Color is an important characteristic
of many ceramic products and when used properly it considerably enhances the
aesthetic appearance. Ceramic colors are calcined blends of metal and ceramic
oxides that have been reground into a fine powder. These stains consist of
crystalline solids and their properties depend on the properties of the crystal
lattices constituting them. Some metal oxides which are relatively inert and do
not undergo significant changes during application and firing can be used as
ceramic stains, however, produced ceramic stains have some superiorities.
Admittedly, these stains produce much more homogeneous, consistent and
repeatable colors than using raw oxide colors. Secondly, some metal oxides
which are normally toxic in character can be safely used when prepared as
ceramic colors. Unfortunately, most ceramic stains have crystal lattices that
are unstable at high temperatures and readily affected by the presence of
fluxing materials such as glazes, fluxes and vitreous bodies. Consequently, a
stable crystal lattice may become unstable when heated to high temperatures. It
is for this reason that most compounds and colors used in ceramic decoration
are very susceptible to the conditions during firing. A successful and repeatable
industrial color application can be obtained with a suitable combination of
crystal lattice, heat treatment and stain environment. From this approach, if
coloring oxides or stains are used in suitable glazes or applied to the ware
with suitable fluxes then they will not react with their environment and change
their crystal structure.
Application techniques of ceramic
colors:
There are five ways in which ceramic
colors can be applied to a glazable ceramic article:
- as body stain,
- as engobe,
- as under glaze color,
- as colored glaze and
- as over glaze or glass color.
The use of body stain refers to a
pigment added to the body formulation itself
An engobe is a layer of colored clay
body, mostly white, which is applied onto an unfired body in order to improve
the decorative finish.
Under glaze decoration is the
application of color to a bisque body before glazing.
In colored glazes, the stain is
dispersed in the glaze itself.
Over glaze or glass colors are
applied to the already formed and fired glaze as an overcoat and fired again.
The selection of technique depends on
the requirements of the particular application.
GLAZE PIGMENTS
Ceramic stains are mixed metal oxide
pigments that crystallize in stable oxide lattices and the color is due to the
incorporation of colored cations in the lattice.
The crystal lattice of each prepared
ceramic stain has different crystallographic structure such as spinel, garnet, zircon,
corundum etc. The properties are quite different from each other but it is
possible to prepare similar colours in different structural systems.
For example pink color can be
prepared in different crystal lattices such as chrome-tin pink, chrome-alumina
pink and manganese-alumina pink. While chrome-alumina pink spinels require the
absence of calcium oxide but a surplus of zinc oxide and alumina in the system,
chome-tin pink requires a lot of calcium oxide but no zinc oxide. Various
factors like the base glaze chemistry, color shade, temperature, and end use
determine the system you should choose.
Thus, stains do not come with an unconditional color
guarantee. The shade produced depends on many of factors including the host
glaze chemistry, on/over/underglaze use, glaze thickness, amount of opacifier,
firing temperature, etc. Certain systems are quite flexible and produce color
in many kinds of glazes (ie. cobalt silicate). Other systems either require
that certain oxides be present in the host glaze in minimum amounts or others
not be present at all. For example, chrome-tin pink stains will not develop
color if zinc is present or if there is inadequate calcia. It is common to hear
people say that their pink stain 'burned out', but generally the stain is being
used in an incompatible glaze base. Inadequate firing or reducing furnace
atmosphere may also cause this trouble.
Among the inorganic pigments, cadmium pigments have
particularly brilliant red and yellow colors as well as high covering power.
However, these pigments which crystallize with hexagonal wurtzite lattice are
not stable at high temperatures and cannot be used in ceramic glazes or as
underglaze pigments.
Many stains are almost standard and
the system of their composition is well known across the industry. For example,
a green stain might contain chrome, cobalt and silica and be labeled 'CrCoSi'.
Although silica is not a colorant itself, it is included to create a stable
silicate crystal structure with the other two.
The system, the maximum firing
temperature ,the required glaze properties for optimum results and the Pantone
color references for each color are given below.
Glaze colors are light fast and
temperature resistant. Depending on the structural system most of them can
reliably be used over 1000?C.
Glaze colors can be used for coloring
ceramic glazes, enamel slips, engobes and glass mosaic, directly by mixing and
dispersing the paint into the coating. They can also be used as underglaze colors
for decorating ceramics and tiles simply by mixing the paint with finely ground
bisquit, glaze and kaolin in proper amounts and adding a suitable medium to
permit the application.
We offer cadmium group pigments only for coloring porcelain enamel for sheet
steel or aluminium.
