Painting plastics is not a simple process, as anyone who has ever attempted to paint a plastic component at home can attest. Specialty paints are usually required to achieve the right finish, and to ensure that the paint bonds properly with the plastic surface. However, modern plastic painting techniques have evolved considerably in recent years, and there are now several different means by which plastic components can be painted to meet any manufacturer’s needs.
Wet Coat Painting
Wet coat painting is a very similar process to spray painting. While many companies prefer to use powder coating, wet coating is certainly a good way to paint plastic. This is largely because powder coating plastics, while feasible, requires special preparations to be made.
First, if powder coating is to be used, then there are three paths by which this can be achieved. One of the most common is to use a very high temperature resistant type of plastic (nylon, for instance), in conjunction with standard thermoset powder coatings. This often requires preheating and a preparation, or base coat on the plastic component.
Another means by which plastic can be powder coated is to combine a lower temperature threshold plastic with very low temperature thermoset paints. Finally, powder coating can be achieved by using standard plastic components with a UV cure solid paint.
Wet painting does not require these preparations, though it does require specialty adjuncts mixed with the liquid paint. Often, you will find these applications in wet-on-wet painting. Here, a thin coat of wet paint is applied, followed quickly by another coat of wet paint (in either the same color or in a different color). The finished pieces are often dried using infrared curing processes.
Finally, wet painting techniques can be used with a number of different applications. These include the application of primer, the use of enamels, lacquers, urethane and alkyds, as well as the application of conductive coatings.
One of the most visible signs of technology evolving is the use of robotics. Of course, you’ll find robots used in all sectors of industry, from automakers to pencil manufacturers and beyond. Robotics has come to play an important role in the plastic painting industry, as well. Using robotic painters, a plastic painting company is able to achieve a number of things.
First, robotic painters are certainly able to speed the production process along. They can operate much more quickly and with greater precision than even the most skilled human painters. In addition, robotic painters are manufactured with multiple axes in the paint head. This allows the head to coat any surface with paint, no matter the angle at which the surface is set.
Robotic painters are ideal solutions for large runs or for very complex plastic parts, as the multiple head axes ensure that the robot can paint all surfaces evenly. Of course, the use of robotic painters is also able to decrease overspray, which can be a considerable problem. Reducing overspray increases the quality of the finished product, while reducing the amount of paint used and, thus, cutting down on the cost of materials for any painting project.
The plastic painting industry has evolved in other ways, as well. For instance, the use of plastic painting lines ensures that any painted product can be delivered in a shorter timeframe than through other painting methods. Automated paint lines offer greater speed, while still ensuring high quality control for projects being painted. Modern paint lines can be fully robotic, or they can combine human painters with their robotic counterparts.