(Cannabis sativa) could be an important crop enabling the production of environmentally-friendly,
locally produced, high quality textiles. Hemp is a traditional fibre crop which
for centuries was important in meeting our needs for textiles, paper and oils.
It is easy to grow organically, that is, without a need for artificial pesticides,
herbicides or fertilizers, so it can make an important contribution to a sustainable
future. Currently the bulk of our demand for textiles is met by cotton and synthetics,
both of which have serious environmental problems associated with them.
once major hemp textile industry has now completely disappeared from the western
world. At Bioregional Development Group we have been investigating the potential
for reviving hemp and flax cultivation and integrated processing to produce textiles,
paper, particleboard and oils on a sustainable basis in our bioregion, The Weald
of Surrey, Kent and Sussex in Southern England.
As part of our work, as a practical experiment we grew a small trial crop of hemp
specifically for textile production. We processed the crop in a variety of ways,
by hand, using conventional flax machinery and a novel decorticator to produce
yarn which was woven into fabric. This had not been done in the UK for many years
and was a very interesting and worthwhile experience.
and bioregional development
is important to consider how industrial development can occur in harmony with
nature. We promote a model of development which we call "Bioregional Development"
by which this can be brought about - I will outline this first before looking
at how it relates to hemp.
The modern global economy is supported by the unsustainable use of natural resources.
At the same time communities are disintegrating in the face of rapid and global
economic changes. Sustainable development" development which meets the needs
of the future without compromising the ability of future generations to meet their
own need" (WCED, 1987 - the Brundtland Report), is advocated as the way forward.
This immensely complicated issue has economic, social, political and technical
Bioregional Development is a pragmatic and simple approach towards the goal of
sustainable development. It is based on the concept of "Bioregionalism"
which recognises the benefits of meeting needs from local resources in a way that
is sensitive to the local ecology of the area (Sale, 1991).
summary, bioregional development works to:
revive traditional sustainable land use, and
- regenerate local industries,
- introducing clean, appropriate scale technologies,
- to build healthy
regional economies supplying local needs from local production.
land-use systems were developed prior to the introduction of artificial pesticides
and fertilisers. Of necessity they were suited to the soil climate and ecology
of the region. They are also an important part of out heritage and culture.
production for local needs is the green ideal, bringing many benefits:
by producing locally we cut down on the need for transportation, conserving fossil
fuels, decreasing our need for roads and cutting down on pollution;
production encourages a local economy which is more stable than one tied to international
- economic stability means fewer fluctuations in employment levels
and greater social stability.
is easily sacrificed in international trade (George,1988). Imports particularly
of commodities, are often cheap because they are produced in ways which from social
and environmental standpoints would be illegal in Britain or Canada. We disadvantage
our own industries while, in effect condoning destructive practices overseas.
Local production encourages accountability and a situation where both self interest
and altruism are better served.
traditional land use is of great interest to us, traditional back breaking work
is less appealing! It is clear that we cannot go back to traditional ways of working.
In industrialised countries a return to the highly labour intensive practices
of the past is just not conceivable from are economic viewpoint. However, it is
possible that efficient small-scale technologies can enable the revival of industries
based on traditional forms of land-use.
Smaller scale technologies enable the decentralization of industries. This in
turn allows the development of smaller, less impersonal businesses, fostering
a sense of community. The obvious human benefits of small scale production need
to be harmonised with the realities of economy of scale. The benefits of the two
can be reaped with modern communications. Industries can be centrally coordinated
whilst production can be decentralised - this is after all the basis of many cooperatives
was an important traditional crop in many countries. We believe that a revival
of hemp cultivation around the world will make an important contribution to sustainable
development provided it is done on the basis of local production for local needs.
textiles in context
significance of hemp to the economic and day-to-day lives of our ancestors is
increasingly being recognised. It was important for textile, paper, rope and oil
production. Indeed, hemp was so important in England in the sixteenth century
that King Henry VIII passed an Act of Parliament which fined farmers who failed
to grow the crop. Although hemp was mainly used to produce ropes, sailcloth and
sacking, the fabric which can be produced from hemp is comfortable to wear, and
this feature, combined with its durability, meant that hemp was a fabric of choice
for many working clothes, often in blends with wool. It is interesting that Levi
Strauss made his first jeans from hempen cloth imported from Nimes in France,
hence the name "denim" which comes from "Serge de Nimes".
