Production process – from clay to paver
Ceramic specialists at Vandersanden have been producing characterful pavers for decades. We produce moulded pavers at our plants in Tolkamer and Spijk and extruded pavers in Kessel and Oberlausitz. Vandersanden is synonymous with high quality, authenticity, craftsmanship, and expertise. These values are embedded in our modern, fully automated production processes – fascinating and highly sustainable processes.
1. Clay extraction
The production of our pavers begins in clay quarries and the floodplains of rivers where we extract the raw material for our pavers – clay. We take great care during the excavation. Working with the WWF, we create the optimal conditions for new natural habitats to develop. At the same time, the extraction of river clay helps to ensure safer waterways and space for the river. As rivers constantly supply new clay, river clay is considered a renewable raw material. By extracting our raw materials as close to our production plants as possible, we also limit the environmental impact of transport.
2. Clay depot
We mix the different clays in the clay depot at our plants to create a single clay mixture. Precise mixing ratios are essential to achieving the right colour and dimensional stability. There are more than 100,000 m³ of prepared clay mixture in the depot at Vandersanden. To ensure the highest possible quality, the composition of our clay mixture is regularly tested by laboratories.
3. Clay pre-treatment
The clay mixture is then transported by lorry from the clay depot to the production plant. First, the mixture is rolled and kneaded. We then add steam and water to make it malleable. If required, we also add colour minerals such as iron, titanium, and manganese oxides. This allows us to create clay pavers in a wide range of colours, from yellow and red-brown to almost black.
4. Stone press
Using a brick press, we shape the clay into the desired paver size. In Tolkamer and Spijk, we produce moulded pavers by pressing the clay into moulds under high pressure. Each paver size requires its own mould. A fine layer of sand ensures that the clay can be released from the mould afterwards. We turn the moulds over and press the bricks onto drying plates. The sand contributes to the colour and character of the bricks, but we can also produce pavers without a sand-covered surface. In that case, the mould is not coated with sand but wetted instead. On an average day, we produce around 50,000 bricks every hour.
In Kessel and Oberlausitz, we use a vacuum extruder to produce a continuous clay column. The clay column is then cut automatically into pavers of the correct size. This produces sleek pavers with a distinctive character. We can also tumble the pavers to create a rustic, nostalgic look.
5. Drying kiln
Once the bricks have been pressed, they enter special drying chambers, where their moisture content is reduced from around 24% to 4%. This is a delicate process: if drying is not carefully monitored, the bricks may crack or break. We use residual heat from the kilns for drying. Depending on the size of the bricks, the drying process takes between approximately 30 and 70 hours, after which the bricks can enter the firing kiln.
6. Measurement and control room
Each kiln trolley takes around two days to pass through the tunnel kiln, during which each paver goes through heating, firing, and cooling phases. The ideal firing curve varies according to the colour and size of the paver. Heating and cooling too quickly can cause breakage and cracking, while excessively high temperatures can cause the bricks to deform. We monitor the kiln and drying processes from the measurement and control room.
7. Unloading and packaging
As the final step in the production process, we unload the bricks from the kiln trolleys. They are then stacked into mechanical paving packages. We can package around 55,000 bricks per hour. The bricks are then moved outside for storage or transferred to the robot hall, where they are assembled into packages suitable for mechanical laying.
8. The kilns
The dried bricks are fired in our 240-metre-long tunnel kilns, where they become extremely hard pavers. The temperature inside the kiln can reach up to 1,130°C. The higher the firing temperature, the harder the bricks become. We fire bricks 24 hours a day, 365 days a year, allowing us to produce up to 180 million pavers annually.
9. Mechanical packages robot line
Mechanical paving significantly improves working conditions and reduces the physical strain on paving workers. That is why we have invested heavily in developing mechanical paving solutions. Our stacking robots create mixed and single-colour paver packages suitable for mechanical laying in a wide range of common laying patterns.
10. Stacking area and batch inspection
The stacking area is where we store our fired bricks. It is a large showcase featuring dozens of different colours and sizes. Our specialists inspect the bricks every day, alongside independent inspectors, checking their dimensions, colours, and hardness. Only after a final independent quality inspection are the bricks transported to cities, contractors, landscapers, and private customers.
Everything you need to know about paving
Contact an expert
Customer Service
Advice on bricks, brick slips and pavers.
+44 (0)1954 268 075 [email protected] Ask your question