Advantages of Injection Mold Coatings
Injection mold coatings (also known as mold surface treatments or surface coatings) are widely used to enhance mold performance and lifespan. Their key benefits include improved wear resistance, corrosion resistance, demolding efficiency, thermal stability, and more.
1. Enhanced Wear Resistance and Extended Service Life
Molds endure frequent clamping, friction, and erosion under high pressure and temperature during prolonged injection cycles. Coatings significantly improve wear resistance.
Common coatings: TiN, TiCN, CrN, DLC (Diamond-Like Carbon)
Lifespan improvement: Extends mold life by several times to over tenfold.
2. Improved Demolding Performance and Anti-Sticking
Plastic parts often adhere to mold cavities during demolding, especially with glass fiber-reinforced or high-temperature materials.
Low-friction coatings: Chromium nitride (CrN), DLC, PTFE (Teflon)
Benefits:
Reduces ejection force and cycle time.
Minimizes mold wear and product damage.
3. Corrosion and Rust Resistance
Certain plastics (e.g., PVC, halogen-containing plastics) release acidic gases during molding, accelerating corrosion.
Corrosion-resistant coatings:
Chromium plating
PVD (Physical Vapor Deposition) nitride coatings
Applications: Ideal for highly corrosive environments.
4. Increased Surface Hardness
PVD coatings elevate surface hardness to HV2000-4000 (far exceeding conventional quenched steel), enhancing compressive strength.
Best for: High-load injection molding and high-strength glass fiber materials.
5. Improved Thermal Stability and Thermal Fatigue Resistance
Repeated heating-cooling cycles in high-temperature molding can cause thermal cracks and failure.
High-temperature coatings:
AlTiN (Aluminum Titanium Nitride)
CrAlN (Chromium Aluminum Nitride)
Performance: Stable operation at temperatures exceeding 800°C.
6. Enhanced Product Surface Quality
Coatings create smoother, more uniform mold surfaces, reducing defects such as:
Flow marks
Drag lines
Cold slug marks
