by Seshata on 18/12/2013 | Cultural

How Hemp Textiles Are Produced

Over thousands of years, humans have refined and perfected the methods to cultivate, harvest and process hemp, to obtain fibre for making garments and much more. Today, we have countless types and blends of textiles available to us, to suit all requirements and applications. But how is hemp fibre obtained and processed?


A Summary of Fibre Hemp Cultivation

Fibre hemp is produced from low-cannabinoid varieties of Cannabis sativa that are planted close together to minimise branching and encourage tall, straight central stems. Unlike most psychoactive strains of cannabis, fibre varieties typically have hollow stalks, which contain far higher amounts of fibre (35% compared to 15%).

In the northern hemisphere, fibre hemp seed is planted when the ground temperature rises above 7.5°C, and is typically harvested in around August, once the pollen begins to be shed. Hemp can flourish in conditions considered less than optimum, and will usually produce more than competitor crops in such instances.

However, for optimum harvests, hemp should be cultivated in mild, humid conditions, in well-drained, non-acidic soil that is high in nitrogen. Soil must be moist but not excessively so, as overly-moist soil has been shown to produce weak fibres; cool summers are also said to assist the fibre in becoming fine and strong.

A spinner in Guizhou province, China, reeling hemp fibre into yarn (Minneapolis Institute of Arts)

Harvesting & Separating the Hemp Fibres

If cultivating solely for fibre, males and females are both cut down as soon as the males begin to exude pollen. If cultivating for fibre and seed, the males are allowed to pollinate the females before being cut; the females are left to mature until the seeds are ripe, at which point the plants are cut and the fibre and seed separated.

Interestingly, traditional farmers of hemp in the UK held that male hemp plants produce fibre much finer and silkier than that produced by the females; this was borne out by a 1996 study conducted in Hungary, which concluded that male fibre was finer but female fibre slightly stronger.

Retting of Hemp Fibre

Once the plants have been cut, the stems are usually laid out along the ground for several weeks so that retting can occur. This is a process of decay whereby the pectin (the gel-like polysaccharide present in most plant cell walls) that binds the fibres together decomposes on exposure to light and air, and the long bast fibres are exposed. Bast fibres are those that occupy the phloem or inner bark of dicotyledonous plants such as hemp and flax.

Retting may also be done in water tanks, which speeds up the process, or in frost and snow, which is said to produce a whiter, finer fibre. Now, there are also chemical and enzymatic means with which to speed up the process of retting.

Decorticating Hemp Fibre

Decortication is the removal of the central woody core from the stem. This step can be performed immediately after retting, while the stems are still wet; in this case, the damp fibres are peeled off the core and then dried. Alternatively, the stems can be dried and then processed with specialised machinery, which breaks up the woody core and separates it from the fibres.

Modern decorticators often negate the need for long retting periods and separate decortication processes, instead combining the processes into one and producing ready-to-bale fibre within a few minutes of cutting the plant.

How Hemp Textiles Are Produced

Treating the Hemp Fibres

Once the fibres have been separated, they are formed into bales and removed from the field to be processed into yarn. Often, the fibre is spun without further processing; however, some producers have developed chemical or mechanical processes that increase the softness or elasticity of the fibres.

For example, one involved process necessitates soaking the fibres in a near-boiling solution of soap and carbonate of soda, before being washed with water and soaked in dilute acetic acid. The fibres are washed in pure water once more, then dried and combed to produce an end result of exceptional softness and fineness.

Removing Lignin from Hemp Fibre

Lignin is a hard, woody biopolymer that makes up 8-10% of the dry weight of hemp fibre, and is responsible for the rough, scratchy feel of traditional hemp fibre. If the lignin is removed, the resulting fibre is much smoother and softer. The inability to remove lignin from hemp without reducing its strength led to other crops being favoured over it—yet another reason that its use began to decline so dramatically in the post-industrial period.

In the mid-1980s, researchers developed a new technique to remove the lignin through enzymatic & microbial means: the protein-digesting enzyme protease is first applied to the hemp fibre, which reduces the nitrogen in the stems; then, a species of fungus known as Bjerkandera is allowed to grow upon the fibres, where it consumes the lignin. The fibres produced with this technique were far more versatile, and hemp began to be used in garment-making once more.

