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Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.Tutorial: Engineering Technology
Topic: Plastic VI. Jetting
Prepared by: Ing. Vladislav Zelinka
EngineeringTECHNOLOGYPlasticJetting
Brielfy:Jetting of welded plastic (especially into multipart mould) are used for production of very shaped difficult products. Process is situated into the only (!) and quite fast productive operation. Cooled and rigid extrudates usually dont need any other corrections and they are directly used for assembly. Process has very stable (permanent) size and shape quality. Whole process is very easily automated.
Jetting machine (press):
Opening and closing device of moldPlasticizing cylinder Granulate Jetting cylinder GearMeasurement unit Operator and steering gearhydraulicsDivided moldCut through injection molding machine(plastic is injected into the closed mold)Opening and closing unitDivided moldPlasticizing and injecting unitPlastic granulateCylinder of injectionSteering worm driveinjectorDensifying steering wormClosing cylinderopening cylinderproductBackflow valveheatingplasticizing cylinderInjection molding machine
Jetting (into molds):
We use knowledge of forming and pouring during jetting
Granulated plasticheatingHeated plastic substanceFilling zonePlasticizing zoneMeasured zoneHeated and plasticizing extruder cylinder
Mold is closed, plastic is injected.Unit with divided moldCooling and take out of the productPlasticizing cylindermoldJetting holeClosing of the mold, cylinder bring upSpace in front of the wormWorking cycle of injection molding machineworm
Plasticizing unit------------- plasticizing worm -----------Shifting homogenization plastification batchingcylinder roll in injection fillingcylinder roll outUnit with mold Mold cooling Mold openingProduct take outMold closing Mold cooling
Summary:Jetting of welded plastic (especially into multipart mould) are used for production of very shaped difficult products. Process is situated into the only (!) and quite fast productive operation. Cooled and rigid extrudates usually dont need any other corrections and they are directly used for assembly. Process has very stable (permanent) size and shape quality. Whole process is very easily automated.
ACTIVITY I.:
Decide and choose the best solution of the problem:
1.) Jetting process is programmed in its all separate parts (heating, cooling, opening, closing, etc.)
Is it more complicated than at cutting process?
Yes / No / It isnt easy to determine
2.) Extrudate from injection molding machine gradually and slowly change their colorful shade.
Is it a fault? Yes / No / It isnt easy to determine
ACTIVITY II.:
Decide and choose the best solution of the problem:
3.) In the extrudate there is a part of a component of different color then the rest.
Is it a problem? Yes / No / It isnt easy to determine
4.) Extrudate isnt quite finished in one place the material is missing.
Is it a fault? Yes / No / It isnt easy to determine
VOCABULARY:
Doughy substancetstovit (hmota)Multi-part moldvcedln (forma)repeatabilityopakovatelnost (vroby)Automated processautomatizovateln (proces)plastificationplastifikacejettingvstikovnHydraulic meanshydraulick (zazen)OpeningotevrnClosinguzavrnSteering warmnek
Resources:
* Wikipedie internetov encyklopedie (cs.wikipedia.org)* Technick Univerzita Liberec (www.ksp.tul.cz)* ENGEL CZ s.r.o. (www.engelglobal.com)* Dillinger, J. a kol. Modern strojrenstv pro kolu a praxi. Praha: EUROPA SOBOTLES, 2007. ISBN 978-80-86706-19-1.* Muk, J. Management ve vzdlvn dosplch. Praha: EUROLEX BOHEMIA, 2000. ISBN 80-7361-269-7.* Operan program Vzdlvn pro konkurenceschopnost, ESF 2007 2013.* Dostupn na: http://www.msmt.cz/eu/provadeci-dokument-k-op-vzdelavani-pro-konkurenceschopnost
