Have you noticed lately that your paint line isn’t producing the quality it once did?

Are your substrates weighing less as a finished product?

Are your thickness measurements showing less versus more?

Have you noticed more overspray in your paint booth?

Are your robots wearing more paint than your substrates?

 If you answered yes to any or all of these questions you certainly have something going wrong in your paint process, not to mention your increased costs of paint as well as your amount of scrap and rework.

 There are many different factors that can contribute to problems within the paint process. Some examples are:

•  The manufacturer changed the composition of the paint
• Something is wrong with the paint nozzles
• There is a bug in the programming

  So you spend countless hours going through this and everything has checked out but the output remains the same.  Have you checked your system to insure you are maintaining an adequate ground for your paint process? Oh, I am assuming you ARE grounding, right?

 The grounding process is not glamorous or fun, but it can make or break your success in producing a great paint job. I would always recommend that you check the resistance between the substrate and your most solid connection to your paint line conveyor. My guess is you will find a reading well above 1 Mega Ohm (some have had infinite readings which means no ground at all) which for many means a poor ground and a bad paint job. It all comes down to making sure you have solid connections throughout your paint process which allows the charges to flow as the paint line requires.

 Some things to check are:

•  Do you have good connections between the substrate and carrier?
• Does the carrier have a solid connection to the conveyor?
• How frequently is the conveyor track cleaned and connectivity checked (I have received answers such as never or very rarely)?
• Does the conveyor ground tie into the ground connection for your paint delivery system?

 This all may sound simple but these issues are the most common areas to check when paint quality deteriorates. Proper maintenance and diligence to grounding is key to providing a great paint output. Adding a grounding assembly (or straps) can be a great inexpensive insurance policy which will help produce a consistent high quality paint output while reducing the cost of scrap, rework and overspray.

For more information on grounding and static electricity in industry, you can check out our whitepaper. 

Mueller Electric can also help design the custom assembly perfect for your application.

When trying to determine the cause of problems encountered with electrostatic painting, it can be confusing. The problem is often solved by updating the grounding process, however this simple solution is often overlooked. 

1. There is a drop in transfer efficiency

Your measurements and output are lower than they should be. 

2. Paint thickness is not what it should be

You may see a reduced paint thickness, uneven paint thickness, or both.  

3. There is a lot of scrap/rework

Lack of a good ground can result in much higher  amounts of scrap and rework than there should be. 

4. There's more paint on the surrounding surface than on the substrate

This can indicate you had a bad ground or no ground at all. 

5. Your cost of paint has gone up

You are going through more paint to coat the same number of items. 

6. Servicing the robots doesn't help

You may have thought there was something wrong with the paint robots, but they are in working order

7. There's a drop in weight

If your substrates come out weighing less than they normally do, this can indicate that less paint is making it to the surface which usually indicates there're something wrong with the ground.

If you think updating your grounding process will help, you can head over to this handy page which addresses the most common considerations and questions for updating your grounding process. 

For more information on grounding, read our whitepaper Static Electricity and Grounding in Industry. 

You can also take a look at our free guides for grounding plastic and metal for painting.