Sciencemadness Discussion Board

ETN pressed density

Grantr - 16-11-2015 at 07:45

Wikipedia (I know not the best source) states ETN compressed to 1.6 grams/cm3 has a VOD of 8000 to 8100 meter per second.

If I have a 1/4 inch inside diameter tube cut to 1 inch, I have .804 Cm3. So pressing 1.29 grams of ETN in this space will give me the density needed for 8000 Mps.

What if the ETN is pressed to a higher density? Will the VOD go up or stay the same?

Does crystal size matter when pressing?


greenlight - 16-11-2015 at 09:27

I always thought it was slightly lower, something like 7900 m/s but I am probably wrong.

For every 1 Cm3 you should have 1.6 grams of ETN so yeah that sounds right:
0.16x10=1.6 grams
0.16x8=1.28 grams

As for pressing to a higher density, I am fairly sure explosive VOD will continue to rise as the density increases until a point is reached where even if you press the explosive to an even higher density, the velocity of detonation will still remain the same or could even cause a failure to detonate.
In some explosives such as Mercury fulminate, the explosive can even be pressed to such a high density (I think around 4.4+) that it becomes dead pressed and just burns instead of detonating when flame is applied to it.

Small crystals like ones you would use to prepare plastic explosive with would be least messy and easier to press to a high density than the fluffy low density powder. Fluffy crystals give a less dense PE than recrystallized product so I am sure they would press to a higher density more efficiently as well.

Grantr - 17-11-2015 at 05:08

Thanks Greenlight.