How does fabric work? As in, going from say, raw cotton, to a cotton sheet or T-shirt


I ended up going down a rabbit hole on this subject tonight, I’ve watched a bunch of “how it’s made” episodes and similar things, and I feel like I get the overall process, but there are still parts I can’t wrap my mind around.

Once cotton has been harvested, and had all the debris removed, it seems to be typically packed into a large bail.

Now, at this point, what you have is a gigantic bail of short hairs. I mean, an individual cotton fibre, hair, whatever you want to call it, is probably only a few inches long, right? And they’re all tangled up at random.

I don’t really understand how you go from that, to having a single long thread of cotton – like, the kind of thread you’d sew with. How do all those short hairs get combined into one long continuous thread, and how does the big mess of a bail get untangled into that?

And then, once you have a spool of thread.. I still don’t fully grasp how you get from thread to fabric. I’ve looked up things on knitting, and sewing machines, and looms, and it still seems like black magic to me. You’re basically making lots and lots of tiny little loops/knots into a grid, forming a 2D sheet, out of what is essentially a 1D line, right..?

I suppose what I don’t get here is how it stays intact. Why, when you get say, a tiny rip in a cotton T-shirt, the whole thing doesn’t just completely fall apart and unravel entirely back into thread.

I found [this really cool image]( of cotton fabric under a microscope, and I can see how it’s all sort of held together with an under/over thing, basically each crossing trapping another piece of thread. But.. logically to me it seems that if you broke that at any point, the whole thing would just fall apart. And fabrics don’t do that. You can maybe pull on a loose thread, but it stays mostly together even when cut.

I find this whole concept fascinating, but I also just sort of don’t get it on a fundamental level, so I’d appreciate if anyone could break it down as an for me 🙂

In: Technology


Consider this.

Take two pieces of paper and lay them on top of each other. Now pull them apart. Easy.

Now take two phone books and overlay the pages one at a time. Now try to pull them apart. The friction from all the pages is so high you would need two semi trucks to pull them apart.

Same goes for rope. You have all those small short fibers. They get wrapped around each other into tiny threads with the friction between individual fiber preventing them from separating. They you wrap the tiny threads around each other to form larger threads. Then you wrap the larger threads around each other. Eventually you have a rope.

Friction is an important component, but it’s the potential energy of the system that allows the friction to keep the fibers in place. The fibers are made into thread/yarn by twisting them tightly, then putting two or more of the twisted strands together and encouraging them to release that twist against each other until they’re locked together. You can try it by twisting about a foot of string until it it starts to kink up, folding it in half keeping a grip on the cut ends, and letting it untwist. The two strands wrap around each other.

Then weaving or knitting (or any number of needlework crafts) bends the threads so that they pull against each other just enough to tend to stay put. You may have tried this as a child by weaving with paper strips, and the paper is so flat that it doesn’t bend much and the edges needed tape to stay together. Fabric is generally woven with a continuous thread that wraps around the edge, keeping the edge thread from slipping loose. Sewing basically uses additional thread to cram the fabric’s threads together so a cut edge can’t unravel easily. Some commercially knit items like t-shirt material are also knit in a more complex way to discourage the fabric from unraveling if a thread is broken.

You might be interested in an IRL sheep to shawl event. Reenactors, Ren faires, and spinning/weaving guilds do these events and it is fascinating to see just how quickly humans can make fabric with only moderately complex tools.