Science of Craft: 003 The Structure of Cotton Fiber

Surely you've heard the fairytale of Rumpelstiltskin. Some chick finds herself in a predicament that requires her to turn hay into gold thread otherwise she'll be executed. Luckily some woodland spirit named Rumpelstiltskin comes to her aid in exchange for the distressed damsel's first born. Things turn out pretty much how one might expect. Now, if you know about bast fibers, you might be heckling our heroine from the sidelines. Congrats, you are the real life Rumpelstiltskin. Certainly, you're not going to be making anything out of hay, but our girl is probably mistaking flax for hay. But she's not the only idiot. The king who wanted her to make gold thread was only ever going to get linen, which is a wonderful material in its own right. Too bad they didn't have Pinterest back then, where they could have learned to class anything up with a spritz of metallic Krylon. Anyway, I grew up enjoying Shelly Duvall's Fairytale Theater, and looking back on this scene (10:54), it's especially hilarious to me now. What a good show.

Now, try suspending judgement on our poor heroine for a moment and try empathizing with her incredulity about spinning plant fiber. It does seem pretty weird, but it's amazingly doable as long as you can find a way to get at the cellulose that makes up every plant. In case you forgot, here's what I'm talking about.

One cellulose unit

This is a unit of cellulose, which has such wonderful properties which human beings have found many uses for. It's part of what makes up the fiber in our diet, it's what makes up the lumber we use, the pulp in our paper, and the plant fibers that we spin. However, there are a couple of factors, polymerization and crystallinity, that make any given source of cellulose better suited for one application or another.

Polymerization

Take a look at that cellulose unit again and notice the oxygens (in red) seemingly just hanging off the ends. That's where the cellulose units attach to each other. These attachments are particularly strong bonds known as covalent bonds. That's when a couple of atoms actually share electrons with each other. For cellulose in particular, the connection between the sugar subunits is called a glycosidic bond, and they always occur on the first and fourth carbons, connecting unit to unit, to another unit, and another, and so on, which makes a polymer. Polymers are molecules made of long chains of smaller units repeated together. A good analogy for polymers would be pop-beads. The beads would represent individual atoms and the "pop" part would be the shared electrons.

The longer the polymer, the better it is for whatever you're doing with it. When making paper, using long cellulose fibers makes a sturdier, more flexible paper. You've experienced this if you've ever noticed the difference between drying your hands on recycled paper towels and using some premium brand like Brawny or Cottonelle. Whenever we recycle paper, those polymer chains get damaged and broken, thereby shortening them. I once had a student insist on using the crummy brown paper towels to make recycled handmade paper. Besides the fact the she wasn't really recycling anything by unwinding the roll of fresh unused paper towels, the paper came out extremely weak and friable, just like I told her it would. There's only so many times you can recycle cellulose fibers until they are too short to do anything with.

It may not be surprising that paper makers often add cotton to their paper pulp to enhance the quality of their paper. I know my interviewers must have been impressed with the cotton stock I printed my resume on. Anyhow, I'm saving the short fibers left over from my cotton spinning and will see if they help a all with my paper making. Of course, the longest fibers are more desirable for spinning, but cotton is notoriously short (usually no more than an inch) compared to animal fibers which intimidates a lot of people, but obviously it's got a long enough staple length because people have been spinning it a very long time. One just needs to use different techniques and make a few adjustments to existing equipment to spin cotton, and someday I will go on at length about it.

Crystallinity

I hope you haven't been equating a single cellulose polymer with a single cellulose fiber. Cellulose fibers are actually a much more complex arrangement of many polymers bonded together more or less in parallel. The more parallel and tightly packed the polymers are, the higher the degree of crystallinity is. This makes cotton pretty strong, especially when wet, a feature animal fibers can't claim.

The hydroxyl groups that are key in dyeing of the fiber, as we have learned, but they are also what gives cotton its high degree of crystallinity, because they are so very attracted to each other. This is due to something called polarity which creates the condition for hydrogen bonds to form. This won't be difficult to understand if you can stick with me. Ha. You know how opposites attract? That's all that's really going on here, and in this case the opposites are negative and positive charges. The oxygen has a slight negative charge and the hydrogen has a slight positive charge.

