Cycle Time thoughts'

Who is responsible for achieving the quoted cycle time?  Where does it come from?  The real question may not be what cycle time was quoted, or how was it based, but was it past along to all the parties involved?

The processor is ultimately responsible, i.e. he must meet a quoted cycle time to meet cost and make a profit. In the building of a new tool, has anyone passed on the information as to what the cycle time is supposed to be?  According to a brief sentence or two from the SPI mold makers division, cycle time is the responsibility of the processor.  This is not an acceptable answer. In concurrent engineering, its the information of all up front that should be considered, and shouldn't cycle time be discussed at that point, becoming a concern for all.  (This of course based upon using that process)

I agree to a point the SPI notion above but…. In a true sense, that is an excuse. (Sorry if I offend the toolmakers). The toolmaker needs to be the review of what is going on with the tool.  He is the one reviewing the finished designs, both the part and tool, and should question the mold design if he sees things that may concern him. The tool is in fact a factory that he is building to produce those plastic parts, at a given rate.

The tool designer is the one whom should calculate the how, a tool is to be built and all the engineering feats of the tool. He needs to have the data / information before he starts to design. This data need be passed on to the toolmaker who in turn acts as a check for the designer.  He should have a basic understanding of BTU content and conductivity of the steels he is using, along with the plastic to be processed. Before building the tool the information given to the toolmaker should include:
 What is the material to be run?
 What is its processing temperature?
 What is the recommended steel temperature?
 What cycle time are we aiming for?

 Than by using past experience or some basic equation the toolmaker can equate, whether or not things are good.
Remember that the tool is basically a heat exchanger in that so many BTU's go into it and we need to take those away, to be able to cool the part down to a temperature at which it well eject. Does this put a burden on the toolmaker? No and Yes, because if the relationship is truly a partnership we all share responsibility and are aiming for the same goal. In many cases, the tool designer is the toolmaker, thus it is important to get all the information.

Thanks for the time.
Steven L Silvey
Senior Technical Service
General Polymers Division
Ashland Distribution