or Industrial Hemp Information
• More comprehensive hemp info covering all uses
• Hemp is the highest source of essential
fatty acids in the plant kingdom
fast growing hemp plant is naturally inhospitable to pests
and thrives with minimal use of chemical pesticides or fertilizers.
- Hemp has taproots 9 to 14 feet long, bringing subsoil
nutrients to the surface and proteting the soil from erosion.
- Hemp fabric has four times the tensile strength and twice
the abrasion resistance of cotton.
- Hemp fabric is similar in texture to linen or raw silk
and possesses a soft hand, or feel.
- Hemp processing and manufacturing steps are also less
enironmentally taxing than those of many other fibres (notably
cotton), requiring less toxic chemicals and dyes to creat
- Cotton crops use 53 million pounds of pesticides and 1.6
billion pounds of synthetic fertilizers each year. These
toxic cheicals are destroying farmland and findinng their
way into food and water. (Source: Inc. Magazine, May 1999,
- The cotton used to creat one 100% cotton t-shirt
requires 1/3 lb of synthetic fertilizers and pesticides
to grow. (Source: Sustainable Cotton Project, USA)
- Hemp is naturally resistant to UV light (meaning you need
less sunscreen), mold, mildew and salt water.
Archaeologists have uncovered hemp fabric in China that is
more than 10,000 years old.
Hemp is one of the world's foremost renewable resources and
has a long and impressive list of attributes. It grows successfully
without the use of chemical pesticides or fertilizers. Where
other crops rob the soil of nutrients, hemp actually replaces
them, making it an excellent rotation crop. It is the strongest
vegetable fiber grown and the most versatile - used for thousands
of years to produce fabrics, paper, ropes and food.
Our Original Hemp Sandal has been the inspiration for everything
that has followed. Like all our sandals, the Original is hand-sewn
from hemp and has a patented sole that uniquely conforms to
A revolution in footwear - natural hemp comfort.
In 1997, the company added a knitwear line, introducing the
first ever 100% hemp sweater as well as exotic blends with
hemp, Tibetan yak's fleece and Mongolian camel hair.
EcoDragon supports traditional farming and handicraft techniques
from our manufacturing base near the beginning of the ledgendary
Silk Road. There, farmers have grown and worked with hemp
for thousands of years, organically and sustainably. As the
3rd world economy struggles to catch up with Western industrial
nations, pollution has become an all too frequent by-product.
EcoDragon, however, creates a valuable export that provides
a significant boon to the local economy, without adding more
toxins to the environment. We are also ever conscious of fair
labor practices and never use child labor or sweatshops, and
this is written into our contracts.
Founded in this global spirit and tradition, EcoDragon creates
natural products for a new millennium from organic thinking,
sustainable land practices, compassion towards others and
giving back to our community - from our home in New England
to our work in Tibet.
EcoDragon and China
and Wes Crain began creating EcoDragon as a fusion of their
deep family roots in China and their desire to establish a
progressive business. The result is a natural apparel company
with strong connections to China built on fair trade, environmentally
sustainable practices and respect for the historical culture.
Today, EcoDragon is a model for global social responsibility
in trade. From community empowerment to ecological standards,
EcoDragon is pioneering an alternative, better way of doing
business in the international economy.The seeds of EcoDragon's
current business in China were planted at home for Eric and
Wes. Their parents were some of the first American travelers
to China in 1975, at the end of the Cultural Revolution. "Our
house was always filled with visiting Chinese professors and
artists," recalls Eric. "Both of us traveled to
Asia on trips where we experienced Eastern traditions at an
early age," adds Wes.
Another important early influence was also local: Helen Snow
returned to the Crain¹s hometown with husband Edgar Snow,
author of Red Star over China, his tale of the 1930s revolution
in China. "Helen told us fascinating history, from the
forming of a new country to helping establish the Gung Ho
cooperatives." says Eric. ³Her vision and tireless
work on behalf of building mutual understanding was an inspiration.
