4. INTRODUCTIO
v Greek term Keramos, meaning "apotter" or "pottery”.
v A ceramic is an inorganic, nonmetallic solid.
v Ceramic materials may have a crystalline,
or
v partly crystalline structure, or may be amorphous (e.g., a glass).
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5. History
Ø Pottery making is one of most ancient of human industries
Ø Burnt clayware has been found dating from about
15000.B.C
Ø In Egypt it was developed 10 centuries later
Ø Museums contain ,as a record of culture , clay products
created independently by races
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6. The three main raw materials
used in making classic or
“triaxial,” ceramic products.
v Clay
v Feldspar
v Silica
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7. From a ceramic point of view,
Clay is referred to a material that is plastic and moldable when
sufficiently pulverized and wet , rigid when dry and vitrous
when fired at suitably high temperature.
There are a number of mineral species called clay minerals ,
which contain mainly mixtures of
Kaolinite(Al2O3.2SiO2) ,
Montmorillonite[(Mg.Ca)O.Al2O3.5SiO2.nH2O]
Illite(K2O,MgO,Al2O3.H2O, all in variable amounts)
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8. Feldspar
Ø Feldspar refers to group of minerals.
Ø It is used as a fluxing constituent in ceramic formula.
Ø It decreases the melting point of sand or quartz present in ceramics.
Ø It may exist in clay as mined, or it may be added or needed.
There are three common types of feldspar.
a) Potash feldspar (K2O.Al2O3.6SiO2)
b) Soda feldspar(Na2O.Al2O3.6SiO2)
c) Lime feldspar(CaO.Al2O3.6SiO2)
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9. q The non-plastic or leading admixture like sand or quartz gives
strength to the body.
q It is incorporated in ceramic formulation to reduce shrinkage
and
q Cracking which occurs during drying and firing.
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10. CLASSIFICATION
Classified based on method of production:
1.Whiteware
2.Structural clay products
3.Refractory material
4.Special ceramic products
5.Vitreous enamel
6. Glass
7. Cement
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11. Whiteware is a generic term for
ceramic products which are usually
white and of fine texture.
They are based on selected grades
of clay bonded together with
varying amounts of fluxes and
heated to a moderately high
temperature in a kiln (1200-1500 C)
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12. They are classified as ,
A. Earthenware : sometime called semi vitreous dinnerware , is porous and
non-translucent with a soft glaze.
B. Chinaware : is a vitrified translucent ware with a medium glaze which
resists abrasion to a degree; it is used for non-technical purposes.
C. Porcelain :is a vitrified translucent ware with a hard glaze
which resists abrasion to maximum degree.
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13. § Sanitary ware : formerly made from clay ,was usually porous ,
hence a vitreous composition is used.
§ Stoneware: one of oldest of ceramic wares ,was in use long
before porcelain was developed . It may be regarded as a crude
porcelain.
§ Whiteware Tiles : available in a number of special tiles ,are
generally classified as floor tiles , which are resistant to corrosion and
impervious to stain penetration and may be glazed or unglazed.
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15. Glass
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For glasses, the processes involve
mixing and melting the raw materials in a furnace
shaping them in molds and by various techniques,
Both discrete products (bottles) and continuous products(flat glass, rods,
tubing, and fibers) can be produced.
Glasses also are strengthened by
thermal and chemical means,
by lamination with polymer sheets (as is done with Windshields and bullet
proof glass).
1. Crushing or grinding the raw materials into very fine particles
2. Mixing them with additives to impart certain desirable characteristics
3. Shaping, drying, and firing the material.
18. Types of ceramics tiles
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1) Common tiles
These tiles have different shapes and sizes.
They are mainly
used for paving, flooring and roofs . available
in different colors, easier to lay, lighter than
marble,
scratch proof, anti-slip, and do not require
polishing.
19. Types of ceramics tiles
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Terra-Cotta
Strong, Durable, Colors, Cheaper,
Easily cleaned, Easily molded, light
in
weight, fire-proof, resistant to
weathering.
