Maximize Your Racking Efficiency and Quality

Proper racking is much more than a logistical requirement for surface finishers. Your approach to racking the parts you process is a critical factor that plays a role in the overall quality of the finish, operational efficiency and production costs. Whether your facility specializes in paint, powder coating, electroplating or anodizing, adhering to best practices for racking parts can mean the difference between success and costly rework. Based on recent articles on the subject, Products Finishing has rounded up some helpful tips for optimizing your racking process.

Racking design considerations

Effective racking planning begins even before the parts hit the finishing line. Collaboration between part designers and finishers can go a long way toward ensuring that parts can be racked successfully. Components designed without racking considerations in mind may have areas that are difficult to finish, ultimately suffering from poor coverage and increased rejection rates. Taking racking into account during part design can help prevent shading, uneven finishes and difficulty reaching all areas during the finishing process. Consistent geometries, easy-to-reach surfaces and sufficient mounting points help make parts easily rackable.

Complex parts or parts with unique geometries often call for a custom racking solution. While this can increase upfront costs, the investment is often justified through higher quality finishes and fewer defects.

• Keep weight distribution in mind. Weight distribution is an important consideration when considering how to rack a part. Lopsided components may shift or tilt when racked, leading to incomplete surface finishes and added strain on the racking equipment.

• Modular racking systems: Consider using adjustable or modular racking systems that can be easily reconfigured to accommodate a range of parts, especially in operations that handle diverse product lines.

 

The right racking materials

Choosing the right materials for racking is important for maintaining the integrity of both the racks and the parts.

• Racking for electroplating. Racks used for electroplating need to be made from highly conductive materials such as copper or titanium to ensure uniform electrical current distribution.
• Racking for powder coating. For powder coating operations, racks should be coated with nonconductive materials to prevent coating buildup. Using PTFE or silicone coatings allows for easy cleaning and reduced contamination risk.
• Avoiding corrosion. Depending on the chemicals used in the finishing process, racks can experience significant wear and corrosion. Stainless steel or coated materials are ideal for operations involving corrosive environments to prolong rack life.

Rack spacing and contact considerations

The way parts are spaced on a rack and their contact points with the rack can dramatically affect the finish quality.

• Minimize contact points. Strive to minimize the number of areas where parts meet the rack in order to reduce blemishes or marks on the parts. However, it is also important ensure that there is enough contact to securely hold the parts in place during the finishing process.
• Strategic placement. Whenever possible, position contact points in noncritical or concealed areas of the part, such as the back or edges, to maintain the visual integrity of the finished product.
• Spacing considerations. Parts should be spaced far enough apart to allow for optimal air, liquid or electrical flow. Positioning parts too close together can increase the risk of an uneven coating or finish. Meanwhile, positioning parts too far apart can decrease the efficiency of your operation.

 

Improving racking efficiency

Optimizing loading and unloading times can increase throughput without compromising the quality of the surface finish.

• Ergonomic considerations. Design racking systems with ergonomics in mind. This can reduce the time and effort required to load and unload parts, especially for large or heavy components.
• Automation. Where possible, automate the racking process. Automated or semi-automated systems can increase efficiency, consistency and reduce labor costs, particularly for high-volume operations.

 

 

Rack maintenance and cleaning

Because racks are exposed to harsh chemicals and high temperatures during surface finishing processes, regular maintenance is essential for racking longevity and performance.

• Regular inspection. Periodically inspect racks for wear, damage or residue build-up that could affect their performance. Damaged or corroded racks may fail to hold parts securely or lead to poor finishing quality.
• Cleaning. In addition to helping prevent uneven coatings, racks should be kept clean and free of residue to prevent contamination of finishing baths. Implement a routine cleaning schedule ensuring that residue or previous coatings are removed regularly.
• Rack coatings. If the racks are coated with a nonstick material, regularly inspect and reapply these coatings as needed. Failing to maintain nonstick coatings could result in material buildup, ultimately leading to imperfections on parts or even damage to the rack itself.
• Testing racks for effectiveness. Periodically test racks under load to ensure they are still performing optimally, especially after several uses or after maintenance work. Poorly performing racks can compromise the entire operation.

Electrochemical considerations

When it comes to electrochemical processes such as electroplating, it’s crucial to manage the electrochemical interactions between the racks and the parts.

• Cathode efficiency. Ensure the rack materials and design support uniform current distribution to all parts. This avoids excessive plating thickness in certain areas and thin deposits in others.
• Insulation where needed. For sensitive areas, consider insulating sections of the rack to prevent unwanted electrochemical reactions that could affect the surface finish.

 

Efficiency, quality, sustainability

Good racking design can have a huge impact on both the quality of the finish and your operational efficiency. In addition, by maximizing the number of parts on each rack without compromising quality, you can reduce energy, chemical usage and costs — which can aid in achieving your sustainability goals. Custom racking designs can help minimize material handling and reduce the potential for damage or waste. In short, whether you’re running a high-volume production line or small batch jobs, a thoughtful approach to racking design and procedures can help you maximize efficiency, minimize defects and maintain high standards of quality.