Mold Manufacturing Process

High-quality mold manufacturing requires precision across every stage: from initial DFM to final tryout and sampling. Here is the typical workflow followed by professional mold makers.

Design & DFM

The process begins with Design for Manufacturability (DFM) analysis. Engineers review the part geometry, propose gate locations, cooling layout, ejection system, and parting line. 3D modeling is done in UG/NX or Creo. Mold flow analysis (Moldex3D or Autodesk Moldflow) predicts fill patterns, cooling, and warpage before steel cutting begins.

Rough Machining & Heat Treatment

CNC roughing removes the bulk of material using large-diameter face mills and high-feed cutters. Heat treatment follows: stress relieving, hardening, and tempering to target hardness. Rough machining before heat treatment allows distortion to be corrected during finish machining.

Finish Machining & EDM

High-speed CNC finishing achieves final cavity geometry within IT5-IT6 tolerances. Sinker EDM creates sharp internal corners, deep ribs, and intricate textures. Wire EDM cuts through-hardened inserts, slider tracks, and electrode shapes. 5-axis machining reduces setups and improves surface quality on complex 3D surfaces.

Fitting & Assembly

Fitters assemble mold plates, install inserts, slides, lifters, cooling fittings, and ejector pins. All moving parts are checked for smooth operation. Slide gibs adjusted for 0.02-0.05mm clearance. Cooling water flow tested for each circuit. Hot runner electrical connections verified.

Tryout & Sampling

The mold is mounted on an injection molding machine for trial runs. Key parameters (temperature, pressure, injection speed, cooling time) are optimized. First shots are inspected for dimensions, weight, surface finish, and defects. Adjustments made to vents, gate size, and cooling. Trial reports document the optimal process window.

Inspection & Delivery

Final inspection includes steel hardness check, surface finish measurement (Ra 0.2-0.4 micron for polished cavities), cooling flow rate verification, and sample part dimension report (CMM). Mould Trial Report and FAIR (First Article Inspection Report) delivered with the tool if specified.