Tracing the Common Causes of Cracks, Chipping, and Insufficient Strength in Bricks

Tracing the Common Causes of Cracks, Chipping, and Insufficient Strength in Bricks

Quality defects in bricks after production are often a signal of uncontrolled processes in one or more stages of production. By tracing back from the defect phenomenon, the root cause of the problem can be quickly identified, allowing for targeted improvements.

I. Tracing the Causes of Cracks (Surface Cracks or Through Cracks)

Cracks are mainly related to raw materials, drying, and early curing.

Raw Materials and Mixing Stage:

Cause: Insufficient plastic components (such as fine clay) in the raw materials, or particles that are too coarse or have poor gradation, resulting in poor bonding strength after molding. Uneven mixing, inconsistent moisture content, and uneven shrinkage.

Traceability Checkpoints: Check the raw material ratio, especially the fine particle content; confirm the accuracy of mixing time and water addition.

Post-Molding Treatment Stage:

Cause: After wet brick blanks are molded, exposure to direct sunlight or strong winds causes rapid surface moisture evaporation, resulting in uneven shrinkage and tensile stress, leading to cracking. This is the most common cause.

Traceability Checkpoints: Check whether shading and wind protection measures are taken during the transfer process from the molding area to the curing area.

Early Curing Stage:

Cause: Insufficient static curing (pre-curing) time or an overly dry environment.

Traceability Checkpoints: Check whether the temperature and humidity management and static curing time in the curing area meet the standards.

II. Tracing the Causes of Chipping and Edge Defects

This problem mainly points to the molding and mold stages.

Mold Stage:

Cause: Severe mold wear, especially at the corners; inadequate cleaning of the mold inner wall, resulting in material sticking and damage to the brick blank during demolding.

Traceability Checkpoints: Check the mold dimensions and the degree of wear on the corners; check the mold cleaning situation for each shift.

Material Feeding and Molding Stage:

Cause: Uneven or insufficient filling of raw materials into the mold, resulting in localized material shortages and loose edges and corners of the brick blank.

Traceability Checkpoints: Observe the material feeding process and check whether the feeding device is working properly.

Demolding and Handling Stage:

Cause: The demolding mechanism is not smooth, or the initial handling of the brick blanks by workers is too rough, causing mechanical damage. Traceability Checkpoint: Observe whether the demolding process and brick stacking operations are standardized.

III. Insufficient Strength and Brittleness Traceability

This is a systemic problem involving the entire process from formulation to curing.

Raw Materials and Proportioning (Root Cause):

Reasons: Insufficient or ineffective proportion of cement and other cementing materials (e.g., due to dampness); excessive clay content or impurities in raw materials.

Traceability Checkpoint: Strictly verify batching records and the accuracy of weighing tools; check the storage conditions of cement and other materials.

Molding Process:

Reasons: Insufficient or fluctuating molding pressure of the brick-making machine, resulting in insufficient density of the brick blanks.

Traceability Checkpoint: Test and record whether the molding pressure is stable and meets process requirements.

Curing Process (Key Cause):

Reasons: Severely inadequate curing – insufficient watering, insufficient frequency, or insufficient duration, or poor curing environment (temperature and humidity), resulting in insufficient hydration reaction of the brick blanks and failure to reach the designed strength.

Traceability Checkpoint: Check whether the curing system is implemented, and check the actual temperature and humidity of the curing area and the moisture content of the brick blanks.

Summary: Defects are the "effect," and the process is the "cause."

The core idea of solving quality problems is to "deduce the production process from the defect phenomenon." Establishing a simple production process record table that links information such as raw material batches, molding pressure, and curing conditions for each batch of bricks is crucial.

When a problem occurs, the problematic batch can be quickly identified, and specific links can be investigated and corrected according to the above traceability path. This data-driven traceability is far more accurate and efficient than relying on experience and guesswork, and it is the only way to achieve stable production of high-quality bricks.