This unbalance didn't just happen for no reason. Oxygen is a greedy asshole, and in bonding covalently with hydrogen, doesn't share the electron quite fairly. It's like if you were to split lawn mower ownership with your neighbor, and yet it spends more time in your neighbor's garage than yours. The lawnmower represents the electron in this analogy, keep up with me here. Anyhow, electrons have a negative charge, and because oxygen is bogarting the electrons, the oxygen ends up being more negative and the hydrogen ends up being more positive.

If the hydroxyl group from a cellulose polymer encounters a hydroxyl from another molecule, the positive hydrogen is going to be attracted to the negative oxygen of the other hydroxyl group. This attraction forms the hydrogen bond. It's not as strong as a covalent bond, but considering how many potential hydrogen bonds could be formed all up and down a cellulose fiber, overall, that's going to make a pretty tough fiber. The more hydrogen bonds form with adjacent cellulose fibers, the more closely organized in parallel the polymers become. This is crystallinity.

A hydrogen bond between the hydrogen in a
hydroxyl unit and the oxygen in water.

You know what else has Hs and Os bonded in it? Oh come on, do I have to spell it out for you? H two Ohhhhhhhh, now you get it don't you? Now remember, oxygen is an asshole, even in water. It has a slightly negative charge and water's hydrogens have a slightly positive charge. When water meets a cellulose fiber, the water becomes attracted to the hydroxyl groups in the cellulose. That's why I have 100% cotton bath towels. Nothing dries your butt crack better.

Fiber Structure

If you've got good eyes, it's pretty easy to tease out a single cotton fiber and look at it. That is not one polymer chain. It's not even a bunch of polymer chains hydrogen bonded together. One cotton fiber is actually many layers of crystalline cellulose chains arranged in different ways, and this is what makes cotton so splendid and easy to work with. Some of the layers are twisted, which makes the fiber strong. The fiber structure of cotton is pretty consistent, having a diameter of about 12-20 micrometers. The result is a fiber that is smooth, soft, and not irritating like wool is. Fine Merino is comparable.

Cotton is so great. It comes right off the plant this way. You can't just start spinning trees you know, even though they contain a lot of cellulose. In order to "spin trees" you have to remove all of the lignins and other compounds to get at the cellulose, and by that time you just have a bunch of unspinnable pulp left over, so then you'll have to chemically polymerize the pulp, which will never be as long or strong as cotton polymers. What I just described there is how rayon is made. Through some physical effort, bamboo, and bast fibers like linen and hemp, can be processed into spinnable fibers. Cotton, though, is a clear winner for me.

If you want to know more, here are a couple of more technical pages on the structure of cotton. Have at it!

Cotton Inc.

Barnhardt Cotton

Bullshit Crafting Product: 002 Toilet Paper Tubes

I was inspired to see if my cotton seeds were still viable, so I put one in a sawed-off water bottle filled with soil to see what would happen. After watering, it sprouted in a matter of days. Truly a miracle since these seeds may very well be 5 years old or older. I can't remember the last time I went picking cotton bolls in my father's garden. When the sprout grew large enough to transplant, removing it from the bottle was very difficult. I had to slice the bottle down both sides to get it out and I'm pretty sure I damaged some of the delicate roots. By this time I had tried sprouting a few more seeds in the same way, and they did not survive the transplant when it came their turn, though I suspect one fell prey the the moth grub problem my patio has.

I would not have even bothered using the plastic bottles, but I have a shitton of them already prepared left over from a student experiment with plants. At the end of the experiments, I eventually had to get to work cleaning out the plastic bottles so I could recycle them. During the grueling work I had ample opportunity to reflect on whether or not repurposed bottles were the way to go. Would my students have used as many water and soda bottles in the first place if I hadn't told them they needed to bring some for an assignment? Was there really any environmental benefit to using the bottle as a pot before recycling it? We already had to rinse them once to use as pots, and then rinse them again so we could toss them in the recycle bin. What a waste of water! There has to be a better way, and I think I found one on Pinterest. What a great idea, using toilet paper tubes as seed starters. You can transplant your seedlings without un-potting them and the paper tube will decompose easily in time. Furthermore, I've always been a little dubious when I toss tp tubes in the recycle bin. These things aren't made out of the greatest paper pulp quality, and I can't imagine they recycle into anything very well anyway.

