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Effective Methods to Solve Green Body Cracks Caused by Over-Fast Drying in Brick stacking and drying systems
2026-08-19
Brick and tile drying technology occupies a pivotal position in the entire brick manufacturing workflow, and green body crack control has always been a key technical difficulty restricting production upgrading in the brick and tile industry. The integrated brick stacking and drying systems are widely adopted in modern factories, yet unregulated over-fast drying of raw adobes easily leads to large-scale defective products. Thoroughly understanding the stress generation and cracking principle of dry shrinkage cracks enables manufacturers to scientifically optimize industrial brick drying processes, stabilize product quality, and boost final product qualification rates.
Mass brick cracking failure in integrated production lines is mainly attributed to two core technical causes related to drying processes. First, irregular sudden mutations of the industrial drying process system destroy the stable dewatering environment for raw brick adobes. Second, premature high-speed dewatering is conducted before the green body reaches the moisture balance critical point, failing to match the structural shaping rules of unfired brick green bodies and causing shrinkage cracking.
The moisture removal capacity of drying media is positively correlated with temperature. In professional brick production drying systems, higher medium temperature means faster green body dewatering. However, one-sided pursuit of drying efficiency by increasing temperature will inevitably lead to structural cracking of brick surface.
The specific cracking mechanism is as follows: when the drying medium temperature is too high, the surface moisture of the green body evaporates and loses water rapidly, while the internal water molecule migration speed lags far behind the surface evaporation speed. The surface layer of the green body undergoes large-scale shrinkage, while the internal structure remains in a low-shrinkage state. This forms a persistent tensile stress from the inside to the surface of the green body. Once the stress value exceeds the mechanical strength of the green body surface, visible cracks will appear on the brick surface.
In actual production, accidental temperature spikes in the drying workshop are the most common cause of batch cracking. A sudden rise in medium temperature will instantly accelerate surface dewatering and shrinkage. Since the internal shrinkage speed cannot match the surface shrinkage rate, the unbalanced structural stress instantly destroys the green body surface structure, resulting in mass crack defects of brick adobes.
FAQ
Q1: What are the two core causes of fast drying brick green body cracks?
A1: Batch cracking of unfired brick green bodies mainly stems from two core technical issues: abrupt violent fluctuations of industrial drying process systems and over-fast high-temperature drying before the moisture balance critical point.
Q2: How to balance brick drying efficiency and crack control?
A2: The optimal solution is to adopt scientific and stable industrial brick drying parameters, eliminate sudden temperature spikes, maintain low-speed drying before the critical point, and realize synchronous internal and external moisture evaporation to balance drying efficiency and green body crack control.
Q3: What is the relationship between drying medium temperature and green body crack generation?
A3: Moderate drying medium temperature efficiently improves green body dewatering without quality risks. In contrast, overhigh temperature or sudden temperature rises cause unbalanced shrinkage and abnormal structural stress, which are the direct causes of brick green body drying cracks.