Page 17 - Curriculum Visions Dynamic Book

(Above) Hand making of bricks using just clay and a wooden former is very time consuming.
(Below) Making pottery is an ancient craft using nothing more than wet clay, a potter’s wheel, and a great deal of skill.
Once cleaned, clay, sand, and feldspar are blended together with water. The blending determines the final character of the whiteware. Not surprisingly, most of the art of making good wares depends on the skill of the blender.
Clay changes its character depending on how much water is added. The objective is to get a mix that is exactly right for the next stage of manufacture – forming it into a product.
In most cases the ideal water content produces a mixture that can support itself and yet still be easily worked. For factory- made wares the clay is shaped into a long roll and chopped off into suitably sized pieces. Each piece is then fed into a press in which one part of a mould moves against another and squashes the clay into the shape of the mould.
Complicated and irregular shapes can be made using moulds, although very simple objects such as bricks and tiles are made
by presses.
Pressing has to be done one item at
a time. Each product has to be removed from the press before another can be fed in. To increase production of identical items such as bricks, clay is forced through a rectangular-shaped piece of metal called a die. The correctly shaped stream is pushed out of the die as a long strip of clay and simply has to be cut to the right brick length by a blade before being taken off for firing.
It is possible to make clay products from clay that has had so much water added that it has turned into what looks like a liquid (although it is in reality a suspension). That is what is done in the process called “slip casting.”
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