Understanding Rayon and Viscose

The care label on a rayon shirt.
Rayon is a semi-synthetic fiber made from wood, paper, bamboo or other pulps and heavily chemically processed into fiber we can wear.

Rayon (or Viscose on some clothing labels) is a fiber that is made from natural materials (like wood or bamboo) that go through an intensive chemical process (including being extruded through tiny holes to form fibers, just like polyester) to become wearable cloth. Although it is made from natural materials, and feels and acts much like cotton, it is not an ideal eco-friendly material in most instances because of the chemical process it goes through. This material is considered semi-synthetic and is only distantly connected to it’s bamboo or wood origins. (In fact, a 2015 lawsuit addresses the mislabelling of rayon products as bamboo in the U.S.A.)

There are different varieties of fibers under different names and brand names in this category, with differing environmental impacts. Rayon and Modal are manufactured in similar ways, with about 50% of chemicals used in manufacturing released into the environment through waste water, and the source material being a type of wood or bamboo.

Lyocell or Tencel® (brand name) are similar fabrics but the chemicals are almost entirely re-used in each batch, making it much more environmentally friendly, and they use eucalyptus trees. This fiber will be covered in a future post, as it is somewhat different from rayon.

Qualities of Rayon
  • Highly Absorbent – Rayon is more absorbent than cotton. For this reason it is often used in things like diapers.
  • Dyes easily
  • Soft and Comfortable – as breathable and soft as cotton, and sometimes more so.
  • Can imitate the feel of silk, cotton, wool or linen, depending on the finishes used.
  • Does not insulate body heat which makes them cool in summer but not very warm in the winter.
  • Good drape – fabric is more slippery than crisp.
  • Poor elastic recovery – fabric will not bounce back into shape as easily as other fibers.
  • Will not hold an electrical charge (no static electricity)
  • Basic rayon is weaker when wet (which is why it is often dry clean only) and may shrink significantly in a washing machine. HWM (High Wet Modulus) Rayon is still strong when wet (often labelled with a machine washing option).
  • Will wrinkle.
Care for Rayon
  • Because of the different varieties and finishes on various rayons, there is no cut and dried solution for caring for rayon. Follow clothing guidelines where possible and try to ask for care instructions when purchasing a rayon fabric.
    • Traditional Rayon
      • Traditional rayon is dry clean only and may shrink 10% when washed in a home washing machine.
      • Some sizings and dyes used to treat rayon to make it stronger or softer are moisture-sensitive and if they get wet, can form wet rings which can’t be removed in the dry cleaning process. If you get water on that type of rayon, the best option is to blot away any moisture immediately.
      • Because rayon loses strength when wet, hemlines may drop or shift during washing, meaning they may need to be adjusted after cleaning.
    • High Wet Modulus (HWM) Rayon
      • Some rayons (High Wet Modulus/HWM Rayon) can be machine washed. Follow label instructions if given (If in doubt, dry clean or hand wash with no wringing and lay flat to dry, reshaping the garment to the desired dimensions and shape).
  • Rayon should be protected from silverfish and mildew, but is not as susceptible to pests as natural fibers like wool.
  • Rayon can be ironed at a temperature slightly below what would be used for cotton.
  • Rayon can be bleached without damaging the fiber, although it may impact the colours of the dyes used on the rayon.
Benefits
  • It’s comfort, breathability and softness make Rayon a pleasure to wear.
  • Rayon from sustainable sources (like sustainably managed bamboo grasses, or sustainable certified forests) are having less impact on the environment at the raw resource stage (but often more impact through chemical pollution).
  • Rayon made in a closed loop production cycle re-use the chemicals instead of releasing them into our water, but most Rayon is not produced this way – only some brand names like Tencel® or Lenzing Modal® (which are covered in a future post).
Disadvantages
  • Traditional rayon may be sourced from forests that are not sustainably managed. Any products not coming from sustainably certified forests are likely contributing to the massive deforestation of our planet, and thus tied to climate change, soil erosion and the loss of the animals and plant life that thrive in those forests.
  • Traditional rayon reuses only about 50% of the chemical (carbon disulfide, a known human reproductive hazard) used in the processing of the pulp into fibers. The remaining chemicals are released in waste water back into the environment.
  • In an examination of microplastic found in the world’s deep seas, rayon accounted for 56.9% of fibers found in the deepest water. This problem stems less from the production process than from the way we treat our textiles after using them (and much of this likely comes from other non-garment products such as diapers).
  • Traditional rayon can be difficult to care for properly (requiring dry cleaning or easily becoming damaged) which may result in frustration or damaged items heading to a landfill sooner than intended.
What to Do With Rayon
  • Because Rayon has so many different types and labels, it’s important to ask as many questions as possible when purchasing, so we can make sure we know how to care for it properly and make it last as long as possible.
  • When we can, we should try to purchase only rayon from sustainably certified forests, and made in manufacturing processes that reuse as much of the chemicals and waste water as possible (like Tencel®). If made properly and sustainably, Rayon is a great eco friendly alternative to other fibers – but if made with unsustainable wood and chemicals dumped back into the environment, it’s one of the least ideal choices.
Additional Resources:

Rayon Fiber (Viscose). www.fibersource.com.

Bamboo and Rayon. The Footprint Chronicles. 2012 Patagonia.

Seeing the Fashion Through the Trees. Zady.

Rayon – The Multi-Faceted Fiber. Joyce A. Smith, Ph.D. March 2010.

 

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