Also, within living memory Italian women were wearing linen-like dresses made
from hempen cloth which was sold in all drapers shops in Italy (Bosticco, 1995).
textile production from hemp has been supplanted by imports of cotton and synthetics.
Most cotton production today is highly intensive, heavily dependent on inputs
of pesticides, fertilisers and water. The environmental and social costs of modern
intensive cotton production are very high. However, in parts of China and Eastern
Europe, a small hemp textile industry remains to this day. Samples of Chinese
and Hungarian hemp fabric show the quality which can be achieved.
as a fibre crop is like flax (which is used to make linen). Both hemp and flax
fibres are known as "bast fibres', that is the fibres are contained in the
stem. The processes and machinery required to produce fabric are similar in principle
for both crops. Whereas the hemp textile industry has died out in the western
world, the flax industry continues with machinery and expertise readily available.
growing never ceased in France, and in response to concerns about the narcotic
uses of the hemp plant low narcotic strains were developed. In recent years hemp
has been grown in France to produce cigarette paper and banknotes from the fibre
and animal litter and bedding material from the woody core, also known as 'hurds'.
Since 1993, hemp has once again been grown in the UK under licence from the UK
government. Hemcore, an Essex based agricultural merchant successfully argued
that under European Community law, if the French could grow low narcotic hemp
then why not UK farmers? In 1995, 1,000 hectares of hemp were grown, 2,000 hectares
are being planted this Spring. Hemcore are growing hemp primarily to produce a
non-allergenic and absorbent horsebedding from the hurds. Some fibre is being
pulped to make tea-bags, cigarette papers and banknotes, but the production of
hemp textiles has proved more problematic.
consumer demand and interest in hemp fabric has stimulated research in this area.
The French have developed a chemical/enzymatic process to produce a textile fibre
which is awaiting funding for a pilot plant (Matthieu,1994). In the UK Hemcore
has been working with a textile company to produce small quantities of hemp blended
fabrics especially using recycled wool and cotton. We, at Bioregional Development
Group, have been working with Hemcore and other organisations to produce experimental
quantities of 100% hemp fabric.
believe hemp merits consideration as a new linen-like, environmentally friendly,
textile fabric. Hemp can be grown easily under organic cultivation as it grows
so fast that it smothers weeds. Indeed, studies have shown that organically grown
hemp has higher fibre yields (Haraszky & Jakobey 1968) and improved fibre
fineness (Jakobey 1968). In addition, hemp is a multiple use crop. The high value,
long "bast" fibres are used to produce textiles, twine, geotextiles
and paper. The shorter "tow" fibres from textile processing are also
suitable for geotextiles and paper making. The woody core or hurds are also fibrous
and can be used for animal bedding, paper making or in building materials, such
as particleboard. The seed is used for fish, bird or human consumption or for
oil production. Growing regimes vary according to whether seed or fine fibre is
required. Obviously, aside from the whole crop utilisation, multiple co-products
will allow far greater income generation from the crop.
Development Group's "Hemp for Textiles" project
order to explore the value of UK gown hemp as a textile fibre we instigated a
project "Hemp for Textiles" with funding from the UK Department of the
Environment Local Projects Fund and the Konrad Zweig Trust. Hemp for Textiles,
which we have now almost concluded, aimed to:
grow four hemp varieties (in Kent in Southeast England) to explore any differences
in fibre quality and yield;
- extract by different methods a textile grade
fibre and produce samples of UK hemp yarn and fabric;
- compare processing
techniques and evaluate the best way to establish a UK hemp textile industry;
- make our results available to interested parties and the general public,
to advance knowledge of hemp and its potential as a sustainable crop.
"Hemp for Textiles" project started in April 1994 and is ongoing. It
involves private, public and academic sectors.
