Ceramic and Vitrified Tile Manufacturing Process

Dnyan Deshmukh

Staff member
Ceramic and Vitrified Tile Manufacturing Process
What is Ceramic tiles or vitrified tiles

It’s basically a product of clay same like brick but made carefully with high precision to ensure the all tiles have the same dimensional as well as strength and aesthetic properties in it.

What make it different from clay bricks and how.

Clay bricks are made without removing the impurities in it and ensuring same grain sizes in it. Also they are fired in very uncontrolled way which makes some bricks over-burnt and some bricks under-burnt and have no equipment to ensure the perfectness of each brick.

So how the Tiles are manufactured in control environment

The clay use in manufacturing of tiles is checked for its clay properties and other chemical requirements. Mostly here in India clay use for manufacturing of tile comes from Gujarat and Rajastan. It’s in very raw form just like excavated earth is loaded in wagons and transported to factory.

Clay is also imported from other Countries to achieve more strength and plasticity during manufacturing and it is blended with the other clays.


In the process of manufacturing of tile first the raw clay is loaded into the hoppers and blended with minerals in batch mixer homogeneously.

Raw material feeding.png

Those clay and minerals are sent via conveyor to a batch mixer to mix in proportion as specified by manufacturer to achieve the desired properties.

feeder conveyor.png
Feeding conveyor 2.png

Then the blended mixture is sent to a ball mill and around 33% water by weight is added into it.

ballmill for grinding.png

33 percent water mixing.png

Ball mills content giant alumina balls which crush the clay into a finest slurry through a rotating action of ball mill and gravity force acting on alumina balls. Below is animated photo of milling action.

inside ball mill.png


The milling action creates a homogeneous slurry which is taken out from ball mill and screened to remove the uncrushed clay or stones.



ball mill output.png


After passing through this hopper the slurry is further moved to a vibrating screens which have the mesh size of 75 microns. The vibrating actions ease out the process of making a fine slurry to pass through it and the oversized material to go out.

vibrating screen.png


The passed material then go through the channel where magnetic purification of slurry is done.


Magnetic purification.png


All the material which does not pass through, is again sent back to a ball mill and re grinded to finer size (not a single stone is wasted at tile manufacturing unit, even a waste from backed tile which is cut and grinded for correctness is also re-used for manufacturing)

After passing the screen and magnetic purification, slurry is then pumped with high pressure pump to a silo through a nozzle which have small holes in it.



slurry pumping to silo with high pressure pump.png



The spraying of slurry into a silo is done along with passing hot air into it. Spraying action and hot air pass makes the slurry to reduce its moisture from 33 to around 5 to 6 % which forms a finest granules of clay which are slightly moist. After formation of granules they are further moved to pressing machine which shape the tile body. The hot air pass and spraying of clay is done in control way to ensure the correct sizes of grains.



slurry drying silo.png



The finest clay powder is then sent to a pressing machine via conveyor.


dry powder from silo.png

Moist powder going for pressing.png


At the pressing machine the properties of tile which to be manufactured are decided, Ceramic tiles are made by pressing powder into the mould at low pressure and vitrified tiles are made by pressing powder into mould at slightly high pressure.

The classification of the any tile is based on its water absorption property which comes from this process. Pressing at high pressure ensure the extra amount of powder to be pressed in same volume of tile creating lesser voids in base tiles which corresponds to low water absorption and vice a versa.

For ceramic tiles the pressing of powder is done at 450 bars of pressure and for vitrified tiles pressing is done at 550 bars of pressure

At pressing machine, we can mould any size tile by providing specification and making arrangements of mould by simply programming it with all data.


Once the command is given, a fully automatic pressing machine fills the mould with moist powder of clay and presses it to required pressure and sends it forward through roller conveyor for further processing machine.



Tile pressing machine powder filling.png


The push tile further here is called as green tile or biscuit.

We can have any shape in the back of tile and can be given in the mould, the top of the tile is plain or have designs on it (rustic tiles) to give the feeling of natural stone.

Rustic finish tiles are slightly costlier as the surface is not plain and the process of its topping do add additional costs but it gives a natural rock filling on top of it.



Green tile out from pressing machine.png


Must know – the size of the moulded tiles is always more than that of required size, generally they are made 15mm + on higher size coz during pressing, there is a chance that tile ends may lift upwards and in further processes may get some defects which can be nullify by cutting it after topping / printing.

The color of biscuit or green tile or the back of tile which is not visible, depends on the properties of the clay and mostly they are brownish or whitish.

So next time when you get two batches of tiles and if there back color varies, then either that tiles are not manufacture at same factory or there is change in source of clay.