³The heart of EcoDragon¹s connection with China
is Xi-an, the ancient capital where 7,000 life-sized terra
cotta warriors wearing hemp-soled shoes and protecting the
tomb of emperor Qin Shi Huang were recently discovered. Xi-an
is the gateway to the ancient Silk Road, the major trade route
to the West and also the agricultural region that has traditionally
grown hemp. Hemp has a rich history in China, dating thousands
of years. EcoDragon has adopted this sustainable tradition
of organic farming and indigenous skills of processing the
fiber to develop our products.
The combination of family history, personal interest in Chinese
traditions, and the wish to promote positive Sino-American
exchange is why EcoDragon does business with China. "We
are creating a progressive model for global business trade
that offers an alternative to the usual approach," explain
Eric and Wes. "Our fair trade principles and high environmental
standards guide the way we do business in China. Add to this
our knowledge of and respect for Chinese culture, and EcoDragon
is able to positively impact this important trade relationship
as a truly socially responsible company."
all about Hemp
Hemp: Natures Forgotten
(Courtesy of Fresh Hemp Foods)
Darrell L. Tanelian, M.D., Ph.D.
That the hemp plant (Cannabis sativa) is used as food initially
surprises and confuses most people. The public information
system has largely restricted knowledge of hemp to its use
for obtaining marijuana (Cannabis sativa), with its leaf content
of the psychoactive substance delta-9-tetrahydrocannabinol
(THC), rope and cloth from the fiber of the plant, and paper
from the plant stalk. Yet both the oldest Chinese agricultural
treatise, the Xia Xiao Zheng, written in the 16th century
BC, and other Chinese records discuss hemp as one of the major
grain crops grown in ancient China.1,2
Besides its propagation in China, the cultivation and use
of hemp has, since the beginnings of recorded history, also
been documented by many other great civilizations, including:
India, Sumeria, Babylonia, Persia, Egypt, and other nations
of the Near East; and the Aztec and Mayan civilizations of
South America; as well as by native cultures in North America
and Europe. Indeed, it might be said that over these thousands
of years, hemp has always followed humankind throughout the
world, or vice versa.
the key point about hemp is that its edible portion--the meat
of the shelled seed--resembles
the seeds of other cultivated grains including wheat and rye,
and does not contain THC.
Moreover, the strains of hemp plant used for food have been
naturally selected so as to produce little THC, generally.
These nutritional varieties of hemp plant grow in temperate
climates to heights of 14 feet, and as with many agricultural
grains, their seeds can be harvested in a conventional manner
with a combine. Since the most modern handling and shelling
of the seed minimize its contact with leaf resins, the shelled
seed itself and the oil, nut butter, and other foods prepared
from the seed have been made with THC concentrations as low
as 1 ucg/g (ppm) to nondetectible. These modern hemp products,
when consumed in normally recommended amounts, should all
but eliminate positive urine tests for THC.3 Studies conducted
on older versions of hemp seed oil found some to contain THC
concentrations that resulted in positive urine tests.
Nutrients in Hemp Seed
The most basic hemp seed product is the shelled seed, sometimes
referred to as the "hemp seed nut." The other major
hemp food products are hemp seed nut butter, which resembles
peanut and other nut butters, and cold-pressed hemp seed oil
and hemp seed flour. These basic products can be consumed
alone or used along with or instead of other grains, seeds,
nuts, and oils in any appropriate recipe.
In terms of its nutrient content, shelled hemp seed is 34.6%
protein, 46.5% fat, and 11.6% carbohydrate (Table I). The
most important feature of hemp seed is that it provides both
of the essential fatty acids (EFAs) needed in the human diet--linoleic
and alpha-linolenic acid--as well as a complete and balanced
complement of all essential amino acids.