The traditional method of
producing hemp textiles
a starting point we investigated the centuries old method of hemp textile production
(Rowlandson, 1849; Eyre, 1913). In principle it is similar to the method currently
used to produce linen from flax. It involved:
sowing the seed densely to produce tall, slender stems which contain a greater
amount of finer fibre.
- harvesting after flowering but before the seeds
set (the fibre content is reduced and becomes coarser toward seed formation);
- "retting" the crop - retting (or rotting) being the name given
to the process whereby bacteria and fungi break down the pectins that bind the
fibres to the stem allowing fibre to be released; one of two alternative methods
were generally used. Water retting, which 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; and/or dew retting, which entails laying the crop
on the ground for 10-30 days, turning as necessary to allow even retting;
- breaking the stems by passing through a "breaker" or fluted rollers.
- separating the fibre from the woody core ("scutching") by beating
the broken stems with a beech stick or passing through rotary blades, and finally;
- "hackling" (combing) to remove any woody particles and to further
align the fibres into a continuous "sliver" for spinning. Spinning was
either carried out on a wet or dry basis. In the case of bast fibres generally,
the best yarns are obtained by wet spinning (Carter,1925), 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 12Nm). Dry spinning is cheaper, producing yarns and
fabrics with a different appearance and handle.
of hemp for textile production
first stage of our project was to grow hemp on a trial basis specifically for
textile fibre production. This we did in 1994 in Kent in partnership with a Kentish
farm, Hemcore (agricultural merchants) and Wye Agricultural College, University
of London. The seed was sown at a rate of 55kg/hectare on 11th May (for fibre
production 55-60kg/hectare is recommended -Franck, 1993). Four different low narcotic
varieties were grown, two French, F34 and F56 and two Hungarian, Kompolti and
Uniko BF. We saw for ourselves hemp's remarkable weed smothering properties and
the crop did not suffer from any pests. However, the crop did badly where the
soil was compacted by tractor wheels, with an obvious reduction in plant height
and increased competition from weeds along these "tram lines".
harvested the crop when the male plants were in flower and shedding pollen and
when the stems were whitening at tie base and the leaves were starting to drop
as recommended in the literature (Rowlandson 1949, Eyre 1913). In our trial the
French varieties were ready for harvest on 7 August and the Hungarian varieties
on 13 August (Uniko) and 27 August (Kompolti). The crop reached 1-2 metres in
height. In our trial we found that the Hungarian varieties yielded 70% greater
biomass (as measured after retting) than the French varieties.
We also harvested 600 kg of Hemcore's 2 metre high commercial crop on 24 August
using an Allen Scythe, which laid the crop in an even swath. The seed variety
was F34, sown on 29 April.
chose dew retting as our main test method to produce enough fibre for a spinning
trial. 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. When turning, we observed that the stems closest to the ground remained
green whilst the top was retting and turning brown. When retting was complete
the crop was entirely brown/grey. The thicker stems took longer to ret. Therefore
uniform tall, fine stems would seem to be best for trouble free retting.
Judging the degree and completeness of retting is currently a subjective exercise
based upon experience. 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. Evenness of retting is as important as the degree of retting.
1 Dew retting:
retting - 20 days at 4-5C
the earliest harvested crop, retting took only 20 days. For the crop harvested
20 days later retting took 50 days and was incomplete (see table 1). This was
due to a cold, wet spell of weather in September and confirmed our suspicion that
dew retting would prove risky in the UK climate.
Once it is considered that retting has gone far enough, the crop needs to be dried
to halt the retting process before it damages the fibre and to prevent further
retting in storage. With flax a moisture content of less than 16% is recommended.
