Medical Goggle Shell Plastic Mold Processing Technology
2026-05-19 10:26:53
Plastic Mold
Medical goggle shells are high-precision plastic components for medical protection. They feature multi-curved outlines, uniform wall thickness, tight frame fitting and strict dust-free sterile molding standards. Main raw materials include high-transparent PC, eco-friendly ABS and food-grade PP. Mold machining accuracy, surface finish and parting sealing performance directly decide finished product light transmittance, wearing tightness and mass production yield. The whole mold follows standardized procedures from raw material preparation to trial production and formal volume production.
1. Preliminary Mold Design and Material SelectionThe shell is designed with arc surrounding structure integrating main frame, side fasteners, lens mounting grooves and ventilation structures. Double-cavity or four-cavity balanced layout is adopted to stabilize melt filling speed and prevent uneven thickness and shrinkage deformation. Parting surfaces are arranged along the maximum outer contour with full flat fitting structure to completely avoid overflow flash and satisfy medical product appearance requirements. Surrounding cooling circuits are laid closely along frame radian to shorten molding cycle and restrain internal stress whitening of transparent plastics.
Standard 45# refined steel plates are used for mold bases to strengthen overall structural stability. 718H pre-hardened steel serves for conventional cavity and core production, while NAK80 and S136 stainless steel are selected for high-transparent mirror surface products. Such steel materials own outstanding polishing property and excellent rust resistance, perfectly adapting to long-term dust-free workshop production environment. Small inserts and ejector pins adopt SKD61 steel to improve wear resistance and extend service life.
2. Steel Blanking and Rough Machining
Steel blanks are cut strictly according to design drawings with reserved finishing allowance. Blanks go through stress relief aging treatment to eliminate internal material stress and avoid shape displacement in later precision machining and long-term application, ensuring stable product dimensional consistency. Large gantry milling equipment is used for rough cutting to remove redundant materials and form basic mold outline, preliminary cavity shape, locking positions and hoisting structures. Water channel holes, pin holes and mounting holes are pre-processed with 0.3mm to 0.5mm finishing margin reserved. After rough machining, deburring and chamfering are carried out, followed by thorough cleaning and anti-rust treatment before semi-finishing.
3. Semi-finishing and Reference Calibration
Unified mold reference benchmarks are set to standardize all machining coordinates and eliminate cumulative machining errors. CNC milling equipment is used to precisely process frame radian, buckle grooves and positioning steps, controlling finished product wall thickness deviation within 0.02mm to maintain overall uniformity and prevent post-molding distortion. Guide assembly holes and positioning pin holes are accurately processed to ensure precise mold opening and closing alignment. Built-in cooling pipelines are fully processed and cleaned to guarantee unobstructed water circulation and stable mold temperature control. Full dimensional inspection is implemented after semi-finishing to confirm qualification before entering precision finishing stage.
4. Precision Finishing and Curved Surface ShapingHigh-speed fine carving machines are adopted for full-range precision finishing to smoothly form outer streamline outlines and inner fitting grooves, ensuring cavity surfaces free of obvious tool marks. Enough polishing allowance is reserved for transparent material molds to eliminate hidden machining traces and avoid light transmission defects after polishing. All matching positions and insert joints are processed to achieve seamless fitting, and small limit structures are integrally formed to reduce manual trimming workload and lock core forming dimensions steadily.
5. Auxiliary Structure MachiningCombined layout of flat ejector pins and round ejector pins is adopted for ejection systems to evenly disperse ejection force and prevent surface whitening and deformation of thin-walled shells during demolding. Precise machining is completed for sprue bushing mounting holes, hot runner reserved positions and temperature measuring holes. Side gates and fan-shaped gates are reasonably arranged to realize steady filling of transparent raw materials, effectively reduce welding lines and optimize overall transparent appearance of finished products.
6. Mold Polishing and Surface Treatment
Graded polishing is conducted from coarse abrasive tools to fine oil stones step by step. Cavities for transparent products are processed to mirror polishing standard to ensure bright and flawless finished shells without foggy texture and surface scratches. Ordinary finishing polishing is applied to non-appearance assembly areas, while flat and smooth treatment is maintained on parting surfaces to block material overflow. Comprehensive dust and debris cleaning is finished after polishing to meet clean production standards for medical-grade molds.
7. Mold Assembly and Gap Adjustment
All accessories are cleaned completely before assembly to remove impurities and metal scraps. Standard assembly procedures are followed to complete core-cavity matching, guide part installation, insert fixing and ejection system combination. Repeated mold opening and closing tests are performed to adjust matching clearance, ensuring flexible operation without jamming. Ejection and reset strokes are accurately calibrated to avoid scratching finished product surfaces in actual production.
8. Pipeline Inspection and Preheating CommissioningWater circulation pressure test is conducted to check cooling pipelines for water seepage, leakage and blockage, realizing uniform heat dissipation across all mold areas. Electric heating circuits and temperature control systems are connected and debugged to set reasonable preheating temperature according to different plastic raw materials, eliminating hidden troubles such as insensitive temperature induction and unstable heating.
9. Trial Molding and Process FinalizationLow-speed and low-pressure injection mode is adopted in initial trial molding to observe melt filling status and targeted solve defects including insufficient filling, shrinkage, bubbles and welding lines. Vent grooves are optimized at dead corners and material converging positions to accelerate internal air discharge and avoid burning marks and material shortage. After repeated trial molding and modification, stable injection process parameters are confirmed. Products that fully meet medical protection standards are approved for formal mass production in dust-free workshops.
10. Daily Maintenance SpecificationsTimely cavity cleaning and professional anti-rust maintenance must be carried out after daily production. Regular inspection and replacement of worn guide parts and ejector components are required. Nitriding reinforcement treatment is implemented for molds producing filled modified materials to prolong service life. Stable injection parameters are maintained in continuous production to reduce internal residual stress and ensure uniform size and clean appearance of finished medical goggle shells.
