Hemp Fibre : The Ideal Fibre for Future

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Hemp is a type of “bast fibre” made from the stalks of the Cannabis sativa plant. Hemp is the oldest cultivated plant in the world with uses dating back to about 8,000 B.C. in tombs.

It was important for textile, paper, rope and oil production. The oldest piece of paper over 2000 years old was discovered in China and is made from Hemp. Hemp was primarily used in making sails & ropes for ships.

The first pair of Levis Strauss jeans was fabricated from hemp. Since that time, hemp has been used to make many types of garments and accessories.

Hemp is called a fibre of hundred uses. Hemp is a bast fibre plant similar to Flax, Kenaf, Jute, and Ramie derived from the stalk of plants. Long slender primary fibres on the outer portion of the stalk characterize bast fibre plants. When spun, it has an appearance similar to flax but thicker and coarser. As a crop, it grows extremely fast & yields more fibre than cotton or flax.

It is robust plant that requires no toxic pesticides or fertilizers. Hemp, controls top soil erosion & even renders the soil fertile for subsequent crops. When spun, it has an appearance similar to flax but thicker and coarser. It was probably used first in Asia.

China produces approximately 70 percent of the world’s output of this textile. However, due to lax labour laws and environmental regulations, it’s unclear whether hemp made in this country is environmentally sustainable or non-toxic. In addition, only a small portion of the hemp produced in China is made into fabric; the vast majority is made into fuel, paper, or other industrial products.

France is the next largest producer of this crop followed by Austria, Chile, and the United Kingdom. In all, over 30 countries around the world produce industrial hemp, and production of this crop in the United States is also on the upswing.

Hemp is part of the cannabis family that includes all varieties that contain negligible amounts of tetrahydrocannabinol THC, the chemical in “marijuana” which is psychoactive and gets you “high.”

The 2018 Farm Bill officially defines hemp as “the plant Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers, whether growing or not, with a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis.”

The Cannabis family contains numerous varieties, yet it is most famously known for psychoactive cannabis (marijuana or “weed”). This is the main reason why people confuse the term hemp with marijuana. Hemp actually refers to the industrial variant which is cultivated for its fibre, hurd, and seeds, as well as the other natural healing compounds found in its leaves.

 

The stalks of the hemp plant consist of two layers: The outer layer is formed from rope-like bast fibres, and the inner layer consists of a woody pith. Only the outer layer of the Cannabis sativa stalk is used for textile purposes; the inner, woody layer is commonly used for fuel, building materials, and animal bedding.

Once the outer layer of bast fibres is stripped from the hemp plant, it can be processed and made into rope or yarn. Hemp rope is so strong that it was once the premier choice for rigging and sails on maritime vessels, and it remains renowned as an excellent material for clothing that surpasses cotton and synthetic textiles by most metrics.

Once it is processed into fabric, hemp is having a similar texture to cotton, but it also feels somewhat like canvas.

In India, Deccan Hemp is grown both as crop and hedge plant. It is cultivated largely in Maharashtra, Tamil Nadu, and north Gujarat.  It can be grown in all temperature and tropical countries of the world.

Steps for Processing Hemp into Textiles

 

The valuable bast fibres, which give the plant its strength, are contained within the hollow wood-like core of the plants stalk under the outer most bark. Hemp quickly reaches maturity & the plants reach a hight of 2 to 4 mtrs. In 80 to 120 days. It can be densely packed into fields with up to 150 plants per square mtr. Of soil. Since it is naturally pest resistance, it can be grown organically without the aid of chemicals. The hemp fibres run the length of the plant anywhere from 3 to 15 ft long.

  1. Harvesting:

 

Harvesting is done with a conventional combine harvester machine during the early to mid-flowering stage. Running cutter bars 4 to 5 feet above ground harvest both the hemp fibre & seeds. Once cut, the plants, which are composed of two types of fibre – long outer fibres suitable for textiles, and short inner fibre suitable for paper or industrial applications – are left in the field for about 10 to 20 days to ‘ret’.                          

 

  1. Retting :

 

The hemp fibres are separated by ratting, which is the process of decaying pectin that binds the hemp fibres to the core of the stem. By ratting, the long bast fibres are separated from the non-fibre parts of the stocks. This can be done either chemically or by natural physical methods as follows:

Retting is of two types:

Water Retting:

It involves lying the stems in water in tanks, ponds or in streams for around 10 days–it is more effective if the water is warm and bacteria-laden.

 

Dew Retting:

It is a natural process that is triggered by dew that falls on the crop each morning. After cutting, the hemp stems were laid parallel in rows to dew ret. The stems needed turning at least once (sometimes) twice in order to allow for even Retting (or rotting) being the name given to the process whereby bacteria and fungi is break down the pectins that bind the fibres to the stem allowing the fibre to be released.

 

Retting is complete when the fibre bundles appear white, separate from the woody core and divide easily into individual finer fibres for their full length. Once this process is complete (dry), the stalks are collected and sent to the “decortication” machine.

