Fibers, Part 3: Animal Fibers - Wool and Silk

Hello, this time I'll be writing about "animal fibers."

Please see the link at the bottom of the page for the previous article.

Now, just like plant fibers, animal fibers can be classified in detail.

"Animal Hair Fibers"

"Silk Fibers"

"Feather Fibers"

"Others"

These are the categories.

As you may already understand from the simple classification names,

"Animal Hair Fibers" are animal hairs, such as wool, cashmere, and camel hair.

"Silk Fibers" are silk threads spun by silkworms.

"Feather Fibers" are feathers from animals like ducks.

"Others" include those that don't fit into the above categories, such as spider silk.

"Animal Hair Fibers" exist in as many varieties as there are animals, so there are many types.

Wool (sheep's wool), cashmere (goat), camel, mohair (goat), alpaca, vicuña, and angora (rabbit) are some of the animal hair fibers that are commonly available.

Among these, sheep's wool is by far the most widely available and familiar.

Therefore, I will write in detail about sheep's wool.

Wool has advantages such as being "soft to the touch," "highly insulating," and "flame-resistant."

On the other hand, its disadvantages include "shrinking when washed," "being susceptible to insects," and "being vulnerable to friction."

Many people have probably experienced wool sweaters shrinking after being washed normally.

Why does wool shrink when washed?

The answer lies in the structure of the fiber.

The surface of wool fibers has scale-like structures called "scales," which open up when wet.

This increases the surface area and allows moisture to evaporate quickly, but these opened scales intertwine due to friction, causing shrinkage.

This phenomenon is called felting. Conversely, sometimes wool is intentionally felted before use.

Recently, kits for making stuffed animals by felting this wool with a needle can be found in 100-yen shops and other stores.

While we generally refer to it as "wool," there are many different breeds of sheep, and the quality of their wool varies depending on the breed.

Therefore, I would like to introduce some of the most representative breeds.

The first is the Merino breed.

This is the most common breed and the breed that produces the highest quality wool.

Through selective breeding, the sheep are left with so much excess wool that their skin becomes loose, allowing for a larger wool yield per sheep.

Originating in Spain, this breed is now raised in various parts of the world, including Australia.

The second is the Romney breed.

Many domestic wool carpets use wool from the Romney breed.

Because its fibers are thicker than Merino wool, it is ideal for carpets. It is often felted and is as well-known as Merino wool in the felt industry.

There are also various other breeds, such as Suffolk, Corriedale, Cheviot, and Jacob.

Next, I'll briefly discuss another animal fiber that the Japanese have used since ancient times: silk.

Silk is the only fiber obtained from nature that is classified as a "long fiber."

Silk has long been used as a luxury item around the world.

Silk produced in China was exported to India, Egypt, Rome, and other places, where it was sold as a super luxury item. This trade route is the famous Silk Road.

Silk has also been produced in Japan since ancient times, and around 1900, Japan surpassed China to become the world's largest producer.

Now, regarding the method of silk harvesting, silk is made from the cocoons produced by silkworm moth larvae when they become adults.

However, the thread spun by the larvae doesn't directly become silk.

Raw silk, which is made up of fibroin and sericin, is refined to extract a fibrous protein called fibroin. Fibroin is extracted from a single strand of raw silk in Japan, and one strand is approximately 1 denier. If stiffness is desired, the amount of sericin removed is adjusted.

Last time, I mentioned that there are also short-fiber silks; these are the waste threads and cocoons left over from raw silk production. These are spun into a single thread, and this process is called spun silk.

The most striking feature of silk is its beauty. Its luster, drape, and dyeability are excellent. However, it also has many drawbacks: it yellows with age, deteriorates in sunlight, is easily soiled, and is susceptible to insects; it is a delicate fiber.

Even with these drawbacks, its beauty makes it a popular luxury item that is still sold today.

Next time, I would like to write about "regenerated fibers."

Summary of this lesson:

Animal fibers are divided into "animal hair fibers," "silk fibers," "feather fibers," and "others."

Wool fibers have a scale-like structure called scales.

It expands when it absorbs moisture and shrinks when it intertwines. This is called felting.

Silk is the only long fiber among natural fibers.

The thread spun by silkworm larvae is called raw silk, and raw silk is made up of fibroin and sericin. Two fibroin molecules can be extracted from one strand of raw silk.

Thank you for reading to the end.

References

Aichi Textile Promotion Association (2016) "TEXTILE HANDBOOK"

Teruhiko Ichimi (2014) "Easy-to-Understand Knowledge of Apparel Materials, Revised Edition" Seiunsha

Etc.

Next article here ↓