In today’s world, silk is one of the most high-valued and luxurious fabrics for clothing, bedding, or upholstery. People admire this natural fiber for its strength, shine, resilience, and softness. Also, its elegant appearance and feel position it as a luxury material within the fashion industry. This makes it a high-end material for garments.
Silk takes up only 0.2% of the global textile industry. However, this small percentage is nothing compared to the actual trading value. The silk industry (also called sericulture) is a multi-billion-dollar industry3. Regardless of the trading value and appearance, below, we explore the question: is silk sustainable?
Quick Links for Silk Fabric:
- What is Silk Fabric?
- How is Silk Fabric Made?
- History of Silk Production
- Is Silk a Sustainable Fabric?
- Pros and Cons of Silk Fabric
- Brands that Use Sustainable Silk Fabric
- Silk vs Viscose Rayon
- Silk vs Lyocell
What is Silk Fabric?
Silk is a natural fiber that consists of fibroin, which is the protein some insects secrete to make cocoons. Essentially, fiber is the material these insects produce to make their cocoons and nests.
Mulberry silk is the most common type, which producers derive from Bombyx Mori, a worm that lives on a mulberry tree. This is the silkworm that the industry primarily uses in the commercial production of silks. Mulberry contributes around 90% of the total global raw silk production1.
Aside from using either wild or domesticated silkworms, sericulture also produces other types of silk. This depends on the type of insect the manufacturers use to produce the silk fibers. Other types include spider silk, coan silk, mussel silk, eri silk, and tussar silk.
On paper, it is possible to generate fabrics without harming the silkworms. However, many sericulture practices involve boiling the cocoons with the silkworms inside because it helps to prevent the long silk strands from breaking. Naturally, this practice of boiling the silkworm inside the silk cocoon has raised many ethical concerns.
Animal cruelty is the main concern here because this process leads to the death of these insects. As a result, peace silk emerged. Peace silk, or Ahimsa silk, uses a less-lethal process. It allows the silkworms to evacuate the silk cocoon before boiling. In this light, the production process of peace silk enables these silkworms to live their natural life. Also, producers breed silkworms under natural conditions. This means these silk farms don’t use chemicals such as insecticides and fungicides.
Silk is an ancient luxury fabric. Today, sustainable and ethical fashion brands are paying attention to the kinds of silk fabrics they use and the means of harvesting silk. As a result, some of them settle on vegan silk alternatives such as Tencel Modal and Lyocell.
How is Silk Fabric Made?
The manufacturing process of silk involves harvesting silkworms for textiles and fabrics. Below we highlight the production methods to arrive at silk fabric.
Mulberry silkworms live on mulberry trees whereas the silkworm larvae feed on mulberry leaves.
Spinning the Cocoon
After molting several times, the silkworms will spin a cocoon. Upon contact with air, the silk will solidify. This will take around two to three days.
Heating the Cocoon
Once the silkworm cocoons are formed and harvested, the workers heat the cocoons. They do this by dropping the cocoons in boiling water to kill the pupae effectively.
Brushing the Cocoon
To unravel or extract the silk threads or strands, a worker or an automated machine will brush the silk cocoons.
Loading and Twisting
The workers load the silk threads or strands onto a reel. Through this process, each strand automatically attaches to another strand to create a continuous string. Afterward, the silk producers twist, weave, or knit these strings together to generate yarn.
Rolling and Dyeing
After placing the yarns on rollers for uniformity, manufacturers may then dye or bleach the fabric. Typically they dye silk filaments before they are spun. They usually place the filaments in acidic water containing the dyes to result in silk dyed with the colors and sheen people like to buy.
Finally, silk workers will weave the yarn into textiles. Different weaving processes lead to different kinds of fabric. These include chiffon, organza, and crepe.
Peace / Ahimsa Silk
Tussar and eri silk products are less lethal alternatives. They fall under the ahimsa silk category. Tussar silk, also referred to as wild silk, comes from wild silkworms that feed on plants other than mulberry. This fabric also possesses a rich texture. On the other hand, eri silk comes from domesticated silkworms that feed on castor plants.
History of Silk Production
Legend suggests that the Chinese Empress, Xi Lingshi, was the first person that discovered silk. In the 27th century BCE in China, a cocoon fell into her cup while sitting under a mulberry tree. The empress admired the shimmering threads as the silk cocoon unraveled. The legend goes on to say that she invented the reel and loom. As a result, she went on to teach young ladies how to weave silk into materials.
China has dominated the silk industry for many years. People have discovered evidence of silk fabrics made by silkworms in 8500-year-old tombs in China. Initially, the Chinese used silk as a form of currency. They also reserved this fabric for the emperor. The demand for these fabrics grew, leading to an ancient trade route called the silk road. The silk road connected industries from the East to the West. Through these relationships, people traded silk for other commodities.
After some time, the production of this fabric moved to India, Thailand, Korea, Europe, and the United States. Today, China remains the world’s largest silk manufacturer. The nation produces 146,000 metric tonnes annually. Next to China is India, which produces 28,708 metric tonnes per year. Uzbekistan comes in third place with 1,100 metric tonnes, and Thailand in fourth place with 692. Brazil is the fifth largest producer, with 560 metric tonnes.
Today, manufacturers use silk to make bedding, upholstery, apparel, curtains, parachutes, and many more products.
Is Silk a Sustainable Fabric?
One of the major concerns for conscious consumers is the level of sustainability and ethics. This umbrella houses the carbon footprint necessary to produce silk, greenhouse gas emissions, and water pollution levels.
