Color carpet dyeings

There were two classes of technical challenges faced in this work. The first challenge was how to prevent variability in carpet color (shade and darkness), carpet coloring method (dyes vs. pigments), and yam and carpet construction (e.g. cut vs. loop pile) from... 

Modified PES fibers are usually more sensitive to hydrolysis than normal fibers. The lightfastness of the dyeings is often lower than on normal fibers. Thus, dyes for coloring carpeting, upholstery, and drapery must be carefully selected. On modified PES fibers dyes start exhausting at low temperatures (ca. 60°C) and the dyebath is exhausted after a short time, so problems with levelness may arise. 

In addition to instrumental color measurements, the dyed carpets have been examined visually by four experienced carpet dyehouse supervisors. All four agreed that both the nylon and polyester carpet dyeings were acceptable as first-quality in both color uniformity and color reproducibility. 

Table III. Color Uniformity in Polyester Carpet Dyeings with Dyebath Reuse...

Nickel also has been used as a dye site in polyolefin polymers, particularly fibers. When a nickel compound, eg, the stearate or bis(p-alkylphenol) monosulfide, is incorporated in the polyolefin melt which is subsequently extmded and processed as a fiber, it complexes with certain dyes upon solution treatment to yield bright fast-colored fibers which are useful in carpeting and other appHcations (189). Nickel stearate complexing of disperse mordant dyes has been studied (190). 

Bicomponent technology has been used to introduce functional and novelty effects other than stretch to nylon fibers. For instance, antistatic yams are made by spinning a conductive carbon-black polymer dispersion as a core with a sheath of nylon (188) and as a side-by-side configuration (189). At 0.1—1.0% implants, these conductive filaments give durable static resistance to nylon carpets without interfering with dye coloration. Conductive materials such as carbon black or metals as a sheath around a core of nylon interfere with color, especially light shades. 

Some 50% of all nylon is in the form of carpets almost exlusively colored with acid dyes, and around 50% of the carpet manufacturing industry is located in the United States. The acid dyes from Group 1 are those most widely used because they exhibit the rapid diffusion needed to penetrate the bulky yams used in carpets, especially bulk continuous filament yam used in tufted constmctions, with high exhaustion. Their wetfastness properties are generally adequate for most oudets. 

The most popular coloration method is to apply the dyes continuously, usually by padding, but printing, spray jet, and droplet appHcations are used. In order to obtain patterned effects, chemical or physical resisting agents can be appHed first, and deep and normal dyeing nylon and basic dyeable nylon blends can be used. In the latter case the basic dyeable nylon is dyed with cationic dyes. Carpets can be printed in an analogous method to other textiles and this process is more popular in Europe than the continuous appHcation techniques used in the United States. 

In Chapters 3-6, the commercially important chemical classes of dyes and pigments are discussed in terms of their essential structural features and the principles of their synthesis. The reader will encounter further examples of these individual chemical classes of colorants throughout Chapters 7 10 which, as a complement to the content of the earlier chapters, deal with the chemistry of their application. Chapters 7, 8 and 10 are concerned essentially with the application of dyes, whereas Chapter 9 is devoted to pigments. The distinction between these two types of colorants has been made previously in Chapter 2. Dyes are used in the coloration of a wide range of substrates, including paper, leather and plastics, but by far their most important outlet is on textiles. Textile materials are used in a wide variety of products, including clothing of all types, curtains, upholstery and carpets. This chapter deals with the chemical principles of the main application classes of dyes that may be applied to textile fibres, except for reactive dyes, which are dealt with exclusively in Chapter 8. 

Plant dyes are more likely to fade when overexposed to light, so protect them accordingly. Today, the chemical dyes so widely used to color our clothes, curtains and carpets leave polluting residues. Using plant dyes instead can give beauty without damaging our delicate ecosystems. 

P.R.176 provides very lightfast polyacrylonitrile spin dyeing products. The samples equal step 6-7 on the Blue Scale. Dry and wet crocking may affect the objects to a certain extent. P.R.176 is also used in polypropylene spin dyeing, especially for coarse textiles, such as carpet fibers, split fibers, filaments, bristles, or tape, but also for finer denier yams. A special pigment preparation for this purpose is commercially available. 1/3 SD samples tolerate exposure to up to 300°C for one minute or up to 290°C for 5 minutes. In terms of lightfastness, 0.1% colorations equal step 5-6 on the Blue Scale, while 2% samples match step 7. 

For, e. g., the coloration of carpet fibers, the industry currently uses pigments which are added to the polypropylene before the spinning process (also known as solution dyeing ). The use of pigments strongly limits the end producers in the selection of colors, as only a limited variety of colored base fibers can be kept in stock. Moreover, many pigments have a negative influence on the mechanical behavior of the fibers. 

The rheology of foams coupled with the proper applicators permits the creation of unique random coloring effects not easily achieved by conventional dyeing methods. Carpets are particularly well suited for the production of random coloring effects. 

Dyeing of Nylon Carpet with Disperse Dyes. The objective of the first trial in the pilot-scale experiments was to dye nylon carpet to the same shade five times with reuse of the dyebath [8). The carpet was tufted from Nylon 6 face yarn with a polypropylene primary backing. Both regular nylon and cationic-dyeable yarns were used in the carpet however, the two types of yarns dyed to essentially the same color with disperse dyes. The carpet surface contained both cut pile and loops. 

The dyed nylon batches were evaluated by color measurement and color difference calculations using the described procedure. Ten random samples were cut from each of the five nylon carpet sections (3 x 38 ) dyed in the reuse sequence. Color differences between the samples from the four reuse runs and samples for the initial (conventional) dyeings were calculated. The tristimulus values and 1 were obtained on the Diano... 

Color differences between each of 10 individual measurements along the carpet sample and the average for the sample for each of the pilot-scale dyeings are shown in Table I (8). The data demonstrated quantitatively that there was 1 ittle difference in end-to-end color variation between the sample dyed in the conventional manner (Run I) and samples dyed in recycled dyebaths (Runs II to V). 

Table I. End-to-End Color Differences in MacAdam Units of Nylon Carpet Dyed with Disperse Dyes (8J...

Dyeing of Polyester Carpet with Disperse Dyes. The second trial run was conducted on polyester carpet dyed with disperse dyes. In this series three shades in a color line—a light... 

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