Setting Shot Size After Closing A Cavity

I was just asked…   Ponce “We are confused on how to calculate the new shot size when we close off a cavity.  Our question is do we calculate shot size minus the Xfer point or do we calculate from the shot size to the cushion.”   My Response Typically, you will maintain the transfer […]

Calculating Residence Time

I was recently asked the question…               Kevin “Do you have any way of easily calculating the residence time in screw / barrels?”   My Response Most general purpose screws contain approximately 1-2 shots within the flights depending on the geometry. To calculate the residence time you will have to know your part volume, […]

Submarine Gating for Polycarbonate…

I received this interesting question through linked-in… Linked-In Member Currently we have provided edge gating for appx. 25 dia @ 1.3 thk mm PC part. We are planning for tunnel or submarine gate… When using polycarbonate material, what kind of gating should be provide? My Response When utilizing a submarine gate with PC, there are […]

Correcting for Cavity Imbalance…

I received this inquiry the last week… Kevin I have been using the intelligent moulder worksheets and have found poor fill balance in our hot runner tooling. I have had variations from 14 to 22%. How do you get to 6% or less? note: The Dynamic Cavity Imbalance Test measures the imbalance by comparing the part weights from each […]

“Steel Safe” Runner Designs

I was recently asked the question… JeffWe are about to build a 2 plate family mold but are not sure which molding machine we will use it in. We may also process two grades of material in the mold. How will these factors effect the size we should cut our runners? My ResponseOften, the feed […]