineer metal usually steel aluminum precision form features desired injection widely manufacturing variety parts smallest components entire body panels cars advances printing technology melt injection lower temperature simple injection parts injection carefully designed facilitate process material desired shape features material mould properties machine taken account versatility injection facilitated breadth design considerations possibilities applications injection create things wire packaging bottle caps automotive parts components pocket musical instruments parts piece chairs small tables storage containers mechanical parts including gears plastic products available today injection common modern method manufacturing plastic parts ideal producing high volumes object process characteristics injection uses ram screw type force plastic material mould cavity shape mould commonly process volume considerably higher prevalent characteristics highly suitable injection ease recycled versatility allowing wide variety applications ability flow heating element safety ejected injection barrel timely manner chemical occur causing screw check seize potentially damaging injection machine injection consists high pressure injection raw material mould shapes desired shape single cavity multiple multiple cavity cavity identical form parts unique form multiple different single cycle generally tool aluminum suitable certain applications aluminum typically ill suited high volume production parts narrow dimensional inferior mechanical properties prone wear damage injection cycles aluminum cost effective low volume applications mould costs time considerably reduced steel designed process million parts lifetime cost hundreds thousands dollars typically raw material fed heated barrel screw entrance barrel temperature increases van der forces resist relative flow individual chains weakened result increased space molecules higher thermal energy states process reduces enables flow driving force injection unit screw delivers raw material forward mixes thermal reduces required heating time material adding significant heating material feeds forward check valve collects screw volume known shot shot volume material fill mould cavity compensate provide approximately total shot volume remains barrel prevents screw transfer pressure screw mould cavity material gathered material forced high pressure velocity forming cavity prevent spikes pressure process normally uses transfer position corresponding cavity screw shifts constant velocity constant pressure control injection times second screw reaches transfer position packing pressure applied completes mould filling thermal high relative materials packing pressure applied gate cavity entrance small size gate normally place entire thickness gate material enter cavity accordingly screw material cycle material mould ejected stable cooling duration dramatically reduced use cooling lines circulating water oil external temperature controller required temperature achieved mould opens array etc driven forward article mould closes process repeated shot mold separate materials incorporated type injection add soft touch product multiple colors produce multiple performance characteristics typically different chemical components injected barrel components immediately begin chemical reactions eventually material single connected network molecules chemical reaction occurs fluid components permanently transform solid injection barrel screw problematic financial repercussions barrel vital typically means residence time temperature chemical injection unit residence time reduced barrel volume capacity cycle times factors led use isolated cold injection unit reacting chemicals isolated hot mould increases rate chemical reactions results shorter time required achieve solidified component solidified close injection system chemical mould opens parts mould closes process repeats pre components inserted cavity mould open allowing material injected cycle form process known insert allows single parts contain multiple materials process create plastic parts protruding metal screws allowing repeatedly technique mould film attached plastic containers parting line gate marks pin marks usually present final features typically desired nature process gate marks occur gate joins melt delivery channels runner forming cavity parting line pin marks result minute wear adjacent parts relative motion dimensional differences mating surfaces contacting injected dimensional differences attributed non uniform pressure induced injection non uniform thermal expansion mould components experience rapid cycling injection packing cooling phases process mould components designed materials thermal expansion factors simultaneously accounted astronomical increases cost design processing quality monitoring mould designer position aesthetic hidden areas feasible history american inventor brother patented injection machine machine relatively simple compared machines use today worked like large needle plastic heated cylinder mould industry progressed slowly years producing products collar stays buttons hair german invented forms eventually available powder form readily injection developed injection press patented injection industry expanded rapidly 1940s world war created huge demand inexpensive mass produced products american inventor built screw injection machine allowed precise control speed injection quality articles produced machine allowed material mixed injection colored recycled plastic added virgin material mixed thoroughly injected today screw injection machines account vast majority injection machines 1970s went develop gas assisted injection process permitted production complex hollow articles cooled quickly greatly improved design flexibility strength finish manufactured parts reducing production time cost weight waste plastic injection industry evolved years producing buttons producing vast array products industries including automotive medical consumer products toys packaging construction examples best suited process referred including total number available materials injection increased rate year approximately materials available trend began available materials include blends previously developed materials product designers choose material best set properties vast selection major criteria selection material strength function required final cost material different parameters taken account common like examples comparatively recently plastic springs possible advances properties practical applications include outdoor equipment equipment injection machines consist material injection ram screw type heating unit known presses hold components shaped presses rated expresses force machine exert force keeps mould closed injection process vary tons tons higher figures comparatively manufacturing operations total clamp force needed determined projected area projected area multiplied clamp force tons square centimeter projected areas rule thumb tons products plastic material stiff require injection pressure fill mould clamp hold mould closed required force determined material size larger parts require higher force mould mould die common terms describe tool produce plastic parts expensive manufacture usually mass production thousands parts produced typical constructed hardened steel pre hardened steel aluminum copper choice material build mould primarily economics general steel cost construct longer lifespan offset higher initial cost higher number parts wearing pre hardened steel wear resistant lower volume requirements larger components typical steel scale hardened steel heat treated far superior terms wear resistance lifespan typical ranges aluminum cost substantially designed modern equipment economical tens hundreds thousands parts copper areas mould require fast heat removal areas shear heat generated manufactured electrical discharge processes injection die pulls mould design mould consists primary components injection mould plate mould plate components referred plastic enters mould gate injection mould seal tightly injection barrel machine allow plastic flow barrel