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.

Fireworks Materials( Ⅳ )

                             Paraffin Oil Compounds

Paraffin oil finds some use in fireworks and frequently performs more than one function at a time. When it is added to a colored fore mixture, for instance, not only does it help to reduce the influx of moisture and reduce the sensitivity, but it also makes the mixture easier to press. Normally about 1% used for these purposes.

Paraffin wax is usually used to coat metal powders or to waterproof finished fireworks, which are merely dipped in the molten wax.

              Potassium Chlorate, KCIO3

It is one of the most important chemicals used in the firework industry. This material is prepared by the electrolysis of potassium chloride solution, and is frequently imported into England from Spain and Switzer land. The sensitive nature of potassium chlorate is a problem to the firework manufacturer, particularly in the presence of s u l p h u r , ammonium salts, and phosphorus, and none of these materials should be used with it.

                    Silicon, Si

 The material is only used in fireworks as an igniter in certain types of fireworks which needs a hot slag to initiate the reaction.

                    Sodium Nitrate, NaNO3

The crystals are readily soluble in water and melt at 308C. in combination with magnesium, it is useful for illuminating flares, but the stores have to be sealed so that they do not come into contact with the air.

                      Sodium Oxalate, Na2c2o4

There are two main uses for this substance. The first use is for the production of yellow colors in combination with potassium per chlorate and suitable fuels. The second use is the production of yellow glitter effects, with gunpowder, aluminum and antimony.

                   S t e a r I n e – S t e a r I c  Acid

The main use for this material is for adding it to some compositions which are somewhat sensitive to friction. It can also be used in those fireworks where  it is desirable to have along flame.

                   Sugars

 Lactose,c12h11o11.h20 is sometimes used as a fuel in firework manufacture. Used in compositions which are required to react at low temperatures, it is of use in the manufacture of some blue colors. It also replaces sucrose, which is more sensitive with chlorates. Perhaps the most extensive use is in the manufacture of smokes using organic dyes.

                      S u l p h u r

It’s one of the most important fuels of the firework industry. It is a pale yellow, fairly dense powder, all of which should pass 120 mesh.

                     Titanium. Ti

The metal is easily ignited to produce brilliant silver sparks. It can be used in just the same way as iron powder, and has the advantage of not needing to be coated . like all new things it may have been overused, but no one regrets the absence of the dirtier old aluminum powders.

                 Titanium Dioxide. TiO2

This oxide is not much used by the firework industry, but occasionally features in some smoke compositions and is sometimes added to waterproof paints.

                 Zinc , Zn

Certain recipes in the old firework books included zinc, but little use is made of the finely powdered variety except in the manufacture of certain types of smokes. Zinc smokes are very efficient and very good, but they are somewhat sensitive to moisture and have been known to react and ignite themselves. Most schoolboys know that a mixture of zinc, ammonium nitrate and ammonium chloride will catch fire when a small amount of water is added to the powder.

                Zinc Oxide Z n O

The principal use for this material is also in the manufacture of smokes.  

Fireworks Materials (Ⅲ)

                     Copper Oxides

   Both copper (I ) and spacing copper ( II ) oxides are used now for ignition and  starter compositions in conjunction with silicon and lead (IV) oxide. However the availability of good halogen donors and the disadvantages of  Paris  Green have caused a revival of the use of copper oxide for making blue colors.

                      Dextrin (C6H10O5)n

  As it is soluble in water and has good adhesive properties, it is used extensively as a binder in fireworks. It is fairly usual to add a few percent of the dry powder to a star composition during the mixing operation and then add water prior to star formation.

                     Dyestuffs

  The quality of the materials used for smoke production is important, particularly the particle size of the dyes and their freedom from inorganic salts.

                    Flour

  It was also used in some compositions to retard the burning speed.

                    Shellac

  Shellac, acaroids resin and copal gum are all used as fuels, mainly for the production of color.

                   Hex a c h l o r o b e n z e n e, C6CL6

  Extensive use of this material as a chlorine donor in color mixtures appears to have been made in the past. This substance is the well known insecticide.

                       L r o n , Fe

  There can be little doubt that iron has used in fireworks from the earliest times. Apart from the steel dust for the manufacture of sparklers, the best iron for fireworks is the ordinary iron borings which have been broken down to a rough powder which will pass 20 mesh. The long needle like fragments give the best effects.

                    L r o n Oxides

   The black magnetic form, fe3o4 is used the r mite and incendiary compositions and the brown form fe2o3 has been used in first fires and ignition compositions where high temperatures are needed.