I did a little bit of research to see how other people were starting seeds. Thanks to the nosy nature of Google (second only to my grandmother) I started getting eBay ads for rolls of toilet paper. It's a thing friends, and I'm not even the only one who has noticed. Now why in the world would someone be willing to pay for and ship bulk toilet paper tubes? In my heart I hoped it's because everyone is really getting into gardening and need tubes for a massive amount of seed starting. Pinterest, well aware that I was showing interest in toilet paper tubes, showed me far more impractical applications that really pushed the boundaries of taste.

Adults are seriously making home decor out of toilet paper tubes. Mostly, the end products really, most definitely, look like they were made out of toilet paper tubes. Like, if someone invited me to their house, showed me their toilet paper tube wall art, and asked me to guess what it was made out of, I would instantly say toilet paper tubes. One of the problems in disguising this art form is that the most common design element is the simple squashed-tube shape which makes
a leaf-like design. It really, really just looks like a squashed toilet paper tube.

One way to disguise the material is to paint it. The problem with toilet paper tubes is that the crummy pulp the tube is made of is pretty absorptive and it's fuzzy, paper-pulpy nature often shows through. Even if it's painted with many layers or given a good dose of spray paint, it still looks like a painted toilet paper tube. Glitter seems to help, but I'm not an advocate of glitter-based solutions.

Some toilet paper tube art uses paper quilling techniques to add diversity to the shapes and patterns your art can take. However, the cardboard that is used to make toilet paper tubes isn't very forgiving. It's really crappy quality, and should be. It's a toilet paper tube. If you try to fold, bend, or roll this material, it tears, crumples, and frays easily. I'm not just imagining this either. I got roped into making party favors once with these things, and it's not easy. Considering what a frustrating craft material toilet paper tubes are, and their terrible quality, I don't know why anyone would put so much effort into something that is going to fall apart.

People with far more patience and skill than I have done some truly impressive things with toilet paper tubes, but you probably aren't one of those people, let's face it. I can see a theater set designer pulling off some impressive faux wrought iron using toilet paper tubes, and to me, the stage seems to be where this skill belongs. Up close, it's obviously toilet paper tubes.

Most likely will not be
used for actual canning

There are enough bottle caps in landfills,
Why do we need pre-decorated ones?

At the very least, craft stores haven't found out about this trend yet and started selling better quality vintage paper rolls like they do with those Ball jars and bottle caps of all things. So, while I have a lot to complain about, these toilet paper tube creations are actually repurposing trash.

Bullshit Scorecard

It still looks like toilet paper tubes	-5
Environmental friendliness...I guess	+5
Durability	-5
Grand Total	-5

The Process: 002 Dyeing Cotton Lint (Cold-Hearted Batch)

I was disappointed with the results from both tub-dyeing and direct application, so I tried something similar to the method I used when I brushed fiber reactive dye directly onto fabric, only leaving out a thickener since I won't be applying the dye as one would apply paint. I was pretty happy with my results from my painting, but unfortunately I don't have any photos. The process involves making a batch of chemical water, which includes urea and sodium alginate. The urea helps dissolve the dye, thereby increasing your yield, and it also keeps it wet, which is necessary for the reaction between the fiber and the dye. The alginate is the thickener, so I left that out. The sketchy part is once you add the dye to the chemical water, you also add the soda ash. This means you need to use the dye within the hour. While soda ash raises the pH, which makes it easier for dye particles to react with the fiber, soda ash also reacts with the dye itself, making it inert. That made painting very nerve wracking. There's no fussing about and no carrying on a painting for longer than an evening. However, I'll be applying the dye to my cotton almost immediately so hopefully the time limit won't matter. Since I had such good results with my painting, I'm feeling a little more optimistic here.

The reason I'm changing the way I'm doing this is because in my previous trials, the cotton was still saturated with liquid by the time I applied the dye, which I suspect caused the pale colors. I'm also unhappy with the state of the cotton after the process was over. Though I was careful, a lot of the cotton is moderately ropey now. It's not unusable, but will definitely be a pain to process into something spinnable. Also, during the process, the clumps of cotton developed air bubbles which may have also affected the availability of the fibers to the dye.

