Monthly Archives: September 2015

Deciding If An Automated Coating System Is Right For Your Operation

Automated powder spray boothsNow that you understand the selection process for a batch powder coating operation, it’s time to determine if a batch line or automated coating system is the right solution for your operation.

Are you launching a large coating operation from scratch and can’t decide what type of line will work best? Have you been powder coating with batch equipment but need to increase throughput? Perhaps you’re bringing powder coating in-house to finish the products your company manufactures, but you’re not sure how to do it. The decision to install an automated finishing system is a considerable one. Before you make the investment, you need to ask yourself if an automated system is right for your company’s operation style and daily coating requirements.

You Need To Powder Coat More Items Per Day

The number one reason to move from a batch line to an automated coating system is to increase throughput. If your business needs to produce a high volume of powder coated parts on a daily or weekly basis, and these parts are somewhat similar in size, you should consider installing an automated line. Since automated coating is a continual process, you’ll almost always be able to coat more parts in a set period of time than if you coated them manually in small batches. But, many problems with throughput can be resolved with less expensive batch equipment.

If you already have a batch system in place, and your production quota is exceeding your current throughput, determine if there is a bottleneck slowing down your operation. If your bottleneck is at the cure cycle, can you add another oven (https://www.reliantfinishingsystems.com/powder-coating-equipment/powder-coating-ovens/) to improve your capacity? If you’re losing time loading and unloading the parts on racks, is it cost effective to add more employees or build more racks? Evaluate your current system and see if you’ve done all of the simple and affordable expansions to your current operation. Bring in a consultant if you need expert advice. Sometimes a simple fix, like adding another gun or hiring an assistant for your coater, can significantly increase your throughput. If you have already upgraded your batch system and solved all of your bottleneck and speed issues, investing in an automated line is the next logical step to increase production.

You Need To Increase Your Powder Coating Consistency

If you need stringent quality control, an automatic line provides repeatable and consistent finish quality that is tough to match with a manual coating operation. Automatic gun systems from companies like Wagner, Nordson and Gema can be programmed to apply specific amounts of powder at just the right setting for best coverage. The process can be repeated automatically for each part. As long as the equipment is properly maintained, the results are ideal and consistent. If your current manual approach is too erratic because your coater is having trouble keeping up, or your customer’s finish requirements are very specific, an automatic system can provide highly consistent results when properly operated and maintained by skilled employees.

Your Parts Must Meet Stringent Coating Specifications

There are several common finishing specifications that you may be asked to meet in order to capture and retain a client’s business. Some of these finish standards require you to employ a specific pretreatment process to achieve acceptable results. Others may simply require finished parts to pass a durability test. Depending on your industry or your end-customer uses, your powder coated parts may need to meet national specifications before they can be used in the field.

One group of standards includes the AAMA (American Architectural Manufacturers Association) 2603, 2604, and 2605 aluminum specifications. Here is a link to a chart with a comparison of the three standards:http://www.aamanet.org/upload/file/2603-2604-2605_Comparisons_4-6-11.pdf

Each standard requires more extensive pretreatment and powder quality processes than the lower one. For example, the 2603 specification can be passed by a manual operation, but the 2604, and definitely the 2605, require an automatic pretreatment process (usually of 4-5 stages or more). Dip tanks can work for specialty parts, but if you are looking at part counts of 1,000-2,000 per day, manual solutions are just not practical. Hanging parts on an automatic line is the most efficient way to prepare large quantities of them consistently. Knowing your production requirements and parts specifications makes your system decision process much simpler.

You Need To Reduce Labor Costs

Cost management is an integral part of efficient production. Reducing labor costs on a per part basis can propel a company forward. Automatic lines can almost always reduce the amount of labor required when compared to their manual counterparts, but there is a minimum of how few employees it takes to run an automatic line.

Typically in a small automatic line you will need someone to load the parts, another person to run the automatic spray booth and perform manual touch-up of problem areas, someone to inspect/unload the parts, and a finish line manager who makes sure the employees are doing a quality job and the equipment is running properly. At least one person needs to know how to adjust the pretreatment section and how to maintain the equipment so that the line remains operational. A minimum of 3-5 employees is recommended for even a small automatic line.