The green tiles then further goes from a drier which removes it moisture content completely.


Green tile drier.png


Once the tiles are reached on other end of drier, they are completely dry and does not have any moisture in it and ready for further processing.

The green tiles are tested for its flexure strength to ensure the quality of batch.

Dried tiles then coated with engobe, glaze and sent forward for printing. It can be either printed with rotary drum or digital printing machine.

Here onwards for each step of coating tile is first coated with adhesive and then air dried and each coating is done.


The green tile is then goes through a conveyor where adhesive is sprayed on it and air dried with fan.


adhesive application.png


After this the engobe and glaze is applied on the tile surface.


engobe.png


Engobe is the main layer on the tile surface which ensure no leakages from top to back of tile or from back of tile to the top surface (it’s just like a waterproofing coat). When you see a wet patches on tile surface then it’s clear indication of improper engobe application on it.

After engobe and glaze application tile is further moved to a printing assembly, it might be a roto type drum printer which gives color in 4 or more layer with adhesive application and drying before printing each layer.

In roto drum printer a color minerals are flowing through drums and when tile passes from the below of drum surface a layer of minerals is printed on it (just like how we apply paint on wall surface with roller brush)


Below photo shows assembly of 4 roto drum printer.


roto printer.png


There are two technologies to print the design on tile surface

Roto Drum printer – As it’s a rotating drum which impress the color on tile surface, we can’t make a same design print on each tile surface and all tiles have different combination of surface texture (more likely they looks same), with this technology we cannot have fancy or more designs printed on it. This is use to give finish on the flat or rustic surface tiles.

Digital printing – In digital printing we can mimic almost any style, color combination and any type of surface finish look (we can make it as to look like wood, aluminium etc). After application of englobe the tiles are sent through a giant digital printer where the program automatically prints the design on each tile surface as per the design, with this technology we can print anything on tile surface, we can make a your photo printed on tile or printed in parts on tile which makes combination of 12 tiles to show what is the photo.

After completion of printing on tile surface, the automatic laser guided robots stack them and move to a kiln where heating of tiles is done.

laser guided robot stacking tiles.png

robotic assembly for heating.png
 

Dnyan Deshmukh

Staff member
After stacking tiles they are further moved to heat treatment through a roller conveyor, tiles are heated up 1200 degree for ceramic and 1350 degree for vitrified. Tiles are heated in 5 different temperature zone in kiln of length 145 meter.

tile heating assembly.png

tile heating close view.png

At each steps firing temperatures are controlled automatically and can be monitored on computer screen or in control panel.

temperature control monitoring unit.png


temperature control monitoring unit2.png



After completion of journey through the kiln, when tile comes out from the kiln, its temperature is around 80 to 100 degree.


dried tile coming out from drier.png



After heating tiles are stacked and allowed for some time to cool down.


stacking of heated tiles.png

Then tiles are moved further by laser guided robot to cutting and chamfering assembly, where a final touch to the tile is given for its size and chamfered edge.



robotic movement of heated tiles.png


Some tiles do have lapato finish on top of it, which are done using polishing head assembly. This treatment gives a unique texture and natural finish to each tile.


Lapato polishing.png
 

Dnyan Deshmukh

Staff member
The tiles them move from roller conveyor into a cutting and chamfering machine.

Squaring and chamfering.png


chamfering.png


Tiles are also given a nano coating on top of it which closes all the micro pin holes on it and gives anti bacteria and stain resistant property.

nano coating.png


nano coat animated.png


Then its moved forward through a roller conveyor where first the lasers check the properties of tiles and discards the tile which have defects in it.


tile checking with laser.png


After going through this, then a manual check by human is done on tile where, the tile inspector marks its grade of tile and also do marking for rejected tiles.


sorting of tiles manually.png

manual tile sorting.png



The tile sorter is a human and siting at there for long time can make him to take wrong decision as human brain can’t identify what is correct if he continuously looks at the same surface finish.

To avoid the human errors, the tile sorter / inspectors works for only one hour at a time on this job and takes a break after an hour and other inspector / sorter continues the work.

Then marked tiles are further moved to a packing assembly through a conveyor where the laser guided equipment do sorting of tile as per the grade (grade of tile had set of parameter and sorter instruction line mark on the tile), the tiles are automatically sorted for grades like A, B, C and D (D is rejected tiles).


When system detects a tile which can’t be sorted in any grade, the roller assembly on conveyor automatically drop the tile from it.


roller pushing it down.png
 

Dnyan Deshmukh

Staff member
Sorted tiles are then pack by a fully automatic packing machine which wrap the box packing on it (in set of tile as programmed).

