How to paint car parts? Plastic parts today account for up to 20% of a car’s weight. Many of them are external and internal elements, to which the varnish coating gives the appropriate visual, tactile and functional properties. The paint technology industry responds to the increasingly stringent requirements in terms of quality, economy and resource efficiency with new solutions and further developments.
By painting, the Kia’s plastic parts are protected against mechanical, chemical and physical influences such as scratches, stone chipping, weathering and UV radiation, as well as against ingredients in cosmetics and cleaning agents.
However, paints and coatings are much more than just technical tools: they create surfaces that appeal to all the senses, evoke an emotional connection with the product and add value to it. The quality of the coating must meet very strict requirements in order to achieve this seductive effect on the human senses. At the same time, global competitive pressures are forcing more and more economical, sustainable and flexible paint processes. To this end, the paint industry is constantly working on optimizing existing solutions and developing new ones. Parts for Korean cars, such as Kia parts, require a professional approach to painting due to their construction.
The cleaning and pre-treatment of plastic parts is of decisive importance for good painting results. Traditionally, a washer with an aqueous cleaner and a dryer are used for this purpose. However, this costly, space- and energy-intensive variant is increasingly being replaced by alternative cleaning processes such as CO2 snow blasting, plasma processes or the steam cleaning method. CO2 snow jet cleaning has found numerous applications in the automotive industry and in the supply sector for the automotive industry. Non-toxic, flammable recycled carbon dioxide snow removes particulate matter and film-like contaminants from exterior and interior Korean car parts made of a variety of plastics and composites, while being gentle on the material. It also reliably removes dirt from very small gaps. Another advantage of the dry process is the greater freedom in the design of the individual components, because, for example, the water-retaining geometry no longer transfers media into the painting process. Plasma processes, which are divided into low-pressure and atmospheric plasmas, are primarily used to remove thin layers of inorganic contaminants. During plasma treatment, the surface is cleaned and activated at the same time. This dual function is based on the physical and chemical characteristics of the process. In addition to a clean surface, increased surface tension is also obtained in this way, which provides ideal conditions for the further painting process of parts for Japanese and Korean cars.
There is a growing trend to reduce the number of stages in the paint process with filler-free paint systems – also for plastic body kit components. And for good reason: no intermediate drying step reduces energy consumption by 15 to 20%. At the same time, material consumption and solvent emissions are reduced. In addition, the paint system takes up less space in the production hall. With a single coat of paint, the pieces exhibit excellent resistance to UV, scratching and chemicals, as well as sunscreen and mosquito repellent. Two-component paint is currently the only paint system in the world that meets the specifications of car manufacturers for painting interior elements. Ultraviolet-curing UV varnishes combine ecological and economic advantages, such as shorter processing times and smaller paint systems, as well as reduced emissions and energy consumption. In addition to these benefits, there are also qualitative aspects of painted surfaces, such as higher gloss, durability and scratch resistance. A solvent-free, 100% UV-curing clearcoat that meets the factory standards of various manufacturers has recently become available for painting interior plastic parts made of ABS. Appropriate tests have shown that this 100% mono-shrink system achieves significantly better scratch resistance than current water-based, solvent-based and dual-cure systems. Curing takes place in an atmosphere with reduced oxygen content – the so-called curing in inert gas – at room temperature in just a few seconds. The atmosphere with reduced oxygen content prevents the reaction of radicals necessary for polymerization with air oxygen, and thus the formation of the so-called oxygen inhibition. This allows the curing time to be extended, and places less exposed to UV rays are cured in a uniform manner. Car parts for the Japanese are painted by specialists.