Validating a mold on different machines

[Jojo63]

Hi all,

How do you validate a mold on different machines? The moulding machine are not completely identical (e.g. the diameter of the plasticizing screw is different).

Thanks.

Jojo

[Josue]

Hi all,

How do you validate a mold on different machines? The moulding machine are not completely identical (e.g. the diameter of the plasticizing screw is different).


We make first a Document according to APQP rules, keep a record of a preproduction sheet to record parameters , resin cycle, etc.. make a meeting with involve departments to announce this project.

you most check if the mold will fit on the machines, what kind of resin are you currently running to avoid mix white or clear resin with black ones etc,,, no just change to any machine available.

make parameters keeping at list the key parameters used on the already validate machine, make samples and submit to dimensional procedures as your std procedure,

Regards

[iautry1973]

Depends on the customers requirement really. We are our own internal customers, but due to tight tolerances and lots of "lights out" hours I just redo the whole qualification process for each mold/machine combo.

[rickbatey]

Convert actual press parameters to plastic parameters. You'll need intensification ratios to calculate proper pressures for new press. ALS you'll need to calculate the volumetric fill rate to mimic the same flow rate between the two different screw sizes. Otherwise the rest is pretty much the same. Don't look at a 2 second fill rate on a 50 mm screw still being 2 seconds with a 25 or even 75 mm screw. You've got to mimic volumetric flow rate and part weight at switch over and hold pressure.
Rick.

[JayDub]

The output of a validation is the validated set-up sheet, so if you can't use exactly the same process parameters for two presses, you need to do a separate validation for each. Following Rick's advice should save you some time on process characterization.

[Lonewolf]

We frequently move molds between different machines, some the same size/type, others different. We just develop and document another process for each machine.