Huacaya and Crimp

Crimp is a much-debated topic. We know it wins in the ring. But why? In general, it is felt to be an indicator of a variety of desirable fleece characteristics, from fineness to density to uniformity. From a production standpoint, some people feel crimp adds loft, memory, or elasticity to an end product. Others say that it is easier for commercial mills to process fleece that has crimp. Some believe high frequency, low amplitude crimp (known as "zipper" crimp) is superior to a deep and bold crimp (often referred to as "French fry" style crimp). We won't let these differences of opinion crimp our style.

Huacaya crimp is often compared to the crimp in sheep wool. While Merino sheep, and others bred for fine textiles, have a higher frequency of crimps per inch than Huacaya, it is not necessarily helpful to compare alpaca to wool. Alpaca fibers are structurally different from wool fibers, as they have a different configuration of scales than wool fibers. We may be essentially comparing "apples to oranges." The vast majority of Suri alpacas have no crimp whatsoever and that is considered a positive characteristic. While some Suris do express crimped fiber, it is rightly considered a defect. Straight Suri fibers reflect light better than crinkly or crimped fibers. Mohair and Angora, both highly prized for their luster and luxurious softness, also do not exhibit crimp. Vicuna fiber, considered to be the finest natural fiber on the planet, has such extreme high frequency, low amplitude crimp, that it is almost imperceptible to the human eye. So, what is the real story on crimp?

Crimp, in the Huacaya, from the breeder’s perspective, is indeed more of an indicator, than a valuable fiber asset in and of itself. The degree to which crimp is expressed, and in what "style," is thought to be determined largely by genetics, although possibly also affected by environmental factors. Crimp does not necessarily equate to fineness, but as we will see below, is a strong indicator of both density and fineness. How do we get from a visual expression of crimp to a determination of density and fineness? First, a highly crimped Huacaya fleece is evidence that the fleece is highly organized. Such a fleece will be highly organized by necessity, due to what is happening at skin level. The organization is the result of many fibers growing together in very close proximity, thereby influencing each other to grow together in an organized fashion. The fibers are "pressured" to evolve as a group, moving in unison outward from the skin surface. The pressure that results from dense packing causes the fibers to grow in a crimping, side-to-side fashion, rather than in straight unimpeded lines, vaguely toward the surface. Crimp, therefore, is a visual indicator of many hair follicles producing fibers in close proximity, i.e. density.

Crimp becomes more "defined" (clearer and sharper) as density increases because more and more fibers join the "club" as the hairs leave the skin. The fibers are forced to become one with all the other hairs leaving the skin at the same time. If the animal is not dense, those hairs will tend to dive all about, as there is no pressure to make them perform together. The result is straighter fibers that may tangle or even lie cross-wise, making it difficult to see the skin when we open the fleece. Consequently, an inability to see the skin clearly upon opening a fleece does not always mean the animal is dense.

In alpacas, whose genetics are related to the vicuña, the llama, and others, there can be a great deal of variability in crimp styles. For reasons of simplicity, however, let’s break crimp into two principal styles: high frequency, low amplitude crimp ("zipper" crimp) and low frequency, high amplitude crimp ("French fry" crimp). Fleeces exhibiting high S/P ratios, as assessed through skin biopsies, will tend to exhibit more crimp, which we know generally correlates to finer fiber. According to research done by Cameron Holt, there is a very high correlation between fineness and crimp frequency. This really makes perfect sense. A smaller diameter, fine fiber will tend to bend more easily than a thick, coarse fiber. There are always some exceptions – animals that are coarse, but also crimpy, as well as animals that are quite fine, but lack both density and crimp.

Most high frequency, low amplitude "zipper" crimp fleece types are very fine. Many animals with low frequency, high amplitude "French fry" fleeces, however, have also been found to be very fine. According to Dr. Watts, the finer fibers are generally characterized by “deep bold crimp.” According to this assessment, the high volume production Huacaya type fleece is that which shows “deep bold crimp,” as it is expected to have high density and finer fiber. It has been confirmed by Dr. Sumar of Peru that this style of crimp, along with attention to S/P ratio and follicular density, have been the criteria used for breeding selections in Peru for centuries.

At present, there is no clear consensus among fiber "experts" and/or fleece judges as to whether one style of crimp, Zipper vs. French fry, is always indicative of greater fineness. However, a highly organized fleece exhibiting a uniform and well-defined crimp style is generally considered a good indicator of both density and fineness. 

From a textile production standpoint, it is not clear that one crimp style is preferable over the other. The majority of crimp disappears in the initial stages of processing, although some people feel that the bolder crimp produces better loft in finished textiles. In processing, one benefit to having crimp in alpaca fiber may be that it adds cohesion to yarn. The overlaying of the individual crimp "speed bumps" catch each other and allow the fibers to go through the drafting process with less drift. High amplitude, or "deeply" crimped fleece, to the extent it contributes to loft in finished yarn, would be particularly appropriate for sweaters or garments that tend to be on the bulky side. If a smoother fabric, with more drape, or a tightly woven fabric is desired, high loft would be counterproductive. Suri fiber does not crimp and is, therefore, a perfect choice for tightly woven textiles.

