Introduction to basic
manufacturing process with
clay and pop
Ad sem III
PLASTER OF PARIS
- Can also be referred to as Gypsum
- Very similar to cement, plaster of paris is
easy to mold when wet and forms a
strong structure to the molded shape
- 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
PREPARATION OF POP
- Pop is made by heating crystalline gypsum
(120c – 160c).
- Than the pop is mixed in water and sets to
hard cast to dry.
- During this process heat is generated due to
ADVANTAGES AND DISADVANTAGES
Easily moulded to different forms.
Easily breaks when comes in contact with water
Mainly used for
decorative and medical
Clay is a special kind of earth which is made by
the decomposition of rocks through the action
- Chemically it is a silicate with alumina, water,
and sometimes some of the other common
elements as well.
- 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
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
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
- is one of the purer forms of clay.
- basically composed of kaolin.
- This type of clay vitrifies at higher temperature
from 2300 degrees F.
- can withstand much higher firing
temperatures without melting .
- Porcelain clay when fired is very white.
- 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
- This clay can also be formulated to withstand
temperatures equal to porcelain.
- 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.
- 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 was formed in prehistoric time due to
volcanic eruptions (large % of silica). This is
found in Western mountain states.
- 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
- 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 is giving specific shape to the clay.
- Use water and press in the center of clay can be
transformed into any shape.
- 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
- It’s the method of Pre cooking stage for high
- It burns the organics and the molecular water
out of the clay.
- Its mainly the process of smoothing or polishing
the clay body.
- Textures on clay can be created by various
methods like stamping, pressing, beating etc