Wikijunior:How Things Are Made/Toys/Dice

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Dice are tools used for generating random numbers in a variety of social and gambling games.

What do we need to make this thing?
Today, the most widely used base material for dice manufacture is plastic. Plastics are high molecular weight polymers that are produced through a variety of chemical reactions. For a plastic to be suitable in dice manufacture it must have good impact strength, low moisture absorption rate, easily coloured, and heat stable. It is also desirable that it must be thermoset (The shape is fixed once it is exposed to heat for first time) plastic.

The plastic that meets all of these requirements is poly-methyl-meth-acrylate (PMMA).

What is the step by step process?

 * Step 1: Plastic pellets are transformed into dice via injection molding. The pellets are plastic beads that have all the colorants and fillers already added. They are placed into a large bin known as a hopper and passed through a hydraulically controlled screw. As they travel through the screw, they are heated and melted. At the end of this screw is a spreader which injects the molten material into a cool, closed two-piece mold.
 * Step 2: The mold is made up of several chambers, which create multiple plastic parts. Inside the mold, the plastic is held under pressure and then allowed to cool. As it cools, the plastic pieces harden. The mold is then opened. When the mold is opened, the individual pieces are forced together to form a single solid cube. Because the mold was appropriately designed, this cube has indentations that will become the dots on each side. The cube is then ejected from the mold, coated and passed to the next phase of production via conveyor.
 * Step 3: To complete the production of the die, they may be washed and dried before the final decorations are applied. First, the spots are appropriately painted by machine. Nowadays, the machine are equipped with sensors and camera and accurately to dispense the paint over the indentation only.
 * Step 4: For board games, the dice are packed up into boxes and shipped to game manufacturers just like any other component material. When they are sold directly to consumers, dice are typically put into plastic blister packs with a cardboard backing.