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Expert Analysis on Fired Brick Production Quality Issues: Root Causes and Standardized Resolution Solutions
2026-07-30
Fired Brick and block products occupy an irreplaceable position in construction engineering due to their excellent structural performance and economic benefits. The overall quality of fired products directly affects project quality and construction safety. Based on ancient brick-making craftsmanship and modern tunnel kiln production technology, the industry has formed a consensus that "raw material is the core, technology is the condition, and management is the guarantee". Years of quality inspection and production practice prove that most fired brick quality failures originate from non-standard raw material treatment, followed by unreasonable process and equipment management. This article summarizes expert practical experience, analyzes the essential causes of six common quality problems in fired brick production, and puts forward standardized, scalable resolution solutions for medium and large brick production lines.
1. Size Deviation: Raw Material Aging and Grading Management
Size deviation is a basic indicator of fired brick quality. The essential cause of unqualified size is unreasonable raw material particle gradation and insufficient aging time, which leads to unstable clay plasticity and uncontrollable shrinkage during drying and firing.
Standard Solutions: Establish raw material screening and grading system to optimize particle structure. Equip aging warehouses with 7-day production capacity to ensure full raw material aging and stable plasticity. Adjust brick machine extrusion specifications according to raw material plasticity test data to match shrinkage deviation and realize precise size control.
2. Edge Crack Defects: Molding Resistance Control
Excessive coarse particles and low molding moisture increase mud strip extrusion resistance, causing stress concentration and edge corner cracks during molding. This problem belongs to process matching error, which can be completely solved by parameter calibration.
Standard Solutions: Optimize raw material crushing fineness to reduce coarse particle proportion. Calibrate roller press gap to 3mm for uniform crushing. Adjust molding moisture to reduce extrusion resistance and ensure complete and regular brick blank molding.
3. Rib and Wall Horizontal Cracks: Scientific Drying Process Management
Horizontal cracks on brick ribs and walls are caused by inconsistent particle shrinkage and improper drying speed and temperature. Rapid surface drying and internal moisture retention lead to irreversible crack defects.
Standard Solutions: Balance raw material particle gradation to unify shrinkage rate. Implement staged constant-temperature drying: 40℃ for blank feeding and 110℃ for finished brick discharging. Dynamically adjust drying time and air volume according to kiln internal environment to achieve uniform drying without cracks.
4. Underfired Bricks: Kiln Sealing and Sintering Parameter Calibration
Kiln car bottom cold air leakage and unbalanced kiln pressure and temperature are the main causes of underfired bricks, resulting in low brick strength and high breakage rate.
Standard Solutions: Regularly maintain kiln car sand seal and sealing groove to eliminate cold air leakage. Adjust the pressure balance of each firing zone to reduce upper and lower temperature difference of brick stacks. Optimize raw material heat value and strictly implement fixed-temperature and fixed-time firing standards to ensure sufficient firing and heat preservation effect.
5. Burst & Overfired Bricks: Heat Value and Stacking Standardization
Excessive raw material heat, dense stacking and delayed firing zone lead to overheating, bending and blistering of bricks. Standardized heat matching and stacking process are the key to solve overfired defects.
Standard Solutions: Scientifically configure raw material internal heat proportion to avoid excessive heat accumulation. Standardize brick blank stacking gaps to ensure smooth heat circulation. Strictly control firing zone position and duration to prevent over-firing deformation.
6. Poor Weathering Resistance: Complete Sintering via Raw Material Standardization
Incomplete raw material homogenization and aging lead to insufficient solid-liquid phase reaction during firing, forming "half-cooked" sintering state and reducing weathering resistance and service life of bricks.
Standard Solutions: Implement mandatory homogenization and aging procedures for all production raw materials. Properly increase firing temperature to promote complete particle reaction. Improve crushing fineness of inferior raw materials to ensure overall uniform sintering quality.
Expert Summary:
The quality competition of modern fired brick production is essentially the competition of raw material processing standardization and production process refinement. Adhering to the traditional brick-making essence and matching modern tunnel kiln precise process management can completely solve common quality defects and produce high-standard qualified fired bricks.