mould known cavity directs plastic cavity images channels faces plates channels allow plastic run referred runners plastic flows runner enters specialized gates cavity geometry form desired required fill runner mould comprises shot trapped air mould escape air ground parting line mould slightly smaller holes retaining trapped air allowed escape compressed pressure incoming material corners cavity prevents filling cause defects air compressed burns surrounding plastic material allow removal mould mould features direction mould opens parts mould designed mould opens components called sides appear parallel direction draw axis position hole insert parallel movement mould opens closes typically angled slightly called draft ease release mould insufficient draft cause damage draft required mould release primarily dependent depth cavity deeper cavity draft necessary taken account determining draft required skin thin tend shrink form cooling warp twist crack cavity pulled away mould usually designed reliably remains mould opens draws runner parts falls freely ejected tunnel gates known submarine mould gates located parting line mould surface opening surface mould parting line cut mould runner system mould known knockout circular placed half mould usually half push finished product runner system mould article etc cause undesirable impressions distortion care taken designing mould standard method cooling passing usually water series holes mould plates connected form continuous heat mould absorbed heat hot plastic keeps mould proper temperature plastic efficient rate ease maintenance divided pieces called sub assemblies called blocks chase blocks mould variations complex parts formed complex sections called cavity perpendicular draw direction form features mould opened pulled away plastic stationary angle stationary mould half enter slot cause backward moving half mould opens ejected mould closes closing action mould causes forward angle allow previously parts allow new plastic layer form referred system allow production piece tires wheels shot multi shot designed single cycle processed specialized injection machines injection units process actually injection process performed twice smaller margin error step base color material basic shape contains spaces second shot second material different color injection spaces keys instance process markings wear remain heavy use mould produce copies parts single shot number impressions mould incorrectly referred tool impression called single impression cavity mould mould parts likely referred multiple impression cavity mould extremely high production volume like bottle caps cases multiple cavity mould series different parts tool family parts related examples include plastic model kits mould storage manufacturers great lengths protect custom high average costs perfect temperature humidity level maintained ensure longest possible lifespan custom mould custom rubber injection stored temperature humidity controlled environments prevent tool materials tool steel mild steel aluminum suitable prototype short production runs modern hard aluminum proper mould design easily capable life proper mould maintenance built main methods standard standard conventional form historically method building injection technological development predominant means making complex accurate mould details time traditional methods electrical discharge spark erosion process widely mould making allowing formation shapes difficult machine process allows pre hardened shaped heat treatment required changes hardened mould conventional drilling normally require mould followed heat treatment simple process shaped usually copper slowly lowered mould surface period hours immersed oil voltage applied tool mould causes spark erosion mould surface shape cost number incorporated mould directly costs fewer require far work limiting number turn result lower initial manufacturing costs build injection mould number play vital role costs complexity design complexity incorporated factors surface finishing tolerance requirements internal external threads fine detailing number incorporated details feature causing additional increase mould cost surface finish core cavity influence cost rubber injection process produces high yield products making efficient cost effective method consistent processes involving precise temperature control significantly reduces waste material injection process injection plastic fed forced ram heated barrel slowly moved forward screw type plastic forced heated chamber melted advances melted plastic forced rests mould allowing enter mould cavity gate runner system mould remains cold plastic soon mould filled injection cycle sequence events injection mould plastic called injection cycle cycle begins mould closes followed injection mould cavity cavity filled holding pressure maintained compensate material step screw turns feeding shot screw causes screw shot prepared sufficiently cool mould opens ejected scientific versus traditional traditionally injection portion process constant pressure fill pack cavity method allowed large variation dimensions cycle cycle commonly scientific method pioneered injection plastic stages allow better control dimensions cycle cycle commonly called shot shot industry consistency cavity filled approximately velocity speed control pressure sufficient allow desired speed pressure limitations stage undesirable cavity machine switches velocity control pressure control cavity packed constant pressure sufficient velocity reach desired pressures required allows dimensions controlled inch better different types injection processes injection processes covered conventional process description important variations including limited die casting metal injection thin wall injection injection liquid rubber comprehensive list injection processes found process like industrial processes injection produce flawed parts field injection performed examining parts specific defects addressing defects design mould characteristics process trials performed production runs effort predict defects determine appropriate specifications use injection process filling new unfamiliar mould time shot size mould unknown technician tool perform trial run production run starts small shot weight fills gradually mould achieved small holding pressure applied holding time increased gate freeze time occurred gate freeze time determined increasing hold time weighing weight change known gate frozen material injected gate time important determines cycle time quality consistency product important issue economics production process holding pressure increased parts free weight achieved defects injection complex technology possible production problems caused defects process methods industrial scanning help finding defects externally internally tolerance specified parameters dimensions weights shapes angles etc maximize control setting usually minimum maximum limit thickness based process injection typically capable equivalent grade possible tolerance millimeters specialised applications low linear features achieved mass production surface finishes better obtained rough surfaces possible power requirements power required process injection depends things varies materials manufacturing processes reference guide states power requirements depend material specific gravity melting point thermal size rate table page reference previously mentioned best illustrates characteristics relevant power required commonly materials robotic means smaller size parts permits mobile inspection system examine multiple parts quickly addition mounting inspection systems automatic devices multiple axis robots remove parts mould position processes specific instances include removing parts mould immediately parts created applying machine vision systems robot extended free mould moves holding location directly inspection system choice depends type product general layout manufacturing equipment vision systems mounted robots greatly enhanced quality control insert parts mobile robot precisely determine placement accuracy metal component inspect faster human gallery
Injection moulding