Detailed Explanation of Plastic Mold Development Process
Plastic mold development is a systematic and process-oriented project. From product analysis to mass production delivery, each step directly determines mold precision, service life and plastic part quality. A standardized development process reduces later modification costs and ensures stable and efficient production.
Product Analysis and DFM Manufacturability Review
Before development, a comprehensive analysis of plastic part drawings is required, focusing on structural rationality, demolding feasibility, wall thickness uniformity, ribs, bosses, undercuts and surface requirements. DFM review is conducted to identify undercuts, sharp corners, sudden wall thickness changes, poor ventilation and cooling difficulties, with optimization proposals provided to avoid production failures caused by design defects. This stage also clarifies plastic material, precision grade, appearance requirements and annual output to provide a basis for subsequent mold structure, cavity quantity and material selection.
Mold Scheme Design and Quotation
The overall scheme is determined based on product analysis, including mold type, cavity quantity, gating method, parting surface position, ejection method, cooling system layout and vent positions. Mold base size, core and cavity materials, and heat treatment requirements are confirmed, with processing costs and cycles calculated to form a formal scheme and quotation. The scheme requires customer confirmation, with clear modification boundaries and acceptance standards to avoid frequent later changes.
Detailed Structural Design and 2D/3D Drawing
After scheme confirmation, formal design begins, using 3D software to complete full 3D structural design of cores, cavities, slides, lifters, ejector pins, inserts, runners and cooling channels, then exporting 2D processing drawings. Design focuses include ensuring parting surface sealing, balanced ejection, uniform cooling, smooth ventilation and no interference in moving mechanisms. Internal drawing review is conducted to check interference, strength, assembly and processing feasibility before issuing for production.
Material Procurement and Preparation
Mold bases, mold steels, ejector pins, guide pins, springs, screws, hot runners and other standard and non-standard parts are procured according to the design list. Cores and cavities usually use P20, 718, H13, SKD61, NAK80 and other materials, with quenching, nitriding and other heat treatments selected based on plastic output and material. All materials require hardness, specification and certification inspection to meet design requirements.
Mold Component Processing
Processing uses CNC, engraving, WEDM, EDM, grinding, milling and lathe equipment. The mold base is positioned first for guide pin and ejector pin hole processing. Cores and cavities undergo rough, semi-finish and finish machining. Slides, lifters, inserts and other moving parts are processed to precision. All parts ensure dimensional accuracy and fitting clearance, with precision parts undergoing dimension inspection to ensure smooth assembly movement.
Heat Treatment and Surface Treatment
High-hardness, high-wear-resistance parts undergo vacuum quenching, tempering, nitriding and other treatments to improve mold life. After processing, surface treatments such as polishing, texturing, chrome plating and titanium coating are applied to meet appearance, demolding and wear resistance requirements. Polishing grade must strictly follow surface standards to avoid bright marks and ripples.
Mold Assembly and Matching
All processed parts are assembled according to the 3D structure, installing the mold base, guide pins, cores, cavities, inserts, slides, lifters, ejection system and cooling system in sequence. Matching, fitting and grinding are performed during assembly to ensure parting surface fitting, smooth moving parts without jamming or abnormal clearance, sealed water channels without leakage, and stable and synchronous ejection.
Pre-test Inspection and Debugging
A comprehensive inspection is conducted after assembly to confirm normal cooling, oil and air circuits, reliable ejection, return, locking and limiting mechanisms, and tightened bolts. The cavity, vent grooves and runners are cleaned, with corresponding plastic materials prepared and drying, temperature, pressure, speed and other molding parameters set for test preparation.
T1 Test Molding and Sample Inspection
The first test molding is carried out. After injection, samples are inspected for dimensions, appearance, deformation, shrinkage, bubbles, flash, whitish marks and sticking. Molding parameters are recorded, with full-dimensional inspection and appearance evaluation performed, and a test report issued listing issues and improvement plans.
Mold Repair, Modification and Multiple Test Moldings
Targeted repairs are conducted based on test issues, such as adjusting ventilation, improving cooling, modifying ejection, optimizing gating and revising fitting clearances. T2, T3 and subsequent test moldings are performed until sample dimensions, appearance and stability meet standards.
Mold Acceptance and Mass Production Delivery
After successful test molding, final mold acceptance is conducted, with customers confirming samples, documents and mold status and signing acceptance forms. The mold is finally cleaned, rust-proofed and packaged, delivered with complete drawings, test parameters and maintenance manuals for formal mass production.
Mass Production Maintenance and After-sales Service
During mass production, regular maintenance, cleaning and wearing parts inspection are required, with timely replacement of ejector pins, springs, sealing rings and other components to extend mold life. Rapid repair responses are provided for abnormalities to ensure continuous stable production.
