How to Dye Wool : Best Dyes and Practices for Dyeing Wool Yarns and Fabrics

Before going directly to the core of the topic, I will talk about some basics of wool in brief.

One of the oldest fiber known by the human being is wool. We find wool mostly from sheep but also from alpacas, goats, and camels. Major producers of wool are Australia, Eastern Europe, New Zealand, and China.

Yarn Dyed Wool

The surface of wool is mainly a series of overlapping scales of protein. The outer surface of wool repels water, so wool remains warm even in damp weather. On the other hand, the inner layer absorbs water, and interestingly it can absorb so much that wool remains reasonably dry even if it absorbs almost double its weight. Wool is also naturally flame retardant due to its inner moisture.

Also, wool is the only natural fiber that exhibits heat of wetting, i.e., generates heat when wetted.

Learning how to dye wool will also enable you to dye other protein fibers as well since the process is pretty much the same.

Wool can be dyed in the same manner as the other animal fibers, for example, Mohair, camel’s hair, angora, and cashmere are dyed. It is because each of the animal fibers is composed of protein.

Twenty primary amino acids combine together differently to form the proteins. Cellulose made from repeating units of sugar; glucose is simpler than wool chemically. Different dyes and chemicals can create bonds with cellulose in more ways when compared to wool. However, there are many ways and many substances that are used to dye protein fibers.

The dyeing of wool requires heat. It can be done by,

Due to these reasons, a dyepot is a must for wool dyeing. So, let’s talk about it in detail.

Compared to other dyeing techniques, you’ll have to be more cautious while selecting dyepots for wool dyeing. The following two factors should be given the utmost importance.

We experimented with a few available dyes that are made for dyeing protein fibers like wool. The following dyes performed the best in terms of or vibrancy, fastness, range of shades.

To get your desired shade, you can follow our dye colour mixing guide. Just remember to check the self-shades first and adjust accordingly. However, we must warn you, it’s almost impossible to get 100% accurate hue and depth on the first try.

There are no interchangeable dyes that can be used on wool dyeing. Many need a weak acid such as citric acid, vinegar, (NH₄)₂SO₄ , or CH3COONa, but not usually in the same quantity, and some need different other chemicals such as salt, Albegal SET, or Na₂SO₄.

Some colorants need a slightly lower (more acidic) pH than others; using a pH that is too low or too high for your particular coloring will limit your dyeing efficiency. Upon choosing your dye, consider a recipe for wool-dyeing that specifies the specific kind of dye.

Now, let’s talk about a method of level dyeing of wool or wool portion of a fiber blend.

1. This exhaust dyeing procedure needs a strongly acidic medium, an aqueous bath of reactive dye that has a reactive group that reacts with the wool fiber under fixed conditions by nucleophilic addition reaction (Vinyl sulfonyl form).
2. The temperature required for dyeing ranges from 95-106 degrees Celsius. One-step rapid dyeing is necessary. Acid or acid donating agents are no required for dye fixation.
3. At dyeing temperature when the exact isothermal state for fixation of the dye is reached, incremental application of sulphuric acid for 10-45 minutes to the heated dyebath is necessary to maintain pH values between 2-3.

A lot of hand dyeing yarn processes exist for wool dyeing. Mainly wool is dyed in package or hank form.

One common wool yarn dyeing procedure in hank form is given below. The name of the process is Short-Skein (Hank) dyeing.

• Loosely packed yarns in skeins or coils are placed over a rung and immersed in a dyebath which contains a large jar. The main advantages of this method are the best dye penetration and softer yarn. Bulky acrylic and wool yarns are mainly dyed in this method.

Dyed Wool Yarn and the Final Fabric

It seems that all dyes and pigments are colored because they usually absorb certain wavelengths of light. Unlike a dye, the pigment is usually insoluble and does not have any affinity to the substrate. Many dyes may be precipitated with an inert salt to create a pigment from the water.

Different animal fibers can be dyed in this same manner using similar dyes. Fur from various mammals, alpaca, Mohair, cashmere, and angora are included in this category. Others won’t take the color as deeply as some will.

1. Superwash wool can be dyed easily. The fibers soak up dye more significantly than natural wool since each fiber ‘s external layer is weakened by the chlorination, so that dye molecules can easily enter the wool fiber interior. The residual scales are trapped with a coating (resin) down into the fiber to avoid felting and shrinking.
2. Smartwool is prepared by the same process, with the chlorination step being substituted by another chemical. Still, it is not known if it can be dyed easily like the superwash wool.
3. Angora has the angora rabbit’s fur. With a given quantity of dye, it appears to produce paler colors than wool does.

The similar process and same dyes can be used to dye the Angora goat’s fur, Mohair. Excellently it takes dyes. During dyeing, you should not boil it but maintain a slightly lower temperature for almost an hour so that the dye molecules can easily penetrate the fiber. Generally, a temperature of not more than 82 degrees Celcius is suggested.

We all know about shrinkage. Smartwool and superwash wool, for example, do not have shrinkage because they are chemically treated. Yet the wool fibers do not shorten in length themselves. Instead, the fibers become more and more tightly interlocked when exposed to heating and tension in water, with the scales that are available on the molecules of the fiber behaving like the ratchet teeth.

If preventing shrinkage and felting is necessary, you have to be careful not to agitate your wool when the wool is in the warm liquor. Stirring your dyebath frequently with cellulose fibers is required for avoiding uneven dyeing, but the dyestuffs and chemicals help wool to dye evenly without stirring,

Be wary of sudden shifts in temperature. Just slowly raise and lower the temperature of your wool. You just don’t want your wool to shake.

Using  Lanaset dyes, which are washfast, when dyeing wool that can be used later for deliberate felting. Less washfast colors, when felt, can bleed.

We didn’t have any intension to make this article any longer than it had to be. Also, we tried to cover all the aspects of how to dye wool.

If you’re interested to learn the dyeing process of nylon, then you can check out previous post as well.