What kind of fabric for your new sofa?

11 06 2015

 

We’ve looked at the frame, suspension system and cushioning on a sofa; next up:  fabric.  We consider fabric to be a very important, yet certainly misunderstood, component of furniture.  It can make up 40 – 45% of the price of a sofa.    So we’ll be breaking this topic up into several smaller bite size portions:  after a general discussion of what kind of fabric to choose for your lifestyle,  we’ll look at the embodied energy in your fabric choice (next post), and then finally we’ll take a look at why an organic fabric is better for you (as well as the rest of us).

One thing to remember is that there is much more fabric used in constructing an  upholstered piece of furniture than just the decorative fabric that you see covering the piece – a typical “quality” sofa also uses about 20 yards of decorative fabric, plus 20 yards of lining fabric, 15 yards of burlap and 10 yards of muslin, for a total of 65 yards of fabric!

So what do people look for in an upholstery fabric?

After color, fabric durability is probably top of everybody’s list.  Durability translates into most people’s minds as “heft” – in other words, lightweight cotton doesn’t usually come to mind.  A fabric with densely woven yarns tends to be more durable than a loosely woven fabric.  Often people assume leather is the best choice for a busy family.  We did a post about leather – if you’re at all considering leather, please read this first (https://oecotextiles.wordpress.com/2012/05/22/leather-furniture-what-are-you-buying/ ).    Another choice widely touted is to use Ultrasuede.  Please see our post about this fabric if you’re considering Ultrasuede: https://oecotextiles.wordpress.com/2010/09/08/is-ultrasuede%c2%ae-a-green-fabric/.

Equally important in evaluating durability is the length of the fibers.  Cotton as a fiber is much softer and of shorter lengths than either hemp or linen, averaging 0.79 -1.30 inches in length.  Hemp’s average length is 8 inches, but can range up to 180 inches in length. In a study done by Tallant et. al. of the Southern Regional Research Laboratory,  “results indicate that increases in shortfibers are detrimental to virtually all yarn and fabric properties and require increased roving twist for efficient drafting during spinning. A 1% increase in fibers shorter than 3/8 in. causes a strength loss in yarns of somewhat more than 1%.”[1]    In fact, the US textile industry has  advocated obtaining the Short Fiber Content (SFC) for cotton classification.  SFC is defined as the percentage of fibers shorter than ½ inch.  So a lower cost sofa upholstered in cotton fabric could have been woven of short fiber cotton, a cheaper alternative to longer fiber cotton and one which is inherently less durable – no matter how durable it appears on the showroom floor.

Patagonia, the California manufacturer of outdoor apparel, has conducted  tests on both hemp and other natural fibers, with the results showing that hemp has eight times the tensile strength and four times the durability of other natural fibers.   Ecolution had a hemp twill fabric tested for tensile and tear strength, and compared the results with a 12-oz cotton denim.  Hemp beat cotton every time:   Overall, the 100% hemp fabric had 62% greater tear strength and 102% greater tensile strength. [2]   And polyester trumps them both – but that’s a whole different ballgame, and we’ll get to that eventually.

There is a high correlation between fiber strength and yarn strength.  People have used silk as an upholstery fabric for hundreds of years, and often the silk fabric is quite lightweight;  but silk is a very strong fiber.

In addition to the fiber used, yarns are given a twist to add strength. This is called Twist Per Inch or Meter (TPI or TPM) – a tighter twist (or more turns per inch) generally gives more strength.  These yarns are generally smooth and dense.

So that brings us to weave structure.  Weave structures get very complicated, and we can refer you to lots of references for those so inclined to do more research (see references listed at the end of the post).

But knowing the fibers, yarn and weave construction still doesn’t answer people’s questions – they want some kind of objective measurement.  So in order to objectively compare fabrics,  tests to determine wear were developed (called abrasion tests), and many people today refer to these test results as a way to measure fabric durability.