You Don’t Need A Great Deal Of Versatility

Automated lines are sized based on the largest, densest parts that will be coated. The pretreatment and curing processes are often calibrated to get premium results with specific parts. Shops that routinely deal with parts that are in the same general size and density range are the best suited for automated coating lines. If you have parts that are substantially different in size and density (such as 10’ long sections of 3” wide railing, heavy 15” by 15” by 20” machine parts and thin 4’ by 4’ by 4’ pre-assembled frames), an automated curing line may not be practical. Although a single automated system can be set up to accommodate all of these parts, the costs to buy and operate it may be prohibitive.

The other consideration that may make an automated system impractical is if your company does not operate in a fairly consistent way from day to day. Specifically, if jobs are frequently being leap-frogged in line ahead of other work or your operating hours vary widely from day to day. It takes a while to get an automated system up and running, and it takes longer than batch equipment to shut down at the end of the day. Shuffling parts around, changing set-ups and re-starting the line can quickly offset the benefits that make an automatic line effective. Automated powder coating lines get the best results when they are used in a consistent and routine manner.

Comparing the Benefits Of An Automated Finishing System Versus A Batch System

If you can satisfy your production and cost requirements with a batch system, you are better served with the flexibility and lower cost of a well-made batch system. However, if your production quotas or part specifications require it, an automated line may be the obvious solution. We always recommend that you have a clear understanding of your production goals before making a system purchase.

If you’re still debating whether you need an automated powder coating system, here’s a summary of  the benefits and drawbacks of an automated line, as compared to a batch system.

Automated Finishing System Benefits:

  1. More parts per shift
  2. Repeatable finish quality
  3. Better pretreatment options
  4. Reduced labor per part
  5. Efficient use of labor due to constant process
  6. Lower powder cost per part  (especially if reclaiming powder)
  7. A single automated line is more energy efficiency than multiple batch appliances
  8. Consistent, high-end finishes are possible with a quality system

Automated Finishing System Drawbacks:

  1. Less flexibility: Parts have to be hung on line in a specific way. Parts are also limited to a certain height, length or width. Changes to any aspect of the coating process can cause costly downtime.
  2. Substantial cost increase: The capital equipment cost is significant greater, usually 3-5 times that of a comparable batch system
  3. Color changes are more difficult: Reclaim booths are usually for just one color unless you buy a cyclonic or equivalent type powder recovery system. Even then, changing colors is not easy in a reclaim operation. A spray-to-waste booth positioned in line immediately after a reclaim booth is not uncommon, but this increases the total equipment cost as well as the footprint of the installed equipment.
  4. Increased training expense: Automatic equipment requires better educated, well-trained employees to operate it. Employee retention is important after they have been trained because of potential downtime when dealing with new hires.
  5. Increased maintenance: Automatic lines must be vigorously maintained or they won’t function correctly. Poor maintenance practices can lead to lost production time and wasted labor waiting on the line to be fixed.
  6. A problem anywhere is a problem everywhere: Unlike batch systems, where the processes are isolated, a failure in one area of an automated system causes a backlash throughout the line. If a coater has a serious problem in the powder booth of a batch line, other parts can still be prepped and cured while the problem is addressed. If there is a problem in the spray booth of an automated line, the other processes will also come to a halt as soon as the conveyor is stopped.

Careful cost analysis should be performed before deciding on an automatic finishing system. Automatic lines can be very beneficial and improve profitability but their functionality is very specific. They are simply not as versatile as manual batch systems. Pretreatment stages, amount and type of powder to be applied, curing schedules and cool down times must all be calculated before the equipment is manufactured. If you’d like to learn more about the various types of powder coating media, the common steps in chemical pretreatment, and other helpful information that must be taken into account when specifying an automated system, check out our other articles by visiting our Resources page.

Choosing Your Powder Coating Equipment

Custom Coating EquipmentIn previous articles, I have talked about selecting a system or process before choosing your powder coating equipment. After you have established your process and have a rough idea of the timing of each step, you can select equipment to meet your production requirements.

Setting up a powder coating shop involves many variables besides powder or pretreatment. The size of part to be coated, layout of shop to be used, labor, parts per day requirement, staging of racks or parts in process, loading area, and unloading area are all factors that must be addressed when designing a work area.

What’s The Largest Item You Will Be Powder Coating?

The first factor to consider when sizing your equipment is the size of the parts you’ll be coating. Determine the size of the largest part you will be routinely powder coating and use that as the base size for your equipment. If your typical part is small, instead decide how many you want to coat at one time and how large the rack(s) will be to accommodate your throughput.

