Complete Production Process for Aluminum Die-Cast Cabinet Pulls
(Applicable to furniture/cabinet door/door pulls, material: ADC12/A380 die-cast aluminum)
I. Pre-Production: Product Design + Mold Development
1. Drawing and Structural Design
Develop 3D/2D drawings based on pull styles (round pulls, bar pulls, split door handles). Allow for die-casting shrinkage, gates, venting channels, and machining allowances for mounting holes. Optimize wall thickness to prevent shrinkage porosity and gas porosity defects.
2. Die-Casting Mold Manufacturing
- Select H13 hot-work tool steel; machine cavities via CNC milling, EDM, and wire-cut EDM
- Design cooling channels, ejection mechanisms, parting lines, and overflow venting channels to ensure complete filling of complex curved pull profiles
- Mold trial runs, corrections, and mass production approval upon dimensional qualification
3. Raw Material Inspection
Mainstream die-cast aluminum alloys: ADC12, A380. Incoming inspection for composition and impurities. Clean recycled material (ratio less than or equal to 30%) may be blended in; reject corroded ingots and oil-contaminated scrap.
II. Aluminum Melting (Pre-Die-Casting Operation)
1. Charge aluminum ingots into centralized melting furnace; heat to 680-720 degrees Celsius for complete melting
2. Nitrogen rotary degassing and flux refining to remove hydrogen gas and oxide inclusions from molten aluminum (preventing surface pinholes on pulls)
3. Transfer purified molten aluminum to holding furnace beside die-casting machine; maintain constant temperature for static holding. Robotic arm dispenses measured shots for die-casting.
III. High-Pressure Die-Casting (Core Process)
1. Mold Preparation: Spray water-based release agent; close and lock mold (pulls typically use 200-500T die-casting machines)
2. High-Speed Injection: Robotic arm delivers molten aluminum into shot sleeve; high-pressure, high-speed injection forces aluminum into mold cavity. Hold pressure for 3-8 seconds to compensate for shrinkage and reduce internal porosity
3. Cooling and Solidification: Rapid cooling via mold water channels; pull casting takes shape
4. Mold Opening and Ejection: Mold separates; ejector pins push out pull casting with gates and overflow channels. Robotic arm transfers part to conveyor for natural cooling
IV. Rough Casting Processing (Gate Removal + Deburring)
1. Gate/Overflow Flash Trimming
Dedicated trimming die on hydraulic press removes gates and overflow scrap in one operation; scrap returned for remelting. Small complex pulls may use saw cutting.
2. Flash and Burr Removal
- High Volume: Vibratory finishing machine with tumbling media for rough deburring of parting-line flash and sharp edges
- Premium Appearance: CNC grinding and manual edge dressing to ensure smooth, non-cutting edges
3. Shot Blasting/Sandblasting (Optional)
Steel shot/white alumina impact cleans die-cast oxide skin and release agent residue; creates uniform matte base to improve surface treatment adhesion
4. Casting Full Inspection: Visual inspection for gas porosity, cracks, short shots, deformation; non-conforming parts sorted for rework or remelting
V. Precision Machining (Mounting Dimension Finalization)
Die-cast castings have machining allowances on mounting holes, screw bosses, and end faces; CNC processing is mandatory:
1. Drilling and Tapping: Machine mounting through-holes and threaded holes at both ends of pulls (to match furniture screws)
2. Milling/Turning: Flatten mounting contact surfaces, adjust pull length, mill anti-slip grooves
3. Straightening and Forming: Correct deformation on curved pulls; ensure left-right symmetry and flush mounting
4. Post-Machining Cleaning: Ultrasonic degreasing and cleaning; drying to remove cutting fluid and dust, preventing spotting during surface treatment
VI. Surface Treatment (Determines Appearance, Wear Resistance, and Corrosion Protection - 4 Mainstream Processes)
1. Anodizing (Most Common for Furniture Pulls)
Process: Degreasing - Alkaline etching/polishing - Neutralization - Sulfuric acid anodizing - Dyeing - Sealing
Advantages: Coating integral with aluminum substrate; wear and scratch resistant. Available in matte silver, black, gold, gunmetal, and champagne. Salt spray resistance 500h+. First choice for indoor cabinet door pulls.
2. Powder Coating (Matte Black Heavy-Door Pulls)
Process: Degreasing - Phosphating - Electrostatic powder spray - 180-200 degrees Celsius high-temperature curing
Advantages: Thick coating, impact resistant, outdoor corrosion protection. Fine matte texture. Suitable for entry door heavy pulls.
3. Polishing + Electroplating (Bright Luxury Style)
Process: Multi-stage wet polishing - Activation - Nickel strike - Chrome plating/brushed nickel
Effect: Mirror-bright silver, brushed metal texture. Higher cost; primarily used for high-end cabinet pulls.
4. Micro-Arc Oxidation (Outdoor High-Wear Pulls)
Ceramic oxide film with ultra-high hardness. Specialized for coastal and humid environments; strongest corrosion protection.
VII. Final Inspection, Assembly, and Packaging/Warehousing
1. Finished Product Full Inspection
- Dimensions: Caliper measurement of overall length, hole spacing, thickness
- Appearance: No scratches, color variation, coating peeling, or burrs
- Performance: Salt spray testing, abrasion testing (sampling)
2. Hardware Assembly
Add plastic anti-slip pads, mounting screws, and expansion anchors to pull sets
3. Packaging
Individual pearl cotton protection per piece; carton subdivision; outer carton labeled with specifications and quantity; moisture-proof warehousing
Complete Process Overview (Simplified Version)
Product Design - Mold Manufacturing - Aluminum Ingot Melting and Degassing - High-Pressure Die-Casting - Gate Trimming - Tumbling Deburring - Shot Blasting Cleaning - CNC Drilling and Tapping - Cleaning and Drying - Anodizing/Powder Coating/Electroplating - Finished Product Inspection - Hardware Assembly - Packaging and Warehousing