Around us almost all plastic articles are colored. The accurate reproduction of a measured color from a leather or painted standard to plastic, for example with the purpose to make a harmonious car interior, is known to be difficult. This issue becomes much more difficult still if the articles contain a texture. In fact many articles such as car interiors, computer monitors, phones, shavers etc. are made with a surface texture. The texture does not affect the measured color much but it can have an enormous effect on the appearance -as we see it. An extra difficulty is also that different polymers vary strongly and in an unpredictable manner in their ability to copy the textured surface of a mold. This implies that the appearance of a textured molded part is unpredictable and needs to be optimized by expensive trial and error processes or by using very experienced personnel. To address these issues we have developed a patented technology named Appearance Engineering. This technology is based on thorough scientific principles and consists of several tools and software building blocks to enable the prediction of the appearance of textured parts. Tools exist to characterize textures as well as colorants and polymers. These data can be combined with color mold fill studies and color models to predict what a real part will look like. The result can be expressed in numeric values such as color differences but can also be shown on screen. Sophisticated rendering software can take a CAD file, combine it with lighting conditions, polymer properties, texture characteristics and molding conditions to calculate a near-realistic image and show it on a calibrated screen. The technology can be used in different ways: it allows to prevent or resolve appearance issues, optimize the work flow to get the right appearance, or allow the combination of different polymers which otherwise would show appearance differences. This paper intends to present a broad overview of this technology, while going into all details is impossible within the limitations of this article.
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