Fine Bone China creates beautiful looking tableware. The effect is almost translucent with an exquisite, delicate feel about it. However, despite its look, it is also the most durable material of tableware ceramics you can buy. This, almost contradiction in terms, may well cause you to pose the question, how is Fine Bone China made? Below we have answered that question for you:
Fine Bone China is a type of porcelain, which means it is manufactured in a similar way. However, the material used to make it are different. The first and perhaps the most emotive material is bone ash, as that has a lower iron content. The bones are crushed into powder form before being added to the other ingredients. The higher the amount of bone ash, usually over 30%, the higher the quality of the Fine Bone China. Other materials include china clay, china stone, kaolin, feldspar and quartz. The bone ash gives the bone china that brilliant white coloring, its durability and translucent appearance.
The material, once mixed together and still in powder form, are then passed through literal screens. This has the effect of removing any particles that are too large or too small. Once all the material has passed through the screening process, water is added to the mix, and a liquid clay is formed. This is known as slip. The slip is then ready to be transformed into the form of a teapot, mug, saucer, plate, whatever piece of tableware is being made that day.
There are two primary ways of creating Fine Bone China products. If the piece that is being made that day is a plate, saucer or bowl, a jigging machine is used to produce them. Any hollowware pieces, such as teapots, cups, mugs, jugs, etc., are created by using two-part plaster moulds. The slip is simply poured in and left to dry. After it has dried, both pieces are removed from the mould and then gently trimmed. The pieces are painted with some casting slip and then firmly pushed together, ensuring that all air is completely eliminated.
Before the pieces go on to the oven to be fired, they are known as greenware. They are set up and supported by specially created setters to ensure that they are upright and will remain in position. They are then ready to be fired.
The first firing process is known as biscuit. This is where the kiln is set to around 1250°C, and during this process, the bone china transforms into a brilliant white, translucent inert material that is extremely durable. After this procedure, the pieces are sprayed with a glaze known as fritz. This fills any pores in the biscuit material with a glass-like coating. The second firing procedure is done at the lower temperature of 1150°C, which melts the glaze, which fuses and merges with the biscuit and toughens the surface even more. It becomes impermeable to liquid. After this, the pieces are all thoroughly checked for any imperfections.
