Injectionmoldtooling通用公司

1、ge plasticsegoodparttooling considerationsresinsupplierend usermoldermold makertooling considerationstooling developmenttoolingprocessing problems black specks gloss jetting delamination fingerprinting plate-outtooling development weld lines burn marks dimensional control streaking sticking brittlen

2、essprocessing problemstooling development short shotsflashsinks/voids warpage splay/silver streaking gate blush/haloprocessing problemstooling development inconsistent cyclethe worst problemprocessing problemstooling development- anonymous“thecheapesttoolis the onethatworks”tooling developmentcustom

3、s andpracticesof themoldmaking industryclassificationsof injectionmolds forthermoplasticmaterialsa guide for the purchaseror manufacturer of thermo-plastic injection moldsup to 400 tons and 400 tons and over. s iptooling developmentmoldmakers divisionthe society of the plastics industry1275 k street

4、, n.w., suite 400washington, dc 20005(202) 371-5200tooling developmentmold typestoolingtypes of molds (tools) (dies)“a” series“b” series“t” series“x” seriesclass aclass bcollapsible coretwo platethree plateacceleration ko“a” side injectionliftercamrunnerless - internally heated - externally heatedpr

5、ototypemudetc.tooling mold typestooling mold typestwo plate designexploded viewb platea”platetop clamping plateejector housingsupport plateelector retainer plateejector plateleader pinreturn pintooling mold typestwo plate designtooling mold typesstandardtwo platemoldsprue bushing“a” plateclamping pl

6、ate“b” platesupport plateejector platetooling mold typesparting linetooling mold typestwo platemoldejectiontooling mold typestwo platemoldejectionejected partinjection molding toolinginjection molding toolingtooling mold typessupport plateejector retainer plateejector plateejector housingb platex pl

7、atea platetop clamping platethree plate designtooling mold typesthree plate designclosedtooling mold typesmain leader pinparting line 1tooling mold typesparting line 1parting line 2tooling mold typesparting line 1parting line 2tooling mold typesparting line 1parting line 2partingline 3partrunnerspru

8、ebushingstooling sprue bushings heated sprue - helical heaters - gas pipe non-heated spruesprue bushingstooling sprue bushingscold sprue bushingtooling sprue bushingssprue bushinggas pipeheater bandgas pipestooling sprue bushingshot sprue bushinghelical heaterthermal shutofftooling sprue bushingsrun

9、nerstooling runnersmaterial flows only through molten portion of runnerouter skin chills on contact with mold surfacerunners flowtooling runnersrunners designfull round mostefficienttrapezoidalgoodhalf roundnot goodpltooling runnersrunnerstrapezoid profilesrdrd rd w d1/83/161/83/161/43/161/45/161/45

10、/167/165/163/81/23/8equivalent round runnerdesign alternativetooling runnerssprue pullerreversetaperbestz pullergoodgroovetrouble-somesucker pinnotrecommendedtooling runnersrestrictivepreferredtooling runnersa small increase in radius dramatically increases the flow through the runner.r = radiusq =

11、volumetric flow rate q = 8n lq proportional to r2 n r p2tooling runnersflow directioncold slugwellround cross section(3/16 “ to 3/8 “ dia.)short lengthcold slug wellscold slugwelltooling runnersunbalanced systemaaaabbbbtooling runnersartificially balanced1/8”1/4”3/8”1/2”1/2” dia”tooling runnersbalan

12、ced systemaaaaaaaatooling runnersrunnerless moldingtooling runnerless moldinghot runner benefits faster cycles - 15-20% faster eliminates material waste - no sprues or runners improves part quality - less stress - better appearancetooling runnerless moldingrunnerless molding systems:incoekonad-m-epl

13、asthing hot onerama cool onehuskymoldmasterfastheatspear europe & asiaspruelesshomemadecompression sealplugmoldmakerschoicediameter fitsealtooling runnerless moldingcavity plate = 500manifold = 5000thermal expansion of steel.00000633 per inch per degree 6 in. = .017 in.12 in. = .034 in.18 in. =

14、.051 in.tooling runnerless moldinggatingtooling gatingdirect sprue gateedge gatefan gatetunnel gatesingle, multipletab gatesdisk gatering gateflash gatediaphragm gatemodified “s” gatepin gatejump gatevalve gate etc.types of gatingtooling gatingdirect sprue gatemolded partspruetooling gatingpartrunne

