Some suggestions:1) Do you dry your AP? I have found that AP contains
moisture, supposedly from absorption from the atmosphere. This water can be
driven off by drying at a temperature of 240 F. Drying the AP before mixing
should also help the cure if you are using OH/NCO chemistry since moisture
contamination uses up NCO functional groups.2) Use slow mix speed. Baking
type mixers on almost any speed will introduce air into the mix. Barry C Sent
from my Sprint Tablet.
-------- Original message --------From: Anthony Cesaroni <anthony@xxxxxxxxxxx>
Date: 7/7/19 14:43 (GMT-05:00) To: arocket@xxxxxxxxxxxxx Subject: [AR] Re:
Vacuum processing of solid propellant Discharge machine extra.:-) Anthony J.
CesaroniPresident/CEOCesaroni Technology/Cesaroni
Aerospacehttp://www.cesaronitech.com/(941) 360-3100 x101 Sarasota(905) 887-2370
x222 Toronto From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx>
On Behalf Of William ClaybaughSent: Sunday, July 7, 2019 12:40 PMTo:
arocket@freelists.orgSubject: [AR] Vacuum processing of solid propellant I ran
some static tests recently using a modified version of the standard RRS
composite propellant (10% Al rather than 7%). Those tests included applying
vacuum to the fully processed mix ahead of casting (5 minutes); the mix was
still outgassing when we repressurized This resulted in an about 5.6 % increase
in density, of which 0.9% is attributable to the increased Al loading. Given
that full mixing under vacuum is not viable given the processing equipment
available at the MTA, is there another vacuum schedule that might provide still
higher density? Does degassing the liquid components before mixing help or does
the subsequent mixing just reintroduce air? Any recommendations on degassing
time after mixing (recognizing that the catalyst is in the mix at this point).
Two static tests, one at 390 psia average and the other at 760 psia average
showed a decreased burn rate and a slightly higher ISP as compared to the
original mix, as expected. Bill
