“A good design is the blueprint, but high-precision manufacturing is the cornerstone that turns it into reality.” The manufacturing quality of each individual component directly determines the mold’s lifespan, stability, and the perfection of the final product.
To achieve better manufacturing of single parts and, consequently, produce more perfect products, a set of interlocking, systematic methods is required. The following chart clearly illustrates the perfect manufacturing workflow from design to part:
1. Collaboration between Design and Process Planning
This is the first and most critical step. The manufacturing department must be involved in the design review from the beginning.
- Manufacturability Analysis: Analyze whether the part’s structure is easy to process. For instance, are there internal sharp corners that cannot be machined by a tool? What is the maximum depth for deep-hole drilling?
- Setting Rational Tolerances: Not every dimension requires micron-level tolerances. Based on functional requirements (e.g., fit, sealing, venting), assign strict tolerances to critical dimensions and relax them for non-critical ones. This significantly reduces cost and time.
2. Selecting the Ultimate Manufacturing Processes
Choose the most suitable cutting-edge process for different part requirements and materials:
- Ultra-Precision Machining
- 5-Axis High-Speed CNC: Used for the one-time forming of complex cavities and surfaces. It avoids errors from multiple fixturing, ensuring perfect positional accuracy.
- Slow Wire EDM: Used for machining high-precision inserts and punches, achieving accuracy up to ±0.001mm and a mirror-like finish, ensuring tight seams and no flash.
- Mirror-Finish EDM: Used for deep slots, ribs, and other features that CNC cannot machine, especially in hard materials. The hardened layer it creates can also improve the mold’s wear resistance.
- Additive Manufacturing – 3D Printing
- As mentioned, it’s primarily used for conformal cooling channels. It creates cooling channels that conform to the cavity surface, fundamentally different from traditional drilled channels, enabling uniform and efficient cooling. This reduces product warpage and shrinkage, shortening cycle times.
- Surface Finishing Technologies
- High-Precision Polishing: The product’s appearance quality is directly determined by the cavity’s surface finish. Using everything from stones and sandpaper to diamond paste, combined with manual and automated robotic polishing, achieves perfect results from mirror finishes to various textures.
- Special Surface Treatments: Such as PVD Coating, which deposits an extremely thin, hard ceramic film on the component surface. This greatly improves wear resistance and corrosion resistance, and reduces the coefficient of friction, making demolding easier and extending mold life.
3. Precision Measurement and Feedback Throughout the Process
“Without measurement, there is no precision.” Data must be used to verify the manufacturing process.
- Coordinate Measuring Machine (CMM): Used to inspect key part dimensions, position tolerances, and geometric tolerances. It is the final arbiter of inspection.
- Laser and White-Light Scanning: For complex free-form surfaces, this quickly captures point cloud data of the entire surface, compares it with the original 3D model, and generates a color deviation map, visually showing where tolerances are exceeded.
- In-Process Measurement: Probes integrated into CNC machine tools measure the workpiece directly during machining, automatically compensating for tool wear, achieving a “machine-measure-compensate” closed-loop control.
4. Strict Material and Heat Treatment Control
- Material Selection: Choose the appropriate mold steel (e.g., S136, NAK80, H13) based on mold lifespan requirements and the product material (e.g., whether it contains fiberglass).
- Heat Treatment Process: Processes like vacuum quenching and nitriding give components a hard, tough core and a wear-resistant surface. Controlling deformation during heat treatment is crucial.
- Stress Relief: Performing stress relief annealing after rough machining releases internal stresses from the material, preventing deformation after finish machining or during use.
The Path to the Perfect Product
When a mold component is tempered by the above system, the direct results are:
- High Dimensional Stability: Parts fit together precisely, and the mold maintains its shape under long-term high temperature and pressure, ensuring consistent product dimensions from batch to batch.
- Excellent Appearance Quality: The mirror finish or refined texture is directly replicated onto the product, eliminating the need for secondary painting and resulting in a perfect appearance.
- Longer Lifespan and Less Downtime: Wear- and corrosion-resistant parts and coatings reduce the frequency of maintenance, thereby improving production efficiency.
- Higher Production Efficiency: Conformal cooling channels shorten cycle times; smooth surfaces and proper draft angles facilitate easy demolding.
Therefore, perfecting each individual component ultimately converges into a stable, efficient, and long-lasting perfect mold. The products it produces are naturally high-quality, low-cost, and aesthetically perfect final products.