Automated Wood Coating Lines: Common Problems & Their Solutions

Automated wood coating systems range in there use and design from flat line spraying to flat line with ovens incorporated and more. They can incorporate anything from a simple automated spray booth to a full line that includes sanding, Coating application, and curing in a single step. Regardless of the system you may have, there are a variety of common problems that can occur with the systems. This article covers a few of the frequent issues that are often found in these systems and potential solutions.

Overspray is excessive in Spray Cabinet

If your automated system has a spray cabinet or a mist cabinet you should typically not see excessive overspray reflecting off of the products or hanging in the air of the cabinet. If this is occurring, it can create problems with the finish quality you will achieve. There are a few different potential sources of this problem.

1. Check to see if your spray equipment is adjusted properly – You will want to check to see if you are using air spray guns that your air pressure is not too high. If you are using HVLP you want the air pressure to not be higher than listed on the air cap of the spray gun. If you are using airless or air assist airless spray guns you typically want to adjust fluid pressure so that it is atomized but not much beyond that amount. If you are using airless spray guns you may want to consider if you can use an air assist airless as this will allow a similar level of production but with softer spray patterns.
2. Check the intake and exhaust filters for the cabinet – Many automated wood coating systems will have an intake and exhaust filter. These filters are typically designed with particular resistances in mind. If you have excessive overspray in your cabinet you will want to verify that your intake filter is designed for your particular finishing system. Additionally, you will want to ensure you have a good change out schedule on your exhaust filter as they can become to loaded with overspray and stop collecting overspray effectively.
3. Adjust any intake air Louvers – Certain automated wood coating systems may also include intake louvers that will allow you to control the volume of air that enters the spray cabinet. It is common to see a certain setting recommendation the manufacture will provide and you will want to verify that you have your intake louver properly set based on that recommendation.

Finish quality is not what it should be

If the finish you are achieving with your automated wood coating system is not as of good as you think it should be there a few key things you can check, this list may not be exhaustive but will be a good place to start.

1. Sanding wheels – If your automated wood coating line includes sanding there are often wheels that keep a products surface pressed against a sanding belt. You will want to check each sanding wheel to ensure that product is being properly held against the sanding surfaces.
2. Spray Gun Condition – You will want to check the spray guns to ensure they are not dripping, that the spray pattern is equal, and the pattern is wide enough for your particular product. You can learn more about common spray gun problems and there solutions here.
3. Spray Gun Positioning – Additionally if you are having issues getting complete coverage of your product then your spray guns may need to be aimed appropriately or you may need a spray gun air cap that offers a wider pattern. Or you may need to consider a larger fluid nozzle or to reduce the line speed of the automated wood coating system. Working with a quality paint equipment provider will be able to help you determine the right steps, you can always contact us for free consultation on an issue with your automated wood coating line application equipment.
4. Fluid Hose Condition – If your fluid hose has significant bends throughout it, is worn at places, or is to small, this can cause issues with getting enough coating fed to your spray gun. This can cause problems where you do not get a consistent spray pattern but get pattern size changes.

Production Costs are High or Production Time are Not Adequate

If your automated wood coating line is not providing the production you hope there are a few factors to consider, the same factors can often also contribute to production costs.

1. Air hoses – One large cost of production is your air compressor operating costs. Leaks in compressed air due to poorly maintained airline can cost thousands of dollars annually (you can get a good overview of air leak costs based on the leak size here..) To reduce these costs you should review your air line in your automated wood coating system and if there are leaks replace the hose.  It can also be a good idea to consider a routine inspection and maintenance program to reduce the long term occurrence of air leaks.
2. Line Not Moving Product Fast Enough – If your line is not completing product fast enough you can consider a few ideas.

• If using Spray Guns – Can you switch to HVLP if using conventional? This will help increase the coating you apply and can help production. You can also try a larger fluid nozzle or air cap to provide more coating and a wider pattern.  If this is not sufficient enough you can try switching to an air assist airless spray gun potentially (though the quality of finish may change slightly)
• If using air assist airless – You can try larger and wider fan pattern fluid tips.
• Regardless of equipment being used – You can adjust line speed to achieve less product passes or better production. If you have to pass the product through multiple times to achieve the right amount of coating on the surface, you could try to slow down the line speed to apply more product and finish each side in a single pass. If you use a single pass and find your getting more coating than you may need you can try speeding the line up slowly to reduce the time per piece.

3.Frequent Equipment Breakdown – If you are using airless/air assist airless you want to ensure your fluid tips on your equipment are not consuming too much of your airless pumps capacity. If they are your pump may be constantly needing to be rebuilt, if this is the case you should consider buying a larger pump. To understand how to properly size an airless pump consider this article here. If your using air spray guns you usually want to try to maintain fluid pressures below 20 PSI as higher pressures will wear parts rapidly. You also want to ensure you are using a solvent that will sufficiently remove any coatings you use on your line and have proper clean up procedures in place that are done after every shift or more frequently depending on the application.

Conclusion

Automated wood coating lines have a lot of benefits. They also require proper care and setting up to provide the greatest benefit. The suggestions provided should offer a great starting place for automated wood coating lines to maximize production and reduce performance issues. If you have any questions on the spray equipment for your automated wood coating line feel free to contact us.