How Eco-Friendly is the Manufacturing Procedure?
Mulberry trees can grow without the use of chemical pesticides and fertilizers. This means that farmers can grow them organically. However, some farms make use of these chemicals.
Compared with cotton production, the growth of these trees require less water. As much as the growth of these trees may have little impact, the conversion to fabric poses some issues.
For the workers, there are possible health risks in various segments of silk processing. The method from mulberry cultivation to silk finishing sometimes involves the use of pesticides and herbicides. There is also the threat of carbon monoxide poisoning. Also, the use of bed disinfectants can lead to breathing problems on the part of the factory workers.
The environmental impact of the processes is also worth examining. One of the reasons why silk manufacturing can cause a negative environmental impact is the boiling process and the use of fossil fuels.
Cocoon boiling and reeling usually require a large amount of firewood2. Therefore, this leads to the release of carbon monoxide into the environment. The impact of these fumes contributes to pollution. Also, hot water, water waste from boiling and reeling, and dye waste contribute to water pollution. Without proper treatment, these wastes negatively impact water bodies and crop fields. This procedure also generally uses a huge amount of water.
Since the manufacturing of silks is primarily concentrated in certain areas like Asia, it becomes necessary to ship these fabrics to various countries. Therefore, shipping silk requires large amounts of energy during transportation. This leads to an increased carbon footprint.
The Ethics of Silk Manufacturing
Animal rights activists and organizations, such as PETA, are against silk manufacturing. This is because conventional farming methods result in killing silkworms in their cocoons. Organic and peace silk farming procedures try to curb these lethal methods of traditional farming.
There are also concerns regarding the treatment of workers in this industry. In parts of Asia, particularly China and India, there have been concerns about workers being exploited. Although producers use machines to automate processes on-site, the work experience of some workers is still unjust.
Organic Silk and Peace Silk
Organic or raw silk is an eco-friendly alternative to conventional silk. The methods of acquiring these silk fibers do not involve chemicals or treatments. As such, they make peace silk without synthetic fertilizers, insecticides, and pesticides.
With peace silk, the procedure allows the silkworms to live out their lives fully and die naturally. An organic silk piece doesn’t contain toxic dyes or treatments. Also, untreated silk is completely biodegradable. This makes it eco-friendly with minimal impact.
Pros and Cons of Silk Fabric
- Texture: Silk has a soft and smooth texture that gives it its luxurious and high-end appeal.
- High-Absorbency: This fabric handles moisture well, especially for clothing items. This makes it breathable. Also, it absorbs dyes well, and manufacturers can use low-impact or natural dyes.
- Durability and Strength: Despite its delicate feel, this fiber is considered one of the strongest natural fibers and results in a durable fabric.
- Biodegradable: Raw, untreated silk is completely biodegradable after its useful life. This makes it an eco-friendly choice.
- Wrinkling: One of the downsides of silk textiles is that they wrinkle easily. This means they require frequent ironing to look presentable.
- Care and Shrinkage: The clothing items shrink easily in the wash. As a result, you may need to dry clean often, which can be expensive.
- Water and Sun Damage: As much as it’s a strong and durable fiber, overexposure to the sun can weaken it. This can also lead to fading of the textile. Also, water damage can occur as a result of water staining the materials.
Brands that Use Sustainable Silk Fabric
The Ethical Silk Company
This company produces loungewear, wraps, scarves, and pillowcases. The brand ethically makes these from 100% natural eco-friendly silk.
Brooke There is a sustainable women’s underwear brand. It provides long-lasting minimalist underwear and lingerie pieces ethically made in the United States. The brand uses organic fabrics such as natural silk and organic cotton.
Skin provides sleepwear, lingerie, and swimwear essentials with natural fabrics. It offers pieces made from washable silk, including silk blends. The company offers a range of options that are GOTS-certified.
Reformation is a sustainable clothing and accessories brand. The brand makes eco-friendly, fashionable pieces that stand the test of time. The selection of textiles for pieces is limited to those with minimal impact on the environment. These include certified silk, recycled cotton, and deadstock.
Silk vs Viscose Rayon
Unlike silk, viscose is plant-based. Viscose rayon is a semi-synthetic fiber from wood pulp. Some producers and brands sell it as an alternative to silk. Rayon fabric has a similar look, thereby mimicking the luxury textile.
Fashion consumers have described it as looking like silk, but feeling like cotton. However, viscose is cheap to produce, and the manufacturing procedure involves heavy chemical usage.
Silk vs Lyocell
Lyocell is another semi-synthetic fiber made from wood cellulose or pulp. On the other hand, silk is a natural protein fiber. The history of lyocell began when researchers and chemists were testing ways to create artificial silk. The method of manufacturing lyocell is less toxic than other types of rayon.
Unlike silk which requires extra care with washes, lyocell is better machine washable. Lyocell is also vegan and relatively cheaper.
There are many layers to unpack when examining silk, from the method of acquiring the fiber to manufacturing and ethics. Although there are now innovations that target protecting silkworms, there are still concerns about whether they are 100% safe.
With regard to sustainability, organic silk proves to be the better option. When picking out fabric, it is important to check for the necessary details. These include the origin or source, manufacturing, treatment of workers, and certifications.
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Priyadharshini, P., Joncy, M., Sivaranjani, B., & Mavilashaw, V. (2016). Health Risks in Silk Industry. Journal for International Academic Research for Multidisciplinary Impact Factor 2.417, ISSN: 2320-5083, Volume 4, Issue 5
International Trade Centre. (n.d.). Silk in World Markets