Monday, March 17, 2014

Fabric 101: Regenerated Fibers [ Part 4 ]

After a brief hiatus, we are now back to my Fabric 101 series! It is time to move on to man-made fibers. I was going to add an exclamation point after the previous sentence, but I prefer natural fibers (because not all fibers are created equal).

If you are interested in reading about natural fibers, you can read part two and part three of this series. If you need a refresher on what the heck Fabric 101 is, feel free to check out part one!

Looking at our fiber chart, you can see that two of the main regenerated fibers are rayon and acetate. Regenerated fibers are fibers made from a natural base, but the base needs to be altered to become a fiber that can be used to weave or knit into fabric.

Commercial production of Rayon begin in 1910, which gives it the the honor of being the first regenerated cellulosic fiber! The base fiber of rayon is usually wood that is broken down by chemicals into a viscous solution that is then extruded through a spinneret into an acid bath. This bath returns the fiber to a solid form (aka filament fiber). An easy way to imagine this is: You push wood pulp through a shower head that is submerged in a tub filled with chemicals. Tada!

Interesting fact #1: Rayon is 50% weaker when wet, and if it is not resin-treated it will shrink progressively. Best practice is to dry clean rayon.

Interesting fact #2: Rayon was originally marketed as "artificial silk" until the name officially changed in 1924. 

When talking about rayon, it is generally viscose rayon people are referring to, and sometimes it is simply called viscose. There is another type of rayon called HWM (high wet modulus) rayon that is usually called modal. Modal is made from beech trees and is preferable to viscose rayon because it has greater stability and strength. Its properties are similar to cotton, it can be treated to minimize shrinkage, and you can wash it in the wash machine!

Another fiber that was originally marketed as rayon (but now considered a separate fiber) is lyocell (or Tencel®). Lyocell is also regenerated, but is extruded into a completely different chemical bath. Lyocell was introduced in the 1990's and, while it is more expensive than rayon, is more environmentally friendly, is hypoallergenic, has high moisture absorbency, and is the most similar to cotton than any other man-made fiber.

Interesting fact #3: Several years ago fabrics and yarns started popping up on the shelves labelled as "bamboo" - these products were rayon that was made using bamboo as the cellulosic base. It was a bit misleading, and I believe the process of labeling fibers and fabrics as "bamboo" is actually illegal now.

photo from

Acetate is another regenerated fiber, and is the second manufactured fiber to be produced in the United States. It is also the first thermoplastic fiber (it melts).

There is little good I can say about acetate as a fiber (in relation to clothing). It is very shiny and very smooth, but its beauty is only skin deep. While it has good moisture absorbancy, it is weaker when wet, prone to static, poor abrasion resistance, and is prone to fume fading (the dye will change colors when exposed to pollution). Acetate is mostly used as lining in coats and jackets.

Interesting fact #4: In World War I acetate was used to coat airplane wings as a varnish.

photo from

Interesting fact #5: Nail polish remover (acetone) will dissolve acetate... so don't take off your nail polish over your coat lining. (This is my PSA for the week)  =P

Anndddd that is all about regenerated fibers! I even sneaked in five interesting facts - feel free to break these babies out at parties (or any social situation that your feel is appropriate)! Next time we will talk about synthetic fabrics and the powerhouse that polyester.