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The process of manufacturing Japanese HANABI hasn't changed since it was established a long time ago. Because the HANABI powder ignites ea sily and is sensitive to friction, it is always mixed by hand and the process can not be mechanized. People can imagine how beautiful fire works are in the sky, but can't even begin to imagine how they are ma nufactured in a factory. So, how exactly are these HANABI shells made ? HAIGOU----the mixing of pyrotechnic chemicals It starts by carefully measuring the various chemicals to be mixed. We use an oxidizer such as potassium perchlorate, and a metal powder, such as aluminum or magnalium, for fuel. By adding different chemic als such as capric oxide, strontium nitrate, or barium nitrate color can be made and these finished powders are called WAZAI. HAIGOU is d elicate work and powders are mixed by hand. 
WARIYAKU----Explosive "Flash" powderWARIYAKU is very explosive so it is made by experienced workers with great care. First we make the flash powder "WAZAI WARIYAKU" and mois ten it with water. Next, we add rice hulls to the mixture so that th ey become coated with the flash powder and act as a buffer which take s up Some volume in the shell. These coated rice hulls must dry comp letely before we can use them to build shells. 
HOSHI----Stars
Stars are made of chemical powders that burn with different colors wh
en ignited. Sometimes they are made with layers of different colored
powder so that they change color when they burn. The making of star
s is called HOSHIKAKE.
A grain of sand or seed, is added to a mixture of wet powder and allo
wed to mix in a tumbler until it is evenly coated with the wet WAZAI.
Next, these coated seeds are mixed in dry powder which sticks to th
e wet seeds. This process can be repeated many times and the star wi
ll grow larger as it is alternately mixed in moist and dry powder. If
the same color is used the star burns longer with that color, but if
different colors are used, the star will change colors as it burns f
rom the outside into the center.
It is very important that the stars are the same diameter and perfect ly round so that they change color and finish at the same time. HOSH IKAKE is an art that originally began in Japan.  This picture on the left shows the size of the stars as they finish e ach step of the manufacturing process. The star on the right is bigg er than the star on the left, because it has had the HOSHIKAKE proces s repeated a few times. The second star has a different color, as we ll as diameter, because the color of the WAZAI powder was changed. F or example, the first star used red powder and then a layer of blue p owder was added. This star will burn from blue to red . |