Mugs are needed to hold liquids for people to drink out of. This is a simple idea, which prevents awkwardness for the person who is drinking out of it, and it keeps the drink together which stops it from making a mess everywhere. It is effective because it is light and small and easy to hold. It is normally made from china, which makes it fragile, but safe to drink out of it has a blunt and smooth rim, which stops any mouths being cut. It is easy to clean and stainless.
The product; visual analysis The product; visual analysis (cont) The product: materials/constituent part analysis When rocks are broken and crumbled by rain falling over it for a long period of time, their minerals break down and new minerals are formed. These minerals are called clay minerals. Their particles are so small that they cannot be studied under an ordinary microscope. These minerals maybe left on the ground where they form what are called “Residual” clays. These may be washed in to rivers and carried down to the sea or lakes.
There they settle slowly through the water to form layers on the sea or lake bed. In the course of time the bed of clay under the sea may be lifted up, if the layers have become closely bedded together, they form new rocks. Clay deposits are very soft and easily moulded and shaped when they are wet. Many useful things can be made such as pots, plates and in this case cups or mugs. Especially in industries many types of clay are useful as they can be burnt in a kiln or furnace to make tiles for floors or walls, vases, ornaments or different quality bricks depending on what clay is used.
Once a mug is made into shape it is then left to be fired in a kiln at a bright red heat, which hardens the clay forever. In order to then make the clay smooth and shiny a glaze is used. The glaze is made of much the same materials as glass (flint, feldspar and litharge). These materials are mixed with water to form a liquid. The cups or mugs are then dipped into this solution then which are covered. They are then put into glaze kilns. The temperature in the kilns are then raised slowly and then lowered again carefully. The glaze melts in the kilns and changed to a thin coating of glass.
A colour can be added to the glaze mixture and beautiful effects are gained by using different minerals. Often the same mineral will produce a different colour depending upon various firing conditions. Designs may be applied separately by hand. The product: production analysis The mug or cup is a one piece object, which is made from the same material all round. The clays used differ greatly in their colour and the way they react to the heat of firing.
The first step in making clay into pottery like mugs or cups is to clean out all small stones and pebbles. This can be done by hand or simply filtered out in a sieve. Bits of iron, which would make a yellowish-brown stain in white pottery, are usually removed by a set of magnets. This is a unique technique, which is most efficient as it is much easier and quicker.
The clean clay is ground very fine and mixed with water. Substances such as flint, fine sand, feldspar, and other minerals are often mixed with the clay. For porcelain, the kaolin is mixed with feldspar, flint and quartz; for bone china, bone is added. Oxide of cobalt is added as a bleach. The soapy mixture of clay and water is strained through very fine meshed screens. Then it is squeezed and pressed until it is about as thick as putty.
In factories, mugs and cups are manufactured on a machine called a jolly, a process called jollying. Clay is measured out into equal portions of the right amount for one mug or cup. One ball of clay at a time is thrown onto a plaster- of- Paris mould which will shape the outside of the mug or cup. While the mould rotates at high seed, a metal arm called the profile is lowered into it. This causes the clay to open out and be drawn up the mould, therefore forming the complete cup shape.
After the cups been shaped, they are dried thoroughly in a drying room. Then they are packed into saggers, which are vessels fire clay shaped like washtubs. The saggers are stacked in a kiln, the door of the kiln is blocked with firebricks, and the fires are lighted. The temperature at which the pottery is fired in the kiln depends on the kind of pottery; ordinary household pottery like cups in this case is fired at about 1,000centergrade (1832 farenhight). It is kept at that temperature from one to three days. In the intense heat the particles of clay are fused together. The pottery is left in the kiln until it cools. It is then unpacked and at this stage it is called bisque ware.
Is then put over the rough bisque ware from a liquid as explained in more detail on the previous page. The glaze can be applied by dipping in which skilled workmen must be careful to ensure an even coating. Spraying, or pouring the glaze over the pottery can also apply it. Die may be added to the glaze at this point, which will change the colour of the pottery. Again the pottery is put into the kiln where the temperature is raised and lowered slowly and carefully to prevent any damage to the products. The glaze changes to thin coating of glass.