Spinning Hemp Fibre into Yarn

Hemp yarn is spun similarly to other natural fibres; typically, the fibres are twisted together to form long, continuous threads, which are often sealed with wax or a similar agent to render the end result waterproof or more durable.

It is usually at this stage of the process that other fibres are added to the blend: rather than blended cloth being woven from threads made purely from one type of fibre, the thread itself is a blend of fibres that influence its final characteristics. However, this is not always the case: fustian, for example, traditionally referred to a textile made from a flax warp (lengthwise thread) interwoven with a cotton weft (transverse thread).

The Hand-Spinning Process

How Hemp Textiles Are Produced

This process was traditionally performed by hand, with the help of nothing more than two simple tools, the drop spindle and the distaff. The drop spindle is a spike-shaped weight to which the raw fibre is attached, and the distaff is a wooden stick around which the lengths of raw fibre are looped.

The hand-spinner sets the spindle spinning, and slowly releases raw fibre from the distaff; the spinning motion and the pull of the weight as it slowly drops cause the fibres to be tightly wound into threads. Some hobbyists and specialist producers still spin by hand using these traditional tools.

When hand-spinning with hemp fibres, the best choice of spindle is a lightweight top whorl, a type that can spin very fast and produce a fine, smooth yarn. Most hemp yarn is dry-spun, but can be spun ‘wet’: the spinner merely moistens the fingers with water and strokes the yarn as it spins, smoothing down the flyaway fibres to produce the smoothest possible result.

Although hemp now has to compete with an array of alternative fibres, both natural and synthetic, improved processing techniques have uncovered ground-breaking new uses for hemp textiles; as well this, the need to find textile crops of low environmental impact is increasing rapidly. For these reasons, hemp is growing in significance once more after a long period of decline, although it may never regain its former status as the number one textile crop.

Comment Section

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HABIB

I WOULD LIKE TO KNOW WHERE I CAN BUY HEMP GARMENTS & OTHER STUFF TO SELL IN PARIS AND WHAT ABTE THE LEGISLATION

20/12/2013

David Cannafacts

Hi Habib,
Hemp garments and food stuffs containing no THC are legal in France so you should have no problem in selling them.
There are many manufacturers of hemp clothing, foods, and cosmetics for you to encounter online.

All the best!

07/01/2014

Regina Johnson

Habib,
Please contact me concerning garments from hemp.
Thank you,
Regina

29/03/2018

jana

hello, i would like to ask you what is your name? because i am writing MA thesis about textile production and i would like to quoute you. thanks jana

17/05/2017

Scarlet Palmer

Hi Jana,

Thank you for your comment. This article was written by our expert author Seshata Sensi, you can find her details (and other posts that she has written) here. I will pass your comment on to her. Good luck with your thesis!

With best wishes,

Scarlet

18/05/2017

Steffany

Hi there

So my question is this:
Is it possible to use indica plants for fabric production?
We farm medical marijuana (high cbd low thc) and I was wondering if it's possible to use the byproduct of the plants for making stuff like paper or fabrics. Seems such a shame to throw away all the stems and leaves if they could be used to make something.

18/05/2017

Scarlet Palmer

Hi Steffany,

Thank you for your comment. In theory, it is indeed possible to use the stems for making textiles and paper. However, one of the big differences between industrial hemp and indica strains is the length of the stems. The reason that hemp is such a strong textile is that the bast fibres are very long, since the plants grow very tall (anything from three to fifteen feet), so bast fibres from indica plants will be shorter, depending on the final size of the plant. The inner core of the stems is the cellulose-rich woody hurds, which can be used to make paper.

I would recommend you have a look at the website of our sister company HempFlax for further information and ideas on what hemp can be used for. If you decide to experiment with the leftover parts of your plants, please let me know - I am really interested in hearing how it works out!

With best wishes,

Scarlet

22/05/2017

Christian

Hi,
I'm from an Austrian university and we are looking for hemp and other natural fiber textiles. We want them for technical use (resin infusion process). Do you know companies where i can buy good quality textiles for technical use in a quantity of 1000kg+? Best i found so far is Cavvas from romania.

