Thursday, January 28, 2010

Fiber Evaluation (Tensile Strength)

If I was granted one wish in the alpaca fiber industry it would be to create a high level of tensile strength in all alpaca fiber. But alas not all alpaca fleeces are created equal! While this article focuses on the implications of tensile strength and how to properly evaluate it in your fleece, we will also consider how farmers can develop a win-win partnership with a local mill.

When you bring your alpaca fleece to a mill for processing, you are entering a partnership with that mill. Obviously, you want the best possible product, and the mill wants to process in a way that you and your customers will be happy with. This will result in additional profits to your farm; increase the reputation of your quality alpaca products and the ability of your local mill. But it will also supply the farm and the mill with new customers through grassroots marketing. So how can properly evaluating tensile strength allow you to help in creating a dynamic shift in local economies?

The answer to that question begins in January of 2007. After two years of processing here at Morning Star Fiber we were finding it difficult to explain why products were turning out the way they did. We wanted to make sure that both the farmer and the mill were working most effeciently and effectively together in their partnership. Therefore we realized we needed to develop an ad hoc grading system for incoming fleece. By implementing this system we might be able to more properly assess the root of problems and also successes. This in turn could allow us to better recommend what type of processing should be done with the fiber that farmers were bringing in. After following this system for three years we wanted to communicate clearly what we have found so that everyone can mutually benefit.

During the implementation of this grading system it was found that there are seven areas that dynamically impact the end product and the response of the market to these value-added steps. You will find that these areas impact not only processing, but breeding and harvesting practices as well. Our hope long term is that standards can be created from these findings that will help improve the consistency and quality of the products being processed, the type of fiber that should be used to produce that kind of product and a greater demand in the marketplace.

This article will focus on is tensile strength. Although in future articles I hope to speak to staple length/variation, variation in micron, crimp, second cuts, vegetable matter and dust. But to start, I can think of no other quality in alpaca fiber that has greater implications on the fiber industry than tensile strength. This is the one area that can render a fleece unusable for processing and require that it only be sold as raw fleece to an artisan for hand spinning or needle felting. This is one area that impacts all the major players – producers, harvesters, processors and artisans. It also provides the key to greatly reducing processing costs which mean lower price points in the marketplace and a dynamic shift in the alpaca fiber industry.

Tensile Strength:
Tensile (tension) strength is the fiber’s capacity to be stretched without breaking. Obviously every fiber has a breaking point but what we are concerned with is how much tension can it endure without breaking. Commercial milling is a very aggressive process and fibers must be able to withstand a certain amount of tension without its structure being compromised.

Testing for tensile strength can be a very objective measurement. However, in the fiber industry there are currently no cost effective tools that would allow individuals to measure tensile strength objectively. Therefore, we are left with varied, subjective means to test for tensile strength. There is an opportunity here for someone to develop a hand held device that would measure tensile strength and it would greatly improve the fiber industry as we shall see.

A method of evaluation:
In our mill we developed a basic evaluation when testing for tensile strength. While it is subjective it has produced consistent results. We start by pulling a representitive lock of fiber from the fleece. It need not be more than 30 or 40 individual fibers. We then take this lock and open them up by hand so that they are no longer clustered together. This allows us to test the fiber in a similar fashion to what will be experienced at the carding stage. We then take this opened lock of fiber and grab each end in our hands using our thumb and forefinger. We then place the opened lock up to our ear and pull, gently at first but with an increasing amount of tension. We listen to the sounds that the fiber makes as it is under these varied amounts of tension, and this allows us to assess it tensile strength capacity.

Like I said before this is simply one of the varied, subjective means by which tensile strength can be tested in the fiber industry. It is subjective because my understanding of “gently at first but with an increasing amount of tension” will not be the same as yours. As a 6’4”, 285 pound ex-collegiate football player my ability to increase the amount of tension will be different from others and sometimes significantly – not to mention my definition of gently! But alas I have found a way to know what a fleece with a high degree of tensile strength sounds like from inspecting thousands of fleeces that have come in over the last three years. At this time I’m not able to state an objective measurement that would be required for greatest processing performance. However, I know that some research has been conducted by Xungai Wang of Deakin University in their Textile Testing Laboratory in Australia. I was not able to conclude that the results found in his report would be comparable with our fiber here in Ohio using Belfast Mini-Mill equipment under the humidity conditions of this region.

Affects on processing:
I have found that tensile strength directly relates to processing performance. For example, a fiber with a high degree of tensile strength can be processed in a mini-mill at four or even five ounce feeds at the carder while fibers with a low degree of tensile strength require much lower feed rates – even as low as one ounce per feed! This directly impacts not only the mills processing turn around time but the price per pound at which these fibers must be processed. If all alpaca fibers could be processed at five ounces per feed a mill could process over 9,100 pounds of alpaca fiber per year. This has staggering implications that I will deal with later. However, if all alpaca fiber must be processed at 1 ounce feeds only a little over 1800 pounds could be processed in that same year. Therefore, tensile strength has a dynamic impact on the price per pound a mill must charge in order to stay in business.

