The production of metal badges requires efforts from four major dimensions: raw material control, optimization of process details, maintenance of equipment precision, and full-process quality inspection. Through standardized operations and data-driven monitoring, the quality of the finished products is ensured. The following are the specific control points and implementation plans:
I. Raw Material Quality Control: Eliminate defects from the source
1. Selection of metal sheets
Material standard:
Copper material (H62/H85 brass) : Copper content ≥62%, good ductility, suitable for embossed stamping. Hardness (HV80-120) and tensile strength (≥294MPa) need to be tested.
Stainless steel (304/316) : Nickel content ≥8%, strong corrosion resistance, surface roughness Ra≤1.6μm, used for outdoor badges;
Aluminum material (6061/T6) : Hardness ≥95HB, oxide film thickness ≥10μm, suitable for lightweight badges.
Incoming material inspection: Each batch of plates must be accompanied by a material report. The element content (such as copper, zinc, nickel deviation ≤±0.5%) should be detected by a spectrometer, and the thickness tolerance (±0.03mm) should be randomly inspected by a thickness gauge.
2. Quality control of auxiliary materials
Electroplating solution: For cyanide plating solution, the free cyanide content should be controlled (6-8g/L), and the nickel ion concentration of the environmentally friendly plating solution should be maintained at 40-60g/ L. Daily detection should be carried out using a hydrometer and pH test paper (the pH value should be controlled at 4.5-5.5).
Baking varnish pigments: Select epoxy resin pigments with thermal stability ≥200℃, color number deviation △E≤1.5 (detected by a colorimeter), particle fineness ≤20μm (measured by a scraper fineness meter);
Adhesive: The viscosity of the epoxy resin used for dispensing should be between 3000 and 5000cps (at 25℃), and the hardness after curing should reach Shore D70-80, which can be tested by a viscometer and a hardness tester.
Ii. Standardization of Process Parameters: Quantify operational details
1. Stamping forming control
Mold accuracy: The gap between the punch and the die is controlled at 8%-10% of the plate thickness (for example, the gap of a 1mm copper plate is 0.08-0.1mm), and the mold pattern line error is detected by a projector (≤±0.02mm).
Stamping pressure: 20 to 30 tons of pressure is required for copper relief stamping, and 40 to 50 tons for stainless steel. The pressure sensor is used for real-time monitoring to prevent metal cracking due to overpressure or blurred patterns due to underpressure.
Blank positioning: Use a visual alignment system to ensure that the stamping position deviation is ≤0.1mm. Before mass production, 3 to 5 samples need to be made, and the contour dimensions are detected by a two-dimensional image measuring instrument.
2. Surface treatment specifications
Polishing process:
Rough polishing (yellow wax) : Speed 1200-1500r/min, time 3-5 minutes, to remove obvious scratches;
Fine polishing (white wax) : Rotational speed 800-1000r/min, time 2-3 minutes, surface roughness Ra≤0.4μm (measured with a roughness meter);
Thickness of the electroplating layer
The nickel base coating is ≥5μm, the gold layer is ≥0.3μm, and the silver layer is ≥2μm. The coulometric thickness gauge is used for random inspection (once an hour, 5 pieces each time), and the thickness uniformity deviation is ≤±10%.
Passivation treatment: The galvanized layer needs to undergo blue-white passivation, with a film thickness of ≥0.5μm. The salt spray test should show no white rust for ≥48 hours.
3. Coloring and curing control
Baking varnish filling
Before coloring, wipe the surface with alcohol cotton to ensure there is no oil stain.
The pigment should be stirred evenly. When filling with a syringe pen, keep it at a 45° Angle to avoid residual air bubbles. The overflow at the edge should be ≤0.05mm.
High-temperature curing
Baking varnish needs to be baked at 180-200℃ for 20-30 minutes, and enamel needs to be sintered at 800-850℃ for 5-8 minutes. The temperature rise curve (temperature rise rate 5-8℃/min) should be recorded with a temperature controller. Temperature measurement paper should be placed in each furnace to monitor the actual temperature.
The cooling process should be carried out in a dust-free environment to prevent dust adhesion, and the cooling time should be ≥1 hour.
Iii. Equipment Maintenance and Calibration: Ensuring Stability
Regular maintenance of key equipment
Punch press: Check the guide rail clearance (≤0.05mm) monthly, replace the lubricating oil (viscosity grade ISO VG 68), and calibrate the pressure sensor annually (error ≤±1%);
Oven: Clean the heating tube every quarter, calibrate the temperature probe (deviation ≤±2℃), and test the hot air circulation wind speed (≥2m/s).
Electroplating tank: Filter the plating solution weekly (filter element accuracy ≤5μm), replace 1/3 of the tank solution every quarter, and regularly check the wear of the anode plate (replace when the thickness decreases by ≥20%).
2. Calibration of precision instruments
Two-dimensional image measuring instrument: Calibrate with standard block gauges every six months (accuracy ≤±0.005mm);
Salt spray testing machine: Measure the spray volume (1-2 mL /80cm²/h) monthly, control the pH value at 6.5-7.2, and the temperature error ≤±1℃.
Laser marking machine: Calibrate the focal length every quarter (error ≤±0.2mm) to ensure uniform marking depth.
Iv. Full-process Quality Inspection System: Establish multi-level inspection checkpoints
First Article Inspection (IPQC)
Three first samples are made before each batch of production. The inspection items include:
Dimensions: Measure the outer diameter and thickness with a caliper (deviation ≤±0.1mm);
Pattern: Compared with the design draft, the clarity of the lines and the height of the relief (deviation ≤±0.1mm);
Surface: No scratches, electroplating leakage, or baking paint bubbles. Observe with a magnifying glass (10x).
2. Process Inspection (IPQC)
During production, 10 items will be randomly inspected every 2 hours, with a focus on:
Stamping: The height of edge burrs is ≤0.03mm (using a roughness tester);
Electroplating: Gloss ≥80GU (measured at a 60° Angle), adhesion is determined by the grid method (with a 100-grid knife spacing of 1mm and a shedding rate of ≤5%).
Baking varnish: Color consistency (△E≤2), surface hardness ≥2H (pencil hardness test).
3. Finished Product Full Inspection (FQC)
Each finished product needs to pass through:
Visual inspection: Observe under a 40W fluorescent lamp (at a distance of 30cm), and there are no defects such as shrinkage cavities, particles, or sagging.
Functional test
Accessory welding: Tensile test ≥50N (using a tensiometer), the pin opens and closes smoothly without any jamming.
Corrosion resistance: Salt spray test (neutral NSS) ≥72 hours (outdoor badge) or ≥24 hours (indoor badge);
Packaging quality inspection: The LOGO is printed clearly, the packaging film is free of bubbles, and the accuracy rate of the number of boxes packed is 100%.
4. Sample Retention and Traceability (OQC
Each batch should retain 5 to 10 samples, record the production time and process parameters, and the retention period should be no less than 2 years to facilitate the traceability of quality issues.
Post time: May-19-2025