What is Wool Fabric? Sustainability, Pros, and Cons

Wool is a natural fiber from hairy mammals like goats, sheep, and camels. To produce wool, they shave off the animal's hair and turn it into wool fabric with a few processes. The fashion sector considers wool a natural fiber even though it is not plant-based. But is wool fabric sustainability guaranteed?

It doesn't require heavy use of fossil fuels in its production process or cause microplastic pollution like synthetic fibers. However, it still has a few measurable impacts on the environment. 

This article explores the structure and origin of wool. We will discuss how to produce wool and its environmental impact, focusing on the effects of animal agriculture and animal welfare.

TABLE OF CONTENTS:

What is wool fiber?

Wool is a natural fiber obtained from the fleece of sheep, goats, camels, and other hairy mammals. In ancient times, early humans used the skin of wild animals as clothing. Over time, they started breeding animals, making yarn, and turning it into full sheets of fabric. 

We use wool fibers to make clothing, rugs, suiting fabric, upholstery, carpets, and many other applications. Australia, China, New Zealand, and the United States are global wool producers. In 2019, the world produced 2 million tonnes of unprocessed wool from 1 billion sheep².

Wool has a fine structure consisting of outer cuticle and inner cortex cells, while one with a coarse texture has a central medulla portion. Wool fibre primarily contains keratin, a protein commonly found in animals. Keratin protein makes wool more vulnerable to chemicals and terrible environmental conditions. 

Wool's texture is not as fine as cotton, linen, silk, and rayon fibers but has a better length. Coarse wools are about 14 inches long, while fine wools are about 3 inches long. The fiber's colors also vary. It is usually white, brown, or black, with coarse wool having a higher sheen than fine wool.

Another wool property is waviness. Coarse fibers have five waves per inch, while fine wool has 30. Wool is highly absorbent, making it easy for dye chemicals to color a fabric. It retains up to 18% of its weight in water.

Wool in the fashion industry

Wool is a staple in the fashion industry because it adjusts its moisture content and weight according to atmospheric conditions. As it absorbs the moisture content in the air, the person wearing wool clothing becomes warmer. Wool doesn't get damp quickly, making it an excellent fabric for clothes during the cold and wet seasons. 

The industry produces wool fabrics in alpaca, cashmere, camel, virgin wool, qiviut wool, llama wool, mohair, and merino wool. Wool from Merino sheep is the most common type and is mostly produced in Australia. Cashmere wool is luxurious and comes from goats native to the Kashmir region of India, while mohair wool comes from angora goats. 

Alpaca wool comes from the alpacas in South America, camel wool is from camels, and virgin wool is from a lamb's first shearing. Some wool types suit clothing and garments, while others are better for woven carpets and other wool product applications.  

Wool Manufacturing Process: How are wool fibers made?

Wool producers get the fibers from sheep farms. Sheep farming refers to the rearing of sheep for the sole purpose of using their wool. It works out because wool is the hair covering a sheep's body, which it reproduces yearly. Wool is a renewable natural fibre. Here are the production processes involved in the creation of wool yarn and fabric:

Shearing

Sheep farmers shear sheep once a year during the spring season. They remove the sheep's hair with a tool similar to a barbing clipper or a razor. It sheds the fleece in a single cut. Shearing is sheared mainly by hand. However, there are new technologies that use computers and robot-controlled hands to remove it gently. 

Cutting the sheep's hair doesn't harm the sheep if done correctly. Shearing helps keep the hair from overgrowing because they don't naturally shed their hair. Overgrown fleece harms sheep by weighing them down and impeding their movement. A sheep can produce an average of 3 to 8 kg of wool.  

Grading and Sorting

Grading and sorting refers to the breaking up of sheep hair according to its quality. Producers break it into sections based on its quality and from various parts of the body. The best quality is the wool from the shoulders and sides of the sheep, while the lower quality wool comes from the lower legs. 

They categorize the wool according to its length, fineness, and color. The sorting stage is crucial because it ensures the quality of wool and wool products. The animal species, geographic location, climate conditions of the area, shearing season, and the composition of the fodder influence the quality of wool. 

Scouring

In wool production, wool directly from a sheep is called grease or raw wool. Grease wool consists of dirt, wool wax, sand, dry sweat, and skin pieces. These contaminants make up 30 to 70% of a fleece's weight. After grading and sorting, the next step in wool production is to remove the dirt and contaminants via washing and scouring. 

Producers put wool in mesh bags and scour it in alkaline baths multiple times. The baths often contain water, soap, and soda ash (or a similar alkali). The water for the scouring is usually at 140 degrees. When the washing is complete, rollers in the scouring machines squeeze out excess water. 

It still dampens the wool because they don't want it completely dry. The byproducts from the scouring process, such as lanolin, can be repurposed and used for other household products. Also, producers often treat scoured wool with oil to make it easy to manage during the different production processes. 

Blending and Dyeing

Blending and dyeing occur at different times during early-stage processing. Blending combines wool from various bales to ensure the yarn and wool products are even and uniform in all properties throughout their entire length. Wool dyeing occurs at any stage. 

Dyed wool can get its color at the fiber, yarn, fabric, or garment stage. Producers use natural and synthetic dyes to color the wool in various ways. This part of production is relatively easy as wool is highly absorbent. They soak the wool with the dye material in boiling water to achieve the desired color. Some manufacturers add the dyes directly to the fabric to produce vibrant colors.  

Carding

Carding is the stage of wool production where the fibers are passed through a carding machine with a series of metal teeth. The delicate metal teeth straighten and blend the fibers into slivers, untwisted rope strands of fiber. Carding also removes dirt and other unwanted materials left in the fiber, making wool soft and fluffy. 

