What is Lyocell Made From? Production Process

Maybe you’re curious about the materials used to make lyocell. We are here to explain the process of making it to you.

Most likely, you’ve heard of Lyocell before, and chances are good that you have some clothing made of it hanging in your closet. The question is: what is lyocell made from? Wood is where it all begins. Eucalyptus predominates, but oak and birch can also be used.

The wood is cut into penny-sized pieces after harvesting, then ground into a pulp where the chemical amine oxide dissolves. Raw cellulose, a viscous, sticky liquid, is all that’s left. Bright, white lyocell fibers are produced when the mixture is forced through spinnerets.

This is a comprehensive guide to making lyocell.

What is Lyocell Made From?

The main ingredient of lyocell is cellulose, a natural polymer found in the cells of all plants. It serves as the foundation for other plant-based fibers like linen, hemp, and cotton. Hardwood tree pulp is the source of the cellulose used in the production of lyocell. The pulp is typically made from a mixture of trees that were selected for their cellulosic characteristics, such as color and the level of contaminants.

Oak and birch are two examples of commonly used tree species. The trees are raised on managed tree farms, usually on land that is unsuitable for other agricultural pursuits. The solvent used in the manufacturing process is amine oxide. Another essential component for making lyocell fiber is water. Additionally, a finishing agent is used, and while this varies, it is typically a lubricant like soap or silicone. Fabrics made of lyocell are typically colored.

How is Lyocell Made?

Although Lyocell is a plant-based fiber, it is also processed with cutting-edge synthetic materials. In other words, it’s a blend of both natural and synthetic ingredients. And technically speaking, that makes it a semi-synthetic fiber.

Here is how it is made:

Preparing the Wood Pulp

Loggers harvest the hardwood trees used to make lyocell, which are then transported by truck to the mill. The trees are cut to 20 feet (6.1 meters) lengths at the mill and have their bark removed using high-pressure water jets. The logs are then fed into a chipper, which creates squares barely larger than postage stamps.

The chips are loaded by mill workers into a tank of chemical digesters, which turns them into a wet pulp. This pulp is washed with water and may be bleached. After drying in a sizable sheet, mill workers wind it onto spools. The sheet of cellulose has the consistency of thick posterboard paper. The massive roll of cellulose weighs about 500 lb (227 kg).

Dissolving the Cellulose

At the lyocell mill, workers unroll several spools of cellulose and break them into one-inch squares. The squares are then loaded into an amine oxide-filled, heated, pressurized vessel by the workers.

Filtering

The cellulose dissolves into a clear solution after just a brief period of soaking in the solvent. To ensure that all the chips are dissolved, it is pumped out through a filter.

Spinning

A spinneret is used to pump the solution through later. These tools are employed with a range of synthetic fibers. The spinneret is punctured with tiny holes in the shape of a showerhead, and when cellulose is forced through it, long strands of fiber emerge. The fibers are then submerged in a new, weaker solution of an amine oxide. The fiber strands are set as a result. They are subsequently washed in demineralized water.

Drying and Finishing

The water is then removed from the lyocell fiber before it enters a drying area. At this stage, the strands move on to a finishing area where a lubricant is applied. Depending on how the fiber will be used in the future, this could be soap, silicone, or another substance. In a sense, this step serves as a detangler, making the subsequent processes of carding and spinning to create yarn simpler.

Final Steps

At this point, the dried, finished fibers are in a shape known as tow. A tow is a large untwisted bundle of continuous-length filaments. The tow bundles are brought to a crimper, a device that compresses the fiber to give it bulk and texture. The crimped fiber is carded by mechanical carders, which separate and arrange the strands of the fiber in a manner similar to combing. The carded strands are then cut and bagged for delivery to a fabric mill.

It takes only about two hours to complete the entire manufacturing process, from unrolling the raw cellulose to baling the fiber. Following this, there are numerous ways to process the lyocell. It might be spun with another fiber, like cotton or wool. The yarn can be knitted or woven like any other fabric, and it can be given a range of textures, from silky to soft and suede-like.