3 ounces of roughly combed cotton

To address these issues, I combed my cotton into foot-long roving like logs. You would probably card them into loose rolags. Nobody I know of hand-combs cotton. Just me, because that's what I have. Combs. Anyway, my idea was that in organizing the fibers ahead of time the cotton will be easier to handle during and after the dying process, and hopefully will make the fibers more available to the dye.

It was a huge pain in the ass, and I kept having to remind myself to do a shitty job since I wasn't going to be spinning yet. I just needed enough effort to roughly organize the fibers. Look at all of that, and it's only 3 ounces! I've got about a pound more to do in the future.

Washed cotton logs drying in the sun

Wearing exam gloves, I washed each log individually with PTD, and then rinsed them in a wire strainer. Then I let the suckers dry. Actually, I ran the hair dryer on them for awhile, but damn it, I had already spent enough time with these guys, so eventually I just crossed my fingers that they wouldn't blow away or get stolen for nesting material, and put them outside in the sun. I took a bike ride to the cafe and had some espresso. That was more fun than running the hairdryer.

Once the cotton was completely dry again, I was ready to dye. My idea was to use the recommended amount of dye per volume of water for one batch, and then increase the proportion of dye in two more batches. I planned to do this for two different colors, 22 Cobalt Blue, which requires twice the amount of dye as most of the dyes, and 50 Jade Green, which requires the standard amount of dye, but because it has a tiny amount of copper in it, it does better when exposed to heat. What's this now? What happened to Deep Orange? Honestly, I do not need any more orange fluff. Changing colors certainly makes this experiment harder to compare to previous methods, but as long as the outcome is intense, as opposed to pastel, I will be happy. Anyway the following table is the result of a lot of math:

	Cobalt Blue	Jade Green
Recommended Amount of Dye	2 tsp dye per ½ cup of water 1:12 ratio	1 tsp dye per ½ cup of water 1:24 ratio
Recommended + ½	3 tsp dye per ½ cup of water 1:8 ratio	1 ½  tsp dye per ½ cup of water 1:16 ratio
2x Recommended	4 tsp dye per ½ cup of water 1:6 ratio	2 tsp dye per ½ cup of water 1:12 ratio

The dye powder measured into scrap paper weigh-boats ahead of time
(Protective mask, eyewear and gloves used of course)

I mixed 3 tablespoons of urea into 3 cups of warmed distilled water to make my chemical water. I used a little bit of this water to paste-up my dye. In a separate cup I poured in nearly a half cup of the chemical water and dissolved a half teaspoon of soda ash into that before pouring it into the dye paste-up. I'd add more chemical water if I didn't quite make it to a whole half cup.

Pasting-up in progress

Golly, for some reason, I thought it would be a good idea to lay out my cotton on plastic wrap and squirt the dye onto it from there. It was not a good idea. My execution left a lot to be desired. First of all, I was shocked when the dye just beaded on the surface of the cotton and then rolled off. Then I was horrified when the dye started to puddle and flow towards the end of the plastic wrap. Look at this stuff. Do you want that spilling onto your countertops and dripping onto the floor? If I made my coffee that black I'd be up for days. Anyway, I resorted to massaging the logs of cotton to encourage them to absorb the dye, which they eventually did. You know, cotton fibers are actually made of layers of cellulose arranged in a particular fashion, with a final waxy coating. I was under the impression that the wax was removed during the process of scouring and washing. So imagine the pit in my stomach upon the realization that the wax was obviously still there, repelling the water. Would it even take the dye? Well, it was too late to turn back now. So I massaged away and then awkwardly wrapped everything up in the plastic wrap.  Time for Plan B.

Ha ha ha look at this slippery blue turd ensconced in plastic wrap. Such a terribad idea

Moving forward, I decided to use sealable bags instead. I put about a half ounce of cotton in each bag. I would then mix up my dye as before, then pour it directly into the bag with the cotton. I sealed the bag and massaged the heck out of that cotton. Once I was satisfied the the dye had been throughly absorbed, I squeezed out as much air as possible and made the final seal.