We stood the crop in stooks in the field to dry, but turning and then baling on
a dry day would have the same effect.
our small-scale trials we harvested the crop by hand or with small machines, but
if hemp is to be farmed commercially for textiles,special or adapted farm machinery
will be needed to;
cut the crop and lay it in swaths,
- turn the crop to allow even retting,
- bale the dried stems.
the fibre from the retted stems
next stop in our project was to investigate the ways in which a fabric could be
produced from the hemp we grew. With the resurgence of interest in hemp fabrics,
manufacturers of fibre extraction equipment, research institutes, spinners and
weavers have all been keen to run trial batches on their machines.
amount of fibre contained within the stem is around 30% of which perhaps 20% is
suitable for textiles. For comparison, yields of flax fibre from traditional scutching
methods are 16-18% of long aligned fibre for textiles and 8-10% short fibres (tow)
from a similar total of 30% fibre within the retted stem (Sultana I991). lncidentally,
the tow would be an excellent paper making material.
attempted fibre extraction by two different methods using;
conventional flax "scutching" machinery (producing aligned fibres) and
- the new "Fibrelin" machine (producing nonaligned fibres) developed
in the UK to process flax.
sent retted stems to Depoortere, a flax processing machinery manufacturer in Belgium
for trial processing on a conventional flax scutch line. The hemp stalks needed
to be cut from their full length to 1.5 metres and yields of only 8.5% fibre were
achieved (given that unadapted flax machinery was used, with a scutch turbine
adapted for hemp, we should be able to obtain greater yields). To be processed
on conventional flax machinery, the stems have to be kept aligned throughout harvesting
and fibre extraction. The long aligned "hanks" of fibre thus produced
will need to be spun and woven on flax machinery. A flax scutch machine adapted
to take hemp could be produced and indeed this is the method used in Eastern Europe
to produce hempfibre. However, it is somewhat labour and energy intensive and
requires that the stems be aligned at all times.
remainder of the stems we sent to Silsoe Research Institute in the UK to be processed
through their new "Fibrelin" machine. The hemp was successfully processed
to produce nonaligned fibres, with a yield of 20-25% fibre. However, the hemp
was very "heavy" on the machinery, which has been designed for flax,
and a rather more robust version of the machine would need to be built to process
the fibre produced into a yarn
sent samples of the fibre extracted by the two different mechanical methods to
a number of different spinners for evaluation. A number of processes are involved
in preparing fibre for spinning. First the fibres have to be combed, then processed
into a sliver which is an assemblage of fibres in a continuous form, then into
a rove (a finer sliver) ready for spinning. Preparing and spinning the traditionally
produced linen fibre was fairly straightforward for conventional linen spinners.
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
hydrogenperoxide. The rove was successfully spun on a wet spinning system developed
by the company Mackie International. Bleached and unbleached yarn of 9.6-10.8Nm
The nonaligned fibre presented spinners with difficulties, in particular in the
preparation of a sliver and rove prior to spinning. The hempfibres were passed
through a breaker card and then a flax card to produce sliver, but losses of fibre
were two to three times higher than when processing flax. The hemp sliver "behaved
badly" on the roving machine, but eventually a rove was produced. It was
boiled in caustic soda and bleached with hydrogen peroxide. Some dry spun yarn
was produced, but it was not of very high quality, and was not even considered
suitable for carpet backing. The majority of the rove was successfully wet spun
to produce a slightly stubby and hairy 6-7Nm yarn.
observed that the line fibre yarn was smoother, finer and stronger than the nonaligned
fibre yarn. Tests to achieve a scientific measurement of the properties of the
two types of yarn are currently being carried out by Leeds University.
produced the yarn, weaving is comparatively straightforward, but not without its
problems! In order to carry out a machine weaving trial 100kg of yarn was needed.
High losses of fibre due to the experimental nature of our work meant that we
only had 12kg of yarn in total, but fortunately two textile colleges, Chelsea
School of Art and Design and Huddersfield University were keen to hand weave small
amounts. We concentrated on producing 100% hemp fabrics for our experiment, but
hemp would be suitable to use in blends with wool, cotton or flax.
weavers found the hemp was rather like linen to work with but stiffer and coarser.
The line fibre hemp produced was easier to work with and produced better results
than the nonaligned fibre yarn. We discovered that in Eastern Europe and historically
in the UK hemp fibres were subjected to a softening process prior to spinning.
