Improving the Quality of Your Industrial Paint Process

Industrial paint quality is a tricky thing. Not so much because reaching precise and accurate application is difficult – nobody’s asking for the Mona Lisa from an autobody shop (ok not “nobody”) – but it’s when you get to the point of painting 100 parts or 1000 that the challenges of maintaining consistency at high quality becomes difficult.

What does this consistency problem come from? There are a few key factors: the application method, the tool used and maintenance, cleaning or changeover required, and the nature of the parts you’re working on in terms of whether achieving a consistent finish is more difficult.

What scenarios could this apply to? Parts with crevasses, unusual curvatures or a unique surface features all can make a consistent finish difficult to achieve with the most basic systems available. By taking advantage of the right technology and approach – whether it’s skilled labor, automated or fully roboticized – achieving a consistent industrial paint quality can be realized through variety of subtle optimizations. 

Painting can be difficult for any metal fabricators because of the variety of parts addressed and varying customer quality requirements. Source: PEP Engineering UK.

Looking at What Your Parts Require

What are some of the most common parts that need painting? They run the gamut but are commonly recognizable in everyday life:

  • Car, bus and truck bodies
  • Structural steel assemblies – bridges, infrastructure and buildings
  • Heavy equipment (earthmoving, construction, agricultural)
  • Medical imaging and software technology
  • Energy equipment (if not simply all those parts at the gas station)
  • Planes, trains (we already mentioned automobiles)
  • Funeral caskets, shipping containers and every metal or wooden box in between

Paint is applied in most of these cases to generate both an attractive finish and to offer long-term protection against environmental challenges or simple weather wearing. In all of these circumstances, it’s not simply large flat paneling or single large assemblies that are painted, but also many small parts which are assembled together after the fact depending on the type of equipment being assembled. 

Furthermore, consistent finish is required because parts must fit together, whether or not your parts hold together well, while customers often first notice the quality of finish before anything else. They are are demanding not only because they expect parts to be visually attractive, but also because the visual quality of that finish will reflect on the final product or service they may offer to someone else. If you want to understand what type of parts fit best with each workflow, check out the next section. 

Painting heavy machinery can be a challenge because parts are usually painted before assembly (due to weight and contours), meaning the variety of paint programs needed is greatly increased compared to unibody painting.

Making Systems Fit Functions

There are three basic orientations towards painting industrial parts that manufacturers of all kinds know today – skilled labor, automated booths and paint robots.

  1. Skilled labor

Skilled labor is the most commonly recognized means for industrial painting. This isn’t true to all sectors, but when it comes to sectors like structural steel and heavy equipment (nominally “high-mix, low-volume” industries) skilled labor is often the best choice because of the changeover and varied shapes or nature of parts, as well as the need to flexibly respond to orders and requests as time goes on. In more mass manufacturing industries (like cars and light duty trucks) robotic painting is the most common way to get things done. We’ll get to that shortly

  1. Automated booths

Automated paint booths are uncommon but still used where large parts need a general and not necessarily consistent level of painting. This can include large flat and structural panels and other parts where a light screen or different shape-perceiving mechanisms can loosely target the paint gun being used to the size or area of the object being coated, but not necessarily to curves or hard edges. Furthermore, it won’t prevent drip – critical to high-consistency and quality finish operations. 

A cartesian-style automated paint booth. Obviously accuracy may be inconsistent, but depending on customer requirements, the quality needed may not be exceedingly high.
  1. Paint robots

Paint robots have been for decades the standard in the automotive industry because of the volume, value and repeatability of those industries. The value of paint robots lies in their ability to consistently execute highly repeatable operations. Where they falter is in their need for programming and precision fixturing. Generating a robot program means that once it is put into production, it is difficult to change, causing the need for precise fixturing during a production process in order to ensure that inconsistencies (or outright process failures) do not emerge as a large volume of parts are processed.

BONUS: Autonomous Paint Robots

Yes, actually, as it happens, the end might be nigh when it comes to the programming and fixturing limitations of traditional paint robots. Autonomous robotics technology is built primarily on the use of 3D perception and AI to see parts as they are in their environment. This means that with the appropriate process model for painting, an autonomous robot can not only generate its own program in real process time – it can also do so in a way that is agnostic of the actual position or orientation of the parts that it’s processing. Because they are able to see parts and generate their own programs, autonomous robots are far more versatile in automating high-mix paint processes than what has been previously achieved.

Autonomous manufacturing robots can apply paint to varied parts – no matter their shape – with maximal consistency, providing the most possible quality improvement for high-mix manufacturers.

Application Techniques, End Effectors, Flow Optimization and Control

With the type of system you want taken into consideration, it’s then important to take into account what type of techniques, end effectors and more you want to apply. Every material has its own strengths and limitations, and paint is no different – it simply depends on what the actual behavior of your material is and if it appropriately achieves your goals. 

If you’re thinking of a manual system, then handheld paint guns are likely to suffice. These are lightweight, easy to manage and require regular but not burdensome levels of cleaning. In this context, reciprocating arms and robots can have end effectors that use purging or self-cleaning functions based on air pressure that reduce the need for overall maintenance. They may also have porous components that provide quick replacement maintenance, but create a cost in replacement. Ultimately, however, for the right type of operation, this cost is far less than actually having to manually clean end effectors on a consistent basis. 

With the appropriate mixing and pressure systems, industrial spray effectors can provide sufficient coverage, accuracy and efficiency for most industrial paint applications. In sectors like powder coating, it is more of a concern to optimize around grounding, part shape, speed and frequency. With industrial paint, most of the trade offs come around pressure, volume and accuracy of operations, which in most industrial cases is generally an easier fit. 

Maximizing Output Quality With Autonomous Manufacturing

For most industrial paint applications, skilled labor is generally required. This is problematic in that – even in parts of the world that we may consider less developed – the willingness of young workers to embark on manufacturing careers has only continued to decline. 

While finding the right engineering and programming staff might be less of a challenge, those people can’t do it all on their own – or can they? With autonomous robots, it becomes much easier to scale the know-how of your most effective team members, eliminating the traditional robotic integration bottlenecks while also realizing greater productivity and improved savings on waste, energy, consumables, rework and general downtime. 

All of this effectively avoids the challenges of achieving a quality finish, while giving you the flexibility you need to address more customers as you grow. 

Omnirobotic provides Autonomous Robotics Technology for Spray Processes, allowing industrial robots to see parts, plan their own motion program and execute critical industrial coating and finishing processes. See what kind of payback you can get from it here, or learn more about how you can benefit from autonomous manufacturing systems.

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