April 10/17, 2017: Volume 31, Issue 22
By Ken Ryan
As most flooring dealers know, there are two ways that fibers are colored, and each method produces different characteristics. One way to color fibers is to dip them in a vat of dye after they are extruded. This method, proponents say, yields bright colors and allows manufacturers to create smaller quantities of dyed fibers. In this method, known as piece dyed or yarn dyed, the dye penetrates just the outer surface of the fiber. (Think of a radish: the interior is white, but the exterior is red.)
The other way to dye fibers is to add the color to the liquid fiber solution before the fibers are extruded. This allows the dye to be mixed into the solution thoroughly, bringing the color all the way through the fiber once it is extruded. In this method, known as solution-dyed, the color goes all the way through the fiber. If piece-dyed is a radish, solution-dyed is a carrot.
Some companies are strictly solution-dyed mills, while others have needs for both methods. “We like the flexibility to do both,” said Todd van der Kruik, vice president of design, Bentley. “Many companies have moved to solution dyed because of the cost, but for companies who want the differentiation and the new looks, we like to keep piece dyed in our line to give designers more options.”
Brad Christensen, vice president, soft surface category, Shaw Floors, can attest. “We produce both solution-dyed and piece-dyed nylon and PET products and fully recognize the advantages of both.”
Seth Arnold, vice president of residential marketing for Mohawk, said dye methods are about creating a color and aesthetic. As such, Mohawk may use solution dyed as an accent yarn along with piece dyed to achieve the color variation its customers want. “We can achieve more color ranges and better performance with piece dyed. We will pay for color blending techniques that attracts customers and helps retailers upsell.”
Executives identified the advantages and disadvantages of solution dyed and piece dyed, and the role technology is playing in this process or coloration.
Advantages
Solution dyed:
With solution dyed the color is part of the yarn, making it resistant to discoloration from bleach and other harsh chemicals. Further, with the increasingly popular multicolor visuals, solution-dyed products allow for more color contrast between the base color and accent colors.
For primary colors like black, yellow, green, red and blue—where precise color matching is not required—solution-dyed yarns are recommended. Solution-dyed yarns are also ideal for use in producing bonded polyester and nylon sewing threads for both indoor and outdoor applications. With this method, experts say, there is little possibility of dye bleeding and UV fading.
Susan Curtis, senior vice president, product development, Phenix, said solution-dyed carpets can be developed that are colorful and complex “through the combining of individual yarns to create unique multis and intricate patterns. Also, solution-dyed yarns are inherently stain resistant and colorfast and deliver high performance.”
Engineered Floors built its story around the purported “superiority” of solution-dyed carpet fiber, first with PureColor, the PET fiber it originally created in 2010, and then later PureColor nylon in 2014. “Solution-dyed fiber has proven to be the future of carpet production, and we believe our PureColor technology will lead the way,” said Mike Sanderson, vice president of product marketing.
Piece dyed:
The primary advantage with piece dyed is the seemingly unlimited range of color options available as well as better service due to the ability to quickly dye already tufted carpet. As Christensen explained: “Piece-dyed carpet also bulks during the dyeing process, resulting in a softer, fuller hand, and the carpet is washed to remove extrusion lubrication, which can leave an oily, soil-attracting residue.”
Bentley uses a piece-dye process called ColorCast, which allows it to manufacture vast amounts of carpet in a continuous process. “If we need a specific color to match a project for a designer, piece dyed allows you to do that,” van der Kruik said. “We can build complex combinations of various dye levels, luster types and textural looks that are unique and not available with solution dyed. It is a huge advantage over solution dyed—you can do some cool things with it.”
Disadvantages
Solution dyed:
The primary disadvantage of solution-dyed fibers, executives say, is the reduced color selection compared to other fibers. “With solution dyed you have to be very committed to that one color,” Arnold said. “With no differentiation it limits the customer’s choice. With piece dyed consumers can be looking at 30-60 colors vs. a solution dyed that offers 16 colors, all very close in tone. It’s like the old Ford [Model T] method: ‘You can have any color you want as long as it is black.’”
Another drawback to solution-dyed fibers is customers may have to wait longer for their carpet. This is because manufacturers don’t always keep large inventories of solution-dyed carpets. From a business perspective, it makes much more sense for the manufacturer to keep a big inventory of greige goods, which can then be dyed into any color the consumer chooses.
Piece dyed:
Piece dyed is more labor intensive and since there are more chemicals and additives used in the process, it is not deemed as environmentally friendly as solution dyed.
Curtis said another drawback is the limitation of working with only one or two colors in a dyebath and only being able to achieve tonal variations of that color. “Managing undyed carpet and dying to order can offset this disadvantage. Piece dyed products due to their dyeability can stain more easily than solution dyed products.”
Piece dyed is also a more costly process, which is a factor in mills opting for the solution-dyed process. However, some executives do not see the cost as necessarily a negative. “Piece dye has some impact on the total cost of goods, but there are ways to set up manufacturing [to minimize the costs],” Arnold said. “In the end it is not a cost decision—it goes back to trying to provide consumers with the color palette that offers the best selling product they desire.”
Technology’s role
Carpet continues to be made using better raw materials and manufacturing technologies, and that evolution includes dye process as well. Greater efficiencies in color blends will allow mills to create additional depth in style and color, according to Rodney Mauter, executive vice president of marketing for Lexmark. “The extrusion process continues to improve with advancements in spinnerets and raw materials.”
Shaw’s CleanStart scouring process is an example of technological advancements that have significantly improved the performance of solution-dyed products. Even though its newer extrusion equipment uses less lubrication, CleanStart ensures the proper removal of the spin finish that is responsible for leftover extrusion residue.
Engineered Floors’ PureColor Nylon relies on cationic technology to effectively reduce the number of microscopic dye sites that occur during fiber extrusion. By reducing the number of sites, stain resistance of the fiber can be greatly improved.