Electroplated Office Chair Polishing

Polishing of electroplated office chairs requires selecting appropriate methods based on the base material and coating type. Common methods include mechanical polishing, chemical polishing, and electrolytic polishing, and strict adherence to safety regulations is necessary during operation.

1. Mechanical Polishing: Precision Control in Stages

Mechanical polishing involves sequential grinding using tools such as sandpaper, flap wheels, and cloth wheels, suitable for most metal base materials.

• Rough Polishing: Use 120 - 240 grit sandpaper or flap wheels at a linear speed of 20 - 30 m/s to primarily remove obvious defects such as burrs and scratches.
• Medium Polishing: Employ 400 - 800 grit sandpaper or cloth wheels with green wax, reducing the rotational speed to 15 - 20 m/s to further smooth the surface.
• Fine Polishing: Utilize wool wheels with over 1000 grit along with white/blue wax at a rotational speed of 10 - 15 m/s to achieve a mirror finish.
  Special Material Handling:
• For nickel coatings, it is recommended to use diamond paste (particle size W3.5 - W1) for mechanical polishing to avoid scratches.
• Chromium coatings require the use of chromium oxide polishing paste + canvas wheels, with a rotational speed not exceeding 12 m/s.
• Silver coatings must use dedicated silver polishing agents to prevent oxidation and blackening.

2. Chemical Polishing: Precise Control of Solution Parameters

Suitable for electroplated layers such as zinc, copper, and nickel, chemical polishing dissolves surface micro-protrusions through a nitric acid - phosphoric acid system solution (concentration ratio adjusted according to the metal) to achieve overall leveling.

• Operating Conditions: Temperature 60 - 80°C, time 30 seconds - 2 minutes.
• Key Control Points: The solution concentration must strictly match the metal type to avoid over-corrosion leading to coating detachment or base material damage.
• Safety Requirements: Operations must be conducted inside a fume hood, with the wearing of gas masks and acid-resistant gloves to prevent inhalation of acidic gases.

3. Electrolytic Polishing: Optimized for Stainless Steel Base Materials

Electrolytic polishing removes surface microscopic irregularities through electrochemical dissolution, showing significant effects on electroplated stainless steel parts.

• Parameter Requirements: Voltage 12 - 18V DC, current density 15 - 30A/dm², temperature 60 - 80°C, time 2 - 5 minutes.
• Electrolyte Formula: Commonly uses a phosphoric acid - sulfuric acid system (ratio 7:3), with regular testing of component stability required.
• Safety Protection: Before operation, check equipment grounding, wear insulating gloves and protective face shields to prevent electric shock or electrolyte splashing.

4. General Safety Regulations

1. Personal Protection: Wear protective goggles, dust masks (for mechanical polishing) or gas masks (for chemical/electrolytic polishing) throughout the process.
2. Test Polishing Verification: For precision parts, test polish samples first to confirm parameter normality before batch processing.
3. Equipment Inspection: Before electrolytic polishing, ensure power stability; during mechanical polishing, check the balance of grinding wheels to avoid vibration damage to workpieces.