Installing a Powder Coating Line

Question:

We are interested in installing a powder coating line. What should we consider? B.R.

Answer:

I have advised many future powder coaters, written several articles and taught many seminars on this very topic. The most often asked question is “How much is it going to cost to convert to powder coating?” It seems that this simple question would have an equally simple answer, but it doesn’t. That’s because every powder coating system is custom designed using standard components to meet specific quality, performance, part size and production requirements. “Right-sizing” your powder coating system ensures that you end up with a process that will accommodate your products in the volumes you need to produce at the quality your customer expects.

You should consider several issues before you purchase a powder coating system:

1. Will powder coating work with your product? This may seem obvious, but you should verify that there is a powder coating material available that meets all your functional performance and visual appearance objectives. Next you should verify that your products can be powder coated (Can your products conduct an electrical ground of less than one megohm for safe electrostatic powder application or handle preheating for flocking applications? Can your product withstand the cure temperature for standard powders or the flow temperature for UV curables?). If the answers to these questions are yes, then proceed to the next issue.
2. Is powder coating economical for you? There are operational cost analyses that can be preformed to determine if powder coating can save you money or cost you more. Most of the time powder coating will be less expensive than liquid coatings, but running the numbers will ensure that you won’t be surprised after you install the equipment. The Powder Coating Institute (PCI) has a spreadsheet application that will assist you in determining the operational cost of a powder coating system and will allow you to compare this cost with your existing or a competing finishing technology. You can obtain the spreadsheet free by calling PCI at 703-684-1770.
3. Do you have some equipment in your existing finishing process that can be used to support the new powder coating process, or must you buy a completely new system? If some of your equipment is compatible for use in your new powder coating process, is it in good shape? You can certainly reduce the cost of converting to powder coating if some of your finishing system components are compatible to the new process (washer, dry-off oven, cure oven, etc.)
4. Is there a Return on Investment (ROI) or payback target that needs to be met? You can obtain budgetary quotations for the equipment and installation costs of your new system and use the operational cost/savings analysis (see No. 2) to determine the ROI or payback for the new powder coating process. Compare your answer to your target.

At this point, you have addressed all the preliminary issues that need to be answered before you can determine if powder coating is right for you. Several issues will affect both the size and cost for your new powder coating system. We will deal with these issues individually.

1. How many parts do you have to coat per unit of time? What is the optimum hang pattern for these parts? What effect will downtime for color change have on the available production time? Is there future production growth that needs to be accommodated? What will be the anticipated reject rate from this process? These issues are used to determine if a batch or conveyorized operation can support your production needs. Also, if your process is going to be conveyorized, these issues are used to calculate line speed.
2. What is the aggregate part size for your new system? This aggregate part size is the height of your tallest part, the width of your widest part and the length of your longest part. Often these three dimensions do not occur on the same part.
3. What is the product quality you are looking to achieve with this new powder coating process? The quality issues that need to be identified are:

   a. Corrosion requirements will affect the pretreatment system configuration (number and length of the washer stages).

   b. Appearance requirements will determine if an environmental room is necessary.

   c. Coating requirements will determine the configuration of the cure process (IR, UV, convection, temperature, time, etc.)

   d. How many colors will you be using and will these colors be reclaimed or sprayed-to-waste?

   The above-mentioned issues size every powder coating system. In powder coating, the bigger the system, the higher the cost. Since most of the powder coating process is time dependent (i.e., washer stage duration, cure time, dry-off time, etc.), the faster the line speed the larger the equipment and the higher the equipment costs. Furthermore, the larger the product the more equipment is necessary to coat it and taller equipment also increases system cost.

   Careful consideration of the issues discussed here will ensure that you obtain a system that is “right-sized” for your needs. A system that is too large will mean that you spent too much for it and will penalize you every minute of operation because it is more costly to operate. Conversely, if you undersize your powder coating system it will become a bottleneck, causing all sorts of production scheduling problems.