Shade matching

High energy dyes are requited in the Thermosol appHcation and in those instances in which the dyed fabric is subjected to a heat-setting treatment. Each energy type has a characteristic rate of exhaust and, as a consequence, only disperse dyes of the same energy class are used in mixes for shade matching purposes. 

P.R.146 is a suitable candidate for a variety of special applications. The list includes wood stains, in which it is frequently blended with yellow pigments, especially with P.Y.83, and also with black to afford shades of brown. The products are fast to overcoating and stable to nitro and acid catalyzed and polyester varnishes. Intense shades match step 5 on the Blue Scale for lightfastness. Other areas of application include office articles and artists colors, cleaning agents, paper mass coloration, laundry markers, etc. In connection with cosmetics, the pigment frequently lends color to soaps. 

Dyeing with premixed disperse and vat dyes is especially easy. The mixed dyes can be applied in a single bath by the exhaustion or continuous process. The dyes are formulated in such a way that the same shade is obtained on both fibers, which facilitates shade matching [85, pp. 62-63, 221-246], They are normally intended for 80 20 to 50 50 PES-CEL blends. 

Prediction of the excess dye necessary to reach the upper exhaust level required development of a computer program. In the initial studies, however, a best estimate" was made as to the proper excess. Good lot-to-lot shade matching was obtained, as shown in the low color differences exhibited in Table XXVII. Color differences with a conventionally-dyed sample were high, however, due to the inaccuracy of the best estimate" method in determining the dye excess. 

In the next series of experiments, a procedure incorporating three low-temperature reactive dyes was attempted on 100% cotton. The procedure was modeled after a participating company s formulation. The flow system detailed in Figure 1 was utilized, and the methods developed for the one-dye system were used to attempt shade match with the company standard. Additional problems that arose with the three-dye system were as follows ... 

To help determine which basic dyes can be combined for shade matching, key dyebath parameters have been developed.16 The first parameter pertains to the dyes themselves and is known as the combinability constant (k). This value provides a measure of how fast a basic dye will dye the fiber, and the dyes are rated on a scale of 1 (fast) to 5 (slow). The second parameter pertains to the fiber type involved and is known as the fiber saturation value (SF). This value provides an indication... 

Essential requirements for maxillofacial materials are biocompatibility, the capability of shade matching to the surrounding soft tissues, and adequate mechanical properties to provide acceptable clinical longevity. It is desirable that the viscoelastic response and creep compliance of these materials mimic the in vivo force response of these soft tissues under ftmctional loading without undergoing excessive dimensional changes over time. 

Shade matching Check visually the color of the yam against the standard in a color matching cabinet under D-65 and TL-84 light. 

A different approach was taken by Ciba-Geigy (Hermann 1996). Left-over printing pastes were collected and combined, and their color coordinates spectro-photometrically measured. Computer software was developed that defines a specifically segmented color space in which all color can be defined and desired shades matched from one, two or three dyes in the fresh and recycled paste. The reclaimed paste could be incorporated without problems. 

To achieve a stable dyeing, it is important to quantify the homogeneity of the dye and to use these data to predict the performance of the dye in the dyeing. Spectral morphing is an indication that components of a dye are exhausting at different rates, which can lead to levelness and shade matching issues. 

Color Mixing. The various types of dye powders used to make dye stains are blended to achieve the desired color. Most finishers purchase wood stains premixed to specified colors. In the wood-finishing industry, various shades of brown are the most common. These colors are usually blended from primary colors. Color-matching skills can be acquired only by practice, but the basic theory of color matching is relatively simple and easily understood. The basic theory of color matching can be demonstrated by using the color circle shown in Figure 1 (see Color). 

Practical methods for synthesis and elucidation of the optimum physical forms were developed at Du Pont (13). The violets fill the void in the color gamut when the inorganics are inadequate. The quinacridones may be used in most resins except polymers such as nylon-6,6, polystyrene, and ABS. They are stable up to 275°C and show excellent weatherabiUty. One use is to shade phthalocyanines to match Indanthrone Blue. In carpeting, the quinacridones are recommended for polypropylene, acrylonitrile, polyester, and nylon-6 filaments. Predispersions in plastici2ers ate used in thermoset polyesters, urethanes, and epoxy resins (14). 

Schwefel-einschlag, m. sulfur match (for casks) sulfuring (of casks), eisen, n. iron sulfide (usiially ferrous sulfide, Iron(II) sulfide), -entfernung,/. removal of sulfur, desulfurization. -erz, n. sulfur ore. -faden, m. sulfured wick, sulfur match, -farbe, /. sulfur color sulfur dye (of wool) stoved shade. 

Colour and opacity have been foimd to be connected for glass-ionomer cements (Crisp et al., 1979 Asmussen, 1983), with darker shades giving increased opacity. However, this is merely a consequence of the underlying physical relationships, and is not thought to be a clinical problem (Wilson McLean, 1988), mainly because the stained tooth material for which the darker shades are necessary for colour match is itself of reduced translucency. 

Fig. 11.6. Predicted amino acid sequence homologies of human CNT1, CNT2, and CNT3. Shaded box indicates a similar amino acid match and a black box indicates an identical amino acid match between the CNT transporters. The alignments were done with Clustal W and shaded with Boxshade.

We often hear this question, either at the clothes shop or at a paint merchant. Either someone wants to know if the pink colour of a sweatshirt matches the mauve of a skirt, or perhaps a decorator needs to know if two shades of green will match when painted on opposing bedroom walls. 

It is also possible to find the amount of pigment which is necessary to produce a match of a reference sample containing a known amount of pigment. The relative tinctorial strength is then defined as the ratio between the two amounts. In this case, two samples are already considered to match if they exhibit the same depth of shade an exact match is not always found. 

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