Injection Mold Maintenance: Complete Guide to Preventive Maintenance, Cleaning and Repair

Last updated: June 19, 2026

Why Mold Maintenance Matters

Regular maintenance extends mold life by 2-3x, reduces defect rates by 40-60%, and prevents costly production shutdowns. A properly maintained mold produces consistent parts with shorter cycle times.

Preventive Maintenance Schedule

FrequencyActions
Every RunVisual inspection, clean cavity, check pins, lubricate
Weekly / 10k cyclesCheck cooling channels, inspect gate, verify alignment
Monthly / 50k cyclesDeep clean, measure dimensions, check vent depth
Quarterly / 150k cyclesAcid flush cooling, full dimension check, replace wear items
Annually / 500k cyclesFull strip-down, hardness test, weld repair, overhaul

Mold Cleaning Methods

Manual Cleaning

Non-abrasive cleaners, brass tools, soft cloths. Best for mirror-polished surfaces.

Dry Ice Blasting

CO2 pellets sublimate on impact. No disassembly needed. Cost: $200-400/session.

Ultrasonic Cleaning

Inserts in ultrasonic bath. Effective for gas residue and micro-debris from vents.

Common Repairs

Surface Wear

Minor scratches: diamond paste polish. Deeper (0.05-0.1mm): welding + finishing. Beyond 0.1mm: insert replacement.

Vent Cleaning

Clean every 10k-50k cycles. Deepen by 0.005-0.010mm if burn marks appear.

Ejector Pin Replacement

Replace when clearance exceeds 0.04mm. Standard interval: 200k-500k cycles.

Mold Storage

  • Clean and dry thoroughly before storage
  • Apply rust-preventative spray
  • Store at 20-25°C, <50% RH
  • Protect cavity face with plywood cover
  • Monthly inspection for rust