As compared with most nuts and seeds, the 46.5% fat content
of shelled hemp seed is relatively low, and hemp food products
have a low cholesterol content and high content of the natural
phytosterols that reduce cholesterol levels. Hemp seed oil
has on average the highest mono- and polyunsaturated fat content
of all oils, taken collectively, of 89% (Table 2). The polyunsaturated
linoleic acid, an omega-6 fatty acid, is present in hemp seed
oil in a content of 55.6 g/100 g, and alpha-linolenic acid,
a polyunsaturated omega-3 fatty acid, is present at 17.2 g/100
g. The ratio of the two EFAs is 3.38, closely approximating
the 4.0 average ratio recommended by the World Health Organization
(WHO), Sweden and Japan for the human diet.5
Conveniently, hemp seed oil
is also one of the only food oils to contain the direct metabolites
of linoleic and alpha-linolenic acid--gamma-linolenic acid
(GLA) and stearidonic acid (SDA), respectively. Because of
this, it can circumvent the impaired EFA metabolism and physical
compromise that can result from genetic factors, intake of
other fats, aging, and lifestyle patterns.
By contrast with unsaturated fat, only 6.6% of the total
calories in shelled hemp seed come from saturated fat--a percentage
that contrasts sharply with the 13 to 14% of saturated fat
calories in the modern American diet.6 This gives hemp seed
oil a polyunsaturated-to-saturated fat ratio of 9.7, in comparison
to the current ratio of 0.44 in the American diet,6 and indicates
that consuming even a small portion of hemp seed oil daily
can contribute strongly to bringing this dietary imbalance
back toward the U.S. Senate Select Committee recommended goal
Besides providing the human EFAs and having a favorable unsaturated-to-saturated
fat ratio, hemp seed is an excellent dietary source of easily
digestible, gluten-free protein. Its overall protein content
of 34.6 g/100 g is comparable to that of soy beans and better
than that found in nuts, other seeds, dairy products, meat,
fish, or poultry.
protein provides a well-balanced array of the 10 essential
amino acids for humans. An important aspect of hemp seed protein
is a high content of arginine (123 mg/g protein) and histidine
(27 mg/g protein), both of which are important for growth
during childhood, and of the sulfur-containing amino acids
methionine (23 mg/g protein) and cysteine (16 mg/g protein),
which are needed for proper enzyme formation. Hemp protein
also contains relatively high levels of the branched-chain
amino acids that are important for the metabolism of exercising
Other Hemp Nutrients
The carbohydrate content of shelled hemp seed is 11.5% and
its sugar content is 2%. Of the shelled hemp seed carbohydrate,
6% is in the form of fiber. The fiber content of hemp seed
flour is 40%, which is the highest of all commercial flour
grains. In addition to containing the basic human nutrient
groups, hemp foods have a high content of antioxidants (92.1
mg/100g) in the form of alpha-, beta-, gamma-, and delta-tocopherol
and alpha-tocotrienol. Additionally, hemp seed contains a
wide variety of other vitamins and minerals.
Hemp in Health and Disease Prevention
high content of omega-6 and omega-3 fatty acids, and the relatively
high phytosterol content of hemp foods, make them beneficial
to cardiovascular health.7 Numerous human and animal studies
have shown that substitution of polyunsaturated for saturated
fats can reduce the risk of sudden cardiac arrest 8 and fatal
cardiac arrhythmia,9 as well as reducing blood cholesterol
levels and decreasing the cellular proliferation associated
with atherosclerosis.10 A high polyunsaturated-to-saturated
fat ratio, especially when it includes linoleic acid, has
also been positively associated with reduced arterial thrombosis.11
Additionally, phytosterols, of which hemp seed contains 438
mg/100g, have been shown to reduce total serum cholesterol
by an average of 10% and low-density lipoprotein (LDL) cholesterol
by an average of 13%.12
Polyunsaturated fatty acids, and especially GLA, have also
been found beneficial in treating various human cancers,13-17
and studies have shown that phytosterols may offer protection
against colon, breast, and prostate cancers.18
Besides the importance of a proper dietary ratio of linoleic
to alpha-linolenic acid in maintaining the polyunsaturated
fatty acid composition of neuronal and glial membranes,19
membrane loss of polyunsaturated fatty acids has been found
in such neurodegenerative disorders as Alzheimers and
Parkinsons diseases, and it has been suggested that
a diet with a proper balance of omega-6 to omega-3 fatty acids
may help delay or reduce the neurologic effects of these diseases.20
A fatty acid preparation with a ratio of omega-6 to omega-3
fatty acids of 4, which is practically identical to that in
hemp oil, has been shown to improve the quality of life of
Alzheimers disease patients.21
Additionally, GLA has been found effective for treating rheumatoid
arthritis and active synovitis,22-24 and the GLA and vitamin
D content of hemp foods may make them beneficial in preventing
and treating osteoporosis.25 Moreover, supplementation with
products containing EFAs has been found capable of reversing
scaly skin disorder, inflammation, excessive epidermal water
loss, itch, and poor wound healing caused by EFA deficiency,26
and GLA has been shown to be beneficial for atopic eczema
in Cosmetics and Processed Food Products
The critical importance of EFAs, and especially GLA, for healthy
skin makes hemp seed oil a highly effective skin care and cosmetic
product. Its lipid constituents allow it to permeate through
intact skin and to thereby nourish skin cells directly while
also carrying therapeutic substances with it into the skin.
