Fireworks Products (Ⅰ)

            

              Colored Flames

Colored flames are made with almost the same compositions as those used for stars, except fuels which are used to make stars burn rapidly ( charcoal for example) are usually omitted. On the contrary it is usual in these items to add materials which will retard the burning rate. Colored fires. Torches and Bengal illuminations which are sold to the public are usually required to burn quite slowly. And normally have the burning rate reduced by adjusting the fuel. The use of coarsely ground materials, or the cutting down or increasing of the amount of fuel can have this effect, but it is also usual to add retardants such as sawdust, wood flour, starch or flour. The addition of these materials also makes the composition cheaper, of course, but care must be taken with materials such as wood meal since they can contain a good deal of water.

                   Bengal illuminations

This special type of flare candle is used for illuminating public buildings and is extensively used in Europe for castles which particularly lend themselves to this type of illumination. In order to fulfill the necessary conditions, the composition should produce maximum color, burn efficiently but as slowly  as  possible, (i.e.40 to 60 seconds per 25mm), and not emit too much smoke.

The candles are made in various sizes, but the large ones are about 60mm in diameter 30cm long and have a wall thickness of about 1.5mm. the end of the candle is fitted with a wooden plug and a screw eye for attachment to the holder. The candle is fixed so that it burns in a horizontal position, so that the dross will not run down the side of the thin wad accelerate the burning time. Lastly, the candle is placed behind some kind of shield so that the onlookers do not see it burning.