Aluminum alloy die-casting demoulding optimization: controlling carbon deposits and improving continuous production stability

# Aluminum alloy die-casting demoulding optimization case: controlling carbon deposits and improving continuous production stability

# Project overview

• Industry/Scenario: Aluminum alloy die-casting high-tempo production
• Production method: Single shift continuous production
• Core Goal: Slow down the growth of carbon deposits, extend the mold cleaning cycle and reduce surface defects

# Initial questions

Customers have three types of problems during the high-tempo stage:

1. Carbon deposits in the mold grow rapidly, and mold cleaning is frequent during subsequent shutdowns.
2. Surface defects fluctuate, affecting subsequent processing rhythm
3. The coverage of key areas is unstable and the consistency of continuous production is insufficient.

# Live baseline (before optimization)

• Surface defect rate: about 4.0%
• Mold cleaning cycle: Clean approximately every 50 to 70 molds
• Stability performance: Fluctuations are obvious in the latter part of high beats, and mold clearing is frequently interrupted.

Statistical caliber: 12 consecutive days of daily production line reports for a single shift, based on the customer’s current appearance and process shutdown records.

# Diagnostic Process (Days 1-3)

First solidify the process baseline, and then optimize the strategy:

1. Record the relationship between spraying timing and defect distribution
2. Compare key area coverage changes and carbon deposition growth trends
3. Investigate the impact of mold temperature fluctuations on surface conditions
4. After clearing the mold baseline, make a comparison of the spraying volume.

Diagnostic Conclusion

• The main contradiction lies in the timing of spraying and unstable coverage of key areas, rather than a single material problem.
• The original window has insufficient fault tolerance under high beats and can easily trigger surface defects and carbon deposits.

# Implementation Plan (Days 4-10)

• Plan A (Timing Optimization): Adjust the spraying timing to match the production line rhythm
• Option B (Regional Strategy): Establish fixed-point spraying in key areas
• Plan C (Temperature Control Collaboration): Optimize mold temperature matching and reduce window drift

Establish SOP simultaneously:

• First article confirmation per shift (critical area coverage and surface condition)
• Random inspection of carbon deposit growth and appearance defects every 2 hours
• Abnormal troubleshooting sequence: Spraying timing → Key area coverage → Mold temperature → Mold cleaning baseline

# 12 days results (trial production stage)

• Mold cleaning cycle: increased from every 50~70 molds to every 90~120 molds
• Surface defect rate: reduced from about 4.0% to 2.1%~2.8%
• Continuous Stability: The fluctuations in the later stages of high beats converge, and the impact of shutdowns is reduced.

# Reusable experience

1. The die-casting scene prioritizes optimization of “timing + key areas”, which is more effective than global extensive parameter adjustment.
2. Carbon deposition control should be coordinated with the mold temperature window. It is not recommended to only look at the total spray amount.
3. Use the dual indicator of “mold cleaning cycle + defective rate” to evaluate closer to the true cost

# Applicable boundary description

The results of this case are based on the current mold status, production line rhythm, temperature control level and quality standards. Under different alloy systems, structural complexity and post-processing requirements, it is recommended to verify the sample first and then scale up the entire line.

# Consulting advice

The cycle time, mold temperature range, defect distribution and current mold cleaning frequency can be provided, and we can provide an initial process window suggestion that can be implemented.