                    Lead Oxides

   The  red form,pb3o4 and the chocolate colored dioxide, pbo2 have been used in first fires and ignitions for military purposes, and  are potentially useful for fireworks also. Combined with magnesium, it is used for crackling micro stars

                  
Magnesium . Mg

On the other hand, it is indispensable in situations where it is essential to gain high candle power in signal flares.

                     Magnesium Mg/AL

  Magnesium is used in fireworks for a variety of purposed;

  1 . in coarse powder of about 30-50 mesh the metal produces a sharp crackling noise in colored flame fountains. The presence of  c r y o l I t e seems to enhance this effect.

  2 . Dust free coarse powders produce pleasant sizzling effects in some stars.

  3 . the finer powders from 120 mesh onwards are used to enhance colored flames, produce some silver effects and to produce the newer blinker strobe effects. Come from magnesium burning with the nitrates of barium or strontium where the irrational burning can be varied with catalysts

Fireworks Materials(Ⅱ)

                 Barium Carbonate,Baco3

Barium Carbonate is no use as a coloring agent in low temperature flames, but is often used to reduce acid formation in mixtures or to slow down the speed of some compositions.

                  Barium Chlorate B a (CIO3)2H2O

Barium chlorate is one of the most sensitive chemicals which is used in firework manufacture, but it is difficult to manage without it when deep green colors are required. It is wise to use this substance as little as possible and to use it in combination with other substances which will tend to reduce the sensitivity.

                  Barium Nitrate, B a (NO3)2

This is perhaps one of the most useful and stable of the nitrates, but is somewhat limited in use. Low temperature green colors are not very strong when they are made with barium nitrate, though the frequently features in compositions made with barium chlorate as the main coloring agent.

More than anything else this substance is used in combination with aluminum powder for the production of silver effects. Silver stars, flares and waterfalls invariably utilize barium nitrate and the aluminum combined with it is frequently mistaken for magnesium by the uninitiated.

A I though barium peroxide is used in pyrotechnics, it is not suitable for use in fireworks owing to its very reactive nature.

                  Beta N a p ht h o l , C10H7OH

Manufactured mainly for the dye industry, this substance has found an occasional use as a fuel in colored stars, mainly because of its carbon content.

                       Boron, B

Mixtures of boron with oxidants, such as oxides, peroxides, chromates, nitrates and s u l p h a t e s, burn in different ways, the combustion ranging from rapid burning accompanied by long flames and showers of sparks to very slow combustion and the evolution of little or no gas.

Mixtures of boron with potassium nitrate produce compositions that consolidate well when pressed, and are easy to ignite as they are sensitive to flash. These are used as priming or first fore compositions because of their ability to transfer heat to other compositions. The addition of silicon enhances this effect.

The majority of compositions containing boron are sensitive to friction and shock. Also the more reactive mixtures are very sensitive to ignition by electrostatic spark.

  

              Calcium Carbonate, CaCO3

The precipitated form of this compound finds an occasional use as a neutralizer in some mixtures, in Armstrong’s Mixture, matches, and snakes made with nitrated pitch. It is also used to make rockets. It  is also used in high temperature flames for orange co lour.

                   Calcium S I l I c I d e, CaSi2

It finds use mainly as a fuel for self-heating cans of soup and is often an important component in smoke compositions.

                  Carbon Black-Lampblack

Carbon black is used to make Flower Pots, the unusual little golden fountains with their own special type of gold spark. Golden streamer stars also employ carbon black for the best effects.

                      Castor Oil

It is used mainly as a protection for magnesium, but it is also as a binder or lubricant in that it reduces the friction of the powder against the walls of the container into which it is pressed.

                        Clay

This material is an important part of firework manufacture, for it is used to block up the ends of tubes or to provide a washer through which fire can be forced in order to produce pressure.

                    Copper Powder

Use has sometimes been made of the bronze and electrolytic copper powders for the production of the blue colors, or as intensifiers for green colors, but this is not very common, for the same effects can be achieved by more efficient means.

               Copper Ace t o a r s e n I t e ( C u O)3As2O3CU(C2H3O2)

                             2-Paris Green

It has an intense green color, is insoluble in water and alcohol, but soluble in acids. Needless to say it is toxic, and sometimes caused nose bleeding and skin rashes. Apart from the compositions employing ammonium  per chlorate , Paris Green still provides the best blue colors.