Sorted tiles for packing.png

Packed boxes then further moved on conveyor and strap with automatic strapping machine.


automatic strapping.png


After strapping the boxes, batch number is printed on it.




batch no printing.png


Batch number.png


Then packed boxes are moved through a conveyor, where robotic hand stack them in pallet which are ready to transport.



robotic box stacking.png

robotic stacking in pallete.png
 

Dnyan Deshmukh

Staff member
The sampling of tile is done and tested in lab for defects, size, thickness, abrasion value, flexure value and crazing resistance etc.



abrasion resistance.png


Flexture testing.png



This is what I learn during my factory visit to tile manufacturing plant, whatever written here is what I see and made me to understand by factory manager. I haven’t allowed to take photographs during factory visit so I used a pictures from a YouTube video to illustrate it in better way.

If you have any suggestion / addition to make it more helpful, kindly do reply.
 

Rohith Rao

Junior Member
Thank you very much for the knowledge sharing, this will make us learn more about our construction industry and progress.
Look forward to have more brainstorming articles like this.
 
Very informative topic ...
Thanks again ! It is clear that when purchasing tiles what should be taken care of by going through this.
During workmanship, we experience defects like wrapped tiles sizes not matching is happens during the
extra material that machine removes from mould and cut.

Regards,
Prashant
 
  • Like
Reactions: Dhiksith
Ceramic and Vitrified Tile Manufacturing Process
What is Ceramic tiles or vitrified tiles

It’s basically a product of clay same like brick but made carefully with high precision to ensure the all tiles have the same dimensional as well as strength and aesthetic properties in it.

What make it different from clay bricks and how.

Clay bricks are made without removing the impurities in it and ensuring same grain sizes in it. Also they are fired in very uncontrolled way which makes some bricks over-burnt and some bricks under-burnt and have no equipment to ensure the perfectness of each brick.

So how the Tiles are manufactured in control environment

The clay use in manufacturing of tiles is checked for its clay properties and other chemical requirements. Mostly here in India clay use for manufacturing of tile comes from Gujarat and Rajastan. It’s in very raw form just like excavated earth is loaded in wagons and transported to factory.

Clay is also imported from other Countries to achieve more strength and plasticity during manufacturing and it is blended with the other clays.

In the process of manufacturing of tile first the raw clay is loaded into the hoppers and blended with minerals in batch mixer homogeneously.

View attachment 1373

Those clay and minerals are sent via conveyor to a batch mixer to mix in proportion as specified by manufacturer to achieve the desired properties.

View attachment 1374
View attachment 1375

Then the blended mixture is sent to a ball mill and around 33% water by weight is added into it.

View attachment 1376

View attachment 1378

Ball mills content giant alumina balls which crush the clay into a finest slurry through a rotating action of ball mill and gravity force acting on alumina balls. Below is animated photo of milling action.

View attachment 1379


The milling action creates a homogeneous slurry which is taken out from ball mill and screened to remove the uncrushed clay or stones.



View attachment 1377


After passing through this hopper the slurry is further moved to a vibrating screens which have the mesh size of 75 microns. The vibrating actions ease out the process of making a fine slurry to pass through it and the oversized material to go out.

View attachment 1380


The passed material then go through the channel where magnetic purification of slurry is done.


View attachment 1381


All the material which does not pass through, is again sent back to a ball mill and re grinded to finer size (not a single stone is wasted at tile manufacturing unit, even a waste from backed tile which is cut and grinded for correctness is also re-used for manufacturing)

After passing the screen and magnetic purification, slurry is then pumped with high pressure pump to a silo through a nozzle which have small holes in it.



View attachment 1382



The spraying of slurry into a silo is done along with passing hot air into it. Spraying action and hot air pass makes the slurry to reduce its moisture from 33 to around 5 to 6 % which forms a finest granules of clay which are slightly moist. After formation of granules they are further moved to pressing machine which shape the tile body. The hot air pass and spraying of clay is done in control way to ensure the correct sizes of grains.



View attachment 1383



The finest clay powder is then sent to a pressing machine via conveyor.


View attachment 1384

View attachment 1385


At the pressing machine the properties of tile which to be manufactured are decided, Ceramic tiles are made by pressing powder into the mould at low pressure and vitrified tiles are made by pressing powder into mould at slightly high pressure.

The classification of the any tile is based on its water absorption property which comes from this process. Pressing at high pressure ensure the extra amount of powder to be pressed in same volume of tile creating lesser voids in base tiles which corresponds to low water absorption and vice a versa.