These properties have led to a multitude of soaps, shampoos,
skin lotions, lip balms, conditioners, and other skin-care products
containing hemp seed oil.
Among food products made from hemp seed, oil, and flour are
beer, pasta, cheese, cookies, waffles, granola, candy, ice
cream, and others, with new products now being regularly developed.
In short, hemp can constitute an important element in nutrition,
health, and cosmetics, with the prospect of playing a major
role in preventing disease and reducing health care expenditures.
Paper: Frequently Asked Questions
What is Tree-Free paper?
Tree-Free paper is best defined as paper made wholly from
agricultural crops ans well as paper that is made without
cutting new trees.
What are nonwoods?
Nonwoods are pulps derived from agricultural crops. Nonwood
paper is made wholly from agricultural crops or blends of
nonwoods with post-consumer waste fibre. Since post-consumer
fibre is nowadays mostly tree material, the term tree-free
can be somewhat misleading here even though no trees were
cut. Nonwood paper contains no virgin tree material.
What is post-consumer waste?
Post-consumer waste is used paper material. This can come
in many forms but mostly comes in corrugated boxes, newsprint
and office paper. Post-consumer waste is mostly tree fibre
these days but as time goes on, (hopefully) more and more
of that material will contain agricultural fibre too. Post-consumer
waste fibre is generally of lower quality due to multiple
processing and is also inconsistent in quality and strength.
Since the reprocessing of this material is uses a lot of energy
(transport, storage and repulping) it is very important to
reuse first, then recycle.
What does recycled paper really mean?
It is very important to qualify what is meant by recycled
because there is no regulatory body governing the use of this
term. It is not uncommon to find papers that are 50% or more
virgin tree labeled 'recycled.' This is misleading to say
the least and most people happily accept recycled paper as
environmentally friendly even though it can be mostly (or
even partially) old growth!! Because recycled fibre weakens
upon repulping and because the source is unknown or varied,
virgin fibre is almost always added to guarantee a certain
level of quality and durability.
nonwood fibres are used in papermaking?
Nonwood fibres can generally be categorized under two headings:
1) Fibre Crops
2) Agricultural Residues
Fibre crops are farmed specifically for their fibre. Literally
thousands of fibre crops can be grown in Canada and make great
paper! Some crops like hemp and flax are ideal papermaking
fibres because of their unique strength and bonding properties.
Agricultural residues are "waste" products derived
from food crops such as wheat and corn. The leftover material
was until recently burned and is now mostly landfilled. Some
agricultural residues are weaker fibres but still can make
great paper. These agricultural residues are available in
vast quantities in Canada.
What about quality?
Nonwood papers are far less of a burden to the earth and do
not compromise quality like recycled paper can. Many nonwood
fibres have always been used by the pulp and paper industry
to create specialty grades of paper such as currency, cigarette
papers, bible papers and art papers. These fibres have superior
bonding quality and strength properties which is why your
money didn't disintegrate in the washing machine.
Still not convinced?
Nonwood fibres contain far less lignin (natural glues) than
tree fibre and therefore require far less processing chemicals
for pulping and bleaching. They are naturally acid free meaning
the paper will last forever without yellowing or crumbling.