The carding process for woolen yarn is different. Producers blend the wool by cross-lapping the sliver formed and re-card the cross-lapped layer in the second part. After carding, they split it into marrow strips called slubbings instead of leaving it as slivers. 

Spinning & Weaving

Spinning and weaving are the last significant steps in creating wool yarn and fabric. Spinning comes first. Producers spin fibers together to form a strand of yarn and combine it with two to four strands. You can easily join, extend, and spin wool because wool fibers stick together.

Producers spin woolen yarn on mule spinning machines and worsted yarn on any type of spinning machine. The woolen spinning creates thick yarn, while worsted spinning creates smooth, thin yarn for garments. After spinning, they wrap the yarn around bobbins and cones and send it to weavers and knitters. 

Manufacturers use two basic weaving techniques to make wool fabric: plain weave and twill. The plain weave method uses woolen yarns to produce a fabric with a loose weave, soft surfaces, and little to no sheen. 

On the other hand, producers use the twill weaving method for worsted yarns to create fine fabrics with intricate patterns. Fabrics made with twill yarns have tighter, smoother weaves and are more durable than woolen fabrics. 

Manufacturers can use simple loom frames or complex automated weaving machines to hold the treads together during the weaving process. Knitters can either hand-knit the wool yarns into ready-to-wear garments or use knitting machines. 

Finishing

Woven fabrics undergo a series of finishing processes, including fulling, crabbing, decating, and dyeing. Fulling involves immersing the fabric in water to interlock the fibers, while crabbing sets the interlock permanently. Decating refers to the process of protecting the fabric against shrinkage. Some manufacturers choose to dye the wool at the finishing stage.

Environmental Impact of Wool Industry - Is It Sustainable?

Impact on Land and Greenhouse Gas Emissions

From the sustainability perspective, wool fabric is a renewable natural material like cotton. The only difference is that cotton is plant-based. Wool also has an excellent lifecycle. It is one of the most recycled fibers in the textile industry. Unlike the synthetic alternatives used to produce garments, wool is also biodegradable. 

However, wool is only partially sustainable. Wool is from animals, commonly domesticated sheep and alpacas. The environmental impact comes from the sheep, not entirely from the production processes. 

Rearing these animals has a negative ecological impact. Wool farming also impacts the environment around the sheep. Sheep are ruminants like cows; they release methane gas through digestion and excretion.  

Sheep's ancestors, mouflon, could naturally shed their winter coat. However, humans have bred sheep to increase the quantity and improve the quality of wool they carry. Rearing sheep requires a large expanse of land for growing sheep feed and grazing. 

Sheep release methane gas from enteric fermentation, a process common in ruminants. Their decaying manure also releases methane. Sheep excrement pollutes the environment, including water and air. It causes eutrophication, which occurs when a river or other body of water receives excess nutrients. Eutrophication causes the excess growth of algae, suffocating aquatic life by reducing water oxygen levels.

According to a study published by the University of Liverpool, sheep grazing affects plant species in the British countryside. Professor Rob Marrs and Professor Richard Chiverrell used two plots of land for their research, one of which sheep grazed on.

The results showed that plants from the non-grazed land were more nutritious than those the land sheep grazed on. It had three times more nitrogen, phosphorus, and some micronutrients and greater concentrations of macro-nutrients. It also revealed plants in non-grazed land had better digestibility and decomposed faster¹. 

Animal Cruelty

Unfortunately, not all sheep farmers rear sheep under humane conditions. No federal regulations strictly uphold animal rights, and some farmers practice castration, tail docking, and mulesing. 

They shorten or cut a sheep's tail with knives, hot tools, or tight bands without giving it some form of pain relief. Mulesing, the act of cutting the skin around a live lamb's buttocks for pain relief, is illegal in Europe, New Zealand, and the UK. However, Australian wool producers still practice it.

Farmers claim that pain relief isn't effective when used. They perform tail docking and mulesing to prevent flystrike. Also known as myiasis, it is an infestation of blowfly eggs in a live body. The hatched larvae eat the sheep's skin tissue, causing infection and sometimes death.

Another form of animal cruelty is violent shearing. Since humans have domesticated sheep, they are prone to death by heat exhaustion without human intervention. Shearers do not care about animal welfare. They do not feed or provide water for the sheep before shearing them because it makes them weak and unable to resist.

There have been reports of animal cruelty during the shearing process. Shearers punched sheep with their closed fists, slammed them on the floor, and restrained them with their knees while holding electric clippers to their necks. They often left the sheep with sewn wounds without administering pain relief.

Inhuman treatment also extends to other animal species producing wool, such as alpacas. An undercover investigation revealed animal abuse occurring in the world's biggest privately owned alpaca farm, Malkini, near Peru. 

Malkini workers used excessive force on the alpacas, even slamming pregnant alpacas onto tables. They also used a restraining device resembling a medieval torture rack to restrain the alpaca, which nearly broke their legs as they struggled to free themselves.

The Wool Industry and The Meat Industry

Some think the wool industry is kinder than the leather industry because leather comes from slaughtered animals. However, that is not the case. The meat and wool industries are intricately intertwined. Once farmers determine they can't produce quality wool, sheep and alpaca are killed for their meat. 

Once they are 5 to 6 years old, farmers send them to live export ships where they must endure inhumane conditions before getting killed at the slaughterhouse. Most times, the sheep die from heat, starvation, and stress because they are often kept in poorly ventilated spaces and untreated waste.

Conclusion: Wool Fabric Sustainability

Wool can become a lot more sustainable than it is when producers adhere to animal welfare regulations and treat them with kindness. Many sheep go through inhumane conditions because we want to wear wool garments.

Sheep farmers can also practice regenerative farming to reduce the impact of sheep farming on the land. Let's be more cautious when buying wool products from vendors with adequate supply chain transparency. Look out for animal cruelty-free wool.