Quality & Inspection | SUNJOY
Welcome to SUNJOY's Quality & Inspection hub. For Western B2B procurement managers, toolmakers, and quality engineers sourcing custom injection moulds from Asia, mitigating project risk begins and ends with rigorous quality assurance.
In custom manufacturing, a minor dimensional deviation or a hidden steel defect can translate to thousands of dollars in lost production time, failed part assemblies, and delayed time-to-market. Our quality management framework is engineered to eliminate uncertainty at every phase of the tooling lifecycle-from raw material receipt to final pre-shipment validation. Below is our systematic approach to ensuring precision, durability, and complete transparency in every mould we deliver.
Quality Management Overview
At SUNJOY, quality control is not a final screening process; it is an integrated discipline embedded into every stage of tool design and manufacturing.
The Zero-Defect Philosophy
Identifying and resolving non-conformities during machining is exponentially more cost-effective than correcting them during mould testing or after export.
Traceability Matrix
Every mould project is assigned a unique tracking dossier. From steel mill certificates to CMM measurement logs and heat treatment reports, all documentation is fully traceable and archived for a minimum of 3 years.
Standardized Gate Reviews
Progression from one manufacturing phase to the next requires mandatory sign-off from our independent quality inspection team inside our temperature-controlled metrology and shop floor environments.
Incoming Material Inspection
Before any steel block, standard component, or hot runner system enters our workshop, it undergoes strict physical and documentary verification.
Documentation Audit
We cross-reference all incoming delivery notes and packing lists against purchase order specifications, verifying brand names, dimensions, and quantities.
Visual & Dimensional Check
Raw steel bars and plates are inspected for surface defects, rust, or rolling fractures. Initial vernier and micrometer checks confirm that stock allowances match machining requirements.
Supplier Quality Control
We source core components exclusively from globally recognized manufacturers (e.g., LKM, HASCO, DME, Misumi) to guarantee interchangeability and global standard compliance.
Steel & Material Verification
Tool steel selection directly dictates mould lifespan, parting line integrity, and surface finish quality. Using substandard steel is a primary cause of premature tooling failure in high-volume production.
Mill Test Certificates (MTC)
Every block of tool steel (e.g., DIN 1.2738, 1.2311, H13, or S136) must be accompanied by the original manufacturer's Mill Test Certificate verifying its chemical composition.
Hardness Testing (HRC)
Prior to deep pocket machining or electrical discharge machining (EDM), sample coupons or rough blocks are tested using Rockwell hardness testers to ensure material meets specified heat-treatment thresholds.
Spectroscopic Material Analysis
For critical high-cavitation or optical-grade moulds, we utilize positive material identification (PMI) testing to verify alloy constituents against international grades.
Dimensional Inspection
Maintaining tight tolerances across complex 3D core and cavity geometries requires a multi-tier measurement strategy deployed directly on the shop floor.
In-Process Checks
CNC machinists use calibrated micrometers, depth gauges, and bore gauges to verify critical dimensions immediately after machining operations.
First-Article Inspection (FAI)
The first component produced on any new CNC setup undergoes mandatory inspection before full-batch processing resumes.
Calibration Compliance
All inspection tools, gauges, and digital indicators are subjected to scheduled internal calibration cycles traceable to national measurement standards.
CMM Inspection
Coordinate Measuring Machine (CMM) inspection provides the definitive geometric verification required for complex geometries, deep rib details, and intricate parting surfaces.
High-Precision Metrology: Our granite-table CMM systems (featuring Hexagon and ZEISS platforms operated in temperature-controlled environments) utilize high-sensitivity touch-trigger probes to capture thousands of coordinate data points across core and cavity blocks.
CAD Comparison: Inspection routines are programmed directly from native 3D CAD models, overlaying measured point clouds against mathematical models to generate color-coded deviation maps.
Tolerance Reporting: We issue detailed CMM inspection reports highlighting flatness, parallelism, perpendicularity, profile tolerances, and critical hole center distances.
