Tag Archive for: Mold cavity filling time

Mold Fill time is another name for melt front advancement. Our fill time animations provide the visualization of the part cavity filling before your very eyes!  As you can see from the animation, phenomena such as race tracking, weld lines formation and air trap formation are easy to visualize. Race tracking is when the plastic flow fills the thicker section of the parts prior to filling the thinner sections.  Race tracking moves the plastic in non intuitive ways which will trap air in the tool in places that are hard to vent.  The use of the melt front advancement tool solves these problems before the tool is built avoiding the quality problems in the part.

Melt front advancement is especially useful in our Gate Optimization Analysis. When trying several gate locations, the melt front advancement helps you visualize how the changes in gate position will change the way the cavity fills.  This allows you to position weld lines so that they are either in low stress or low visibility areas of the part.  Notice  that the weld lines (red lines in image below) are formed on the bolt side of the ports where the flow meets together as it comes around the port.  This was done to place them in a less visible location on the part.

Melt front advancement is also imperative when performing a Runner Balance analysis.  The critical requirement of a runner balance is to have all of the different sized cavities complete filling at the same time.  This creates a condition were all cavities receive the same packing pressure.  This prevents a short shot in the harder to fill cavities or over packing or sticking in the easy to fill cavities.