What are the differences between an open loop and closed loop injection molding machine?

The difference between open loop and closed loop injection moulding is to do with the type of control system used. An open loop system changes the input signal relative to the pre-defined perameters of the system. A closed loop system uses a feedback signal ie it takes information from a point in the process usually the end and sends it back to the start where the system adjusts the input accordingly. To fully understand this I would suggest getting a good book on control theory. I use 'Modern Control Engineering' by Katsuhiko Ogata. Many people also use Richard Dorf but I find Ogata easier to follow. AuthorOgata, Katsuhiko.TitleModern control engineering / Katsuhiko Ogata.