Dyeing Carpet
by the Mill or Fiber Producer

from Bane-Clene^®

Dyeing is the process of coloring materials. Carpet is dyed at one of two stages in the manufacturing process:

PRE-DYED: Dyestuffs are added to the fibers or yarn PRIOR TO the tufting process.
POST-DYED: The yarn was undyed when tufted and then the unfinished carpet is dyed.

There are four primary PRE-DYED methods:

Solution dyeing: Dyestuffs are added to the fibers or yarn PRIOR TO the tufting process.
In solution dyeing, pigment is added to the molten polymer before extrusion into a colored filament. Thus, the filament is impregnated with the color pigment throughout. The only way to dye olefin is by solution dyeing. Commercial nylon is also quite often solution-dyed. However, unless appropriate acid dye blockers are applied after carpet manufacturing, solution-dyed nylon can continue to accept acid dyes from food spills, coffee, colas, etc.
Stock dyeing: The yarn was undyed when tufted and then the unfinished carpet is dyed.
Skein dyeing: (pronounced “skane”). Dyeing yarn in skein form is used for small lots. Yarn is unwound from cokes to skeins and then are mounted and immersed into a large hot dye vat. After dyeing and drying the yarn is rewound onto cones.
Space dyeing: Several colors are printed along the yarn length to produce a tweed effect when tufted.

Most residential carpets are POST-DYED:

Beck or piece dyeing: is primarily for solid colors in limited runs. In this method, the carpet is dyed "in a piece" after tufting but before other finishing processes such as attaching the secondary backing. Large rolls in rope form of uncolored carpet (greige goods) are placed in a large vat of dye solution (dye beck), heated to high temperatures, agitated continually while it is soaking up the dye, making the color come out very even from end to end and side to side. It is then removed, washed, and dried. This is most commonly used for cut pile carpet. Beck dyeing a roll of carpet usually takes between three to six hours, depending on the color and the amount of carpet to be dyed.
NOTE: Greige goods (pronounced "gray goods") is a term designating carpet just off the tufting machine and in an undyed or unfinished state.

In continuous dyeing, the carpet (greige goods) is rinsed, and then passed under a dye applicator, which spreads or sprays dyes evenly across the entire width of the carpet. The carpet then enters a steam chamber, where the dyes are "set" into the fibers. This method is for longer runs of both solid and multi-color applications.

Print dyeing is the process of producing a pattern with dyestuffs on carpets and rugs, done with screen-printing, roller equipment, or ink jet printers. This is easily checked for in the field by bending over the fiber tuft – if the tuft is only dyed part of the way down, it is print dyed. After print dyeing, the carpet is steamed and dried. Do not use high-pH aggressive detergents on print dyed carpet. This type of dyeing allows tone on tone and multi-color effects. Included in this method are flat bed printing, rotary printing, silkscreen printing, and computerized jet spray printing.

Differential Dyeing: Tufted carpet with yarn treated chemically so that when placed in a dye bath each yarn type will react differently to the dye, resulting in different shades of the same color.