Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/ je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky. Tutorial: Engineering Technology Topic: Plastic VI. – Jetting Prepared by: Ing. Vladislav Zelinka

Engineering TECHNOLOGY Plastic Jetting

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 don´t 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 mold Plasticizing cylinder GranulateJetting cylinder Gear Measurement unit Operator and steering gear hydraulics Divided mold Cut through injection molding machine (plastic is injected into the closed mold) Opening and closing unit Divided mold Plasticizing and injecting unit Plastic granulate Cylinder of injection Steering worm drive injector Densifying steering worm Closing cylinder opening cylinder product Backflow valve heating plasticizing cylinder Injection molding machine

Jetting (into molds): We use knowledge of forming and pouring during jetting Granulated plastic heating Heated plastic substance Filling zone Plasticizing zone Measured zone Heated and plasticizing extruder cylinder Mold is closed, plastic is injected. Unit with divided mold Cooling and take out of the product Plasticizing cylinder mold Jetting hole Closing of the mold, cylinder bring up Space in front of the worm Working cycle of injection molding machine worm

Plasticizing unit plasticizing worm Shifting homogenization plastification batching cylinder roll in injection filling cylinder roll out Unit with mold Mold cooling Mold opening Product take out Mold 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 don´t 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 isn´t easy to determine 2.) Extrudate from injection molding machine gradually and slowly change their colorful shade. Is it a fault? Yes / No / It isn´t 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 isn´t easy to determine 4.) Extrudate isn´t quite finished in one place – the material is missing. Is it a fault? Yes / No / It isn´t easy to determine

VOCABULARY: Doughy substancetěstovitá (hmota) Multi-part moldvícedílná (forma) repeatabilityopakovatelnost (výroby) Automated processautomatizovatelný (proces) plastificationplastifikace jettingvstřikování Hydraulic meanshydraulické (zařízení) Openingotevírání Closinguzavírání Steering warmšnek

Resources: * Wikipedie – internetová encyklopedie (cs.wikipedia.org) * Technická Univerzita Liberec ( * ENGEL CZ s.r.o. ( * Dillinger, J. a kol. Moderní strojírenství pro školu a praxi. Praha: EUROPA SOBOTÁLES, ISBN * Mužík, J. Management ve vzdělávání dospělých. Praha: EUROLEX BOHEMIA, ISBN * Operační program Vzdělávání pro konkurenceschopnost, ESF 2007 – * Dostupné na: k-op-vzdelavani-pro-konkurenceschopnost