DFM Pre‑optimization Project for Electrical Control Housing Mold

The client submitted 3D drawings to Kunshan Maifeng Precision for this electrical control housing. Featuring complex internal structures, multiple cut‑out windows and clustered button positions, the part has uneven wall thickness. Direct mold‑building would easily cause molding defects such as short shot, sink marks, weld lines and air traps. We launched a complete DFM review to identify hidden risks before mold machining.

Made of PC/ABS alloy, this mold requires 500K shots service life with 1.2344 & H13 tool steel for a 300T three‑plate mold. Simulation of the initial gate design revealed high pressure loss and insufficient filling at button zones. Our engineers revised the gating strategy: kept two overlap gates and added six individual pin‑gates for each button to balance melt flow. Appearance risks caused by gate vestige and surface features were discussed and confirmed with the customer.

During DFM review, undercuts were found on ribs at both sides which would cause demolding interference. We proposed draft optimization by shifting relevant geometry onto the core side, with a controlled 0.2 mm step‑off. Revision illustrations were provided for customer appearance approval. Full wall‑thickness inspection was carried out to spot sink‑mark risks. Custom ejection layout including extra ejectors for button tips was designed to avoid whitening and deformation.

With Moldflow simulation for filling pattern, weld lines, air traps and sink marks, we iterated gate layouts to move weld lines away from critical cosmetic surfaces. Venting structure was designed for detected air‑trap zones to keep sink marks within production‑tolerable range. We also reviewed parting line, mold layout, cooling circuit, material marking and date‑code features.

Most molding risks were resolved in advance via this comprehensive DFM report instead of costly post‑trial mold revisions. Thorough pre‑project technical review lays a solid foundation for mold manufacturing, trial runs and stable mass production, saving customer cycle time and modification costs.