Machining Quality Control
Quality must be machined with absolute precision. Our manufacturing floors enforce strict process controls across all core machining modalities.
High-Speed CNC Milling: Utilizing rigid machining centers with high-RPM spindles and thermal compensation to minimize tool deflection and chatter during roughing and finishing passes.
Precision EDM & Wire-Cut: Employed for sharp internal corners and fine rib details. We monitor electrode wear rates and spark parameters to maintain consistent surface finish (VDI standards) and dimensional accuracy.
Deep Hole Drilling: For conformal cooling channels and long water lines, specialized deep hole drilling machines ensure straightness and precise intersection without drift.
Mould Assembly Inspection
Mould assembly transforms individual steel components into a cohesive, high-performance production tool. Even perfectly machined inserts will fail if assembly tolerances are mismanaged.
Blueing Test (Parting Line Fit): Engineers apply machinist's blueing paste to core and cavity interfaces and perform a mechanical press-fit check, requiring a minimum of 85% contact surface verification along parting lines.
Ejection & Sliding Mechanism Check: All ejector pins, lifters, slider blocks, and angled pins undergo manual and pneumatic actuation tests to ensure smooth, binding-free movement across operational strokes.
Cooling & Hydraulic Integrity: Water channels and hydraulic core-pull circuits are pressure-tested (up to 15 bar) to verify flow rates, check for internal blockages, and ensure zero leakage.
T1 Trial & Sample Inspection
The T1 trial is the milestone where theoretical design meets physical reality under actual injection molding conditions.
Systematic Sampling: During the T1 trial, we record key machine parameters (injection pressure, clamp force, cycle time, melt temperature) to establish a baseline processing window.
Initial Shot Evaluation: Sample parts are collected across different cavity positions to evaluate fill balance, weld line aesthetics, gate freeze-off, and dimensional stability.
Trial Feedback Loop: Any shrinkage anomalies, sink marks, or flash observed during T1 are immediately documented in a corrective action report (CAR) and routed back to engineering for design or steel modification.
Final Mould Inspection
Before a mould is approved for wooden crate packaging and international shipment, it undergoes a comprehensive pre-shipment audit.
Component & Spare Parts Audit: We verify that all specified spare parts (e.g., extra ejector pins, springs, nozzles, limit switches, and O-rings) are packed securely inside the crate.
Anti-Corrosion Protection: Internal cavities, parting surfaces, and cooling channels are treated with water-displacing protective coating and sealed against moisture ingress.
Documentation Package Verification: We ensure physical shipment includes the complete technical binder: engineering drawings, schematics, steel certificates, CMM reports, and T1 sample dimensional inspection sheets.
Inspection Equipment
Bridge CMM
Hexagon Global & ZEISS Prismo High-Accuracy Series - Used for 3D coordinate measurement, GD&T analysis, and CAD deviation mapping.
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Toolmaker's Microscope
Optical and Digital Measurement Systems - Used for inspecting fine micro-details, EDM surface textures, and small inserts.
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Digital Hardness Tester
Rockwell & Brinell Benchtop Testers - Used for verifying heat treatment hardness (HRC/HB) of core and cavity steel blocks.
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Roughness Testers
Mitutoyo Portable Surftest - Used for quantifying cavity and runner surface finish (Ra/Rz values).
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Pressure Testing Rigs
Custom Hydraulic and Pneumatic Benches - Used for leakage and flow testing for cooling and hydraulic circuit integrity.
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Quality Documentation
We provide a complete data package with every mould to support ISO compliance, customs clearance, and long-term maintenance:
Steel & Material Certificates
Original mill test reports confirming steel grades and heat treatment logs.
Trial & Parameter Sheets
T1/T2 injection parameters, resin data sheets, and initial sample approval reports (ISAR).
Dimensional Inspection Reports
Full CMM measurement sheets covering critical interface dimensions, mounting footprints, and core profiles.
2D & 3D Final Drawings
Complete electronic documentation including assembly drawings, spare part lists, and circuit diagrams.