Ceramic/Porcelain - How It’s Made
All floor covering products for your home are constructed in some manner, but how
ceramic tile is made is in a class by itself.
The process is ancient and the resulting benefits are long and desirable: beauty,
durability, practicality, versatility -- a work of art you walk on.
Come join us as we describe how this unique product is born, and who knows, with
the knowledge gained from this section, ceramic tile just may be the flooring solution
for the way you live.
A product of earth and fire.
The main ingredients of ceramic tile and its general manufacturing process has not
changed that much throughout the centuries.
All ceramic tiles are created from natural products extracted from the earth that
are shaped into tiles and then fired in kilns at extremely high temperatures.
In this section we will take a look at ceramic tile types, the manufacturing processes,
and tile rating systems. Ready? Good. Let’s get started.
On the surface, there are two kinds of tile.
There are 2 main types of tile construction: glazed and unglazed.
When you look at a glazed tile from the side you can see 2 layers. The body of the
tile, or largest layer, is called the bisque. The top layer is called the glaze,
as in glazed donut.
Glazed tiles have a hard non-porous, impermeable surface after firing. They are
more stain resistant than unglazed tile and are easy to clean. Something to consider
for those more active areas of your home like the kitchen and baths.
Unglazed tiles add a whole different beauty to your home.
They are solid colored all the way through and do not have a top layer of glaze.
This is often referred to as through-body construction.
They have no additional surface applications and are typically more dense and durable
than glazed tile. Thus they are more suitable for interior and exterior applications
where wearability is a concern.
If your home has areas of heavy activity or kid “zones,” unglazed tile
may be just the answer.
There are 5 steps in the ceramic tile manufacturing process: Mining, Blending and
Mixing, Pressing, Glazing, and Firing.
Unglazed ceramic tiles are very hard and dense. They come in various surface
treatments and textures. Typically, these are installed outside your home as they
do not offer much protection against stains compared to glazed ceramic tile.
Unglazed tiles do have good slip resistance, however please note that they do require
sealing to help prevent staining.
Step 1 is raw and natural.
The process begins with the mining of the raw materials, which is a mixture composed
of mostly clay and minerals.
Step 2 makes mud part of the magic
. The clay and mineral mixture is blended and mixed into a semi fine powder.
Water is added to form a wet slurry or mud-like consistency. Then the slurry
is pumped into a large dryer.
And the result? A fine clay powder that feels like warm, fine sand.
Step 3 puts the pressure on.
Next, the clay is pressed or formed into a tile shape. These pressed tiles are called
green tiles at this stage.
There is also another method called extrusion which can replace the pressing
step. Extruded tiles are formed by forcing the clay material through a mold for
the desired shaped versus pressing the tile.
However, pressing is the more common method used today. And after the green tiles
are formed they are dried to remove some of the moisture.
Step 4 introduces the glaze phase.
It’s the next step in the manufacturing process for those tiles that will
have a glaze.
If the tile is to remain unglazed it skips this step and goes directly to the firing
kiln.
The glaze liquid is prepared from a glass derivative called frit and colored
dyes. The glaze is applied by either a high-pressure spray or is poured directly
onto the tile. Either way, Mr. tile is covered.
Step 5 brings on the heat.
The ceramic tiles are now fired in the kiln at temperatures around 2000 degrees
Fahrenheit. Think blast furnace.
Tiles that are fired once after the glaze is applied are called monocuttura tile
or single fired.
The other type is called biocuttura or double fired tile. Biocuttura
tiles are first fired after the green tile is dried and then fired again after the
glaze is applied.
An enduring alternative is porcelain.
Aside from the 2 types of ceramic tile, glazed and unglazed, there is another category
that continues to gain popularity – beautiful, elegant, porcelain tile.
Porcelain tile is made up of 50% feldspar and is fired at a much higher temperature
than regular ceramic tile. This makes porcelain tile much harder and more dense
than other tile products.
Their high performance and low water absorption ratings of less than 0.5 percent
make these tiles a worthy choice for your home.
Additionally, porcelain tile can be used for interior and exterior applications
as well as heavy or commercial areas.
After the finished tiles have been inspected for quality assurances, they are packaged,
crated and ready to be shipped.
Be a smart tile shopper.
Not all ceramic tile is suitable for each area of your home. The beautiful, decorative
tile you might put on your kitchen backsplash may not be recommended for installation
on the floor.
A rating system is called for and that’s exactly what the tile manufacturers
have provided. Now let’s take a look at that system.
Got traffic? Here’s just the ticket.
Most manufacturers will have a rating system that is based on or supported by the
American Society for Testing & Materials (ASTM). Many times you can find these
ratings on the tile sample or in the product catalog.
The most common system rates ceramic tile abrasion resistance or the overall durability
of the tile. There are 5 classes you should be aware of.
Class 1: no foot traffic.
These tiles are suggested for interior wall applications only and not for the floor.
May a shoe never touch them.
Class 2: light traffic.
These tiles are suggested for interior wall applications and for residential bathroom
flooring only.
Class 3: light to moderate traffic.
These tiles can be used for residential floor and wall applications including bathrooms,
kitchens, foyers, dining rooms and family rooms. They’re a good all-around
performer.
Class 4: moderate to heavy traffic.
These tiles are recommended for residential, medium commercial and light industrial
floor and wall applications including shopping malls, offices, restaurant dining
rooms, showrooms and hallways.
Class 5: heavy/extra heavy traffic.
These tiles can be installed anywhere. They will hold up in floor and wall applications
at airports, supermarkets and subways. Tile doesn’t get any tougher.
You may also see a rating for Slip Resistance, which is measured by its Coefficient
of Friction (COF). The higher the COF the more slip resistant the tile. This is
important when selecting a floor tile for areas that get wet, such as your shower
or bathroom floor.
Other ratings listed by the manufacturer might include: scratch resistance, moisture
absorption, chemical resistance and breaking strength.
This concludes our section on How Ceramic Tile Is Made – its different
types of construction and how tile is rated.
We hope that knowing how ceramic tile is made will help you with the decision on
whether it’s made for your home.