Similar color tints have specially been produced for glass
mosaic. They have different product codes and formulation. They all should be
used in clean and white glass powder.
Onglaze colors are applied on the
surface of the fired glaze to which they adhare by fusion after being fired at
a suitable temperature.
Onglaze colors can be applied in the
following ways:
1- Direct screen printing
2- Transferring (decals)
3- Brush application
4- Spraying
5- Powdering
They can be used for the decoration
of enamelled and ceramic ware. The desirable properties of onglaze colors are
that they should fuse in the kiln to form a glassy bond with the underlying
glaze, they must not run and blur the design, they must be resistant to acids
from foods and alkalies from detergents, and they must have almost the same
thermal expansion with the glaze.
Onglaze colors are being sold in
powder form. Depending on the application method they should be mixed with
water based or oil based medium at the ratio
28-35 %, stirred and pasted well
until having a homogeneous creamy mixture.
The ratio of color to medium may not
be the same in every color.
Powder colors should be kept dry.
Color pastes should be kept in tightly covered containers and stirred well with
a spatula before use.
Correctly applied and fired color
will have a smooth and glossy surface, no cracks and blisters appearing on the
surface. You should avoid from too much thick application. If two or three
coats will be applied one over the other, you should choose a finer screen and
use less medium.
Recommended mesh sizes :
for multiple coat
application 100-120 threads/cm
for one coat
application 70-90 threads/cm
Recommended firing temperatures :
for enamel 780-800?C
3-4 minutes
for ceramic 850-900?C 20-30 minutes
In order to get a good result, the
glaze under the decoration should have a higher melting temperature. If the
glaze is dark in color, before applying the colors, covering white can be used
as a base coat.
Almost all colors can be mixed with
each other, however, expected shades can not be reached in every case. Cadmium
containing red and orange colors can be mixed at every ratio with each other
but restrictively with the others. These colors give good results only in fast
firing cycles. Some colors, especially pink, are affected from the reducing
gases in the kiln atmosphere so well ventilated kilns should be used.
All ceramic pigments and paints are
due to crystal structures resulting from chemical reactions between some
chemical compounds. They shouldn't be inhaled or swallowed.
Glass colors are used for the decoration of flat glass to be
tempered. For maturing and gaining their physical and chemical resistance they
should be cured at 680-720?C for at least 3-4 minutes or common firing cycle
for tempering should be followed. The thickness of the glass is important when
choosing the firing period.
These colors have very good temperature resistance so most of
them can be used in high temperature applications on glass and ceramics.
Glass colors have very attractive colors and they can be mixed with each
other. Thus, almost all color shades can be reached. However, expected shades
cannot always be reached with Cadmium containing red, orange and yellow colors.
They can be mixed with each other in every ratio but in controlled proportions
with others.
They can be mixed with white in the
ratio maximum 1/1 , otherwise, color will be damaged.
These colors contain lead in their
composition, however, if correctly applied and fired, solubility of lead is
very low, but still these colors are not intended for being used on kitchen
wares which will directly contact with acid containing foods.
Glass colors are provided in powder
form or as color pastes prepared with a suitable medium.
Color pastes must be stored in
tightly closed containers and must be stirred well with a spatula before use.
Recommended mesh sizes for screen printing : 70-90
threads/cm
Recommended medium / powder ratio 25-30 %
If dilution is required use a
suitable thinning solvent tested previously.
Solvent should be vaporized by drying
at 40-50°C .
Never use cleaning thinner to dilute oil
based color pastes.
If extra medium is used for dilution,
resin would be added as well, which will cause violent firing in the oven.
Powders must be stored in dry
conditions, if they gather moisture, problems may arise especially when using with an oil based medium.
These colors are being used in fusion technique that means high
temperature firing of glass, including forming, for decoration purposes. When
correctly used they give very attractive and bright colors matchable with
glass. They can be used either over the glass plate or between two glass plates.
Fusion colors are of two types which are bubbling colors and plain or
opaque colors.
Bubbling colors are applied between the glass plates and when fired a
bubbly appearance comes out. The size of the bubbles changes with the quantity
of color.
In order to get an even distribution of bubbles, the quantity of applied color
should be almost the same all over the surface. Thickness of the glass is
important. Glass plate on the top should be thinner than the base or, at least,
equally thick.
Bubbling colors are transparent and some of them can be used on glass
surface too.
Both wet and dry applications are possible. Water based or oil based
medium can be used for wet application.
Firing temperature is between 820-840?C depending on the thickness of the
glass.
Temperature should be rised under control, fast heating will cause
problems and unpleasent appearance.
