Researchers in the manufacturing processes engineering group at the University of Córdoba (Andalusia, Spain) recently validated a new method to remove fluoropolymer coatings on an aluminum alloy substrate using an Nd:YAG industrial laser stripping technique.
According to the team, the Nd:YAG laser is a continuous wave and solid-state laser possessing yttrium oxide and aluminum doped with neodymium. Though it has many applications, including in welding, they say it has not been previously used for fluoropolymers.
Fluoropolymers are macromolecules made up of carbon and fluoride which, due to their properties, are often used as non-stick and anticorrosion coatings on a wide range of materials. According to the team, their characteristics enable resistance to abrasions, stability at high temperatures, and their structure is not affected by most chemical agents.
Nonetheless, despite their resistance, these fluoropolymer coatings can still wear. In these situations, the researchers explain that rather than replacing the entire piece of material, the usual process is to remove the coating, take out any impurities and parts that are attached, and then recoat it. This is usually more cost-effective than full replacement.
However, since fluoropolymers are extremely resistant and chemically inert materials, they adhere strongly to a surface and do not come off easily. To address this problem, the researchers performed several tests on a sample material using their laser technique.
After doing several tests involving laser exposure, they characterized different parameters such as the material’s toughness, roughness, and mechanical properties. According to the team, the results were comparable to those obtained using traditional coating removal processes such as blasting, plasma, pyrolysis, chemical processes, and high-pressure waterjetting. Complete data is available in the Polymers journal.
The researchers say that while the laser technique has historically required costly equipment, they note that the price has decreased in recent years. Professor Guerrero Vaca, who led the research, says the next step to improve the efficiency of the process is to make the process automatic. He believes this could be done in the future by using robotics.
Source: University of Córdoba, www.uco.es.