–Nakka’s site describes “sugar” motors in tremendous detail. The vast majority of commercial high-power motors use aluminum casings most of these will handle pressures well in excess of 1000 psi. –Aluminum tubing is more hazardous than paper casings, much less hazardous than PVC. An extremely detailed list of impact sensitivities of various compositions can be found in “Fireworks from a Physical Standpoint, Part IV” by Takeo Shimizu
OTOH ammonium perchlorate composite propellant (APCP), the sort of mixture used in space boosters, can be quite difficult to ignite deliberately, let alone accidentally. Armstrong’s mixture (KClO3:red phosphorus:Sb2S3) is extremely sensitive, period it has been known to ignite simply from carelessly opening a container of the mix. –The sensitivity of a pyrotechnic mixture to spark, flame, friction, impact varies enormously depending on the mixture’s composition and preparation Examples: black powder (KNO3:charcoal:sulfur) is highly sensitive to sparks and flame but quite insensitive to pressure and impact. A G-motor containing just two ounces of low-hazard propellant (APCP) can lift itself and a well-designed rocket a mile into the air, nearly reaching mach 1 on the way up….and close to that speed on the way down, if it comes in ballistic. –I’ve always tried to avoid using the words “safe” and “propellant” in the same breath “low hazard” is preferred.
:-) This is gonna be long, so you’d better go pee before you start reading… Some background: I’ve taught college/university chemistry for 36 years, co-authored six editions of two chemistry textbooks, given one or two small pyrotechnics shows annually for over 20 years, written articles for the late “Extreme Rocketry” magazine, and made rocket motors of various types for almost 30 years. Coming into this very late because I didn’t know about the article until :
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