Technology / product information

Common Defects in Green Sand Casting and How to Control Them to Reduce Scrap Rate
Common defects in green sand casting and how DISOCO ensures quality control

Green sand casting is a highly efficient and flexible method for producing mechanical components ranging from small to medium-sized parts. However, without proper control of critical factors such as sand moisture, molten metal temperature, and mold design, defects such as gas porosity, shrinkage, and dimensional deviations can easily occur, leading to increased scrap rates.

At DISOCO, we operate a fully automated Japanese green sand casting line (SINTO), combined with SolidCast simulation software, strict quality control procedures, and systematic workforce training. This integrated approach enables us to minimize defects and maintain consistent product quality.

Common Defects and DISOCO’s Control Measures
• Gas Porosity

Cause: Excessive sand moisture or poor gas permeability
DISOCO’s control measures:

Precise moisture control using SINTO sand analyzers

Proper core processing to improve gas venting

• Shrinkage

Cause: Uneven solidification during cooling
DISOCO’s control measures:

Flow and solidification simulation using SolidCast software

Optimized gating and riser system design

• Dimensional Mismatch

Cause: Mold misalignment or improper fixture setup
DISOCO’s control measures:

High-precision automatic green sand molding machines

Standardized pattern design and mold assembly procedures

• Poor Surface Finish / Burn-on

Cause: Excessive pouring temperature or poor sand quality
DISOCO’s control measures:

Controlled pouring temperature via automated pouring systems

Batch-by-batch metal composition analysis

• Blow Holes

Cause: Trapped air within the mold cavity
DISOCO’s control measures:

Optimized venting system design

Standardized core design and manufacturing to ensure proper gas release

Quality Control System at DISOCO

Automated green sand molding machines (SINTO, Japan):
30 seconds per mold, casting weight up to 70 kg per part

Dedicated sand management system:
Continuous monitoring of sand compactability, moisture, and strength for each production shift

SOLIDCast simulation software:
Predicts potential defects before casting and optimizes gating and cooling system design

Post-casting inspection:
3D CMM measurement, ultrasonic testing, magnetic particle inspection, hardness testing, and chemical composition analysis

By operating a fully automated green sand casting system and enforcing strict process control, DISOCO not only reduces post-casting defects but also consistently delivers stable quality to customers in Japan, the United States, and FDI enterprises in Vietnam.

For further details, please download our PDF or contact us directly if you are interested in green sand casting solutions in Vietnam.