Success StoriesPractical
2026年1月28日
The Art of Precision: A Technical Guide to Finishing Processes in High-End Mold Manufacturing
In the competitive landscape of plastic injection molding, the difference between a functional tool and a world-class mold lies in the finishing phase . While rough machining sets the foundation, fin
In the competitive landscape of plastic injection molding, the difference between a functional tool and a world-class mold lies in the finishing phase. While rough machining sets the foundation, finishing determines the mold's dimensional accuracy, surface integrity, and overall service life.
At JST Mold, we believe that "good enough" is never enough. To help our clients understand the rigor behind our manufacturing, we’ve broken down the four essential pillars of the mold finishing process.
1. Advanced Heat Treatment & Stress Management
Heat treatment is the "DNA" of a mold component. Without precise thermal control, even the best steel will succumb to deformation or cracking under high-pressure production.
- Optimizing Conventional Steels (Cr12MoV, 40Cr): For materials like Cr12MoV, we implement a specialized quenching process followed by "Secondary Hardening" (tempering at 200-220℃). This process significantly boosts wear resistance and toughness, specifically for complex punch and die components.
- The Powder Metallurgy Advantage: For high-intensity environments, we utilize powder steels like V10 and ASP23. These require high-temperature quenching (1050-1080℃) and multiple tempering cycles (90-520℃). This ensures maximum thermal stability and prevents the "chipping" issues common in lower-grade tooling.
2. Micro-Level Precision Grinding
Grinding is the final frontier for achieving sub-micron tolerances. However, the biggest enemy of precision is Heat Expansion.
- Thermal Control: A temperature shift of just 3℃ can cause a 300mm steel part to expand by over 10μm. At JST Mold, we utilize constant-temperature environments and specialized coolants to ensure that dimensional accuracy stays within the ±0.01mm threshold.
- Surface Finishes (Ra0.2μm): Depending on the material hardness, we select specific abrasives—from GD monocrystalline corundum for standard alloys to CBN (Cubic Boron Nitride) for hardened steels. This allows us to achieve mirror-like finishes that reduce friction during the injection process.
- Specialized Geometry: Whether it's thin-plate parts requiring stress-free magnetic chucking or cylindrical parts requiring high-concentricity grinding, our technicians use "Back-and-Forth" verification to ensure zero geometric distortion.
3. The Precision of EDM and Wire-Cutting
Electrical Discharge Machining (EDM) allows us to create geometries that are physically impossible to mill.
- Slow-Feed Wire EDM: We achieve tolerances of $\pm0.003\text{mm}$. By carefully managing water temperature and ion concentration, we minimize the "re-cast layer" that can lead to premature tool failure. For sharp corners (R < 0.2), we apply specialized offset compensation to maintain structural integrity.
- Electrode Technology: Using Copper-Tungsten (Cu-W) electrodes for high-precision cavities allows for minimal wear and higher surface fidelity, ensuring that the final plastic part matches your 3D design perfectly.
4. Final Conditioning & Master Assembly
A mold is only as strong as its weakest link. The final assembly at JST Mold is a rigorous "Total Quality" process.
- Surface Strengthening: Post-machining, we remove the "hardened layer" caused by EDM through meticulous hand-polishing and stress-relief techniques. This prevents micro-cracks from propagating during high-volume production.
- The JST Assembly Protocol: Every component is demagnetized and cleaned with ethanol. We follow a strict assembly sequence—fitting the guide system first, followed by the cavity and core—to ensure perfect alignment and zero-leakage performance.
Why Partner with JST Mold?
Precision finishing is not just a service; it is our commitment to your product's success. By combining advanced material science with master craftsmanship, JST Mold delivers tools that offer shorter cycle times and longer lifespans.
Ready to elevate your manufacturing standards?
Our engineering team is standing by to provide a technical consultation for your next project.
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