Make clay hydrophobic and oleophobic by impregnation with our coatings | Print |

Clay is a natural base material for the production of bricks, roofing tiles, terracotta, tiles, etc.
Clay is mined in open mining areas. Clay is found in the subsurface. The mining covers a limited area. In most cases, the mining areas become agriculture areas. In this way a balance is created between the areas that are mined and which are returned to agriculture.
The brickworks are usually adjacent to the mining area.

To the clay, natural materials (sand, sawdust) and water are added. This mixture of primary materials is converted to a homogeneous mixture. The clay is formed in the shape of a brick stone (by extrusion or molding) and is dried and baked at a temperature of about 1000 ° C . The dry and baking curves are characteristic for the mixture of raw materials and for the kind of brick.
The preparation consists of two main operations: first kneading and grinding, afterwards mixing and dosing.
Kneading and grinding are designed to create homogeneous clay mass and giving its plasticity which is important to form the stones. Also during this process the solids present in the clay are crushed and are finely divided into the clay mass. This very important operation is done in the edge runner mill or in the clay roller.

Finally, Clay also contains undesirable organic components which can be decomposed by micro-organisms. To facilitate this process the clay is stored in dark and humid storage areas.
The constant quality of the finished product has become a key requirement that only can be achieved if the raw materials have the same properties. Therefore, under permanent control, various types of clay are mixed.
Fat clays are emaciated by the addition of sand. Sawdust makes the shard more porous. Manganese Ore gives the brick a certain color.
Stabilizing the optimum moisture content of the clay is very important.
Formerly, hand made stones was made entirely by hand by throwing a ball of clay into a wooden mold. Now this is done mechanically.
Before the formed clay is going into the oven, the clay has to lose a significant proportion of its water content. Otherwise the stones are going to crack when baking or will brake because of the expansion of the water vapor within the mass. The final dimension stability of the clay forms are achieved when the shrinkage due to water loss is completed.

The clay forms are dried in drying tunnels or drying rooms (usually 2 to 4 days).
The baking process is progressively with other words the temperature must be increased according to a specific timetable to achieve the final firing temperature (between 850 º to 1200 º C, depending on the clay) and cooled down progressively to complete cooling. Each composition has its own clay baking curve.