Application methods:
1- Spraying
2- Sprinkling
3- Brush application
4- Screen printing
Sprinkling is recommended only for bubbling colors. With the others, when
the color is not evenly applied and thickness is too much cracks may appear.
A few important points to be taken
into consideration while handling these paints.
- If you use printing oil, we call it
medium, the ratio of medium to powder should be 25-35/ 75-65 depending on the
color. It means that, whether water based or solvent based, medium ratio should
not exceed 35 % in any case. Some paints, for example white, like medium very
much. If you use too much medium, too much resin will be introduced into the
color paste as well, which will burn
violently during firing causing
destruction of the paint surface.
If you think that fluidity is not
enough, use a suitable solvent to decrease the viscosity.
The solvent to be used should not
evaporate during application but will evaporate with drying process before
firing.
- Thinner should be used only for
cleaning purpose.
If you use thinner as a solvent, it
may work sometimes but generally all types of thinners don't have a fixed
composition and the same chemical and physical properties .If it is not
approved by the resin of the medium some surface faults may come out after
firing.
- If you don't use force drying,
especially in cold and wet atmosphere you cannot get complete drying. The
surface seems to be dry but the interior still remains wet, as a result, rapid
vaporization of the solvents in the oven destructs the paint layer.
- If medium will be used between two
glass plates, prefiring at a low temperature up to 400- 450° C is advised so
that the fumes from burning resin of the
medium could remove..
General information
In glass decor paints, the sample set is 15 kinds of colors and is 50 grams each. B-36,B-39,B-41,B-45,B-46, B-60-211604-221406-231404-242706-263601-261308-261310-273007-263011 we have coded paint samples.
The sample set in glaze dyes is 16 kinds of colors and is 100er grams. Within our set we have paint samples with the code 110202-160210-160202-130101-160304-180402-140704-1502204-150500-140702-150201-160801-170800-221209-221810-221408.
YAPI:Fe-Cr
SICAKLIK:1050C
UYGUN SIR:In glazes containing zinc, the color tone may turn brown.
PANTONE REF.:1245C
YAPI:Ti-Sb
SICAKLIK:1200
UYGUN SIR:It turns light in glazes containing a lot of alkali. It gives some lead color to life.
PANTONE REF.:107C
YAPI:Pb-Sb
SICAKLIK:1000C
UYGUN SIR:It is more stable in glazes containing lead, tin or zircon, and whose zinc is not very high.
PANTONE REF.:101C
YAPI:Zr-Pr-Si
SICAKLIK:1300C
UYGUN SIR:It is generally compatible with all secrets. It is more stable in glazes containing zircon opacifiers.
PANTONE REF.:364C
YAPI:Cr
SICAKLIK:1100C
UYGUN SIR:It is more stable in glazes that do not contain zinc and tin. Calcium and alkalis improve color.
PANTONE REF.:349C
YAPI:Cr-Co-Al
SICAKLIK:1200C
UYGUN SIR:It is more stable in glazes that do not contain zinc and tin. Calcium and alkalis improve color.
PANTONE REF.:470C
YAPI:Fe-Cr-Al-Zn
SICAKLIK:1250C
UYGUN SIR:It gives better results in high glazes containing zinc and aluminum and low calcium.
PANTONE REF.:477C
YAPI:Fe-Cr-Zn
SICAKLIK:1250C
UYGUN SIR:It is compatible with all kinds of glaze. It is more stable in glazes containing zinc.
PANTONE REF.:335C
YAPI:Co-Cr-Al
SICAKLIK:1300C
PANTONE REF.:323C
YAPI:Co-Cr
SICAKLIK:1300C
PANTONE REF.:3025C
YAPI:Co-Cr-Al
SICAKLIK:1300C
PANTONE REF.:286C
YAPI:Co-Al-Zn
SICAKLIK:1300C
UYGUN SIR:In soft glazes, both covering and determination are higher. Color tone varies according to the glaze composition. Pale blue, leaded glaze with alkaline glazes
PANTONE REF.:364C
YAPI:Cr
SICAKLIK:1000C
UYGUN SIR:It is more stable in glazes that do not contain zinc and tin.
PANTONE REF.:2756C
YAPI:Co-Si
SICAKLIK:1300C
UYGUN SIR:Color tone varies according to the glaze composition. Silica-based blues can melt and soften the glaze. To prevent this, a little bit of chinese clay is added.
PANTONE REF.:2985C
YAPI:Zr-V-Si
SICAKLIK:1300C
UYGUN SIR:It is compatible with all kinds of glaze and every atmosphere.