Since many nonwoods are stronger than tree fibre, they can
be recycled more times and they add durability and integrity
to recycled sheets.
Why then are we using trees for paper?
Tree fibre is cheap. Really cheap. The cost of building the
forest is of course not incorporated into the cost of the
Do nonwoods cost more?
Yes and no. Nonwood paper is more expensive for regular commodity
papers but the cheapest photocopy paper available is after
all 100% old growth. However when looking for a quality sheet
(either environmental quality or the feel of the paper) nonwoods
are comparable in price. The GreenMan Nonwood Papermill carries
only papers that are made without the use of any trees in
an effort to reduce the demands placed on our remaining forests.
It is the goal of the GreenMan Nonwood Papermill to separate
the pulp and paper industry from the forest industry. Currently
they are one and the same but the pulp and paper industry
should be able to draw fibre from a variety of sources integrating
a bioregionalist approach and choosing the most sustainable
sources of fibre for each region, product and application.
A brief review of the history of paper making reveals the important
role of hemp in the development of the industry. The technical
aspects of classical hemp pulping and paper making and the present
status of the hemp pulp and paper industry are discussed. It
is shown that for new applications of hemp as a paper making
fibre source, new pulp technology is required. This article
is the first in a series about hemp pulping and paper making.
(Courtesy of Westhemp Canada)
of paper making
The use of fibre hemp (Cannabis sativa L.) for pulp and paper
dates back more than 2,000 years. The oldest surviving piece
of paper in the world was discovered by archeologists in 1957
in a tomb near Sian in Shensi province, China (Temple 1986).
It is about 10 cm square and can be dated precisely between
the years 140 and 87 BC.This paper and similar bits of paper
surviving from the next century are thick, coarse, and uneven
in their texture. They are all made of pounded and disintegrated
hemp fibers. Pa per historians agree that the earlier Egyptian
papyrus sheets should not be referred to as paper, because the
fibre strands are woven and not -wet-laid (Hunter 1957). The
Chinese paper-making craftsmanship was transferred to Arabic
and North-African countries, and from there to Europe. The first
European paper making was reported in the first half of the
16th century (Hunter 1957).Until the early 19th century, the
only raw material available for paper making was rags. Rags
are worn-out clothes. Since at that time clothing was solely
made of hemp and flax (sometimes cotton), almost all paper in
history was thus made of hemp and flax fibers. With the industrial
revolution, the need for paper began to exceed the available
rag supply. Although hemp was the most traded commodity in the
world up to the 1830+s (Conrad 1993), the shortage of rags threatened
the monopoly for hemp and flax as paper-making fibers.This was
the major incentive for inventors and industries to develop
new processes to use the worlds most abundant (and cheap) source
of natural fibers: our forests. Currently, only about 5% of
the world's paper is made from annual plants like hemp, flax,
cotton, sugarcane badges, esparto, wheat straw, reeds, sisal,
abaci, banana leaf, ananas and some other more exotic species.
The world hemp paper pulp production is now believed to be around
120,000 tons per year (FAO 1991), which is about 0.05 % of the
worlds annual pulp production volume. Hemp pulps are generally
blended with other (wood-) pulps for paper production. There
is currently no significant production of 100 % true hemp paper.
Renewed interest in hemp paper
The recent renewed interest in hemp as a paper-making fibre
seems to originate from a strong environmental motive. All primary
forests in Europe, and most in North America have been destroyed,
amongst others for paper production. Now we accuse the nations
which still have primary forests of not guarding theirs.In Europe
all trees harvested for paper making were intended for that
purpose, so there seems to be no valid reason to switch to a
non-wood or -tree-free fibre source. This of course is a little
different in the Americas and in Asia and Australia, where primary
forests are cleared at a huge environmental cost. In these regions
hemp has a number of advantages as an alternative source of
paper-making fibre. Hemp does not need pesticides or herbicides,
and yields three to four times more usable fibre per hectare
per annum than forests.And last but not least: paper recycling
was invented to make up for the mistake of cutting down our
primary forests. Technically speaking, one doesn't need to recycle
hemp paper, because it is a renewable raw material. One disadvantage
of using hemp or other annual plants as fibre source is that
the present pulping technology has been optimized for tree-fibre
pulping, so some adjustments in the pulping processes need to
be made when applying this technology to hemp fibres. Before
going into technical details, we will first examine the technology
of pulp and paper making.
