Surface Finishing Treatment

Overview

PUNI offers comprehensive in-house surface finishing services to deliver components that meet both functional and aesthetic requirements. From corrosion resistance to decorative finishes, our finishing lines ensure consistent quality batch after batch.

Mechanical Surface Treatments

• Shot blasting: Steel shot, glass bead, ceramic bead for cleaning and surface preparation
• Sand blasting: Various media grades for matte finish or paint prep
• Vibratory finishing: For deburring and edge radiusing
• Tumbling: Bulk finishing for small parts
• Polishing: From satin to mirror finish (Ra 0.05 μm achievable)

Chemical Surface Treatments

• Pickling & passivation: Stainless steel (per ASTM A967, EN 2516) — restores corrosion resistance after fabrication
• Electrolytic polishing: Mirror finish on stainless steel, ideal for food/pharma applications
• Black oxide / blackening: For steel parts (decorative and mild corrosion protection)
• Phosphating: For paint adhesion and corrosion resistance
• Anodizing (铝阳极氧化): Type II (sulfuric) and Type III (hardcoat) for aluminum parts; colors available

Coating Services

• Powder coating: Polyester, epoxy, hybrid systems; all RAL colors; gloss levels 5-95%; textures available
• Wet painting: Primer + topcoat systems, custom colors, multi-layer finishes
• Zinc plating: Clear, yellow, black chromate, or RoHS-compliant trivalent
• Nickel plating: Decorative and functional, bright or matte
• Chrome plating: Decorative and hard chrome for wear resistance
• PVD coating: Decorative TiN (gold), CrN (silver), ZrN (rose gold) for premium finish

Quality Standards

• Salt spray test per ASTM B117 (96 to 1000+ hours depending on coating)
• Coating thickness measurement (X-ray or eddy current)
• Adhesion test per ISO 2409 (cross-cut)
• Hardness test per coating type (Vickers, Rockwell)
• Color matching per RAL or customer-supplied samples

Capability Highlights

• Maximum part size: 2000 × 1500 × 800 mm in powder coating line
• Wet paint line capacity: 600 × 600 × 1500 mm hanging
• Anodizing line capacity: 1500 × 800 × 600 mm
• Plating line: 1000 × 600 × 400 mm

Industries Served

Architectural hardware, automotive, food processing equipment, marine hardware, medical devices, machinery enclosures, lighting fixtures, consumer electronics — any industry where surface quality and corrosion resistance matter.