Sometimes I write things and there is a lot of information I can say about us and our involvement with the process, but brick manufacturing is a straightforward process. We use any of these style bricks and sometimes reused bricks as well. Bricks are very universal and such a green building material. They last a very long time, but not forever.
There are 3 common methods:
- Soft Mud Process
- Stiff Mud Process
- Dry Press Process
At the end of the day, each of these methods creates a tried-and-true type of brick.
The Soft Mud Process
This method a wet clay is created, allows the clay to be partially fluid. This clay mixture is pressed through a mold and the brick is formed simply by scraping off the top of the mold what comes through. There is sticking if the sand is pressed, so there are 2 methods to prevent sticking, either a water edge or a sand edge. This is where a layer of water or a layer of sand is used to line the mold during the process.
The brick face if water is used is quite smooth, while the face will be a little more like a sandpaper if the sand is used. This is because the sand will stick to the brick clay material and then wash away leaving a little roughness.
The Stiff Mud Process
This method uses almost dry clay. It’s wet just enough to stick together. I kind of think of this is like pie crust, how it’s crumbly, but when you squeeze it. It all works out. This mixture is pressed through a extruder and then a wire is used to cut it at dimension.
These bricks are usually not quite as smooth as soft water pressed pieces, but not as rough as the sand pressed pieces.
Dry Press Process
The clay is dry in this method and loose. It’s pressed together under high pressure. This produces a very dense brick.
The bricks manufactured are called green bricks after any of these processes. These green bricks then need to be dried or fired to finalize create the product “Brick”.
Coating and Glazes
This is the place in the manufacturing process where any coating or glazes that are desired are placed onto the clay. Glazed bricks are always used as facing bricks, meaning that they are used for looks less than function. They have different characteristics and strengths than a brick without these extra coatings. They are great for use on walls or the undersides of large openings of buildings.
No matter the manufacturing process all bricks need dried there are different ways to do this. Bricks have between 5% and 30% moisture coming through the extruding machines. This percentage will be determined and that will determine their path forward and speed for manufacturing completion.
The moisture needs to leave the brick at a certain rate and if it happens too fast, the brick will crack. Some bricks are put in a kiln that is temperature controlled for this process and other bricks are air dried which basically just means left under a roof with airflow between them.
After the bricks are at the proper moisture level, they are then fired which will completely dry. It can take from 50 to 150 hours to completely dry the brick depending on size and environmental conditions. Equally important to how fast the bricks dry to prevent cracking it’s equally important how they are cooled. Bricks that are cooled from fire temperature to room temperature too quickly will crack. Cooling is also vital for the coloration of the brick, cooling to quickly can change the colors, so needs to be consistent to ensure a consistent coloration of all the pieces.
Bricks are bricks like those that most of us know after the firing process is completed, bricks that crack or don’t pass quality checks are culled out and the rest are sent off to places for distribution. The lucky ones get the be touched by one of the professionals at Dayco General.