This involves passing the scutched fibres through crushing rollers. If we were
to repeat our experiment we would include this step.
was around 7%. We found that the hemp fabrics softened and improved with washing,
rather like linen does. Simple industrial or handwashing improved the fabric,
softening it, filling out gaps and adding smoothness and lustre.
British grown and designed hemp garment
British designer Katherine Hamnett, well known for her strong commitment to environmental
issues, was very impressed with the fabric produced from the line fibre and offered
to design and make a garment from it.
niche will hemp find in the textile market?
The fabrics and garment produced from our Hemp for Textiles trial are impressive,
the bleached line fibre hemp fabric in particular. The line fibre hemp could be
produced in the same manner as flax linen and for a similar cost. Hemp fabrics
are in fact very similar in appearance, handle and other properties to flax and
industry wisdom would say that there would be little to be gained in producing
hemp unless it had some advantage - unique selling point - over flax. In certain
respects hemp has some disadvantages when compared to flax. Its spinning limit
(fine-ness) seems to be lower; about 12-14 Nm compared to 35 Nm or more for flax
- though extremely fine hemp yarn at 30 Nm is apparently produced in China. Our
textile consultant has estimated that bearing in mind hemp's similarity to flax
and it's likely lower spinning limit it would seem that hemp would only be successful
as a textile fibre for the international markets if its price came somewhere below
flax and above cotton, perhaps in the region of US$ 7-10 per Kg (for the long
fibre). He considers that at the same price as flax there would of course, still
be a market, but it would be small. However, the potential to grow hemp organically,
which is difficult in the case of flax, would assist hemp gain a place in the
small, but growing, market for eco-friendly products.
were carried out at Huddersfield University this year to ascertain hemps suitability
as a furnishing fabric. Chinese hemp fabric, usually used for waistcoats, was
compared with 100% cotton and a flax/synthetic blend. The hemp fabric had superior
tear and break. The hemp was slightly less resistant to abrasion than the other
fabrics, being most suitable for heavy domestic use.
Bearing in mind hemp's particular properties, the types of fabric and uses that
hemp would seem to be most suited to are:
the furnishing fabric area, especially drapes, and;
- "bottom weights"
in clothing; perhaps jeans and sportswear, in both 100% hemp fabric and blends
with cotton, linen or wool and with synthetics. At the moment it is difficult
to estimate the size of the potential market except to say that it is somewhere,
depending on price, between cottons 50% of total fibre consumption and flax's
problems to be overcome
are pleased with the results of our experiment, as we succeeded in producing the
first machine processed, UK grown 100% hemp apparel fabric probably this century.
In the short term we feel that it would be possible to establish hemp textile
production in Southern England to produce high quality hemp yarn and fabrics at
a similar cost to linen. However, if hemp is to be grown and processed in cooler
climates or at a more competitive price there are two technical problems which
would need to be overcome.
Firstly, as hemp is harvested late in the season (a month later than flax) dew
retting of hemp is unreliable. Therefore we must develop retting technologies
that are suitable for our temperate climate, or bypass the need to depend on the
weather. A lot of work has been done on retting flax, particularly by the French.
In the UK we are also trying various techniques but it is too early to asses their
probability of success. A great deal of work still needs to be done. What is certain
is that unless the problem of retting is overcome we will not be able to produce
textiles from hemp in countries where the climate is unsuitable for reliable dew
The second problem is technically easier to overcome, but still needs substantial
research and development. After retting the hemp stems, the fibre needs to be
removed from the rest of the plant. As we have discussed, adapted flax machinery
can be used, but it is not entirely suited to hemp which requires a more robust
machine, and unless cutting the stems in half as we did for our trial is practiced,
a much larger machine. We believe that the problem could be rapidly solved if
the market demands the final product.
