Common AAC Block And Panel Production Defects Caused by Aluminum Paste: Root Causes And Solutions

Common AAC Block and Panel Production Defects Caused by Aluminum Paste: Root Causes and Solutions

1. Mold Collapse

Defect Phenomenon

Cause

Solution

Normal slurry thickening, but gas generation too fast

Pouring temperature is too high.

Reduce pouring temperature.

Too much aluminum paste.

Reduce aluminum paste dosage.

Normal gas generation, but slurry thickening too slow

Water-to-solid ratio is too high.

Reduce the water-to-solid ratio and increase slurry consistency.

Insufficient lime or cement, or excessive gypsum.

Increase lime or cement, or reduce gypsum.

Large bubbles, bubbles damaged

Fly ash (sand) is too coarse; slurry viscosity is too low.

Grind fly ash finer, increase dry material content (dry fly ash, lime, cement), use foam stabilizers, prepare slurry earlier, and reduce lime dosage.

Too much lime; internal temperature of green body is too high.

Water-to-solid ratio too high; water is bleeding around mold frame.

Increase slurry density, use foam stabilizer, and reduce slurry volume.

High casting temperature and excessive gas generation.

Reduce pouring temperature.

Too high carbon content is in fly ash; water is bleeding around edges.

Replace fly ash.

Gas generation from aluminum paste overly concentrated

The particle size of aluminum paste is too fine,

Replace aluminum paste.

Mold leakage

Aging seals; mold or rail deformation.

Replace seals and repair mold rails.

Unexpected mold collapse

Manual or mechanical vibration; roof dripping.

Staff training and preventive measures.

Common AAC Block and Panel Production Defects Caused by Aluminum Paste: Root Causes and Solutions

2. Insufficient Expansion Height

Defect Phenomenon

Cause

Solution

Normal gas generation, but thickening too fast; green body cannot expand normally.

Slurry too thick.

Reduce slurry density.

Too much lime (or cement), or insufficient gypsum.

Reduce lime (or cement) and increase gypsum.

Pouring temperature too high.

Reduce pouring temperature.

Gas generation and thickening are normal, but the overall green body volume is insufficient.

Insufficient total batch quantity and low aluminum dosage (or poor-quality aluminum paste with partial oxidation).

Increase total batch quantity.
Increase aluminum paste dosage.