Computer Color Matching System (CCMS)?Flow Chart of CCM?

Computer Color Matching System (CCMS): 

It is the one of the modern technologies for the realization of color measure and recipe prediction by the use of computer and spectrophotometer. CCMS can find out the most accurate recipe which has a good quality and cheap price from database. This method overcomes the deficiency of experimental color matching. Sometimes it is more convenient, accurate and time saving.

Functions of Computer Color Matching System:

The following works can be done by using CCMS -
1. Color match prediction.
2. Color difference calculation.
3. Determine metamerism.
4. Pass/Fail option.
5. Color –fastness rating.
6. Cost Comparison.
7. Strength evaluation of dyes.
8. Whiteness indices.
9. Reflectance curve and K/S curve.
10. Production of Shade library etc.


The Mathematics of Computer Color Matching


For a computer formulation program to work effectively there must be a mathematical relationship between the concentrations of each dye used to produce a sample and the sample‘s color.

The mathematical basis for all color matching software is the Kubelka-Munk series of equations. These equations state that for opaque samples such as textile materials, the ratio of total light absorbed and scattered by a mixture of dyes is equal to the sum of the ratios of light absorbed and scattered by the dyes measured separately.

Where absorption is defined as ―K‖ and scattering is defined as ―S‖, Kubelka-Munk states that :

(K/S) mixture = (K/S) dye 1 + (K/S) dye 2 + (K/S) dye 3 + ...

K/S is not a readily measurable quantity, but it can be calculated from the reflectance of a sample -- ―R‖ -- by the Kubelka-Munk equation that states :

 K/S = ( 1 - R ) ² / 2R

As an example, if a sample has a reflectance of 20% at a wavelength of 500nm, then the K/S can be calculated as:

 K/S = ( 1 - 0.2) ² / 2(0.2) = 1.6

 If the K/S of a target color is measured at several wavelengths, the concentrations of each dye can be calculated by trial and error from primary dyeings to achieve the closest match. A computer color-matching program is capable of performing hundreds of iterations in a short period of time to produce the initial dye concentrations.

Flow chart of CCM system (Modern dye laboratory procedures)

Computer Color Matching System (CCMS): It is the one of the modern technologies for the realization of color measure and recipe prediction by the use of computer and spectrophotometer. CCMS can find out the most accurate recipe which has a good quality and cheap price from database. This method overcomes the deficiency of experimental color matching. Sometimes it is more convenient, accurate and time saving. Functions of Computer Color Matching System: The following works can be done by using CCMS - 1. Color match prediction. 2. Color difference calculation. 3. Determine metamerism. 4. Pass/Fail option. 5. Color –fastness rating. 6. Cost Comparison. 7. Strength evaluation of dyes. 8. Whiteness indices. 9. Reflectance curve and K/S curve. 10. Production of Shade library etc. The Mathematics of Computer Color Matching For a computer formulation program to work effectively there must be a mathematical relationship between the concentrations of each dye used to produce a sample and the sample‘s color. The mathematical basis for all color matching software is the Kubelka-Munk series of equations. These equations state that for opaque samples such as textile materials, the ratio of total light absorbed and scattered by a mixture of dyes is equal to the sum of the ratios of light absorbed and scattered by the dyes measured separately. Where absorption is defined as ―K‖ and scattering is defined as ―S‖, Kubelka-Munk states that : (K/S) mixture = (K/S) dye 1 + (K/S) dye 2 + (K/S) dye 3 + ... K/S is not a readily measurable quantity, but it can be calculated from the reflectance of a sample -- ―R‖ -- by the Kubelka-Munk equation that states : K/S = ( 1 - R ) ² / 2R As an example, if a sample has a reflectance of 20% at a wavelength of 500nm, then the K/S can be calculated as: K/S = ( 1 - 0.2) ² / 2(0.2) = 1.6 If the K/S of a target color is measured at several wavelengths, the concentrations of each dye can be calculated by trial and error from primary dyeings to achieve the closest match. A computer color-matching program is capable of performing hundreds of iterations in a short period of time to produce the initial dye concentrations. Flow chart of CCM system (Modern dye laboratory procedures)



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