Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky. Tutorial:

Prezentace na téma: "Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky. Tutorial:"— Transkript prezentace:

1

2 Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky. Tutorial: Engineering technology Topic: Plastic X. – Tools Prepared by: Ing. Vladislav Zelinka

3 Engineering TECHNOLOGY Plastic Tools

4 Briefly:  The Mold is most often the tool for plastic processing.  The mold is divided into two parts when shape and process of the dividing plane is very important.  Mold deaeration must be in dividing plane so that the holes are not silted up by stiff plastic.  Mold heating or cooling is automated and result from the mold size and extrudate.  Molds are probably the most expensive tools and that is why it is necessary to take good care of them.

5 What is a mold?  Mold is a tool with a hollow which has a shape of negative of finished product.  The hollow must be slightly enlarged so the product could shrink into the correct proportions while cooling.  All inner active surfaces of the mold must be at most perpendicular (to 90°) to the surface between the mold halves.  But it is better when bigger depths have adequate inclination, mainly the cores must have necessary draft so they could be taken out of the holes.  All inner sharp mold corners, hot plastic flows around them, must have optimal radius so that the flow is continuous.  Outer shape and mold proportions are typified and they respect inner machine space – presses.

6 Manufacturing accuracy:  All parts which should seal against hot plastic penetration must be lined up with adequate accuracy and with optimal allowance.  Fit refers mainly to ejectors and cores which could very quickly seize up in the holes and cause mold malfunction.  Dividing plane is large and that is why just close by the extrudate outline must fit (match) very tightly without allowance.  The Larger and more voluminous extrudate is, larger and heavier mold is.

7 Mold material for plastic.  Regarding to low temperature of forming plastic is enough to use ordinary metal for the mold. But better is such steel which can be permanently surface finished according to the extrudate requirements and which doesn´t oxidize so much.  Mainly for Perspex jetting it is good to use tough steel which surface can be very well polished.  Some outer parts of the mold can be from non-rusting steel, and large and not so stressed parts can be from light duralumin.

8 Summary:  The Mold is most often the tool for plastic processing.  The mold is divided into two parts when shape and process of the dividing plane is very important.  Mold deaeration must be in dividing plane so that the holes are not silted up by stiff plastic.  Mold heating or cooling is automated and result from the mold size and extrudate.  Molds are probably the most expensive tools and that is why it is necessary to take good care of them.

9 ACTIVITY I.: Decide and choose the best solution of the problem: 1.) The mold has gross weight around 60kg, on the upper side there are inner threads for pulling eyes. Will you use crane for manipulation? Yes / No / It isn´t easy to determine 2.) It is necessary to change one worn out simple sliding core inside the mold. We have similar new one but we do not know which steel is it made up. Do we examine the steel quality? Yes / No / It isn´t easy to determine

10 ACTIVITY II.: Decide and choose the best solution of the problem : 3.) Product should have structured and matt surface. Do we enlarge drafts in the mold? Yes / No / It isn´t easy to determine 4.) Extrudate will have very smooth – almost mirror – surface. Do we polish the mold hollow? Yes / No / It isn´t easy to determine

11 VOCABULARY MoldForma DeaerationOdvzdušnění Dividing planeDělící forma Mold tightnessTěsnost formy HeaterVyhřívací těleso Cooling ductChladící kanálky Alignment pintVodící kolíky EjectorVyhazovač Surface polishLeštění povrchu Line upslícování

12 Resources: * Wikipedie – internetová encyklopedie (cs.wikipedia.org) * Technická Univerzita Liberec (www.ksp.tul.cz)www.ksp.tul.cz * ENGEL CZ s.r.o. (www.engelglobal.com)www.engelglobal.com * Dillinger, J. a kol. Moderní strojírenství pro školu a praxi. Praha: EUROPA SOBOTÁLES, 2007. ISBN 978-80-86706-19-1. * Mužík, J. Management ve vzdělávání dospělých. Praha: EUROLEX BOHEMIA, 2000. ISBN 80-7361-269-7. * Operační program Vzdělávání pro konkurenceschopnost, ESF 2007 – 2013. * Dostupné na: http://www.msmt.cz/eu/provadeci-dokument- k-op-vzdelavani-pro-konkurenceschopnost