Injection Molding cycle time benchmarking - Ball State University student

[ZachV1]

Hello everyone. I am a student at Ball State University. I am currently working on my senior capstone project and I am needing to benchmark injection molding cycle times. As of now, I am looking for any guidance or help as to what metric would work best for this study. I know cycle times vary, but would it be relevant to compare average cycle times, or maybe view cycle times according to part thickness? Currently I have data from the company I am working with, and they record sec/shot as there cycle time metric (one shot is one cycle). Is this a common measure? So, ultimately, I want to know if anyone knows of where I can find data like this, or what should be done to go about obtaining such a benchmark. Any help would great, and I appreciate everyones time. Thanks,

Zach

[Marc]

Any takers on this?

[ZachV1]

Any help would be great!!!

[bobdoering]

Originally Posted by ZachV1

Hello everyone. I am a student at Ball State University. I am currently working on my senior capstone project and I am needing to benchmark injection molding cycle times. As of now, I am looking for any guidance or help as to what metric would work best for this study. I know cycle times vary, but would it be relevant to compare average cycle times, or maybe view cycle times according to part thickness? Currently I have data from the company I am working with, and they record sec/shot as there cycle time metric (one shot is one cycle). Is this a common measure? So, ultimately, I want to know if anyone knows of where I can find data like this, or what should be done to go about obtaining such a benchmark. Any help would great, and I appreciate everyones time. Thanks,

Zach

Not sure where your project is heading. One shot one cycle is a decent metric - it includes mold open, eject and close (which can be a significant portion of the cycle.) But, trying to relate this to thickness is not going to work too well. Depends on the material, the mold design, including mold flow, number of cavities, material properties (cooling required?), and much much more. So, you might be able to benchmark the fact that cycle time is a shot, but benchmarking times is like benchmarking how long it will take to prepare supper.

"It depends!"

[ZachV1]

Thank you for you reply. Is it possible, that there could be a way to generalize the overall cycle time? Possibly by looking at the wall thickness, shot size, and material? There is a correlation between wall thickness and cycle time, correct? In this case, could one benchmark according to the cycle time-wall thickness relationship?

[bobdoering]

Originally Posted by ZachV1

Thank you for you reply. Is it possible, that there could be a way to generalize the overall cycle time? Possibly by looking at the wall thickness, shot size, and material? There is a correlation between wall thickness and cycle time, correct? In this case, could one benchmark according to the cycle time-wall thickness relationship?

I have a hard time thinking of a way to generalize by wall thickness alone. Consider this: a drinking cup shot versus a tray. If they have the same shot size, material and thickness, it will still take longer to do one versus the other based on fill flow, venting, cooling, etc. Mold design plays a huge role. Ejection - a tray will eject faster than a cup, will also play a huge role. Inserts, molded threads, lots of common exceptions that make a generalization very, very difficult. I am not sure if I am over-complicating your exercise, or you are over simplifying the process thought. But, sounds difficult to "benchmark" unless you identify a "standard part", including dimensions, materials, mold, etc. You may be familiar with the spiral mold for evaluating material flow. Maybe that would be a "standard"....not sure.

[DanteCaspian]

PM me on this if you need further help. I would be willing to speak with you via telephone.
As bobdoering said though, "Depends on the material, the mold design, including mold flow, number of cavities, material properties (cooling required?), and much much more".

[ZachV1]

Dante,
I'm sorry, but I do not understand your lingo...PM??? Sorry,

Zach