15、rgatelandfan gatetooling gatingcold slugwellradiusfan gatetooling gatingedge gateland length0.030inches maximumtooling gatingsingle tab gatemultiple tab gategatetab sprue6 in. max12 in. maxtab spruegategatetab tooling gatingknit linemultiple tab gatetooling gatingdisk or diaphragm gaterunnerpartrunn

16、erspruetooling gatingtooling gatinggatepartrunner diskgatering gaterunnerparallel runnergateflash gateparallel runnertooling gating0.020 land length0.050900tooling gatingpin point gatingmolded partsprueparting linetunnelgatezero land lengthknock out pingrind flat on gate side, min. 20fasten pin head

17、 to prevent turningtunnel gatetooling gatingtunnelknock out pinmolded partsprueparting linegatezero land lengthgrind flat on gate side, min. 20fasten pin head to prevent turningtunnel gatetooling gatingrrgatecashew gatetooling gatingknit linegate areahigh stressescosmeticsimpacttooling gatingknit li

18、ne and gate areainjection molding toolingvalve gate shut off systembushings are opened for injectioninjection molding toolingvalve gate shut off systema fills, bushing a closesinjection molding toolingvalve gate shut off systemb fills, bushing b closesventingtooling ventingparting line.001-.0025dept

19、hgatevent.060 min.note step.500.050min.tooling ventingclearance around knockout.0025ejector pintooling ventingtemperaturecontroltooling temperature controlthe most efficient cooling systems are those which operate such that the inlet and outlet coolant temperatures are within 100 of each otherfluid

20、velocity ft./sec.turbulent flowtransition areaheat transfer efficiencywater coolantheat transferbtuhr x ft2 x 0f0.51.01.52.0laminar flowtooling temperature control120125125135135145130140140130150145ooooooooooooinouttooling temperature control balanced cooling uniform cooling maximum temperature dif

21、ferential of 10 oftooling temperature controlinjection molding toolingmold cooling series bubbler inoutpoorpinbladeinjection molding toolingmold cooling parallel bubbler incorrectoutpintubeejector mechanismstooling ejector mechanismspin diameter is as large as possiblepins are as numerous as possibl

22、epins exert a uniform force on molded parts tooling ejector mechanismsfactors effecting ejection forcesidewall draftsidewall contact areasidewall polish/texturingdegree of packingmold temperaturemold releasetooling ejector mechanismstexturing and draft angletooling texture and draft angledraft angle

23、draft angle1/2o mintooling texture and draft angleadditional 1 degree per mil in depth of texturedraft angle for textured sidewalltooling texture and draft anglequality of texture varies with type of steelidentical grades of steel can etch differentlytexturing guidelinestooling texture and draft ang

24、le enhances styling and aesthetics reduces rejectstexturing mold finishestooling texture and draft anglecore pullstooling core pullshydraulic core pullsplasticcorepincored holecorehydraulic cylindercavitytooling core pullstooling core pullstooling core pullstooling core pullsprototypingtooling proto

25、typingprototypetool materialsaluminum beryllium alloysmild steelp20steelthermal conductivity(btu/hr ft of)956526219.42aluminum thermal conductivity is 4.5 times that of p20 steeltooling prototypingparts cool more quickly in aluminum toolingparts shrink less in aluminum toolingshrink is different in

26、steel and aluminumtooling prototypingchoose prototype tool materials afterconsideration of : dimensional criteria of part surface finish required wear resistancetooling prototypingpart design dictates performanceperformance dictates materialtooling summaryplastic part production material dictates to

27、olingmold typesmold materialssprue bushingsrunnersgatesventingejectorsdraft anglemold finishestemperature control prototypingshrinkagetooling summarymold design goodparttooling considerationsge plasticsejector mechanisms design80 to 100 insidewall contactpin diameter1/8”1/4”3/8” requirespin bearing

28、surface1 in21 in21 in21 in pinbearing surfacenumberof pins8220922tooling ejector mechanismsinternal threadsnap lidcommon undercutstooling ejector mechanismsdetail on sideexternal threadcommon undercutstooling ejector mechanismslatch or hookbobbin or spoolcommon undercutstooling ejector mechanismsblade atdeep ribsrounds pinssleeveejectorbossejectmold pinstationarypartsstripper platestationary forceknock outbarsgood knock outfor round partsused aroundpins & bossestooling ejector m