Alpaca Fiber – Form & Function

1. Fiber – A Textile Building Block 

Fiber is the fundamental component required for making textile yarns and fabrics. There are two types - natural and synthetic. Natural fibers come from animals (sheep, goats, camelids, etc.) or vegetable-based fibers (cotton, flax, linen, and other plant fibers). Mineral fibers (asbestos, etc) are also classified as vegetable-based fiber. Synthetic fibers are man-made and manufactured from synthetic chemicals – (byproducts of the petrochemical industries) – nylon, polyester, acetates. 

2. Follicle – A Fiber Building Block

One of the unique characteristics of mammals is hair. Hair is made up primarily of the protein keratin, which also produces our own skin, finger and toe nails, animal hooves, and even bird feathers. There are many types of hair, depending on the species, each with its unique architecture to serve a specific purpose. The thousands of follicles present within the skin of man and beast are responsible for growing hair fiber. 

Fibers grow from follicles. Follicles are arranged as oval clusters (follicle groups) covering the entire body. Each alpaca hair follicle is a mini-factory lying within the alpaca’s skin, which manages the growth and well-being of each individual fiber and fiber type. The more follicles in each cluster, the closer together and, therefore, denser the fleece (i.e., more follicles per square inch or millimeter). The primary follicle consists of a sweat gland (to help manage body temperature), a sebaceous gland (to help protect the fiber), and an erector muscle with allows the primary fiber strength to stand straight for support of the secondary fibers. (Horses are able to use their erector muscles to actually adjust the direction their fibers point depending on wind conditions). We have erector muscles also – as when the hair on the back of your neck stands up.

The primary fiber, which grows from a primary follicle, is usually the longest and thickest of fibers. Its job is to protect both the alpaca and its secondary fibers from the harsh environment. The secondary follicle is generally host to a finer secondary fiber and often also some “secondary derived fibers,” which tend to be finer still. Primary follicles generally form in groups of three (trios), with a number of secondary and derived secondary fibers clustered around each of the primary fibers. A follicle group can be as small as 0.5 mm across. A staple bundle is a number of these follicle groups bundled together. The width of the staple is determined by how densely packed the follicle groups are within the skin. 

Note: Just because a skin biopsy may reveal 15 secondary follicles per primary, it does not necessarily follow that all 15 will grow fiber.

3. Cuticles/Scales – The Armor

 Hair grows outward through the follicle. Each hair is made up of many cylindrical strands of protein. If you think of a thick wire, made up of many thinner individual wires, you can get a feel for the added strength in numbers. This architecture is used for the huge cables that support suspension bridges.

Each group of protein strands cluster and grow together to produce a single hair. For additional protection and support, numerous cuticles (we often call them scales and so we will use the term “scales” from hereon) overlap each other (like roofing shingles) and collectively envelope the entire hair shaft. This structure protects the inner strands of fiber from the environment, yet also allows vital nutrients to seep into the strands for nourishment. These scales vary in hardness, length, and height, depending on the type of hair. The serrated edges of alpaca scales along each hair shaft, coupled with the inner and often twisted structure called fibrils, are the secret of the variability, strength, and elasticity of different types of fiber. The glue that holds the scales together is called elasticum. Try working that into a conversation.

One of the secrets of why alpaca fiber is so strong (resistance to breakage) has to do with its particular architecture. The major difference between Suri and Huacaya fiber has to do with their different fiber architecture. The Huacaya fiber crimps and the Suri fiber does not. 

This is due to the ortho- and para-cortical cell structure, as with sheep wool. Using differential scanning calorimetric (DSC) and scanning electron microscopy (SEM) techniques, a recent Ohio State study confirms that ”huacaya have an ortho and para bicortical structure whereas suri fibers mostly consist of paracortical cells.” 