Abrasion test results are supposed to forecast how well a fabric will stand up to wear and tear in upholstery applications.  There are two tests generally used:  Martindale  and Wyzenbeek (WZ).  Martindale is the preferred test in Europe; Wyzenbeek is preferred in the United States.  There is no correlation between the two tests, so it’s not possible to estimate the number of cycles that would be achieved on one test if the other were known:

  • Wyzenbeek (ASTM D4157-02):  a piece of cotton duck  fabric or wire mesh is rubbed in a straight back and forth motion on a      piece of fabric until “noticeable wear” or thread break is evident.  One back and forth motion is called a “double rub” (sometimes written as “dbl rub”).
  • Martindale (ASTM D4966-98):  the abradant in this test is worsted wool or wire screen, the fabric specimen is a circle or round  shape, and the rubbing is done in a figure 8, and not in a straight line as in Wyzenbeek.  One circle 8 is a cycle.

The Association for Contract Textiles performance guidelines lists the following test results as being suitable for commercial fabrics:

Wyzenbeek Martindale
Low traffic / private spaces 15,000 20,000
High traffic / public spaces 30,000 40,000

According to the Association for Contract Textiles, end use examples of “low traffic” areas where 30,000 WZ results should be appropriate include executive offices, corporate boardrooms, luxury hotel lobbies, suites and guest rooms. Areas of “high traffic” include: single shit corporate offices, waiting rooms, and high traffic hotel lobbies and guest rooms.

Sina Pearson, the textile designer, has been quoted in the Philadelphia Inquirer as saying that 6,000 rubs (Wyzenbeek) may be “just fine” for residential use”[3]   The web site for Vivavi furniture gives these ratings for residential use:

Wyzenbeek
from to
Light use 6,000 9,000
Medium use 9,000 15,000
Heavy use 15,000 30,000
Maximum use >30,000

Theoretically, the higher the rating (from either test) the more durable the fabric is purported to be.  It’s not unusual for designers today to ask for 100,000 WZ results.  Is this because we think more is always better?  Does a test of 1,000,000 WZ guarantee that your fabric will survive years longer than one rated only 100,000 WZ?  Maripaul Yates, in her guidebook for interior designers, says that “test results are so unreliable and the margin of error is so great that its competency as a predictor of actual wear is questionable.”[4]  The Association for Contract Textiles website states that “double rubs exceeding 100,000 are not meaningful in providing additional value in use.  Higher abrasion resistance does not necessarily indicate a significant extension of the service life of the fabric.”

The reason these test results might not be predicative is because there are, apparently, many ways to tweak test results. We’ve been told if we don’t like the test results from one lab, we can try Lab X, where the results tend to be better.  The reasons that these tests produce inconsistent results are:

1. Variation in test methods:       Measuring the resistance to abrasion is very complex.  Test results are affected by many factors that include the properties and dimensions of  the fibers; the structure of the yarns; the construction of the fabrics;  the type, kind and amount of treatments added to the fibers, yarns, or fabric; the time elapsed since the abradant was changed;  the type of  abradant used; the tension of the specimen being tested,the pressure between the abradant and the specimen…and other variables.

2. Subjectivity:    The  measurement of the relative amount of abrasion can be affected by the method of evaluation and is often influenced by the judgment of the operator.  Cycles to rupture, color change, appearance change and so forth are highly variable parameters and subjective.

3. Games Playing:     Then there is, frankly, dishonest collusion between the tester and the testee.  There are lots of games that are played. For instance, in Wyzenbeek, the abradant, either cotton duck or a metal screen, must be replaced every million double rubs. If your fabric is tested at the beginning of that abradant’s life versus the end of its life, well… you can see the games. Also, how much tension the subject fabric is under –  the “pull” of the stationary anchor of the subject fabric, affects the  rating.

In the final analysis, if you have doubts about the durability of a fabric,  will any number of test results convince you otherwise?  Also, if your heart is set on a silk  jacquard, for example, I bet it would take a lot of data to sway you from your heart’s desire.  Some variables just trump the raw data.

