Additive color systems

Additive color system A color system based on transmission where RGB colors are combined to 5deld a color, such as on a computer monitor. 

RGB Red-green-blue additive color system used in computer monitors and other projection systems... 

Both subtractive and additive color reproduction are utilized in instant color films. Subtractive systems include all of the instant print and large format transparency materials except Polachrome 35-mm sHde films, which are additive. 

Polaroid introduced Polavision, a Super-8-mm instant motion picture system, in 1977 (97). Polachrome CS 35-mm sHde film followed in 1982 (98), and a high contrast version, Polachrome HCP, appeared in 1987. Each of the films comprises a very fine additive color screen and an integral silver image transfer film. The Polavision system, which included a movie camera and a player that processed the exposed film and projected the movie, is no longer on the market. The Polavision film was provided in a sealed cassette, and the film was exposed, processed, viewed, and rewound for further viewing without leaving the cassette (97). 

ADDITIVE COLOR PROCESS. An early system of color imagery in which the color synthesis is obtained by the addition of colors one to another in the form of light rather than as colorants. This color addition may take place (1) by the simultaneous projection of two or more (usually three) color images onto a screen, (2) by the projection of the color images in rapid succession onto a screen or (3) by viewing minutely divided juxtaposed coloi images. 

For siloxene (see p. 99) the color and the fluorescence of the derivatives are shifted toward longer wavelengths when the Si ring is subjected to the action of electrons from substituents carrying free electron pairs. This led to the postulation of an additional bond system within the Si6 ring as the chromo-phoric part of the molecule. 

Using many-flux technology, computer color-matching systems can automatically formulate with or without white, at all levels of opacity, from a single database. In addition, satellite systems can offer added value by providing the same high-quality formulation results as a full system, with a low cost and feature limited satellite system. 

Binder The polymer, wax, or liquid used to bind or hold colorants and additives together to form the colorant system. 

Colorant System A mixture of colorants, additives, and/or polymers that when added to polymers deliver and disperse the colorants and additives into the finished molded part. 

Color Concentrate A colorant system where colorants and additives are compounded into a binder material. These can be in the form of pellets, coarse powders, granules, liquids, or pastes. 

The resin manufacturer and the specific resin product code should be established. Processors are very knowledgeable in molding and extrusion techniques but are not well versed in colorant use and resin compatibility. That is the job of the colorist. It may be helpful to contact the resin manufacturer directly for additional information regarding colorant and additive compatibility, especially when designing colorant systems for some of the more exotic engineering resins and alloys. The resin manufacturers may have done research or had experience that may help in selecting the colorant or avoiding certain problematic colorants or additives. 

Knowing the end application for a plastic part when designing a colorant system is important. The end application plays an important role in colorant and additive selection. Some examples follow ... 

Thus, it is necessary to determine the end application for the colorant system and select colorants and additives that will meet those requirements. 

For some applications, the processor may want certain additives included in the colorant system to aid in the performance of the polymer or improve the durability of the colorant system during the expected service life of the plastic part. These... 

The color formulator must learn as much as possible about the processing conditions the colorant system will encounter. Important conditions to determine are cycle times and process temperatures. Hot runner systems commonly used in today s injection molding processes may add temperature to the polymer melt and add to the time the polymer is under heat. Remember that the heat stability of any colorant and additive system is a function of both time and temperature. An excellent color match may be produced, but if the formulation cannot withstand the stress of processing without breaking down or changing shade, then effort and time have been wasted. 

Colorant systems are available in several forms, and it is a good idea at this juncture to establish with the customer the method they prefer to use to introduce color into their molded or extruded part. Colorant system form may have an influence on colorant selection and will influence additives and binder selection. Colorant systems are available in the following forms ... 

Liquid color is not a universal coloring system, but nothing is. It can perform in a variety of processes, in nearly all resins. Liquid is at its best in small percentages, where its distribution in the resin is excellent it does modify physical properties somewhat but enhances some properties. It is excellent for heat-sensitive additives, such as blowing agents. Look into using liquid color as a coloring system the economics may work out favorably. 

Special effect pigments are used as colorants or part of color formulations for all systems where traditional pigments are applied, but where additional color depth, brilliance, iridescence, color travel, and other spectacular effects are required [5.122, 5.123]. Mica-based pigments dominate their combination of pearl and interference effects, brilliance, stability and behavior in different application systems is as yet unsurpassed. Pearl luster pigments require transparent or at least translucent binders. Formulations with absorption pigments have to take their transparency and color mixing rules into account... 

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