There is an entire family of fabrics made from trees!

As I discussed in Part 8 of this series, semi-synthetic fabrics (also know as “man-made cellulosic” fabrics) are made from materials like wood pulp and bamboo, using some pretty intense chemicals and processes.

When tree pulp is used, about 60% of the tree is lost/wasted in the process. Yes, clothing is contributing to deforestation! In moderation, it wouldn’t be such a problem, but…right now nothing is being made and consumed in moderation.

Meet modal.

• More breathable and durable than standard viscose/rayon.

• Often used for bedsheets, yoga pants, swimwear, and bike shorts.

• Designed to hold its shape and color when washed in warm water.

And yes, making modal from trees is a serious process!

• The process for making modal is virtually identical to producing viscose. Trees (often beech) are harvested, turned into chips, and then the cellulose is extracted

• Sodium hydroxide and carbon disulfide help turn the cellulose into a viscous solution via a series of processes, including pressing, shredding, crumbing, mixing, exposure to oxygen, and aging.

• The viscous liquid is filtered, degassed, and extruded through a spinneret into in a bath of sulfuric acid.

• The resulting yarn is washed, bleached, dried, and spun into yarn. At this point, the yarn is subjected to other chemical treatments like pre-shrinking, fire resistance, wrinkle resistance, anti-odor, etc. Then it is woven into fabric and dyed/printed.

So is modal a better option?

Kinda? By now you know all things clothing and fabric related are complicated.

There are some aspects of modal that make it slightly better than regular viscose/rayon: less chemicals are used throughout the process, the fabric is more durable and washable, and many manufacturers have developed processes that help mitigate release of toxic chemicals into the ecosystem.

However, we also know that the production of viscose/rayon is an environmental justice issue. There are manufacturers who are thoughtful/careful and others who are reckless/polluting. Lenzing TENCEL modal is a name brand that has a lower environmental impact. Look for that on labels.

What’s lyocell?

The lyocell method of making viscose is generally considered a more sustainable (but not perfect) alternative.

• Very strong, soft, and breathable.

• Often blended with other fibers like cotton and polyester. The resulting fabric is super strong.

• Also used for medical dressings, filtration devices, and conveyor belts.

Explaining the lyocell method of making viscose…

• Lyocell viscose begins as hardwood trees like birch and oak. The trees are turned into chips and then softened into pulp with chemical digesters.

• The pulp is washed/bleached, dried into a sheet, and then rolled into spools. The spools are broken into little squares. These squares are turned into liquid after being placed in pressurized vats of amine oxide. The solution is filtered and forced through spinnerets, turned into thread, and then washed. Next, the threads are treated with a lubricant like soap or silicon and then carded.

• This process is “closed loop,” meaning that the chemicals are reused.

• Look for TENCEL (made by Lenzing) or Birla Excel for true lyocell options.

These fabrics can be a “better” option, but there is a catch…

• Overproducing and overconsuming clothes made from trees leads to deforestation.

• In some ways this is similar to the relationship between paper consumption and trees…but the big difference is that paper is widely recycled, while fabric currently is not.

• Some manufacturers (like Lenzing and Birla) are committed to strategic, thoughtful tree harvesting. And other producers are working on reusing tree waste and discarded textiles.