Organic coatings include the deposition of polymer-based films to enhance surface appearance, corrosion resistance, and hardness. Organic coatings are used on a large scale in the automobile, consumer durables, and machinery industries. Methods include paint coating by conventional process, powder coating, and electrocoating (e-coat), each of which is appropriate for various sizes of production quantities and finish needs.

Process Cycle

1. Cleaning of surface (degreasing, abrasive blasting, phosphating)
2. Pre-treating and masking
3. Application of coating (spray, dip, or electrostatic)
4. Flash-off (for solvent evaporation if required)
5. Curing (oven, UV, or air drying)
6. Inspection and quality checking (adhesion, thickness, gloss)

Equipment

• Manual or automatic spray booths
• Electrostatic powder coating guns and control units
• Rectifier system equipped with E-coat tanks
• Curing ovens (convection, infrared, UV)
• Air filtration and exhaust systems
• Conveyors and part handling systems for high-volume lines

Tooling

Primary:

• Fixtures and jigs for part holding
• Grounding clamps (e-coat and powder coat)

Secondary:

• Masking tools (plugs, tapes)
• Coating thickness gauges
• Adhesion testers and gloss meters

Materials

Possible Defects

• Orange peel surface finish
• Runs, drips, and sags
• Pinholes due to trapped gases
• Lack of edge coverage
• Contamination (dust, oil)
• Under- or over-cure defect

Design Guidelines

• Steer clear of sharp edges or deep recesses to provide a uniform coating
• Make sure to include grounding points for electrostatic techniques
• Hanging and racking with design in mind
• Steer clear of coating buildup with rounded corners
• Make sure it is compatible with the base material's curing temperature range

Cost Drivers

• Coating type and cost of material
• Surface area and complexity of geometry
• Line speed and degree of automation
• Energy utilized during curing
• Disposal of wastes and environmental controls

Organic coatings provide high-performance, general-purpose surface finishes to improve appearance and durability for a broad scope of materials and market applications. Cost-efficient and lasting protection is possible for manufacturers by optimizing design for coating compatibility and proper process selection.