Powder coating is used to create durable finishes in many industries, including automotive, appliances, furniture, construction equipment, and agricultural machinery. But as production volumes grow, so do the needs of manufacturers to enhance sustainability, reduce energy consumption, accelerate production, and cut costs. Traditional powder coat curing methods pose obstacles to reaching this goal, creating inefficiencies that producers can no longer afford to ignore.
Laser curing is a game-changing innovation that delivers a rapid, energy-efficient, and highly controlled solution for users of powder coating. It offers a sustainable curing process that meets modern manufacturing demands without compromising quality or efficiency.
Let's learn exactly how.
What is Laser Curing
The powder coating process starts by spraying a dry, electrostatically charged powder onto metal part surfaces. The electrostatic force causes the powder particles to adhere to the part in a layer of uniform thickness.
Once applied, the coated part is cured using heat. This melts and fuses the powder particles which resolidify to form a coating with a smooth finish. This curing step ensures the coating forms a tough, protective layer which is typically thicker, harder and more durable than paint.
Traditional powder coat curing methods rely on bulk part heating to melt the powder particles. The most common approach uses convection ovens which heat large volumes of air to raise the temperature of an entire part. This ensures the powder coating reaches the temperature required for curing, but it also wastes significant energy by heating the entire part – as well as the production environment around the oven.
Infrared (IR) ovens offer a faster alternative. These use radiant heating to warm the powder coating directly, so they’re more efficient than convection ovens. But they still emit light in all directions, leading to inefficiencies and energy loss. Plus, IR heaters output broadband light, most of which isn’t well absorbed by the powder coating and therefore doesn’t contribute to heating it.
Laser curing takes a fundamentally different approach by utilizing a high intensity, highly directional, narrowband diode laser source as its heat source. This intense light from the laser can be efficiently collected, shaped and projected on to the part surfaces.
This enables the laser to heat just the desired part surfaces and virtually nothing else. Plus, the narrow range of infrared wavelengths produced by the laser are well-absorbed by the powder coating particles, thus curing them efficiently while largely avoiding unnecessary heating of the part itself. The net result is about a 10X reduction in curing cycle time over convection ovens
Finally, the electrical conversion efficiency of lasers – that is, the amount of electrical power required to produce a the necessary amount of laser light – is significantly higher than any other type of infrared source. This means that a large percentage of the electrical power supplied to the laser system goes to actually curing the coating rather than being wasted. This efficiency, together with the high speed of the process, is a critical factor contributing to the high sustainability of laser curing.
IPG Photonics Puts the Benefits of Laser Curing into Production
IPG Modular Laser Curing Systems let manufacturers fully realize the benefits of laser powder coat curing in a high-volume production environment. These systems deliver tangible savings in cost, time, and floor space over convection and IR lamp ovens. Most importantly, IPG laser powder coat curing systems provide a more sustainable alternative by reducing energy consumption and waste while simultaneously enhancing process control.
The basic building block of IPG Modular Laser Curing Systems is an 8' (2.4 m) long cell that is built just wide enough to accommodate powder coated parts. Typically, the parts move continuously through the system which typically cures them in approximately 2 minutes, including ramp up and cool down.
The throughput of this basic configuration can be scaled up by making the system longer. Additional 4' (1.2 m) long modules can be added to Modular Laser Curing Systems as needed to extend system length indefinitely.
There are actually quite a few different ways the IPG Modular Laser Curing System can be configured to meet specific requirements or to integrate it with existing production equipment. For example, it can be built to support continuous conveyance or stop-and-go conveyance. It can incorporate robotics to handle changing part mixes or to cure parts with curved surfaces.
But no matter what form a laser curing system takes, it will typically occupy about 10X less floorspace than a convection oven with the equivalent throughput. Plus, the ability to scale the system means that it can be expanded over time if production volumes increase. In contrast, manufacturers typically need to purchase a convection oven large enough to meet their foreseeable long-term needs, as upgrading later is not a cost-effective option.
Another key advantage of the Modular Laser Curing System is that it offers precise process control. This is enabled by two key factors.
First, it is a “cold” oven, radiating virtually no waste heat. This allows integration of advanced metrology instrumentation, such as thermal cameras, which can measure coating surface temperatures in real time. In contrast, convection and IR ovens can only provide internal air temperature readings, which provide little direct value for process control.
Second, laser output power can be changed virtually instantaneously. This allows for real-time, on-the-fly adjustments based on measured coating temperatures. This ensures that the curing temperature always matches the recipe for that particular powder material.
Laser powder coat curing is nothing short of a revolutionary break with prior technologies. It increases throughput, enhances control, and reduces operating costs, while still being a far more sustainable process with a reduced carbon footprint. The IPG Modular Laser Curing System provides the simplest, most flexible, and most cost-effective way to implement laser powder coat curing in a wide range of production settings.
Getting Started with Laser Powder Coating Curing
Many applications and manufacturers can benefit from a laser curing solution. IPG offers both laser heating sources for powder coat curing as well as laser curing R&D workstations and complete modular laser curing systems.
Getting started is easy – send us a sample, visit one of our global application labs, or just tell us about your application.