Eventually, the cotton accepts the dye and the volume decreases.

Rinsing

Meanwhile, I warmed up a pot of water on the stove. I took the pot off the heat and put the bags of Jade Green cotton in the hot water bath. The Cobalt Blue bags were unceremoniously dumped in a plastic basin. My plan was to leave all of this stuff outside for 24 hours, but I got a little, um, distracted by someone special and I didn't get to rinsing until 10 hours later than what I had planned. I took the cotton out of the bag and rinsed and rinsed and rinsed and, oh my gawd, blue dye is still coming out and the cotton is still BLACK. You can see the rinse water in the photo. Every bag was like this. My conclusion is that I really went overkill on the dye and don't need that much at all. Also check out the holidays. I need to work on my masseuse skills. Once I was satisfied with the clarity of the rinse water (in all honesty I was just bored waiting) I put it all in plastic basins outside, filled them with water from the hose and let it sit overnight. The next morning the soak water was freakin' dark with excess dye. After one more rinse and a squeeze, look at what I've got.

Conclusions and Results

Cobalt Blue post-soak

Jade Green post-soak

Well, that's certainly more intense than my previous results.  You'll notice there are holidays where the dye didn't penetrate despite my massaging. I did a little combing and compared the different dye batches, avoiding the holidays. I'll still use the undyed fiber, but I really want to focus on the color of the fibers that did get exposed to the dye.

From right to left: Cobalt Blue at 1:6, 1:8, and 1:12 dye to water ratio and Jade Green at 1:12, 1:16, and 1:24 dye to water ratio. The leftmost log for each color represents the recommended ratio.

That's nice and all, but is this what these colors are supposed to look like? Not really. The color came out way darker than the color swatch indicated. Swatch 22 to the left there is for Cobalt Blue, and as you can see, the fibers, even at the very tip of my combed log, are way darker than the swatch. Though my camera is crap at showing it, I'm much closer to 130 Strong Navy. Swatch 50 indicates Jade Green, but the actual fibers are much closer to 153 Mermaid's Dream and 146 Kingfisher Blue.

So freakin' what you say, but here's my objection. If I wanted those colors, I would have just used those dyes. When I did the final rinse, there was way too much dye going down the drain. What a waste of both dye and water. Because of my fuzzy navel experience I went overkill. Don't get me wrong though, I appreciate the level of color saturation for sure, and I'm much encouraged. So, moving forward, here's my plans for next time:

• Combing the cotton ahead of time was a great idea, though tedious. The fiber didn't tangle during the dyeing process, and after all was said and done, it wasn't that difficult to re-comb it. Next time though, I will make the logs smaller (say, less than a foot long) and less thick (less than three layers of combed cotton) in order to reduce the amount of holidays during dyeing.
• In no way did I need as much dye as I used. It produced unexpected results and way too much wasted water and excess dye that gets washed out. Next time I will try another experiment, probably with the Jade Green again, because it's such a lovely color. I will try three more batches 3/4 tsp, 1/2 tsp, and 3/8 tsp of dye per 1/2 cup of water. (1:32, 1:48, 1:64 water to dye ratio.) It should be interesting to see which one of those hits the target color.
• I'm debating whether or not I really need to wash with PTD ahead of time or not.
• A 1:1 ratio of cups of water to ounces of fiber seemed to work well, despite the holidays in this round. With enough massaging, and making thinner logs of fiber, I think there's plenty of fluid to saturate the fibers.
• It seems to me adding the soda ash to the dye rather than pre-soaking the fiber in a soda ash solution was key in producing the saturation seen in my samples. It's really the only meaningful difference between this experiment and the tie dye-like direct application method I used. That time I let the fibers sit for over 24 hours as well. While I'm sure letting it sit and develop os important, I think what's more important is to not have fiber that is already wet, thereby diluting the dye.
• Since I'm not trying to paint the fibers a rainbow of colors at once, there is no reason to use plastic wrap. I plan to keep using sturdy resealable bags. They can be rinses and used multiple times, and they really help me keep everything neat and organized.

Anyhow, I won't be getting to this next experiment any time soon as I have other projects that I need to finish, but I will share my results when I get to it.