Rayon Fiber Facts – Part II of Rayon: Love It or Hate It
In PART II on Rayon: Love It or Hate It, learn all about the different types of Rayon. Finally, understand terms like Viscose, Modal™, Lyocell and Tencel®. Learn about the manufacture of these types of Rayon, as it is all really quite interesting. If you’ve just joined in, you would be well advised to go to Saturday’s Post and read Part I – which gives the basics of Rayon – the ‘Poor Man’s Silk’, or ‘Artificial Silk’ – or ‘Art Silk’ as it was shortened to.
To review, here is a definition of Rayon: “Rayon is made from cellulose, commonly derived from wood pulp, and more recently from bamboo. They are neither a truly synthetic fiber, in the sense of synthetics coming from petroleum, nor are they natural fibers, in the sense of processing fibers that are produced directly from plants or animals (such as wool). However, their properties and characteristics are more similar to those of natural cellulosic fibers, such as cotton, flax (linen), hemp and jute, than those of thermoplastic, petroleum-based synthetic fibers such as nylon or polyester.
All three fibers are referred to generically as “regenerated cellulosic fibers” due to the combination of the natural raw cellulosic material and the chemical manufacturing process that breaks down the cellulose so it can be “regenerated” into a fiber from the original pulp.”
Types of Rayon
Joyce Smith in her paper on rayon for Ohio State University Extension, identifies 4 major types of modifications of Rayon. These are:
Regular or (Viscose) Rayon
HWM – High Wet Modulus Rayon – ‘Modal’ rayon
High Tenacity Rayon – mainly industrial uses – like cords and in tires
Cupramonium Rayon
Similar to ‘regular’ rayon or ‘Viscose’.
Manufacturing process is NOT environmentally friendly. No Cupramonium rayon is produced any longer in the USA. Most comes from European nations.
Ed Mass (an environmentalist), in his article: Rayon, Modal, and Tencel – Environmental Friends or Foes, divides Rayons into ‘Three Generations’ of Rayon development:
First Generation – Rayon or Viscose. Upon this first development of rayon, further enhancements were built. Developed first in 1855, and patented in 1894, it took until 1910 for rayon fiber production to begin in the U.S. Here are some characteristics:often identified on labels by term ‘Viscose’.most of the rayon we see in the marketfound in apparel and home furnishings have the distinguishing characteristic of being weak when wet. Therefore, it may shrink or stretch when wet.Dry cleaning is usually recommended to preserve the appearance of fabrics made from this fiber. If machine washed, untreated regular rayon can shrink as much as 10%
Second Generation – High Wet Modulus – which was developed to conquer the ‘weak when wet’ problem of Viscose. One of the two world manufacturers, Lenzing AG, manufactures Modal from sustainably harvested Beech trees, or Bambo. This Modal™ Rayon was developed in Japan in 1951. Modal is extra strong when wet and extremely soft. Because of its softness, it is often found in underwear and sleepwear. Here are some characteristics:
washing and tumble drying can be the care of HWM rayons
similar to cotton, it can be mercerized for increased strength and lustre.
terms used are ‘Polynosic’ or trade name MODAL™.
Third Generation – Lyocell. The generic name, Lyocell, is perhaps better known by its brand name, Tencel®, and uses Eucalyptus as its cellulose source. The ‘claim to fame’ for Lyocell is its ability to absorb excess liquid (perspiration) and quickly release it into the atmosphere – all while being resistant to developing odors. Lenzing’s Lyocell plant went into operation in 1997, so, yes, the term ‘Tencel’ or Lyocell is a fairly new textile term.