PANTONE REF.:702C
YAPI:Cr-Sn
SICAKLIK:1250C
UYGUN SIR:In zinc glaze, the color turns brown. It gives the most appropriate results in glazes containing calcium and strontium. Color in reduced atmosphere and low temperature
PANTONE REF.:1807C
YAPI:Zr-Fe-Si
SICAKLIK:1250C
UYGUN SIR:It is compatible with all kinds of glaze. It gives better colors in lead-free, less leaded and less alkaline glazes.
PANTONE REF.:165C
YAPI:Cadmium Group-For Enamel
PANTONE REF.:186C
YAPI:Cadmium Group-For Enamel
PANTONE REF.:193C
YAPI:Cadmium Group-For Enamel
PANTONE REF.:108C
YAPI:Cadmium Group-For Enamel
PANTONE REF.:1565C
YAPI:Cadmium Group-For Glass Mosaic
PANTONE REF.:486C
YAPI:Cadmium Group-For Glass Mosaic
PANTONE REF.:485C
YAPI:Cadmium Group-For Glass Mosaic
PANTONE REF.:158C
YAPI:Cadmium Group-For Glass Mosaic
YAPI:Ti-Sb-Ni
SICAKLIK:1000
YAPI:Fe-Cr-Co
SICAKLIK:1250C
UYGUN SIR:The color tone may turn brown in glazes containing zinc.
PANTONE REF.:131C
YAPI:Ti-Sb
SICAKLIK:1200C
UYGUN SIR:It turns light in glazes containing a lot of alkali. It gives some lead color to life.
PANTONE REF.:100C
SICAKLIK:780-850C
PANTONE REF.:108C
SICAKLIK:780-850C
PANTONE REF.:1385C
SICAKLIK:780-900C
PANTONE REF.:138C
SICAKLIK:780-900C
PANTONE REF.:186C
SICAKLIK:780-850C
PANTONE REF.:193C
SICAKLIK:780-850C
PANTONE REF.:2718C
SICAKLIK:780-900C
PANTONE REF.:2727C
SICAKLIK:780-900C
PANTONE REF.:304C
SICAKLIK:780-900C
PANTONE REF.:322C
SICAKLIK:780-900C
PANTONE REF.:364C
SICAKLIK:780-900C
PANTONE REF.:367C
SICAKLIK:780-900C
PANTONE REF.:700C
SICAKLIK:800-950C
SICAKLIK:780-950C
SICAKLIK:780-950C
SICAKLIK:780-850C
PANTONE REF.:700C
SICAKLIK:780-950C
PANTONE REF.:Şeffaf
SICAKLIK:780-900C
PANTONE REF.:Şeffaf
SICAKLIK:600-900C
PANTONE REF.:181C
SICAKLIK:780-900C
PANTONE REF.:364C
SICAKLIK:680-850
PANTONE REF.:477C
SICAKLIK:680-850
PANTONE REF.:700C
SICAKLIK:680-850
SICAKLIK:680-900
SICAKLIK:680-800
SICAKLIK:680-800
SICAKLIK:680-700
SICAKLIK:680-850
PANTONE REF.:3282C
SICAKLIK:680-850
PANTONE REF.:315C
SICAKLIK:680-850
PANTONE REF.:297C
SICAKLIK:680-850
PANTONE REF.:2728C
SICAKLIK:680-850
PANTONE REF.:2727C
SICAKLIK:680-850
PANTONE REF.:193C
SICAKLIK:680-800
PANTONE REF.:139C
SICAKLIK:680-850
PANTONE REF.:124C
SICAKLIK:680-850
PANTONE REF.:100C
SICAKLIK:680-850
PANTONE REF.:032C
YAPI:Cd-Se
SICAKLIK:680-830
PANTONE REF.:2718C
PANTONE REF.:315C
PANTONE REF.:297C
PANTONE REF.:1495C
PANTONE REF.:153C
PANTONE REF.:181C
PANTONE REF.:364C
PANTONE REF.:181C
PANTONE REF.:3282C
YAPI:Bubbly
YAPI:Bubbly
YAPI:Bubbly
YAPI:Bubbly
YAPI:Bubbly
PANTONE REF.:507C
YAPI:Bubbly
PANTONE REF.:310C
YAPI:Bubbly
PANTONE REF.:305C
YAPI:Bubbly
PANTONE REF.:5115C
YAPI:Bubbly
PANTONE REF.:5195C
YAPI:Bubbly
PANTONE REF.:2736C
YAPI:Bubbly
YAPI:Bubbly
PANTONE REF.:109C
PANTONE REF.:108C
PANTONE REF.:032C
PANTONE REF.:021C
YAPI:Solvent Based