Why eject?

Ejector pins are a constant source of flash, they break, and the ejection system is a major component on the mold.  If the mold is hung improperly the ejector plate can bend.  Hooking up the ejector system takes time in the mold hanging process.  Here are two hints that can save you money:

Pre-eject:  Who says you have to eject when you finally hit the full open position?  Nobody.  Why not begin ejection immediately after the suction break or when you are clear of any mechanisms.  So long as the ejector system is moving slower than the mold it won't push the part back into the cavity.  Remember the rule of thumb is the opening should be no more than 2.5 times the largest dimension of a falling part.  How to folks tend to set the full open? It's usually the width of the fattest setup technician with a screwdriver digging out a stuck part.  Opps.

No ejector system – if you are molding some kind of a box, think about this:  Many of the mold supply houses sell what are called Poppet Valves.  You press these valves into the cavity.  When the mold opens to a certain point, you fire compressed air into a circuit and the air “blows” the part off.  No ejector system to move, no pins to break, cycle time saved.  Interesting.

Do the math. Keep the profits.

Call with questions
Bill Tobin – President WJT Associates
wjtassociates.com
303 604 9592