Polyamide nylon fabrics
Nylon, a synthetic fiber also sometimes labeled as polyamide, can be dyed with either of two completely different dye classes, acid dyes and disperse dyes. Both of these types of dye require the application of heat to fix the dye to the nylon, so be sure the item you are dyeing can withstand the heat called for in the recipe you choose. (This is a problem for nylon/Lycra blends, as the spandex fiber is heat-sensitive, made from polyurethane fiber. Use acid dyes on these blends, and carefully avoid stressing the fabric while it is hot, such as by twisting or stretching; temperatures above that indicated on the garment's care label (usually 105°F) may deform the shape of the garment.)
Some surface fabric treatments may prevent nylon from 'taking' dye. Dye only fabrics that are free of treatments that provide stain resistance or water repellence, such as Teflon coating.
Nylon is not only used as a textile fiber. It is also used to make solid objects such as frisbee discs and lacrosse stick heads. Solid nylon can be dyed with the same types of dye as nylon fabric.
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Jacquard Acid Yarn Dye Starter Set
All-Purpose Dye for nylon
Nylon is a synthetic fiber, but its unique chemistry means that it can be dyed, easily and well, using the same acid dyes that are commonly used on wool and other animal fibers. A typical recipe calls for dissolving dye and salt in enough water to cover the material and allow it to move freely in the pot, adding the material, heat it to a simmer for ten minutes, add vinegar and simmer another ten minutes, then allow to cool gradually and rinse out. Microwaving or steaming might be used as an alternative form of heat application, if the dye is painted onto vinegar-water-soaked material, as in the case of tie-dyeing nylon.See Dyes for Protein Fibers, under the About Dyes section of this web site, for the rest of the story.
Do not expect a color mixed from two or more dyes to produce the same hue on nylon that it does on silk or wool. If you call your dye suppliers, they should be able to recommend specific acid dyes that they sell that work particularly well on nylon, and tell you whether they discharge well or poorly. In general, any acid dye should work reasonably well on nylon, given acid and heat.
how to tie-dye nylon
A recipe for tie-dyeing with one type of acid dye is given on the page Tie Dye with Kool-Aid. This recipe may be adapted for use with other acid dyes. See also PRO Chemical & Dye's instructions for direct application of acid dyes on wool and silk, which should work quite well with nylon, and their instructions for immersion dyeing nylon.
fiber reactive dyes
Most fiber reactive dyes, such as those commonly used to dye cotton and rayon, cannot react with nylon. However, fiber reactive dyes can, as a rule, be treated exactly like acid dyes, with the addition of small amounts of acid (such as vinegar) and with the necessary application of heat. When used with an acid dye recipe, a fiber reactive dye actually acts as an acid dye. In my experience with Procion MX dyes, nylon typically dyes to a paler shade than silk dyed under the same circumstances, but sometimes more intense than that achieved by wool. See Fiber reactive dyes on protein fibers. Although wool will dye with Procion MX dyes at basic (high) pHs, nylon will not; nylon will either take a pale and temporary stain, or remain completely white, when dyed with Procion MX dyes and soda ash.
all purpose dyes
Most all purpose dyes, such as Rit dye and Dylon's Multipurpose dye, contains two kinds of dye, mixed together - 'direct' dye which does a fair job of dyeing cotton, and 'leveling acid' dye which will dye both wool and nylon. It is best to use pure acid dyes on nylon, instead, as you can see more clearly what color you will end up with, and you avoid wasting money on the direct dye portion that cannot stick to nylon, and you can choose to use acid dyes about which more detailed information is available. However, if you are in a hurry and do not wish to wait for mail-order, all purpose dye is readily available in many grocery stores and pharmacies.
Many natural dyes are acid dyes, which work well on nylon if heated in a dyebath with an acid, such as vinegar or citric acid. Cochineal dyes nylon a good intense red with a slightly brownish tone, whether mordanted with alum or not. Turmeric, a natural direct dye which tends to fade in the light, dyes nylon a nice medium golden yellow, with or without alum pre-mordanting.
However, indigo is said to perform poorly on all synthetic fibers, including nylon, because the fibers lack the internal spaces found in natural fibers, into which the soluble form of the dye may penetrate and then become trapped upon oxidation.
The dye in nylon must not be discharged with hypochlorite (ordinary household chlorine bleach), because the fiber itself, like wool or silk, will be severely damaged. A good choice for discharging nylon is the chemical sodium formaldehyde sulfoxylate; see ProChem's instructions for dicharging with Formusol.
Dyeing nylon like polyester
Nylon can also be dyed with the same disperse dye that is used for polyester. Surely no one uses disperse dye for immersion dyeing when they could use acid dye, instead - PRO Chemical says that acid dyes are more washfast on nylon than disperse dyes are, and they are also more plentiful and versatile - but alternative forms of dyeing with disperse dye, including ironing-on pictures prepared on paper with special disperse dye rubber stamp pad ink, paints, and crayons are a lot of fun and well worth trying, even with young children.
What is Nylon, anyway?
Nylon is a polymer, which is to say a long molecule composed of many identical units, chemically known as polyamide. The form described as Nylon 6, 6 is stretch nylon (brand names include Ban-Lon and BriNylon). Nylon 6 is a polycaprolactam (brand names include Akulon, Amilen, Carpolan, Enkalon, Grillon, and Perlon). Nylon 11 is yet another form of nylon (one brand name is Rislan). Synthesizing nylon was one of the more fun labs in my college organic chemistry classes.