Introduction to basic manufacturing process with clay and pop

Submitted by-Darshika guptaAd sem III

PLASTER OF PARIS

- Can also be referred to as Gypsum Plaster.

- Very similar to cement, plaster of paris is easy to mold when wet and forms a strong structure to the molded shape when dry.

- Plaster of Paris is formed by heating Gypsum to 300 degrees Fahrenheit

- Plaster of Paris got its name from a large gypsum deposit that is located in Paris.

PREPARATION OF POP

- Pop is made by heating crystalline gypsum (120c – 160c).

- 2(CaSO4.2H2O)+heat=2CaSO4.1/2H2O+3H2O

- Than the pop is mixed in water and sets to hard cast to dry.

- During this process heat is generated due to chemical reaction

ADVANTAGES AND DISADVANTAGES

Advantages

cost effective

Non allergic

Easily moulded to different forms.

Disadvantages

heavy

Easily breaks when comes in contact with water

USES

Mainly used for decorative and medical

purposes.

CLAY

Clay is a special kind of earth which is made by the decomposition of rocks through the action of weathering.

- Chemically it is a silicate with alumina,  water, and sometimes some of the other common elements as well.

CLAY

- Clay common name for a number of fine-grained, earthy materials that become plastic when wet. Chemically, clays are hydrous aluminum silicates, ordinarily containing impurities, e.g., potassium, sodium, calcium, magnesium, or iron, in

small amounts.

HISTORY OF CLAY

- The first evidence of the production of bricks dates back to the day more than 5000 years ago. At first they were used in their unbaked form, simply left to dry in the sun and it was only in 2500 BC that they began to be baked.

- Stone wasn’t always available and when it was, the crafting process was difficult and time consuming. Clay on the other hand, was perfectly easy to mix and mould and, once dry, was a valid support for early constructions.

HISTORY OF CLAY

-

- The terracotta brick continues to one of very few products made exclusively of natural materials: clay, sand, water and fire being the elements used in the creation process. 

TYPES OF CLAY

Porcelain clay

-  is one of the purer forms of clay.

- basically composed of kaolin.

- This type of clay vitrifies at higher temperature ranges

from 2300 degrees F.

- can withstand much higher firing temperatures without melting .

- Porcelain clay when fired is very white.

STONEWARE CLAY

- is a form of high firing clay containing kaolin as well as, lower firing clays.  

- It may also include iron, which results in it's off white to reddish appearance before and after firing.  

- This clay can also be formulated to withstand

temperatures equal to porcelain.

EARTHENWARE

- These are low-firing clays .

- Earthenware clays normally contain a high percentage of iron which acts as a flux when fired quite fragile and porous 5 to 15%.

- Earthenware cannot be made vitreous because of various fluxes.

- Earthenware deforms, blisters or bloats when fired above 2100o F.

FIRECLAYS

-

- These are high-firing clays commonly used for insulating bricks, hard firebrick and furniture.

- Some are plastic, some aren't. Generally, they contain iron & calcium .

- They are found almost anywhere and can be high in Alumina and/or silica.

BENTONITE

- Bentonite was formed in prehistoric time due to volcanic eruptions (large % of silica). This is found in Western mountain states.

PROCESS

Glazing

- Glazes are the coating on pottery.

- They act to seal as well as give pottery it's texture, color and brilliance.  

- Glazes can be purchased .

- Before deciding which glaze to use you must first consider a few variables:

1.  The Clay body of the particular piece.

a.  The firing temperature of the clay body.

b.  Clay body type: Some clay bodies for example,

already have strong iron contents,

this factor will directly affect the finished glaze color.  

FIRING

- Firing clay transforms it from its humble, soft beginnings into a new substance, ceramic. Ceramics are tough, strong, and very similar in some ways to stone.

- Firing is the process of bringing clay and glazes up to a high temperature. The final aim is to heat the object to the point that the clay and glazes are “mature” – that is, that they have reached their optimal level of melting.

THROWING

- Throwing is giving specific shape to the clay.

- Use water and press in the center of clay can be

transformed into any shape.

ALTERING

- This technique is used by artist when the clay is wet to give the desired shape.

- Various type of craving tools are used in thids proccess.

BISQUING

- It’s the method of Pre cooking stage for high fired pottery.

- It burns the organics and the molecular water out of the clay.

BURNISHING

- Its mainly the process of smoothing or polishing the clay body.

TEXTURES

- Textures on clay can be created by various methods like stamping, pressing, beating etc

Nature textures

MANMADE TEXTURES

UTILITY OF CLAYFUNCTIONAL PRODUCTS

DECORATIVE ITEMS

Thank you