Nautilus 8 Tips (Finding data for entries)

[BJones94]

Hello,

I am a new user to Nautilus 8. I have a question or two about how to locate data necessary to create an entry in the Material Database. The figure "maximum residence time" seems rather difficult to find, and obviously depends on temperature (I would assume that this is based on 'average melt temperature'). I see the use of this in giving a go/no-go on a different machine based on % of barrel capacity.

Let me know if you have a good resource or method for finding maximum residence time, or if you sidestep this figure.

[I have similar questions regarding maximum screw speed and injection velocity, when my machine is old and without a good spec sheet :D . I also can find a variety of values for clamp tons/sq. in, and am unsure of how to guess at that figure. Lastly, do you use the software with just a handful of 'representative' materials, and as a starting point for translating processes to other machines? How do you normally use Nautilus?]

-Ben Jones

[Suhas]

Hello Ben,

Thanks for the questions. All good and valid questions that I get asked all the time.

Residence times: Unfortunately, there is a no good resourse for this. And as you rightly said it would depend on the melt temperature. So far I have only found GE ULTEM resin having such a graph of Res Time vs Melt Temp. I wish all the suppliers provided that. Here are some typical generic numbers that I use:
Nylons - 5 mins.
PBT - 6 mins (I generated have data for Valox)
Acetals - 4 mins
PVC - depends on the grade but not more than about 4 to 5 mins.
ABS - 10 mins
PC - 5 to 7 mins - also depends on screw rotation speeds

For screw speeds and tonnages it is the same issue. Unfortunately there is no good data yet. But I do now have a procedure to follow on how to optimize the screw speeds. That may help. Basically, set your barrel temps close to the melt temp you want and then adjust the screw speeds to get the temps. Too high will raise the temps and too low will lower your temps.

Tonnages is tricky. Check out my website (www.fimmtech.com) and there is an article on tonnages.

Hope this helps. Thanks for being part of this forum.

Regards
Suhas