 

Fireworks Materials( I )

 The followings are the materials which usually are used in fireworks manufacture and their functions.

                               Aluminum
Over the last seventy or eighty years aluminum has added tremendously to the last brilliance of fireworks, and yet the great variety in production techniques has caused problems in the production of uniform effects. The powders are prepared in hammer mills, in ball mills, or by atomization.

Flake aluminum in mesh sizes is known as “ flitter ” and there has been a tendency for manufacturers to sell this to the firework trade under the categories of “ fine”, “middle” and “coarse”.

The so called Dark p y r o  Aluminum consists of a very fine flake powder that is produced in varying shades of dark grey.
Atomized aluminum is being used increasingly in fireworks. But up to the present time only limited use has been found for this material.

      

                       Ammonium Salts
In the past , white smokes have been made with potassium chlorate and ammonium chlorate, and it has to be admitted that mixture appears to be reasonably stable, though at first sight theoretically this should not be so .

 

                           Ammonium per chlorate
In recent years ammonium perch orate has been used extensively, not only in fireworks for the production of rich blue and red colors, but also in the manufacture of propellants. It can be safely mixed with pure potassium per chlorate but must not be used with chlorates, and it is unwise to mix ammonium per chlorate stars with other chlorate stars in the same shell or rocket.

                         Anthracene

The  pure form occurs as fine blue fluorescent crystals which melt at about 213c. it is insoluble in water and rather sparingly soluble in most organic solvents.

Anthracene is mainly used in combination with potassium per chlorate to produce black smokes.

                              Antimony, S b

Antimony is mainly used to produce white fires in combination with potassium nitrate and s ulph u r or it is used in combination with aluminum to aid ignition. Antimony is also responsible in part for the well known glitter effect which is basically a combination of gunpowder, antimony and aluminum.

       

                           Antimony Tri s u l p h Id e , Sb2S3

As a fuel, its uses are much the same as the metal powder, though it ignites more easily. It has disadvantage also that it is more dirty to handle than the metal powder.

Synthetically produced material is not usually used in fireworks and it can be difficult to get good glitter effects from it.

                     Arsenic disulphide,As2s2 Real gar

The native ore, real g a r , is sometimes ground to a fine powder and used to make white fires. It has also been used for making smokes.

  

                      Arsenic T r I s u l p hide , As2s3 Orpiment

The commercial powder has two forms, one yellow and one red . the yellow form changes to red on heating to  170 c.

The red form is often used to make white stars which have the advantage of being easy to ignite when moving at very fast speeds. A part from the occasional use in smokes, orpiment is used in combination with carbon black for making. Flower Pots with their characteristic golden spur fire.

Arsenic is safe to handle, of course, provided that precautions are taken to keep it out of the nose and mouth.

Fireworks History

Working with fire probably began about half a million years ago when patriarchal cavemen realized that they felt cold and began rubbing pieces of wood together until the friction caused an ignition.

It is only within the last 200 years or so that fireworks was correctly interpreted as being a form of energy where the flames are defined as regions of luminous hot gas.

By about the eighth century AD , the Chinese alchemists, amongst others, were preoccupied with discovering the elixir of life . Concoctions were made containing all manner of substances including oils, honey and beeswax, but among the most significant, were the ingredients sulfur and saltpeter.

A bout 1000 AD the Chinese were using a propellant similar to gunpowder in crude forms of rockets fireworks(Flying Fire),together with grenades and even toxic smokes. For example, a recipe in the Wu Ching Tsung Yao dated 1044 describes a mixture, containing sulfur, saltpeter, arsenic salts, lead salts, oils and waxes to give a toxic incendiary that could be launched from a catapult.

The pyrotechnic art has been remarkably slow

In Europe, pyrotechnics for military purposes saw an early peak of achievement in the form of Greek fire. Old manuscripts suggest several ways of attempting to combat the fireworks, especially the application of wine, vinegar, sand and even urine.

More peaceful uses of these crude articles appeared in the form of firecrackers-the first fireworks? One mixture corresponded quite closely to modern gunpowder in that it contained saltpeter, sulfur and willow charcoal. The firecracker was said to consist of a loosely-filled small hole to accept a match or fuse.

Firework manufacture has a long history, but the development of the pyrotechnic art has been remarkably slow.

The Chinese may have made fireworks of sorts over a thousand years ago; displays have been fired popularity, now worldwide, seems undiminished. Nevertheless, basically, firework displays have changed little over the centuries, with rockets, shells and roman candles, in various forms, remaining the main display components.