Concerning the further processing of hemp to produce the finished textile: We
know that wet and dry flax spinners can adapt their machinery to handle hemp without
too much difficulty, particularly the line fibre hemp. There is some practical
experience in spinning hemp fibre in blends with cotton but as far as we know,
no experience of blends with polyester or acrylics. As environmentalists we would
prefer not to blend oil based synthetics with hemp but have been told that the
addition of 10% of synthetic material greatly improves abrasion resistance and
extends the range of end uses for hemp. For blends, it would probably be necessary
to cut the hemp fibre to required lengths, but this will not prove to be a problem
if the market is as substantial as expected. We foresee no particular problems
in commercial weaving, dyeing and finishing.
From the information that we have gathered we can calculate the amount of fabric
that could be produced from each tonne of hemp if it were produced on a commercial
One tonne of hemp could comfortably be grown on 0.2 hectare (approximately 0.5
acre). A tonne of hemp would produce at conservative yields of 15%, 150 kg of
line or high quality fibre. We should expect losses of 35% in hackling or carding,
5% in yarn production and a further 20% in boiling and bleaching the yarn to accept
dye. This would leave us with 73 kg of fine hemp yarn producing 182 square metres
of 400 gsm (jeans weight) fabric.
addition, 100kg (10%) of shorter tow fibres would be generated which could be
used for paper making or geotextiles and 500 kg (50%) of hemp hurds which would
make excellent building materials or paper or can be sold as animal bedding. Whole
crop utilisation is obviously beneficial from both an economic and an environmental
point of view.
conservative yields of fabric
hectares, (I tonne) hemp -> 150kg textile fibre -> 97.5kg sliver -> 73kg
yarn -> 182 square metres of 400 gsm fabric
conclusion - Opportunities and challenges
learnt an enormous amount from our Hemp for Textiles trial. We have written up
the results along with details of hemp for textiles in UK history and around the
world in our report "Hemp for Textiles" (Riddlestone et al, 1995). The
major conclusions of our trial are that:
hemp can be grown and dew retted in our bioregion South-East England, to produce
- the Hungarian hemp varieties we trialled have a higher yield
than the two French varieties;
- flax processing machinery can be adapted
easily to process hemp;
- line fibre hemp (from a 'scutch' mill) produces
yarn and fabric which are noticeably superior in quality and strength to the nonaligned
fibre hemp yarn and fabric;
- boiling with caustic soda, bleaching with hydrogen
peroxide and wet spinning on flax machinery produced the best results.
are greatly encouraged by the results of our experiment. Hemp, as a crop suited
to organic cultivation has considerable potential as a new eco-textile, but the
achievement of this potential is not certain and will require both hard work and
investment. However, we believe that the revival of hemp industries worldwide
would have many environmental, social and economic benefits- but if it is another
internationally traded commodity, but if it takes place in the context of local
production for local needs and whole crop utilisation.
1995 - Miss Mary Bosticco, personal communication
Carter, 1925 - Modern flax,
hemp and jute spinning and twisting (2nd edition) Scott, Greenwood and Son, London.
Eyre, 1913 - Some Minor Farm Crops, Hemp, Journal of the Royal Agricultural
Society 1913, V74, pp 141-149.
Frank, 1993 - Cultivation of hemp, Translated
from Fiches Techno-Economiques, Institut Agricole et Horticole Genech 1992 (French).
George, 1988 - A Fate worse than debt, Penguin.
Haraszyta A & Jakoby
I, 1968 - Effects of trace elements on the harl formation of hemp. Acta Biol.
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Jakobey,1968 - Effects of micro-elements
and fertilisers on the fineness of hemp. Rustnovenyek Kompolt 1968, 13-20 In;
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Mattheiu, 1994 - personal communication with Monsieur
Mattheiu, Federation Nationale des Producteurs de Chanvre (FNPC), Le Mans, France.
Rowlandson, 1849 - On Hemp, Journal of the Royal Agricultural Society 1849,
Riddlestone et al., 1995 - Hemp for Textiles, growing our
own clothes, Bioregional Development Group, Sutton, Surrey UK.
- Dwellers in the land - the bioregional vision. New Society Publishers.
Sultana 1991 - La culture du lin fibre. Institut Technique Agrirole du Lin, France.
WCED, 1987 - Our Common Future, The World Commission on Environmentand Development.
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