Recovery of the Solvent

The amine oxide used to dissolve the cellulose and set the fiber after spinning is recovered and re-used in the manufacturing process. The dilute solution is evaporated, removing the water, and the amine oxide is routed for re-use in the pressurized vessel in step 2. In the typical lyocell manufacturing process, 91% of the amine oxide can be recovered.

Quality Control

Only a few plants in the world manufacture lyocell. Modern, specially constructed mills, with sophisticated computer monitoring systems for quality control.

The computers continuously check a variety of key factors, such as the tenacity of the fiber, its color, the denier (a measurement of the fiber’s diameter), elongation, moisture level, and level of the finish application. Computers also monitor for “trash” that results when one hole in the spinneret becomes blocked, and the filament comes out splintered or undrawn.

Byproducts/Waste

Lyocell production is significantly less toxic and wasteful than the production of other cellulosic fibers because it generates no hazardous byproducts. The industry has not been accused of having bad forestry practices, and its main component, cellulose, is easily obtained from managed tree farms.

The amine oxide solvent is non-toxic, and because it is almost completely recycled during manufacturing, it is not released into the environment. Natural biodegradability is another benefit of Lyocell fabrics. Manufacturing lyocell is also environmentally sound because less water and energy are used than in the manufacture of other manmade fibers.

Lyocell’s Advantages and Disadvantages

Below are the pros and cons of lyocell.

• Thanks to its breathability, Lyocell is an effective anti-bacterial and great moisture absorbent.
• Lyocell provides high moisture absorption, even better than cotton. It ought to be your first choice if you frequently perspire or have sensitive skin. The same applies if you live in a rainy, humid climate.
  Lyocell will not only benefit your comfort by keeping you dry and giving you a soft-to-the-touch feeling, it will also save you time and money. Your time and finances won’t be put at risk when you choose Lyocell products because you won’t need to buy new clothes as frequently.

• Because of its lightness, Lyocell does not wrinkle so easily. But it’s always a good idea to look at tags to see how the item should be handled. By the time the article is finished, you might want to check out the FAQ section.
• Lyocell material offers great strength and elasticity, which transforms it into a highly durable fabric.
• Lyocell is so soft to the touch that it has often been compared to silk. It feels smooth against the skin, which is ideal if you have skin rashes, and it has a lovely appearance.
• As we said earlier, Lyocell is a versatile fiber, maybe the most flexible of them all and that’s what makes it so attractive for diverse manufacturers. Lyocell can be molded into a variety of shapes without sacrificing quality using controllable fibrillation. It can either have a smooth, silky finish or a consistency more akin to suede.

The benefits have been discussed, but what about the drawbacks? Performance-wise there aren’t any, but when it comes to pricing, they rise up. Lyocell production requires specialized technology, which drives up the cost of production. In contrast to conventional fibers like cotton, Lyocell, therefore, ends up costing consumers more.

In simpler terms, Lyocell is more expensive than other fabrics on the market. But because of all its great qualities 一particularly its durability一, it should actually be seen as an investment.

What Does Lyocell Feel and Look Like?

Lyocell can have many different textures, but the basic fabric is soft to the touch. It doesn’t stick and is hypoallergenic. Lyocell is also 50% more absorbent than cotton, making it a popular material for athletic clothing.

The three main advantages that lyocell has over many other options are its softness, skin-friendliness, and moisture management.

Here is what you need to know about lyocell fabric:

• Pros and Cons of Lyocell Fabric
• Is Lyocell Sustainable?
• Is Lyocell Stretchy? Can You Stretch Lyocell?
• Does Lyocell Shrink When Washed?

Conclusion: What is Lyocell Made From?

The making of Lyocell starts with harvesting wood, which often comes from eucalyptus trees. But oak, bamboo, and birch trees are also frequently used in the production of Lyocell. This wood is broken down into tiny pieces and then chemicals are added to dissolve it into wood pulp.

Raw cellulose is left behind, which is liquid and sticky. Once more, using a solvent called amine oxide, this liquid mixture is heated and broken into small pieces. After being filtered, the cellulose goes through a spinning process that turns it into bright, long, and thin fibers.

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