Some believe that it is the arrangement of the ortho and para cortex that determines crimping. Suri fiber has “strands” of ortho around the circumference, which is thought to effectively “balance” the fiber, eliminating crimping. Huacaya fiber, on the other hand, has a top and bottom half of each, resulting in different surface tensions that create the twist which is part of crimp.

The health of the alpaca, its diet, and the weather can and does affect each hair. During processing, how fiber is washed, dyed, and spun will also affect the final product. To compound the complexity, many mammals, including alpacas grow different types of hair for various functions. 

One aspect of the American herd that is different from many other countries is that we have a focus on breeding for color. Most other countries focus on breeding white animals. Since we have the most color in the world, this should be an item on which we capitalize. Rather than trying to compete with dyed white fiber, we should consider focusing on the many natural colors available within the North American herd. We have the highest quality colored alpacas in the world. This is a niche advantage!

We will address primary, secondary, and guard hair in a separate section. All three types are needed, per Mother Nature, to comprise the alpaca’s natural shield, its fleece. Genetically altering the alpaca to remove guard hair, for example, may seem to benefit textile markets, but it may negatively impact alpaca health. On the other hand, breeding to create primary and secondary fibers that are of similar length and close in micron count will provide comparable textile benefits, but would not be expected to result in harmful health effects. Long fibers is a smart goal also. For those of us who have dams with very short fibers, imagine if we could breed them to be much longer for more years to reap the profits from Fiber for Profit.

4. Hair/Fiber/Wool - Definitions

Hair is critical to most mammals’ survival. Hair provides insulation from the cold by preventing the loss of body heat and is also able to keep the heat at bay when the body wishes to stay cool by wicking sweat through porous fibers and away from the skin. Animal hair also protects from the negative effects of humidity and rain. Our own human hair does not protect us from the elements as effectively as animal hair does. Scientists still debate and offer theories as to why we human mammals have hair at all. Given our lack of protection from the often-harsh environment, we have learned how to utilize the hair of other mammals and adapt their wonderful thermal properties to our own benefit. We have created and protected ourselves with these mammal-based textiles for thousands of years and will continue to do so.

So, what is the difference between hair and fur? Technically - nothing. Yes, whales are mammals and actually do have very fine hair. But, we do not call that fur! The term “fur” is usually reserved for a thick-coated animal. An otter has fur, as does my Great Pyrenees guard dog. There are no furry whales. The term ”wool” presents a special case. While ”wool” usually refers to the protective hairy covering of sheep, goat hair, camel hair, and even caterpillar hair can be referred to as “wool.” And, of course, alpaca fiber is often called wool fiber, as in, ”What do you do with their wool?” To complicate things a bit more, many mammals are two-coated animals, with thicker outer fibers that function to product the finer, warming inner fibers from harsh environments. The finer coat is typically called down or wool. And, of course, an alpaca is a two-coated animal.

So, for a two-coated mammal, such as the alpaca, the outer, coarser layer, generally consisting of primary fibers, heavily medullated fibers, and guard hair or kemp, is often called “hair,” while the inner, finer, and more delicate secondary fibers are sometimes referred to as “wool.” But, whether we simply call it alpaca fiber or wool, alpacas produce one of the world’s finest and most luxurious fibers. Many say that alpaca is as soft as cashmere. The truth is – it depends. Many say alpaca is warmer, lighter, and stronger than wool. The truth is – it depends. Many say alpaca comes in more natural colors than any other fiber-producing animal. Now, this is definitely true! 

If we alpaca breeders intend to maximize profit from our annual harvests, we must understand exactly what we are growing in our back yards and paddocks. If it is our goal to produce the highest quality alpaca products, it will require great genetics, a nurturing environment, expert harvesting and processing, and an understanding of both market demands and quality control. Let us start by separating fiber fact from fiction.

The above is the profile of a Huacaya fiber. If you take the orthocortex and put each of the cortical cells around the perimeter of the fiber you get a Suri fiber – the placement of the ortho around the perimeter neutralizes the tension difference between para and ortho, resulting in straight Suri fibers.