For ceramic tiles the pressing of powder is done at 450 bars of pressure and for vitrified tiles pressing is done at 550 bars of pressure

At pressing machine, we can mould any size tile by providing specification and making arrangements of mould by simply programming it with all data.

Once the command is given, a fully automatic pressing machine fills the mould with moist powder of clay and presses it to required pressure and sends it forward through roller conveyor for further processing machine.



View attachment 1386


The push tile further here is called as green tile or biscuit.

We can have any shape in the back of tile and can be given in the mould, the top of the tile is plain or have designs on it (rustic tiles) to give the feeling of natural stone.

Rustic finish tiles are slightly costlier as the surface is not plain and the process of its topping do add additional costs but it gives a natural rock filling on top of it.



View attachment 1387


Must know – the size of the moulded tiles is always more than that of required size, generally they are made 15mm + on higher size coz during pressing, there is a chance that tile ends may lift upwards and in further processes may get some defects which can be nullify by cutting it after topping / printing.

The color of biscuit or green tile or the back of tile which is not visible, depends on the properties of the clay and mostly they are brownish or whitish.

So next time when you get two batches of tiles and if there back color varies, then either that tiles are not manufacture at same factory or there is change in source of clay.

The green tiles then further goes from a drier which removes it moisture content completely.


View attachment 1388


Once the tiles are reached on other end of drier, they are completely dry and does not have any moisture in it and ready for further processing.

The green tiles are tested for its flexure strength to ensure the quality of batch.

Dried tiles then coated with engobe, glaze and sent forward for printing. It can be either printed with rotary drum or digital printing machine.

Here onwards for each step of coating tile is first coated with adhesive and then air dried and each coating is done.

The green tile is then goes through a conveyor where adhesive is sprayed on it and air dried with fan.


View attachment 1389


After this the engobe and glaze is applied on the tile surface.


View attachment 1390


Engobe is the main layer on the tile surface which ensure no leakages from top to back of tile or from back of tile to the top surface (it’s just like a waterproofing coat). When you see a wet patches on tile surface then it’s clear indication of improper engobe application on it.

After engobe and glaze application tile is further moved to a printing assembly, it might be a roto type drum printer which gives color in 4 or more layer with adhesive application and drying before printing each layer.

In roto drum printer a color minerals are flowing through drums and when tile passes from the below of drum surface a layer of minerals is printed on it (just like how we apply paint on wall surface with roller brush)

Below photo shows assembly of 4 roto drum printer.


View attachment 1391


There are two technologies to print the design on tile surface

Roto Drum printer – As it’s a rotating drum which impress the color on tile surface, we can’t make a same design print on each tile surface and all tiles have different combination of surface texture (more likely they looks same), with this technology we cannot have fancy or more designs printed on it. This is use to give finish on the flat or rustic surface tiles.

Digital printing – In digital printing we can mimic almost any style, color combination and any type of surface finish look (we can make it as to look like wood, aluminium etc). After application of englobe the tiles are sent through a giant digital printer where the program automatically prints the design on each tile surface as per the design, with this technology we can print anything on tile surface, we can make a your photo printed on tile or printed in parts on tile which makes combination of 12 tiles to show what is the photo.

After completion of printing on tile surface, the automatic laser guided robots stack them and move to a kiln where heating of tiles is done.

View attachment 1392

View attachment 1393
Is there any standards specify the allowable percentage for hollowness in flooring(Tile and Stone)
 
The sampling of tile is done and tested in lab for defects, size, thickness, abrasion value, flexure value and crazing resistance etc.



View attachment 1418


View attachment 1419



This is what I learn during my factory visit to tile manufacturing plant, whatever written here is what I see and made me to understand by factory manager. I haven’t allowed to take photographs during factory visit so I used a pictures from a YouTube video to illustrate it in better way.

If you have any suggestion / addition to make it more helpful, kindly do reply.
 
Thanks for sharing the details
Kindly clarify what is double charged tile and how to test it whether it's single or double charged
In the local market at Bangalore they say it's double charged and hence it is costlier
 

BruneiShiva

Junior Member
The sampling of tile is done and tested in lab for defects, size, thickness, abrasion value, flexure value and crazing resistance etc.



View attachment 1418


View attachment 1419



This is what I learn during my factory visit to tile manufacturing plant, whatever written here is what I see and made me to understand by factory manager. I haven’t allowed to take photographs during factory visit so I used a pictures from a YouTube video to illustrate it in better way.

If you have any suggestion / addition to make it more helpful, kindly do reply.
Dear D Deshmukh

Thank you very much for sharing!

Have a good day & week ahead!

Best Regards
Shiva