  1. Decortication:

In this process the de-leafed Hemp stems are then dried, i.e. conditioned and freed from the wood kernel in a sequence of a squeeze, break and scutching processes. In other words, it is described as breaking the stems by passing through a “breaker” or fluted rollers. Then the fibre is separated from the woody core (“scotching”) by beating the broken stems with a beech stick or passing through rotary blades.

  1. Softening :

By using a so-called Hemp softener or roller, the decorticated fibres are made softer and suppler.

  1. Combing :

 

The shortening of the initial fibre lengths from up to 3 m down to 650 mm is done on a special cutting machine. Then the short and tangled fibres are combed out, the long fibres are parallelized and smoothed using a hackling machine. In other words “hackling” (combing) means to remove any woody particles and to further align the fibres into a continuous “sliver” for spinning.

  1. Spinning :

After several drawing and doubling passages, the manufactured slivers are pre-spun roving yarns and according to quality and the desired yarn fineness, spun into Hemp yarn by wet or dry spinning processes. Although as Hemp is coarser than Flax, the pins on the board for drafting the combed fibre into a sliver needed to be set differently. The rove produced was then boiled in caustic soda to refine it and most of the yarn was bleached with hydrogen peroxide. As it is similar to Flax fibres, generally the best yarns are obtained by wet spinning. In which fibres are allowed to pass through a trough of hot water before being spun. This softens the Pectin allowing a greater drawing out and separation of the fibres and producing a finer yarn (greater than 12 Nm). Dry spinning is cheaper, producing yarns and fabrics with a different appearance and handle.  Using the above process two types of 100% Hemp yarn is made known as long yarn and short yarn.

Properties of Hemp :

Hemp fabric is not susceptible to shrinkage, and it is highly resistant to pilling. Since fibres from this plant are long and sturdy, hemp fabric is very soft, but it is also highly durable; while a typical cotton T-shirt lasts 10 years at the most, a hemp T-shirt may last double or triple that time. Some estimates suggest that hemp fabric is three times stronger than cotton fabric.

In addition, hemp is a lightweight fabric, which means that it is highly breathable, and it also effectively facilitates the passage of moisture from the skin to the atmosphere, so it is ideal for hot climates. It is easy to dye this type of fabric, less prone to fading, and it is highly resistant to mold, mildew, and potentially harmful microbes. Because of hemp’s superior insulating properties, it keeps you warm in the winter and cool in the summer.

Hemp fabric softens with each washing, and its fibres don’t degrade even after dozens of washings. Since it’s also relatively easy to produce organic hemp fabric sustainably, this textile is practically ideal for clothing. Hemp fibre is completely biodegradable, holds its shape as good as polyester but also has breathability. Hemp fibres, which are naturally light in color, require little or no bleach.

It is a very strong fibre and is used in the manufacture of carpets, rugs, ropes etc., but has limited use because bleaching is difficult. Hemp fibre is dark tan or brown and is difficult to bleach, but it can be dyed bright and dark colors.

There are thirty varieties of Hemp fibre. It is a tall plant with a natural woody fibre. All these varieties resemble one another in general appearance and properties, but only those having fibres of high tensile strength, fineness, and high luster have commercial value. As Hemp is not pliable and elastic, it cannot be woven into fine fabrics. Hemp is more effective at blocking the sun’s harmful ultraviolet rays.

Types of Hemp

 There is only one major variety of hemp fabric. While the quality, feel, and texture of this fabric may vary from manufacturer to manufacturer, the same basic process is used to make hemp fabric around the world. The resulting fabric is stronger than cotton, softer than canvas, and is durable enough to last for decades.

Dying :

The nature of Hemp fibres make them more absorbent to reactive dyes, vat dyes and sulfur dyes, which coupled with Hemp’s ability to better screen out ultraviolet rays, means that Hemp material is less prone to fading than cotton fabrics are.

Blending :

Like Cotton, Hemp can be made into a variety of fabrics, including high-quality Linen. When blended with materials such as Cotton, Flax, Wool, Linen, and Silk. Hemp provides a sturdier, longer lasting product while maintaining quality and softness.

When combined with the natural strength of Hemp, the soft elasticity of Cotton or the smooth texture of Silk creates a whole new genre of fashion design. Modern hemp blends created today for the garment industry are cool to touch and comfortable to wear. While hemp garments are often comparatively more expensive than those made from cotton due to higher processing costs and limited quantities, its superiority is clear.

Environmental Benefits of Hemp

Hemp is basically nature’s purifier. The plant rapidly captures carbon dioxide from the atmosphere and makes what we breathe much cleaner. In fact, for every tonne of hemp produced, 1.63 tonnes of carbon is removed from the air (which makes hemp a much more effective sequester of Carbon Dioxide than trees).

The stem and leaves of the hemp plant are jam-packed with nutrients. As the plant matures and the seed grows, leaf matter falls to the ground and decomposes replenishing the soil with goodness ready for the next crop. And after harvesting, the remnants of the hemp plant can be returned to the soil to make for a richer yield the following year, making another influential environmental benefit for hemp.