20. Manufacturing Process Of Ceramic Tiles:
● Preparing The Raw Materials
● Batching
● Mixing And Grinding
● Spray Drying
● Pressing
● Drying
● Firing
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22. 22
Batching Process
Batching or proportioning
may be done by volume
or by mass. However,
proportioning by mass is
far more accurate than
that by volume.
23. The grinding of solid raw
materials involves a whole
series of operations aimed
at reducing the size of
materials.
Mixing And Grinding Process
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24. Spray drying is the
process that converts the
body slip obtained from
the mill to a granulate with
a size distribution and
moisture content suitable
for pressing.
Spray Drying Of Ceramic Tiles
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25. Pressing is the
simultaneous compaction
and shaping of a powder
or granular material
confined in a rigid die or
flexible moulid.
Pressing Process
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26. This is carried out to
increase the strength of
the unfired tile and also to
reduce the risk of tile loss
due to deformation as the
tile rapidly shrinks or
cracks as the steam is
rapidly evolved in the kiln.
Drying Process Of Ceramic Tiles
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27. Firing is usually the final
stage in the ceramic tile
manufacturing, at which
the weak, unfired, newly
pressed piece of tile is
transformed into a strong,
durable product due to the
effect of chemical and
physical reactions within
the green body during
heating.
Firing Process Of Ceramic Tiles
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29. 1. It should be free from any cracks, flaws and bends.
2. It should be in regular shape and size.
3. It should be hard and durable.
4. It should be well burnt.
5. It should fit properly when placed in position.
6. It should possess uniform color.
Characteristic features of a good tile;
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33. Hazardous Effects Due to
Components of Ceramics
Clay
Inhalation of all clay materials especially silica can damage
your lungs.
All clay bodies contain some free crystalline silica which can
scar your lung tissue and cause irreversible loss of breathing
capacity.
Safety
Avoid excessive dust exposure.
Make sure you know what ingredients are in the clays you use
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34. Glazing
Luster glazes contain toxic mediums as well as toxic metallic
compounds.
Crystalline silica is present in almost all glazes and can scar lung
tissue if inhaled.
Safety
Use a mask for vapors and gases when working with luster glazes.
Spray glazes only in a properly constructed, vented and filtered
spray booth.
Used spray booth filters for certain glazes may have to be treated as
toxic waste.
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35. Firing
Kilns are potentially hazardous if they are installed or fired incorrectly.
Safety
Kiln installation must be done with strict commitment to precise fire
codes.
All gas and electrical hookups must be done by a professional.
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36. Toxic Hazards in the Ceramics
industry & studio
Toxic Emission From Kiln
CARBON MONOXIDE. (CO)
SULFUR OXIDES (SO,SO2,SO3)
CHLORINE AND FLUORINE (Cl2,F2)
METAL FUMES (Fe,Al)
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37. • Do not use any wheel, kiln, spray equipment, slab roller, grinder, etc. unless
you have received personal instruction and permission from a staff person.
Permission to use kilns requires training period and testing.
• You must turn off any electrical equipment after using it - wheels, kilns, fans,
hot plate, etc.
• If you are the last to leave, make sure that all the windows are closed, and
that the lights have been turned off.
• Use the buddy system fora pedestrian travel at night to and from the studio
General Safety Measures :
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38. Industries
The American giant Mohawk Industries, Inc. One of the Greatest industry
with an estimated output between 230 and 250 million sq.m/year.
The Thai group (SCG) is in second place in terms of output volumes (201
million sq.m/year),
The Mexican group Lamosa also the third world largest ceramic
industry.Its production capacity 180 million sq.m/year.
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39. Recommendation
Based on the knowledge summarized in this sections, the
following recommendations are made:
1) Before a factory is established, the production manager
should visit a fully functioning.
2) Materials should be stored safely, under appropriate
conditions.
3) Production can be smoothly coordinated if kiln capacity
matches the number of filters that will be produced in 2 days,
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