Once you have those measurements, you’ll need equipment that is appropriately sized for your application. For the powder spray booth, typically you will need 2-3 additional feet around the part so the operator can easily apply powder to the part without walking or spraying outside the booth.

The powder oven (checkout one from Reliant) can usually be smaller than the booth, but you still must account for the size of the rack(s) in the oven. If you are using multiple racks, you will want enough space inside the oven so the racks do not bump against each other and the doors can still be completely closed.

For example: If your rack of parts is four  (4) feet wide, five (5) feet tall, and six (6) feet long, you will want an eight (8) feet wide by ten (10) feet long booth with at least an 8 foot ceiling. This will give you two (2) feet all the way around the part, so the operator does not have to move the rack while powder coating. The additional height above the rack will allow the powder to go around the parts and not get deposited on the ceiling lights. This same rack can go in a six (6) feet high, six (6) feet wide, and eight (8) feet long oven. The smaller oven helps to bake the parts more efficiently.

Shop Workflow and Layout

Exterior dimensions of the equipment need to be known so that you can plan a good shop layout. Make sure you have enough room in your shop for not only the equipment, but adequate turning space for your parts or racks, and staging areas for parts moving into and out of your pretreatment, coating and curing areas.

Powder Coating System Layout Sample

Sample powder coating system layout with curing oven, powder booth, blasting booth and wash area shown.

When laying out your shop, be certain you have enough space to satisfy your local safety code requirements. Code varies from place to place (and I strongly encourage you to make the local code inspector your friend prior to a large equipment purchase) but a good rule of thumb is to make sure all components are at least three (3) feet away from each other and the shop walls or structures. Roof height is also an issue. You want at least three (3) feet clearance above the components and you do not want sprinkler systems (unless rated for 350F) or air hoses running over your oven. Your roof supports can sometimes be closer, but you will need to determine that with your local code authority.

Walkways, emergency escape routes, and staging areas for racks are other factors to consider when planning your shop layout. Be sure and have good access to utilities such as gas and power for the booth and oven. Water should be run to the area where you plan to have pretreatment and cleaning processes. Drains or water capture alternatives are also important; depending on your finishing process, you should plan these well in advance.

How Many Parts Per Day Do You Need To Powder Coat?

Another key factor for equipment planning is production requirements. In a batch system, you are only as efficient as your slowest stage. Typically this stage will be cure time.

Since the average cure time for polyester is metal temperature reaching 400F for 10 minutes, this usually means a 20 minute dwell time for gauges around 18-16 gauge. Quarter inch angle iron can take 30-40 minutes and some castings can take 45-60 minutes to reach the part temperature of 400F for ten minutes. Of course, powders vary in cure cycles as do metals in time it takes to reach their required cure time. I recommend running an oven recorder regularly to set your dwell times to reach optimal cure times.

Figure out your slowest cycle time, I’ll assume curing, although it could be metal preparation. A typical cycle time would be 20 minutes. That gives you 24 cycles times in an 8 hour shift, if you run everything at 100% efficiency. For example, if you do muffler tubes and can rack 100 tubes per cycle, your maximum daily production rate will be 2,400 muffler tubes. If you need more production, you can add more ovens till something else becomes your lowest cycle time, or bottleneck. When labor cost starts to increase too much by adding multiple ovens or booths, then you can look at automatic solutions.

Many beginning powder coaters think of automation right away, but I would almost always recommend trying to achieve your production goals with batch systems first. That way you learn the process and what it takes to achieve a good finish. Batch systems also give more flexibility and adjust to different powders, metals, thicknesses, and process better than automated lines. Now if they have to have 10,000 parts a day, automation is probably the way to go.

Selecting The Right Powder Coating Equipment Checklist

Purchasing the correct equipment can be a little overwhelming, but by identifying the key factors, the equipment purchasing decision gets easier.

Preparation: Am I blasting and/or washing? If yes, then you need a blast booth and/or wash booth.

Preheat/Dry: Do I need to preheat my parts due to pretreat drying, process or out gassing? If yes, then decide whether an extra oven is necessary or if you have capacity with your cure oven.

Size Of Parts And Racks: This determines the size of your equipment and necessary workflow requirements.

Available Area In Shop: This determines the amount of equipment you can fit or whether you need additional shop space.

Parts Per Day: Determines the amount of booths and ovens you will need to achieve your current and future production goals.