Small quantities, many colors
The EcoSupply P paint supply system provides a range of colors quickly, economically, and residue-free.
Black, silver, white, and gray remain the top colors in automotive painting and will be the favorites for the foreseeable future. However, more and more customers want to customize their car with a unique color. To meet the demands, car manufacturers face the challenge of keeping an increasing number of colors on hand. Specialized paint supply systems emerge as a more economical and sustainable alternative to conventional circulation pipes, significantly reducing paint loss, waste volume, and flushing agent consumption.
Offering a vehicle in just one color, as with the legendary Ford Model T only in black, is unthinkable today. The global demand for cars in a variety of colors is increasing. One of the driving forces of this trend is the ever-shorter model cycles in which a model change always has a new color palette. In the truck sector, it has long been the norm that almost every vehicle is the specific corporate color of its future owner, resulting in up to 1,000 different colors in commercial vehicle paint shops. Specialized paint supply systems not only cater to this color diversity but also offer enormous savings potential. These systems support a significantly more sustainable and cost-effective application of a growing variety of color hues than conventional circulation pipes, especially in the passenger car sector.
Analyses conducted at various car manufacturers have shown that more than 90 percent of the total production volume comprises up to ten colors, meaning that the remaining colors – many used only once a day or even less frequently – make up a negligible percentage of the total production volume.
Traditionally, most paint shops have employed several conventional circulation pipes to apply numerous small batch colors with low production rates, which makes neither economic nor ecological sense.
Why are circulation pipes not suitable for small batch colors?
Liquid paints must circulate constantly to prevent color pigments from settling. Mechanical forces cause shearing during circulation, negatively effecting the properties of complex paints. Paints that are not used often and rarely refilled with fresh material quickly reach critical levels, negatively impacting paint quality. Fresh paint would have to be added regularly to ensure the quality of these irregularly used paints. However, since only a small quantity of paint is used at one time, appropriate quantities must be disposed of to maintain the paint quality.
Special paint supply systems, such as Dürr's EcoSupply P, store the necessary paint colors in air-conditioned paint mix rooms. These colors are then provided to the painting robot right before a car body enters the paint booth. Since shearing does not negatively impact paint quality, it minimizes paint loss and hazardous waste. Therefore, circulation pipes are best suited for the most popular colors, such as white, black, silver, and gray, as well as for the few colors with a production rate higher than five percent. A maximum of ten circulation pipes are required for this. For all other colors, a special paint supply system is not only less expensive to operate, but also more sustainable.
The EcoSupply P special paint supply system offers remarkable flexibility and can provide an unlimited number of colors for application in succession. Pigs, the components perfectly tailored to the inner diameter of the hoses, push the paint to the color changer and, after painting, push the remaining paint back into the paint tank. Since the hose stays residue-free, cleaning is unnecessary, reducing both paint and flushing agent consumption – beneficial for both a company's budget and the environment.
Given the sharp increase in paint prices, particularly for special paints, piggable systems for special paint supply quickly prove cost-effective thanks to the almost total recovery of unused paint. The EcoSupply P paint supply system, used worldwide around 600 times already, boasts an average payback time of 18 months.
Efficiency reigns supreme in special paint supply systems, especially for rapid color changes. While it takes days to change to a new color with a circulation pipe, special paint supply systems need only about 20 minutes, depending on the length of the robot line and the number of robots installed. The DXQ3D.onsite software automatically calculates paint volume, contributing to fast color changes and optimized loading. Yet another Dürr innovation speeds up the process even further. An additional injection valve, which injects a small amount of solvent into the line before paint recovery, now allows the pigs to return at a speed of up to 3 m/s, instead of 1 m/s as before. This shortens the color change process to only approx. 15 minutes.
Due to their modularity, these systems are flexible and suitable not only for new plants, but also for existing plants. For instance, for modifying an existing line to accommodate a model change, it makes sense to replace the circulation pipes- previously used for colors with low production rates with a special paint supply system. These systems offer benefits such as minimal paint loss, low flushing agent consumption, extremely short color change times, and less environmental impact due to less waste.
In the future, special paint supply systems won’t be exclusive to the automotive industry; a solution for general industry is on the horizon. EcoSupply P Core will debut at PaintExpo 2024.