Best wishes,
Christian

17/06/2017

Tara

Hi

I am a farmer of organic veggies and we want to start growing Hemp for clothing. We live in BC and want to know what's the best way to go about this. How much land do you need to grow? How many bales would we need in order to produce clothes? Would we grow the hemp, bale it and ship it to China for spinning into clothes? Or, alternatively, we would prefer to have a sustainable product that is made in BC however I'm sure costs are very high. After the Hemp is cut down, what is the growers responsibility to get it to the next step? (would we need all the other equipment to turn it into yarn or would we send the Hemp bales somewhere else?). I know my questions are all over the map but we aren't sure where to start! Any info you can provide would be awesome! Thanks :)

14/02/2018

Scarlet Palmer

Hi Tara,

Thanks for your comment, for sharing your excellent plans, and for all your questions! I'm afraid that I cannot answer most of them as we are a Dutch company so we don't have direct experience of Canadian or Chinese hemp industries. I do recommend that you contact HempFlax, our sister company, who may be able to give you information about the size of land, amount of bales, etc. I also recommend getting in touch with the International Hemp Association, and the National Hemp Association, who can hopefully give you advice and maybe even practical help.

I hope this is useful to you, and please do check back and let us know how you get on!

With best wishes,

Scarlet

14/02/2018

karyotica

hello, I'm very happy to saw this information, it's very useful to me. Thank you for sharing this article.

26/04/2018

Yaqub Ahsan

Hi, I am writing from Pakistan. In the place I live, there is abundant and wild growth of hemp plant. I am not sure if it is the same variety that can be used for making natural fibres or any other useful material. Is there a way to find out if this wild plant can be of use?

regards

18/05/2018

Scarlet Palmer

Hi there,

Thank you for your comment. I think that it is impossible to say for sure, but if it is growing wild, the females have almost certainly been pollinated by the males so they will be concentrating on producing seeds rather than bud. The seeds are a great source of nutrition. If they are growing very tall, then the stems might be useable for fibres. This post, which covers the basic differences between cannabis and hemp and contains many links to more detailed information, might be useful to you.

With best wishes,

Scarlet

28/05/2018

Makadunyiswe Doublejoy Ngulube

Hi,

I am doing a research on the process of turning hemp into fiber. What chemicals are used in this process. Other sources suggest chemicals such as NaOH. So far this is what I have. Is there a website that provides information of a step by step process of turning hemp into fiber for clothing.

Thanks.

-Joy

11/07/2018

Scarlet Palmer

Hi Joy,

Thanks for your comment. I recommend that you contact our sister company HempFlax, who produce various grades of hemp fibre and should be able to provide you with further information. Good luck with your research!

with best wishes,

Scarlet

11/07/2018

Daniel schmidt

Hi,
I'm 16 and I'm from Italy and I'm attending a agricultural school. I'm really interested in the cultivation of both hemp and cannabis and I want to start a project in Burkina Faso, Africa with my stepfather who already lives and works there. We wanted to try to start cultivating hemp for textiles and If it's possible, when I'm older, to cultivate cannabis for medical use.
I'm writing this comment to ask you which equipment is needed to produce the fiber and where can i buy it.
P.s. I can use up to a maximum of one hectare of land for the cultivation.

Thanks.

Daniel

12/08/2018

Scarlet Palmer

Hi Daniel,

Thanks for your comment, it's great to hear from someone so enthusiastic and determined! Unfortunately I don't know the answer to this question, but if you get in touch with our industrial hemp sister company HempFlax, they should be able to help you. Please let us know how you get on, your project sounds brilliant and I wish you every success with it!

With best wishes,

Scarlet

16/08/2018

Pushkar Chaturvedi

Hi

I am doing a project related to the hemp yarn so Can you please elaborate what are the changes required in a ring spinning system to manufacture a hemp yarn.

04/09/2018

Scarlet Palmer

Hi Pushkar,

Thank you for your comment. Unfortunately I do not have the answer to this question, but my colleagues at HempFlax and the Hash Marihuana & Hemp Museum might be able to help you if you email them. Sorry I can't help you further! Good luck with your project,

With best wishes,

Scarlet

05/09/2018

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