Cost Difference Analysis Between Partial Mold Revision and New Mold Fabrication
Product upgrading, size correction and structural optimization often occur in injection molding production. Factories adopt two solutions for product modification: partial mold revision based on original molds, and full new mold manufacturing. Partial revision retains most original mold structures with low cost and short cycle, while new mold production is built from scratch with high investment and better structural stability. The two schemes differ greatly in manufacturing cost, cycle, hidden loss and long-term maintenance cost, providing cost decision reference for mold factories.
1. Direct Cost Composition of Partial Mold Revision
Partial revision retains mold base, guide components, cooling circuits, ejection systems and complete parting surfaces of original molds, only cutting, replacing or repairing local cavities, inserts and sliders corresponding to modified product areas. Steel consumption only accounts for 5%~20% of the whole mold, cutting raw material cost sharply. Simple revision for daily necessities molds costs hundreds to 2000 RMB in steel expenses; even precision insert replacement for electronic connector molds costs no more than 8000 RMB. Machining work only includes local CNC finishing, EDM trimming and polishing, taking 1~7 days to finish with total labor cost between 2000 and 12000 RMB. Design workload is extremely low, only requiring local revision drawings within 1~4 hours. Overall investment of conventional partial revision is merely 10%~25% of new mold cost, making it the economical choice for minor product modifications. Partial revision can be arranged during factory shutdown at night, causing only 0.5~2 days of production halt and negligible capacity loss.
2. Direct Cost Composition of Brand-New Mold Manufacturing
New molds purchase mold bases, core steel and all accessories from scratch, with material cost occupying about 35% of total mold cost. Ordinary medium-small plastic molds cost 15000~50000 RMB in steel and mold base materials; medical and automotive precision molds using S136 and STAVAX anti-rust steel cost 60000~150000 RMB for raw materials. Complete structural analysis, parting design, full drawing output and process planning are required before machining, consuming 2~7 days for design work costing 3000~12000 RMB. New molds go through rough machining, wire cutting, full-area EDM, assembly and repeated mold trials, with a production cycle of 7~25 days and labor cost accounting for over 45% of total cost. The total cost of ordinary plastic molds ranges from 20000 to 80000 RMB, and high-precision molds exceed 150000 RMB. The one-time investment of new molds is 6~12 times that of partial revision, bringing heavy capital pressure for factories. During new mold production, old molds usually stop production for over one week, easily causing hidden losses such as delayed orders and customer compensation.
3. Long-Term Service Cost & Applicable Scenarios Comparison
Proper minor revision will not damage mature cooling and ejection structures of original molds, keeping mold service life and later maintenance cost unchanged. Yet multiple large-scale revisions increase core splicing gaps and disorder water channel layout, easily triggering flash, water leakage and ejection jamming in later mass production. New integrated molds feature complete structures, uniform water channels and high matching precision, with ultra-low failure rate within 50000~100000 shots of early mass production and stronger stability for long-term continuous manufacturing.
Partial revision suits scenarios of slight size correction, appearance fine-tuning and local structural optimization, matching fast-iterative consumer plastic products with moderate service life. When products need overall structural reconstruction, full appearance revision, or old molds are severely aging and scrapped, partial revision cannot meet precision requirements, and new mold manufacturing becomes more suitable. Although new molds require high one-time investment, their integrated structure brings lower comprehensive operation and maintenance cost in long-term mass production.
Conclusion
Partial mold revision reduces investment, shortens modification cycle and cuts shutdown loss for minor product changes, adapting to fast-updating civil plastic products. New mold manufacturing applies to overall product reconstruction and long-term mass production projects. The core of mold cost control is matching solutions flexibly according to modification range, production volume and iteration frequency of products: adopt partial revision for small changes to control single expenditure, and select new molds for overall revision with long production cycles to realize optimal balance between mold development cost and production stability.