An important aspect Sustainable farming is all about rotating crops according to the season in order to keep soil nutrients up. Because hemp is an annual crop which grows within just four months of being planted, it’s an ideal candidate for rotation and makes for a wonderful environmental benefit for hemp. Farmers all over the world rejoice – this means richer, cleaner soil and a greater crop yield.

Unlike other natural fibres like cotton or flax, another environmental benefit of hemp is that it doesn’t require any pesticides or herbicides to grow. Exposure to these nasties has been proven to cause environmental problems like water contamination, and has also been linked to health issues like cancer. A potential solution? Use hemp all over the world and reduce the amount of toxins and pollutants in our air and water.

The roots of the hemp plant grow strong and up to a whopping nine feet deep! These kinds of root networks can help to hold soil together and prevent erosion, which is one of the greatest problems facing farmers today. In some cases, the environmental benefit of hemp is that it has even restored soil that was already damaged. It’s the real deal.

Hemp has the miraculous ability to irrigate itself naturally, which means it requires very little water to grow. This sets hemp apart from other plant-based milk options like soya or almond and other natural fibre plants like cotton which are very thirsty indeed.

Did you know that hemp can be used to produce over 25,000 products?! That means that absolutely nothing goes to waste with this plant. Another miraculous environmental benefit of hemp, once harvested the seed is used to produce healthy food products, the flowers are leaves are used to make beauty products and the stalk for natural fibre.

We’ve looked at how hemp can clear the air and replenish soil, but it can also eliminate harmful toxins by absorbing them. Famously, the plant was used following the nuclear disaster at Chernobyl to remove radioactive strontium and cesium, and has even been considered for removing radiation from Fukushima.

Number nine is allll about the birds and the bees. Our second last environmental benefit of hemp is that its plants grow up to three feet tall which makes them an excellent little hiding place for wildlife. Oh and when hemp flowers bloom they’re are good pollen source for bees.

 Uses of Hemp Fibre :

A variety of tactile experiences can be created by weaving hemp as intricately as lace, smooth as silk or as coarse as burlap.

Hemp fibre is believed to be a natural alternative to cotton or linen. Most of the fashion market see hemp as loose-fitting clothes with the unattractive color palette.

Coarse Hemp fibres and yarns are woven into cordage, rope, sacking and heavy –duty tarpaulins. In Italy, fine Hemp fibres are used for interior design and apparel fabrics. Hemp is used in tapestry, hats, shawls, rugs, posters, and towel.

Manila “Hemp” is a fibre from the leaves of the Abaca plant; it is very strong, fine, white, lustrous and, though brittle, it is adaptable for the weaving of coarse fabrics.

Dyed hemp yarn from Hungary is suitable for rug weaving, placemats, crochet and other craft items. It has been found that 3 plies, 6 plies, and 12 plies are used for weaving, knitting or crochet.

Hemp is stronger than linen and jute fibre, hence it is ideal for making twine, ropes, cables, carpets, canvas, ship cordage, sailcloth, etc. Central American Hemp is chiefly used for cordage.

Slowly but surely, hemp is reclaiming its venerable character.  Apparel brands are introducing consumers to the durability and comfort of hemp garments. Outdoor gear and apparel brand Patagonia have offered legally sourced hemp fibre in their clothing line since 1997.

Big names such as Patagonia, Adidas, Calvin Klein, Giorgio Armani and Ralph Lauren have recently marketed products made from hemp.

Post Farm Bill the brand is collaborating with domestic supplies of hemp. Legendary fashion brand Levis featured a ground breaking “cottonized-hemp” in collaboration with lifestyle brand Outerknown. The hemp went through a process that softened the textile giving it an appearance and a feel almost indistinguishable from cotton.

Other apparel brands such as Toad & Company, Recreator and Hemp Tailor are offering consumers a selection of hemp garments to introduce  the benefits of choosing and wearing the fibre.

All hemp Products are completely biodegradable, recyclable and hemp is a reusable resource in every form


Article by Ms. Hetal Mistry

B.Sc. Textile and Apparel Designing Department from Sir Vithaldas Thackersey College of Home Science (Autonomous), SNDT Women’s University – Juhu

Trainee Intern : Textile Value Chain

References :

https://ministryofhemp.com/hemp/

https://www.the-sustainable-fashion-collective.com/2014/12/02/hemp-fibre-fabric-eco-benefit/

https://www.textiletoday.com.bd/extraction-processing-properties-and-use-of-hemp-fibre/

https://sewport.com/fabrics-directory/hemp-fabric

https://www.fibre2fashion.com/industry-article/5016/hemp-fibre-eco-friendly-fabric#:~:text=While%20the%20fibre%20is%20one,health%20food%20and%20biodegradable%20plastics.

https://princewilliamliving.com/hemp-weaving-the-fibre-into-the-fashion-supply-chain/

https://hempgazette.com/industrial-hemp/hemp-fiber-production/