Pulping and paper making
making is essentially the rearranging of elementary fibers from
whatever source (a tree, a hemp stalk, an old pair of jeans
or even a scoop of algae) into a flat thin sheet. Elementary
fibers are the basic building blocks of trees and many plants.
The average paper making fibre is about 2 mm long and about
20 micrometers (0.02 mm) thick. All fibers are assembled of
chains of cellulose molecules, arranged as a rigid structure.
These building blocks are glued together with other biological
components (lignin's, pectin's), which give a certain flexibility
and strength to the tissue, so that the tree or plant can bend
at high stresses, and doesn't break in a storm, and is able
to carry its seeds and fruits.
The following explains what is needed to process a fibre
source into paper (Smook 1982):
Pulping (from fibre source to pulp):
* Cleaning: all non-fibrous components need to be removed
from the raw material, and the remaining fibers must be cleaned
of dirt, rocks and other contaminants.
* Fiberizing: the elementary fibers are taken apart by either
chemically removing the glue that holds them together, or
mechanically tearing the fibre structure apart. From this
step on, the material is referred to as "pulp".
* Cutting: especially hemp fibers are too long to give a homogeneous
paper sheet, so the fibers have to be cut to the right size.
* Classification: the fibers suitable for use in paper are
separated from the ones too short, too long, too wide, too
thin, too crooked, too dirty and too old. Fibers can be classified
by weight (centrifugal and gravitational processes) and size
(various sieving processes).
* Bleaching: optionally, the suitable fibbers may be bleached
to a higher "whiteness". The whiter a sheet, the
better the contrast with the ink. Old-style pulp mills use
chlorine compounds with hazardous side-effects. Modern pulp
mills use oxygen-based b leaching (compounds like oxygen,
ozone and peroxide). Hemp pulp can be bleached with relatively
harmless hydrogen peroxide. For some applications bleaching
is not required, for instance for packaging paper and board.
* Refining: this is a separate process step in which the fibre
surfaces are "roughened". The greater surface roughness
of a fibre, the better it adheres to other fibers in the paper
sheet and the greater the strength of the paper. Paper making
(from pulp to paper):
* Dilution: in order to lay the fibers evenly into a homogeneous
sheet, the pulp is diluted with large amounts of water (sometimes
up to 200 times as much water as fibre pulp).
* Formation: the fibre-water slurry is poured on a fine mesh
wire. Most of the water will fall through the wire, leaving
the fibers to settle into a flat sheet.
* Drying: in the next steps, the wet sheet is dried by subsequent
pressing and steam heating.
* Sheeting: finally, the formed sheet is cut to the required
processes are essentially the same for manual paper making
and for modern paper machines, with the difference that the
old paper maker put out one handmade sheet per minute, and
the state-of-the-art Fourdrinier newsprint paper machine puts
out 15,00 0 square meters a minute: a 10 meter wide sheet
at 90 kilometers an hour! Remainders of the hemp pulp industry
Although there are thousands of non-wood paper mills in the
world, only a few of them use hemp as a fibre source. At present
23 paper mills use hemp fibre, at an estimated world production
volume of 120,000 tons per annum. Most of the mills are located
in China and India, and produce moderate quality printing
and writing paper. Typically, these mills do not really have
a fixed source of fibre, but they simply use whatever can
be found in the region. About 10 of the mills are located
in the western world ( US, UK, France, Spain, eastern Europe,
Turkey), and these mills produce so-called specialty papers
* cigarette paper: even popular American cigarette brands
have a 50% hemp cigarette paper and filter. Some countries
still have legislation prescribing the use of hemp in cigarette
paper, because other fibers (like spruce) generate hazardous
fumes w hen incinerated (!).