Note: The carding process will take much of the crimp out of fiber. Once processed, that portion of the crimp does not return. If a processor wants crimp in the fiber for a specific application, she may use a machine that will put crimp back into the fibers. So, from a fiber producer's perspective, crimp is not an important attribute on its own, but rather it is a highly useful indicator of fleece quality. Uniformity of length and uniformity of fineness are important in presenting fleece for sale to textile manufacturers. Crimp definition, crimp frequency, and crimp uniformity provide Huacaya breeders with a visual clue to help assess a fleece. Crimp itself has little value with respect to end products, although it does facilitate fiber processing.

The Benefits of Crimp

The following analogy may help in visualizing the value of crimp:

Picture a large parking lot, with all those slanting yellow lines painted on the blacktop to remind drivers to park within the orderly structure. Now, picture a parking lot without those lines. Drivers can park where they will, in various directions and at varying distances from each other’s cars. Which parking lot would hold the greatest number of cars? The one with the yellow lines, right? The structured parking lot (painted yellow lines) will hold the greatest number of cars (think high density). This is efficient. In the alpaca, crimp structure is analogous to the painted yellow lines. Highly-defined crimp is an indication that the fibers are tightly and efficiently packed, as are the cars in a painted, well-defined parking lot. Crimpy, highly organized fibers can be tightly squeezed together, utilizing every bit of space, which is more efficient than a chaotic, fly-away fleece structure. Therefore, the more organized, defined, and uniform the crimp, the greater the density. And, since fine fibers will bend more easily and often than coarse fibers, highly organized crimp structure is also indicative of fineness. 

Research corroborates these conclusions, showing that finer fibers tend to exhibit crimp more often than do coarse fibers. Given a highly organized crimp structure, breeders generally may assume a fine and dense fleece. The value of crimp, therefore, lies in our ability to use it as an indicator of important attributes for producing alpaca fiber for profit – uniform fineness, which translates to soft end products, and density, which translates to heavy fleece weights and higher yields.

Crimp Evaluation Checklist:

• Highly defined crimp, in terms of frequency and amplitude, are indicative of a high S/P ratio.

• The tighter and more defined the crimp, the less moisture and dirt will penetrate to the skin

• Crimpy fleece is generally cleaner, because its greater density helps to keep out dirt and debris, as well as insects and moisture. This helps to eliminate problems with fleece rot, that can cause breaks or discoloration of the fiber. Alpacas with little or no crimp tend to be less dense and have open fleeces that are more likely to pick up dirt and vegetable matter.

• Well-crimped fleeces generally have fewer coarse medullated fibers. Variation in crimp along individual fibers can be indicative of a period of sickness, stress, or poor nutrition.

• Curvature is a measure of crimp amplitude. The higher the curvature number, the higher the crimp amplitude. When coupled with a low CV, a high curvature number generally correlates with a low AFD.

• "Bold" crimp usually means low frequency crimp, while "deep" crimp means high amplitude. Deep, bold crimp, therefore, describes a relatively low frequency, high amplitude style.

• "Zipper" crimp is characterized by a high frequency, low amplitude style and it is usually soft, fine, and even. In addition, it tends to reflect more light, making it appear brighter.

• Alpacas with high frequency, high amplitude crimp are very rare.

• "Deep bold crimp" is considered by some to provide a good balance of fineness and density for sale to commercial markets. However, there are many different styles of fleece that will need to be classed into separate lots according to their differing attributes, including crimp style, staple length, color, and fineness, among others. The variety in end products that can be manufactured as a result of this fleece diversity is advantageous to designers, offering a wide array of options for utilizing alpaca.

• Well-defined crimp indicates fibers of a similar nature and size growing together, into a tight, uniform staple. Uniformity is crucial to the production of valuable fleece.

• In commercial production, uniformity is key, whether it be with respect to color, fiber length, AFD, or crimp style. Larger lots will produce more consistent end products, but only to the extent that fiber characteristics are uniform within the fleeces making up the lots.

A Few More Notes on Crimp:

• Some very fine alpacas are also blessed with having very long staples. These long staples weigh more than short staples of the same AFD and density. At times, these very long and fine staples may droop, due to their weight, which may cause those fleeces to appear open and less dense.

• There are many styles of crimp, as fiber crimp is a multi-dimensional structure, and crimp is affected by cortical cells, bi-lateral structure, amplitude, frequency, and micron count.

• Style is less important than uniformity, although many breeders prefer high frequency crimp as an indicator of fineness. Some believe it provides more elasticity (stretch).

• Crimp is thought to increase the ability of alpaca fiber to provide thermal insulation, as the additional loft helps trap air within a garment.

• Crimpy fibers are easier to spin and often add loft to garments,

• Crimped fibers are significantly easier to spin than non-crimping fibers for the hand spinner. Hand spinning of crimped fleeces may or may not produce a more regular and uniform yarn. The ability and experience of the spinner has more to do with uniformity of yarn than any other factor.

• Most processors feel that crimp is not a factor in the decision to process using the woolen vs. the worsted methods; rather, length of fiber is the biggest factor in determining which method should be used.

• Some feel that too many crimps per inch interfere with handle. Is there is an optimum crimp frequency?

• Luxurious fabrics that are exceptionally bright seem to result from fleeces with long staples and low curvature.

• More robust and somewhat thicker fibers, with good curvature, are particularly suited to the manufacture of durable outerwear.