When to Look at Racking Options on a New Line
Where does racking fit in planning a new powder coating line? Production Plus’ Donovan Dixon says right from the start.
Q. I am in the process of getting a powder coating line. When should I look at racking, and what are the first steps that I need to take?
A. The best time to start looking at racking is in the beginning of the designing process for the powder coating system, when the size of booth openings, conveyor height, corner radiuses and line speeds are being determined.
At our company, the first step in rack design is looking at the customer’s part dimensions, often using STEP files of the parts. We will then take those files and create a 3D rendering of exactly what the racks will look like going through the new system. This will help the customer visualize what kind of density it will be facing. This data can help determine how long the line needs to be, how many feet per minute it should run, etc.
Q. How important is grounding in our powder coating system, and how does rack design affect it?'
A. Grounding is essential to a properly powder-coated part. The first question we ask ourselves is, “What is the most optimal design to get the best grounding and the most cycles out of a rack before burn-off or cleaning?” Our crossbars are designed with internal grounding in mind. This means that, because the part hooks fit inside of the crossbar, the hooks are completely shielded from powder. Because of this, the hooks can just be swapped out for fresh grounding points without having to burn-off entire racks. This will save the customer money, as it will not have to clean the racks off as often, and the racks generally pay for themselves rather quickly.
For more custom parts and racking, there are still many ways to ensure a good ground every time. We will consider the shape of the parts, and if there are any internal areas in the part, we will start by developing hooks and racking to fit these areas, thus shielding the contact points. Another point to consider is the weight of the parts. For heavier products, when larger-gauge racking is required, the weight of the part (combined with sharp edges on the rack) can contribute to having a properly grounded piece. The use of sharper edges allows the part to cut through the powder build-up already on the rack. Any extra cycles that customers can get out of the racks will save them money.
Q. How does this process work?
A. At our company, every rack design project begins with a nine-step analysis to ensure a successful outcome:
- Greater density for more profitability
- Better part control
- Maintaining electrostatic ground
- Wash penetration and drainage
- Positioning parts for a Class A surface
- Minimal to zero blemish
- Ease of load and unload
- Cleaning methods and rack materials
- Time and labor savings
This comprehensive analysis ensures the rack design will accomplish the customer’s objectives.
Q. How do I load racks while the line is moving, and are there any other options?
A. Being able to load parts efficiently on a rack is all about the time and difficulty involved in hanging the part, and whether the parts are being loaded online or off. The more density you can get in your line, the more value you can get out of your system.
Online loading works the best with medium and large-sized parts, because you can get as many on a rack, so you can still run the line at a good speed and keep up with the loading process. However, with small-parts racking, where density can increase exponentially, offline loading is a better option.
Offline loading usually consists of an operator (or operators) loading a large number of parts on a rack held by a cart in a loading area beside the line. The fully loaded rack then is lifted into the continually moving line. Several stations can be set up in this manner to continually feed the line with highly dense racking. Picture a wall of parts moving through the system with minimal spaces.
Another benefit to loading carts to hold the racks is that they can double as storage and burn-off carts as well.
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