Understanding Solution Dyeing

Weaving loom with colorful strands of dyed fiber
Monty Rakusen/Cultura/Getty Images

When shopping for carpet, you may hear the term ‘solution-dyed.’ It refers to a method used to dye the carpet fibers, but what exactly does it mean?

There is a key difference in the final products between fibers that have been solution-dyed, and fibers dyed by other methods. Let’s explore solution dyeing, and why you probably should care about it if you are buying new carpet.

What Is Solution Dyeing?

Solution dyeing is a technique used to add color to synthetic fiber. There are many different methods used to dye carpet fibers, but essentially, they can be broken down into two categories: solution dyeing, and all other methods. This is because solution dyeing is so different from all of the other methods that it truly is in a class of its own.

How Is Solution Dyeing Different?

The traditional method of dyeing fibers involves first producing the fiber and then adding the color. In traditional dyeing methods, the fiber is produced in a colorless form (called a ‘greige good’, because of its appearance of being a color somewhere between gray and beige). After production, the fiber is then dipped in the dye to add the color. (This is a very over-simplified explanation of the process, but it provides the general idea.)

In the solution dyeing method, the color is actually added to the liquid state of the fiber components, before the fiber is actually produced. Synthetic fibers are made of chemical compounds, or polymers, depending on the type of fiber. To bring the process down to its most basic explanation, the liquid chemicals are fed into the top of the machine and are forced through tiny holes called spinnerettes (picture a shower head) where the liquid is drawn out, leaving the newly created yarn.

Solution-dyed fibers have color pigments added directly into the polymers (chemicals) at the initial stage of production. This means that when the fiber is extruded from the spinnerettes, it is already the desired color.

What About Natural Fibers?

Solution dyeing is not applicable to natural fibers (such as wool) because the fibers are already in existence. As described above, solution dyeing involves adding color to the chemical compound that makes up the fiber, before the fiber is made. Natural fibers are harvested from their source, so they must be dyed using traditional dyeing methods.

Why Does Solution-Dyed Matter?

There are several advantages to solution dyeing fibers, all of which are because the color is part of the fiber, and thus goes through the entire solution-dyed fiber.

When a fiber is dyed post-production (as in traditional dye methods), the dye soaks into the fiber and fills the fiber’s cells. After being dyed, the fiber appears uniformly colored, at least to the naked eye. However, there are always cells in the fiber that did not absorb the dye–these are known as empty dye sites. These are not visible except, perhaps, under a microscope, but they do exist nonetheless.

To understand the difference this makes, picture a radish and a carrot. The radish represents the traditional-dyed fiber, where the color is on the exterior but does not go through. (The radish is red on the outside but white on the inside.) By contrast, the carrot is orange all the way through, in the same way, that a solution-dyed fiber has color throughout.

The Benefits of Solution Dyeing

Solution-dyed fibers are much more colorfast (resistant to fading or color bleeding) than other fibers. This is because the color is locked into the fibers. So, solution-dyed fiber is a great choice for areas that will be subjected to intense light. Also, because the fibers are stabilized during production using ultraviolet inhibitors, they are the best choice for use in outdoor carpet applications.

Another huge benefit of solution-dyed fibers is increased stain resistance. Because traditional-dyed fibers contain empty dye sites, as discussed above, they can be more easily stained. Spills are absorbed by these empty dye sites, which make them very difficult to remove.

Because solution-dyed fiber has no empty dye sites (since the color goes all the way through) spills are not able to be absorbed by the fibers, and so the result is a carpet that is as close to stain-proof as is possible. Therefore, solution-dyed fibers are great for use in commercial carpets.

The Drawbacks of Solution Dyeing

The primary disadvantage of solution-dyed fibers is the reduced color selection, compared to other fibers. In the past, the colors of solution-dyed fibers were not as vibrant as other colors, due to the difference in manufacturing. However, today, there is a wide selection of solution-dyed carpet in many colors, and with technological advancements, the colors available today are much brighter than before.

The other drawback to solution-dyed fibers is that as a consumer, you may have to wait longer for your 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, rather than keep lots of rolls of carpet already dyed through solution dyeing. This doesn’t mean that mills don’t keep any solution-dyed product in stock, it just means that it may not be as readily available as a carpet that can be, essentially, dyed to order.

Solution-Dyeing: The Verdict

Overall, solution-dyed fiber is a great choice for both residential and commercial carpets, for its stain resistance. However, solution-dyed fibers can be made into virtually any carpet, so just because fiber is solution-dyed, doesn’t mean that it is always the best choice. Like anything, it is available in a wide range of styles and qualities, so it is just one more factor in a carpet’s story that must be taken into consideration.