fabric friday: petroleum-based manufactured fibers

So let’s continue our discussion of manufactured fibers, shall we? Last time we talked about plant-based manufactured fibers, or cellulosics, which originate when plants are broken down by chemicals and are then forced through little holes in a spinneret to make the filaments, much in the same way that a silkworm spins its cocoon.

solution being forced through a spineret to make fibers

But the most common manufactured fibers are petroleum-based. With these fibers, the shape of the spinnerets and how the filaments are processed affect the finished fabric enormously. Obviously, anything made from petroleum isn’t going to be very environmentally friendly. But I’ll talk more about that later.

Here are some of the most common petroleum-based fibers.

Acrylic is a polymer fiber that has a lightweight, soft, warm, and wool-like feel. It takes dyes beautifully and has excellent colorfastness. It resists shrinking and wrinkles. Those pashmina wraps that New York sidewalk vendors sell in every color of the spectrum are actually made of acrylic because it can be finished to have a similar feel to cashmere. (Yes, I know the labels say they’re made of pashmina or cashmere, but you don’t really believe you can buy a large pashmina wrap for under $10, do you?) Unlike cashmere, however, acrylic tends to fuzz or pill easily, and it isn’t nearly as warm. It also builds up static and can irritate the skin of people who suffer from eczema. (Can you tell I’m not a big fan?)

Polyester has a bad reputation, but as a fiber it possesses some valuable qualities. It is strong and resistant to stretching and shrinking. It dries quickly, and it’s crisp and resilient both when dry and wet. It’s also wrinkle and abrasion resistant, and it retains heat-set pleats and creases well. It’s easy to wash, but it’s difficult to remove stains from polyester because it repels water so well. It’s also prone to static and pilling. So that sort of explains why polyester was so popular in the 60’s and 70’s, doesn’t it? At the time, it seemed like a miracle fiber, sort of like prepared foods were miracle foods; they were so easy to prepare. The sad truth, however, is that although it’s the most commonly used manufactured fiber in apparel, polyester is also one of the least environmentally friendly fabrics to produce. Not than any of these fibers are terribly environmentally friendly, but polyester is the worst offender.

This is Polly Ester, not Polyester

Nylon is the second most widely used manufactured fiber in the U.S. The polymers used to make nylon give it strength as well as good elasticity and resilience. Nylon also has a nice drape. It can be washed or dry cleaned, but because it repels water (the technical term for this is “hydrophobic” if you want to know how to sound like a real fabric geek), it tends to build up static and pills easily. You’ll find nylon used most often in intimate wear, swimwear, exercise wear, hosiery, and sometimes in jackets.

Spandex has excellent stretch and durability without pilling or building up static. Spandex is quite expensive to produce, however, and tends to yellow and become brittle over time. This doesn’t usually pose a problem for most street wear, however, because spandex is usually blended in small quantities (sometimes as little as 1%) with other yarns to make fabric with some stretch. You don’t need much spandex to get stretch in a fabric, but if you’ve ever had a swimsuit give out after spending time in a chlorine pool, you’ve experienced the drawbacks of spandex.

Some of the most interesting innovations in the manufactured fiber industry over the past few decades have been in the production of microfibers. These fibers are much finer than the manufactured fibers I’ve just discussed, and there are two methods used to produce them. In the first, very fine filaments are produced which are then stretched to make an even finer yarn. In the second method, two polymers are combined into a filament which is then split it into a number of even finer filaments.

The fineness of these fibers gives them their unique qualities. The hand is softer than other manufactured fibers, they drape better, and they wick moisture (which means that they’ll pull moisture away from your body to keep you comfortable). Microfibers can also be combined with other fibers to improve on the original qualities of another fiber. For example, microfibers blended with wool can make the wool appear to be a better quality than it actually is. (Tricky, hmm?)

And now that some fibers are actually being produced from recycled materials, not all petroleum-based fibers are as bad for the environment as their reputation would lead you to believe. Post-consumer polyethylene terephthalate (PET) soda bottles are commonly recycled into polyester fibers, and from what I understand this doesn’t require any more energy or processing than the creation of new polyester. So we can feel at least a little better about recycled polyester and polyester microfibers now that we’re recycling materials.

Now that we’ve discussed common fibers used in apparel fabrics, we’ll turn next to discussing some of the finished fabrics themselves. Within each fiber category there are such a wide variety of fabrics, we’ll never be able to discuss them all, but maybe you’ll learn about some fabric you hadn’t previously considered. I’d love to hear about your favorite fabrics to sew, too. Have you discovered any fabrics that have surprised you and that you’ve enjoyed sewing or wearing?