4 Practical Methods to Improve Clay Plasticity for Perfect Brick Extrusion

2026-05-18

In modern brick manufacturing, clay plasticity determines the success rate of brick extrusion, green body strength, and final finished brick quality. Many brick factories face common problems: loose clay, poor formability, easy collapse of wet bricks, and low production yield. These troubles are mostly caused by insufficient clay plasticity.

For brick plants using vacuum extruders and tunnel kilns, stable and high clay plasticity is indispensable. This article introduces four mature and practical methods to improve raw material plasticity, suitable for various clay, shale, and lean soil raw materials.

1. Natural Weathering: Low-Cost Clay Optimization

Mined raw clay is piled in the open air for 3 to 6 months. Under natural conditions including sunlight, rainwater, freezing and thawing, massive clay blocks gradually decompose and become loose. Weathering can evenly distribute internal moisture, dissolve soluble salts, reduce harmful impurities, and fundamentally optimize the physical properties of clay. It is the most economical and environmentally friendly way to improve plasticity without extra energy consumption.

2. Clay Aging (Kunning): Essential for High-End Brick Products

Clay aging means adding water to clay in layers and storing the raw materials for a certain period before molding. During the natural curing process, clay particles are fully wetted and dispersed with balanced moisture. After aging, the clay becomes delicate and sticky. This method is necessary for roof tiles, thin-walled hollow bricks, and high-porosity brick products, which effectively reduces molding defects and improves surface smoothness.

3. Fat Clay Blending: Improve Lean Raw Material Performance

Most sandy clay belongs to lean raw material with poor plasticity. Manufacturers can mix an appropriate proportion of fat clay to enhance viscosity and ductility. If high-standard bricks are required without high-plasticity fat clay, cheap and qualified inorganic binders are optional. Note that all mixtures must be stirred evenly by professional mixing equipment to avoid adverse chemical reactions.

4. Steam Heating & Hot Extrusion: Industrial Efficient Solution

Steam heating treatment is widely adopted by artificial drying brick factories. In twin-shaft mixers, steam penetrates tiny gaps between clay particles rapidly. The moisture distributes evenly to greatly boost clay plasticity. Hot extrusion technology reduces molding water content, increases wet brick temperature and green body strength. It shortens the drying cycle and improves continuous production efficiency.

Conclusion

Different clay raw materials require targeted plasticity improvement solutions. Our company provides raw material testing, formula optimization, and complete clay processing production lines including crushers, mixers, and vacuum extruders. If you have problems with low clay plasticity and unstable brick molding, contact us for a free customized solution.