What are the Main Machining Machines for Plastic Injection Mold Manufacturing Process?

Main Machining Machines for Plastic Injection Mold Manufacturing Process (with Precision Data)

1️⃣ CNC Milling Machines (3-Axis / 5-Axis)

• Purpose:

  • Roughing and finishing of mold bases, cavities, and cores.

  • Producing complex 3D contours and precise geometries.

• Advantages:

  • 5-axis milling can machine undercuts and complex angles in one setup.

• Latest Precision Capability:

  • Positioning accuracy: ±2–3 µm

  • Repeatability: ±1–2 µm

  • Surface finish: Ra 0.2–0.4 µm with high-speed spindles

• Examples of Use:

  • Machining cavity blocks, parting surfaces, and insert pockets.

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2️⃣ Electrical Discharge Machines (EDM)

a) Sinker EDM

• Purpose:

  • Creating sharp corners and deep cavities.

• Advantages:

  • Excellent for hardened steels or complex details.

• Latest Precision Capability:

  • Dimensional accuracy: ±1–2 µm

  • Surface finish: As fine as Ra 0.1–0.15 µm (mirror-grade finish)

b) Wire EDM

• Purpose:

  • Cutting intricate profiles in hardened steel.

• Advantages:

  • Minimal heat-affected zone, excellent for inserts and punches.

• Latest Precision Capability:

  • Dimensional accuracy: ±1 µm

  • Surface roughness: Ra 0.2–0.3 µm

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3️⃣ Grinding Machines (Surface & Cylindrical)

• Purpose:

  • Finish flat and cylindrical surfaces, ensuring perfect alignment.

• Latest Precision Capability:

  • Flatness tolerance: ≤1 µm over 100 mm

  • Cylindrical roundness: ≤1 µm

  • Surface finish: Ra 0.02–0.05 µm

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4️⃣ High-Speed Drilling Machines (Deep-Hole Drilling)

• Purpose:

  • Drilling long cooling channels and ejector pin holes.

• Latest Precision Capability:

  • Hole straightness deviation: <0.1 mm over 1,000 mm depth

  • Diameter tolerance: ±0.02–0.05 mm

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5️⃣ Lathe Machines (CNC Turning)

• Purpose:

  • Manufacturing leader pins, bushings, spacers, and cylindrical inserts.

• Latest Precision Capability:

  • Dimensional accuracy: ±2–3 µm

  • Roundness: ≤1 µm

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6️⃣ Laser Engraving and Texturing Machines

• Purpose:

  • Marking logos, part numbers, or creating functional/aesthetic textures.

• Latest Precision Capability:

  • Engraving resolution: ≤10 µm

  • Depth control: ±5 µm

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7️⃣ Coordinate Measuring Machine (CMM) (for Verification)

• Purpose:

  • Measuring complex mold components to verify compliance with tolerances.

• Latest Precision Capability:

  • Measurement accuracy: ±0.7–1 µm

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8️⃣ Polishing Equipment

• Purpose:

  • Achieving mirror finishes or specified roughness for optical and cosmetic parts.

• Latest Finish Capability:

  • Surface finish: Ra 0.01–0.02 µm (mirror-quality finish for optical lenses).

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✅ Summary

State-of-the-art machining for plastic injection mold manufacturing can now achieve micron-level tolerances:

• CNC milling and EDM routinely hold ±2–3 µm.

• Wire EDM and grinding can achieve ±1 µm or better.

• Polishing and laser texturing deliver mirror-quality surfaces and ultra-fine details.

These capabilities ensure superior mold quality, shorter trial cycles, and enhanced production efficiency—critical advantages for industries like automotive, medical devices, electronics, and micro molding.