oldguy Posted April 16, 2011 Posted April 16, 2011 If a person wanted to create a NC celluloid resin bead or powder that was highly flammable. How would one go about it, in the safest manner? A typical formulation of celluloid might contain 70 to 80 parts nitrocellulose, nitrated to 11% nitrogen, 30 parts camphor, 0 to 14 parts dye, 1 to 5 parts ethyl alcohol, plus stabilizers and other agents to increase stability and reduce flammability. From that I gather 70 parts nitrocellulose, nitrated to 11% nitrogen & 30 parts camphor would do the job.
Mumbles Posted April 16, 2011 Posted April 16, 2011 Why would you want celluloid for anything pyro? Camphor is for making films and the like. It will probably only be detrimental to most pyro applications. There are ways to powder or reduce the size of NC if that is what you were interested in. For films, you have to dissolve it in a suitable solvent, paint on, and let dry.
NightHawkInLight Posted April 16, 2011 Posted April 16, 2011 You can easily make nitrostarch by replacing the cellulose in the nitration with corn starch. It comes out as powder just as it went in. It behaves very similarly to nitrocellulose and should be a suitable replacement for every purpose. In fact it was not discovered to be a different compound for several years after both were invented.
oldguy Posted April 17, 2011 Author Posted April 17, 2011 (edited) Why would you want celluloid for anything pyro? Camphor is for making films and the like. It will probably only be detrimental to most pyro applications. There are ways to powder or reduce the size of NC if that is what you were interested in. For films, you have to dissolve it in a suitable solvent, paint on, and let dry. LOL, you have to remember I am fairly new to all this. NC plasticized with Camphor appears to be used in many pyrotechnic & military applications. There is a considerable volume of both patent applications & patents covering pyrotechnic NC over the last decade. What I am looking for is a microcrystalline nitrocellulose plasticized energetic fuel/binder that is castable & way to produce it both safely, as well as relatively inexpensively. By castable, I mean will harden up when tamped into a plastic tube, rather than a Kraft paper tube. Which will allow some degree of off-gassing, where a plastic tube will not (except on the open ends). Edited April 17, 2011 by oldguy
asilentbob Posted April 17, 2011 Posted April 17, 2011 I have often wondered about the feasibility of a low fallout filler material made of very thin, hollow celluloid-like flammable plastic spheres or ovaloid shapes. These would be coated in BP or KP as normal. I only wonder how they would preform near when the shell internal pressure ramps up... Would they create too high a pressure spike? Or not high enough? Either way it would be expensive unless a low-cost way to make very thin hollow NC/NS based plastic-like shapes is available.
oldguy Posted April 17, 2011 Author Posted April 17, 2011 I have often wondered about the feasibility of a low fallout filler material made of very thin, hollow celluloid-like flammable plastic spheres or ovaloid shapes. These would be coated in BP or KP as normal. I only wonder how they would preform near when the shell internal pressure ramps up... Would they create too high a pressure spike? Or not high enough? Either way it would be expensive unless a low-cost way to make very thin hollow NC/NS based plastic-like shapes is available. They would not necessarily need to be hollow. Cellulose acetate proprionate (CAP) is a hot fast burning plastic. Acetal is also a clean burner & easier to find. Although Acetal breaks down into formaldehyde as it burns, which is noxious, it is actually about the cleanest burning plastic there is.It burns with a smokeless blue flame with little odor because the formaldehyde burns off in the flame.
oldguy Posted April 18, 2011 Author Posted April 18, 2011 White light comp w/plastic resin bead sparks flying, long hang time.
asilentbob Posted April 18, 2011 Posted April 18, 2011 Thats nifty. Gives a bunch of hanging sparks though, I wouldn't really want that in the middle of a burst. Comparatively heavy, especially when getting into larger shells... where-as hollow shapes would be much lighter, requiring less lift to reach the same height. And if it was a nitrated thin resin, it could possibly contribute some to the break, instead of just being dead weight. Course, the rice hulls we all use work pretty great already... but its not a reason to not consider alternatives. Its easy to imagine several times more volume of such ovaloid resin chips having the same overall mass of those pictured there, if they were hollow. More filler for the same mass of chips. It would kinda be like comparing rice crispies and larger seeds. Similar mass for different volumes. Those foamed, white starch packing peanuts also burn with a very clean flame. Course they also dissolve in water quickly, so I'm not sure how well they would work as a filler material. Would be tough to coat with BP/(dex/SGRS/CMC)/water. I guess you could always use some sort of other binder and solvent system when coating them, but doing multi-kilo batches of that... with for instance, acetone... would be quite noxious. I dunno. Don't think there is any demand for this anyways lol.
oldguy Posted April 18, 2011 Author Posted April 18, 2011 I’m just tinkering with various plastic resins for purposes of a binder. Military uses 2 part epoxy like binders in many applications. But, they are expensive. At least to me, it would be cool to have a highly flammable, but relatively stable plastic as a binder.
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