Shenzhen Alu Rapid Prototype Precision Co., Ltd.
Industry News
Die casting and injection molding are manufacturing processes for producing precise, complex parts at high volumes, but they differ in materials, equipment, and applications. Below is a comparison:
1. Definition
Die Casting: Molten metal (e.g., aluminum, zinc, magnesium) is injected under high pressure into a steel mold (die) to form metal parts.
Injection Molding: Molten plastic (e.g., ABS, polycarbonate) is injected under pressure into a metal mold to create plastic parts.
2. Materials
Die Casting: Non-ferrous metals (aluminum, zinc, magnesium, copper alloys).
Injection Molding: Thermoplastics, thermosets, and sometimes elastomers.
3. Process
Die Casting:
Uses hot-chamber (for low-melting metals like zinc) or cold-chamber (for high-melting metals like aluminum) systems.
Higher pressures (10–175 MPa).
Metal solidifies quickly; part is ejected after cooling.
Injection Molding:
Plastic pellets are melted in a barrel, injected into a mold, cooled, and ejected.
Lower pressures than die casting (typically 5–140 MPa).
Cooling times vary based on plastic type and part thickness.
4. Equipment
Die Casting: Heavy-duty steel dies, high-pressure injection systems, furnaces for melting metal.
Injection Molding: Steel or aluminum molds, injection molding machines with heated barrels and screws.
5. Part Characteristics
Die Casting:
High strength, durability, and heat resistance.
Excellent dimensional accuracy (±0.02 mm) and smooth surfaces.
Potential for porosity in parts, requiring secondary processing.
Injection Molding:
Lightweight, flexible, or rigid parts with diverse colors and textures.
High precision (±0.05 mm) and consistent quality.
Less prone to internal defects but may warp or shrink.
6. Production
Die Casting:
Ideal for medium to high volumes due to high tooling costs.
Faster cycle times for thin-walled parts (seconds to minutes).
Injection Molding:
Suited for high-volume production; tooling costs are also high.
Slightly longer cycle times due to plastic cooling (seconds to minutes).
7. Cost
Die Casting:
Higher initial tooling costs due to durable steel dies for high-temperature metals.
Material costs (metals) are generally higher than plastics.
Lower per-part costs at high volumes.
Injection Molding:
Tooling costs are high but often lower than die casting (aluminum molds possible for lower volumes).
Plastic materials are cheaper.
Cost-effective for mass production.
8. Advantages
Die Casting:
Strong, durable metal parts with excellent mechanical properties.
High thermal and electrical conductivity.
Minimal post-processing for surface finish.
Injection Molding:
Wide range of material properties (flexible, rigid, transparent).
Easily customizable with colors, additives, or inserts.
Lightweight parts reduce shipping and assembly costs.
9. Disadvantages
Die Casting:
Limited to non-ferrous metals; not suitable for steel or iron.
High tooling costs make low-volume production expensive.
Porosity can affect part integrity.
Injection Molding:
Plastic parts are less durable and heat-resistant than metal.
Potential for warping, sink marks, or shrinkage.
Environmental concerns with plastic waste.
10. Applications
Die Casting:
Automotive (engine blocks, transmission housings).
Aerospace (structural components).
Electronics (heatsinks, enclosures).
Injection Molding:
Consumer goods (toys, packaging, appliance housings).
Medical (syringes, device casings).
Automotive (dashboards, interior components).
Summary
Choose Die Casting for strong, durable metal parts requiring high precision, heat resistance, or conductivity, especially in automotive or industrial applications.
Choose Injection Molding for lightweight, cost-effective plastic parts with diverse material options, ideal for consumer products or medical devices.