Since alpaca is a protein fiber, it’s tensile strength is greatly reduced when it is wet. This requires that mills allow for adequate drying time of fiber before moving on to the opening stage. However, when alpaca fiber is too dry the mill can be rendered inoperable due to static electricity. This problem increases in the winter months when lower humidity levels are experienced. Therefore it is key to constantly monitor the humidity level in the mill and in the fiber, so that tensile strength is not compromised and static electricity is kept to a minimum.

Not properly evaluating tensile strength prior to processing can greatly compromise the end product and reduce its market value. This becomes a factor during the opening and carding process, and indirectly during the spinning and plying of those fibers. While these fibers are being opened and carded their tensile strength is put to the test, and if they fail those fibers will be broken and damaged creating neps in the roving. A nep is a small tangle or knot of short fibers. These neps are very difficult to remove from the roving and have an impact on the rovings ability to draft and for twist to be uniformly added to the roving.

In the marketplace:
When these fibers are processed into yarns it results in a yarn that looks slubby and inconsistent. These qualities deplete its market value as they have very limited applications – knit and felting projects may be the only exception. Not only does the yarn look inferior, its performance in knitting, crocheting or even weaving will be compromised. Even after the artisan’s project is completed the fabric created will continue to pill and shed these short neps. As each nep is removed the fabric weakens. But as suggested some of this can be overcome by felting the project. Therefore tensile strength has a direct impact on price points in the marketplace.

Implications for the industry:
A low degree of tensile strength poses several problems for the alpaca fiber industry. There is a movement within the industry to push for finer micron animals. While this finer micron will allow alpaca fiber grown in Ohio to hold a greater exotic fiber status, we must understand that this finer micron will inevitably have a weaker tensile strength which will require a higher cost in processing. Do these finer fibers draw a market price that justifies the additional processing, harvesting and even breeding costs? This is a question that must be well thought through when considering how fiber fineness will play a role in your business plan.

Our studies show that fibers that are 23 micron and higher typically have a high degree of tensile strength and can be processed at a three and half ounce or greater feed rate in the mill. This has huge implications on price points in the marketplace. If a mill could expect this kind of performance from alpaca fiber it greatly increase its output. In theory a mill could generate 6,400 pounds of fiber or more per year allowing it to charge as little as $18.75/pound for bulky yarn – however there are other areas to evaluate. But if these rates were possible and no other factors limited the mills ability to process, the mill would still be profitable and sustainable with two full time mill operators and a part time office manager. At the same time the farmer could obtain 4 ounce skeins of yarn for less than $6/skein even at a 25% processing loss. While this is a theoritical proposition it is worth investigating further.

What if farmers and mills could partner together in the most effective and efficient ways possible? What if farmers were able to produce fleeces that were uniform in their high degree of tensile strength? What if mills could process at five ounce feeds with confidence and lower their cost per pound accordingly? What if we could organize a state-wide evaluating system that could provide local mills with this kind of fiber on a consistent basis? If we could do this the implications are staggering!

Consider this… if the 22,870 registered alpacas in Ohio could produce a little over 137,000 pounds of fiber (6# per animal) with a high degree of tensile strength, and there were 15 regional mini-mills staffed by three people who could process bulky weight yarn at 40 pounds/day, we could create a dynamic shift in local economies. This would effectively create an additional 35 jobs just in the mills alone, fuel local farmers with an additional $5.25 million dollars in net income, and showcase Ohio as a premier spot for the alpaca fiber industry.

However, the reality is that many local mills struggle to finish 15 pounds per day when processing alpaca due largely to tensile strength issues. Therefore the price per pound is closer to $26 or even $30. This is just one way in which we are limiting the growth of our alpaca fiber industry.

In conclusion:
We hope that this has helped you to see the dynamic impact just one area of evaluation can have on the processing performance of alpaca fiber. This is just one of the ways in which Ohio farmers and millers can better partner to realize high quality end products in the marketplace and an explosive new trend in the alpaca industry. It’s important for everyone involved in the industry to develop a win-win partnership with a local mill, by developing an accurate method to evaluate effectively the tensile strength of the fiber. By doing this we will begin to see a dynamic impact in the marketplace. Because this issue requires dialogue I’m suggestion we continue this discussion and read about the other six areas for which fiber should be evaluated by visiting (this blog).

We hold the future in our hands – even if it is with the thumb and forefinger! It’s time to establish a cottage industry level platform from which the alpaca fiber producers, harvesters, processors and artisans will be able to realize an ever expanding market that is both profitable and sustainable for all involved.

JC Christensen