Continuous Cast Iron: The Cornerstone of High-Performance Injection Molding Machine Components

I. Injection Molding Machines and Material Requirements

Injection molding machines transform plastics into finished products through a process of melting, high-pressure injection, and cooling. The component system is the core of this process. High-performance components must offer high strength, stability, and cost-effectiveness, making continuous Cast Iron Bars the ideal material due to their comprehensive properties.

II. Five Key Advantages of Continuous Cast Iron

High Strength and Rigidity

• Materials: Grey cast iron (EN-GJL-250/300), Ductile Iron (EN-GJS-450-10)
• Applications: Manifolds and injection cylinder fronts, withstanding 200MPa melt pressure without deformation to ensure flow channel accuracy.

Wear Resistance and Damping Capacity

• Features: Graphite structure for self-lubrication, better vibration damping than steel
• Applications: Cylinder pistons, resisting high-speed friction (2-5m/s), reducing noise and extending seal life.

Machinability and Dimensional Stability

• Machining: Excellent for turning, milling, drilling
• Applications: Adjusting nuts, with residual stress <30MPa for reliable long-term adjustment.

Heat Resistance and Thermal Stability

• Specs: Thermal expansion coefficient 11.5×10⁻⁶/℃, deformation <0.23% under 200℃ fluctuations
• Applications: Manifolds, maintaining geometric accuracy in temperature variations.

Cost-Effectiveness and Reliability

• Advantages: 45% lower cost than forgedsteel, mature casting processes
• Applications: Mold clamping cylinder fronts, with <0.15mm deformation under 5,000-ton loads.

III. Key Component Applications of Cast Iron Bars

• Manifold: As the "highway" of the hot runner system, precision-machined from high-strength grey/ductile iron to ensure uniform melt distribution and system longevity.
• Adjusting/Brake Nuts: Made from machinable grey iron for precise positioning and mechanical locking, with excellent thread precision.
• Cylinder Piston: Core actuator in hydraulic systems, using ductile iron (e.g., EN-GJS-500-7) for high strength, wear resistance, and damping, extending service life through reduced friction and vibration.
• Injection Cylinder Front End: High-rigidity grey iron for pressure-bearing and sealing, critical for injection accuracy and cylinder integrity.
• Mold Clamping Cylinder Front Cover: High-strength grey iron absorbing clamping force impacts, ensuring hydraulic sealing and machine reliability.

Continuous cast iron bars play an irreplaceable role in injection molding machine components, leveraging strength, wear resistance, and machinability to underpin efficient and stable operations. With advancing material technology, their potential in high-end injection molding will continue to grow.