* filter paper (for technical and scientific uses)
* coffee filters, tea bags
* specialty non wovens
* insulating papers (for electrical condensations)
* grease proof papers
* security papers
* various specialty art papers
These papers can generally only be produced from special
fibers like hemp, flax, cotton and other non-wood fibre sources.
The average hemp pulp and paper mill produces around 5000
tons per annum. This should be compared to a -normal pulp
mill for wood fibre, which is never smaller than 250,000 tons
per annum. The only reason the remaining mills can still produce
at this extremely small size is that there is a very special
use for the pulp. This partly explains the high price for
a hemp pulp: about US $25 00 per ton versus about US $400
for a typical bleached wood pulp. The remaining mills in the
western world are unable to cope with western environmental
regulations because of their small size and archaic technology.
Some mills survive by shipping their waste water to a large
wood pulp mill nearby, others have to close down. There is
a clear shift in capacity towards countries that do not as
yet take environmental problems very seriously. One reason
for the high price of hemp pulp is the inefficient pulping
processes used. Another reason is that hemp is harvested once
a year (during August) and needs to be stored to feed the
mill the whole year through. This storage requires a lot of
(mostly manual) handling of the bulky stalk bundles, which
accounts for a high raw material cost.
Classical pulping technology
Most mills predominantly process the long hemp bast fibers,
which arrive as bales of cleaned ribbon from preprocessing
plants located near the cultivation areas. The bales are opened
and fed into a spherical tank, called a digester. Water is
added (5 to 1 0 times the fibre weight), together with the
cooking chemicals to remove the "glue" components
lignin and pectin from the fibers. Most mills use sodium hydroxide
and sulphur cocktails.The fibers are cooked for several hours
(sometimes up to eight hours) at elevated temperature and
pressure, until all fibers are separated from each other.
After cooking, the cooking chemicals and the extracted binding
components are separated from the fibers by washing with excess
water. This is where most of the polluting waste emerges from
the process. Often wastes are discharged as such into the
local surface water. The remaining clean fibers are then fed
into a Hollander beater, which is best compared to an industrial
size bathtub, with a large wheel revolving around a horizontal
axis at one point in the tub. The wheel pumps the pulp round
and round, and meanwhile cuts the fibres to the right length,
and also gives the fibres the required surface roughness for
better bonding capacity. This beating goes on for up to twelve
hours per batch. Some mills add bleaching chemicals in this
beating process, other mills pass t he pulp from the beating
machines to separate tanks for bleaching. These separate bleaching
treatments often use chlorine compounds, which are also discharged
into the environment. The bleached pulp is then ready to be
pumped to the paper machine, or can be pressed to a dryness
suitable for transportation to a paper mill elsewhere. The
processing time of more than twenty hours make this process
very expensive, as the costly equipment and handling must
be depreciated over a very low throughput.
Necessity for new technology
New applications for hemp as a paper making raw material require
a new pulping technology which must be able to use hemp from
wet storage. Some new technologies have been developed, albeit
in laboratory or on pilot scale.
*Abel E.L. 1980. Marihuana, the first twelve thousand
years.Plenum press, New York, 289 pp.
*Conrad C., 1993. Hemp, lifeline to the future. Creative Xpressions
Publishing, Los Angeles, California.
* FAO 1991. The outlook for pulp and paper to 1995. Paper
products, and industrial update. Food and Agricultural Organization
of the United Nations, Rome.
* Hunter, D. 1957. Paper making, the history and technique
of an ancient craft. 2nd Ed. Albert A. Knopf
* Smook G.A. 1982. Handbook for pulp & paper technologists.
2nd Ed. Angus Wilde Publications, Vancouver, B.C.
*Temple R.K.C, 1986. China, land of discovery and invention.
Patrick Stevens Ltd., United Kingdom.
*Gertjan van Roekel jr. ATO-DLO Agro-technology, P.O.box 17,
6700 AA Wageningen, The Netherlands
* Van Roekel, G J, 1994. Hemp pulp and paper production. Journal
of the International Hemp Association 1: 12-14.