REFERENCES FOR WEAVE STRUCTURE:

1.  Peirce, F.T., The Geometry of Cloth Structure, “The Journal of the Textile Institute”, 1937: pp. 45 – 196

2. Brierley, S. Cloth Settings Reconsidered The Textile Manufacturer 79 1952: pp. 349 – 351.

3. Milašius, V. An Integrated Structure Factor for Woven Fabrics, Part I: Estimation of the Weave The Journal of the Textile Institute 91 Part 1 No. 2 2000: pp. 268 – 276.

4. Kumpikaitė, E., Sviderskytė, A. The Influence of Woven Fabric Structure on the Woven Fabric Strength Materials Science (Medžiagotyra) 12 (2) 2006: pp. 162 – 166.

5. Frydrych, I., Dziworska, G., Matusiak, M. Influence of Yarn Properties on the Strength Properties of Plain Fabric Fibres and Textile in Eastern Europe 4 2000: pp. 42 – 45.

6. ISO 13934-1, Textiles – Tensile properties of fabrics – Part 1: Determination of Maximum Force and Elongation at Maximum Force using the Strip Method, 1999, pp. 16.

[1] Tallant, John, Fiori, Louis and Lagendre, Dorothy, “The Effect of the Short Fibers in a Cotton on its Processing Efficiency and Product Quality”, Textile Research Journal, Vol 29, No. 9, 687-695 (1959)

[2]  http://www.globalhemp.com/Archives/Magazines/historic_fiber_remains.html

[3] ‘How will Performance Fabrics Behave”, Home & Design,  The Philadelphia Inquirer, April 11, 2008.

[4] Yates, Maripaul, “Fabrics: A Guide for Interior Designers and Architects”, WW. Norton and Company.

About these ads





Climate change and the textile industry

15 10 2014

Time sure flies doesn’t it?  I’ve been promising to reiterate the effects the textile industry has on climate change, so I’m re-posting a blog post we published in 2013:

In considering fabric for your sofa, let’s be altruistic and look at the impact textile production has on global climate change. (I only use the term altruistic because many of us don’t equate climate change with our own lives, though there have been several interesting studies of just how the changes will impact us directly,like the one in USA Today that explains that wet regions will be wetter, causing flash flooding; dry regions will get drier, resulting in drought. And … a heat wave that used to occur once every 100 years now happens every five years (1)).

Although most of the current focus on lightening our carbon footprint revolves around transportation and heating issues, the modest little fabric all around you turns out to be from an industry with a gigantic carbon footprint. The textile industry, according to the U.S. Energy Information Administration, is the 5th largest contributor to CO2 emissions in the United States, after primary metals, nonmetallic mineral products, petroleum and chemicals.[2] And the U.S. textile industry is small potatoes when compared with some other countries I could mention.

The textile industry is huge, and it is a huge producer of greenhouse gasses (GHG’s). Today’s textile industry is one of the largest sources of greenhouse gasses  on Earth, due to this huge size.[3] In 2008, annual global textile production was estimated at 60 billion kilograms (KG) of fabric. The estimated energy and water needed to produce that amount of fabric boggles the mind:

  • 1,074 billion kWh of electricity or 132 million metric tons of coal and
  • between 6 – 9 trillion liters of water[4]

Fabrics are the elephant in the room. They’re all around us but no one is thinking about them. We simply overlook fabrics, maybe because they are almost always used as a component in a final product that seems rather innocuous: sheets, blankets, sofas, curtains, and of course clothing. Textiles, including clothing, accounted for about one ton of the 19.8 tons of total CO2 emissions produced by each person in the U.S. in 2006. [5] By contrast, a person in Haiti produced a total of only 0.21 tons of total carbon emissions in 2006.[6]
Your textile choices do make a difference, so it’s vitally important to look beyond thread counts, color and abrasion results.
How do you evaluate the carbon footprint in any fabric? Look at the “embodied energy’ in the fabric – that is, all of the energy used at each step of the process needed to create that fabric. Not an easy thing to do! To estimate the embodied energy in any fabric it’s necessary to add the energy required in two separate fabric production steps:

  1. Find out what the fabric is made from, because the type of fiber tells you a lot about the energy needed to make the fibers used in the yarn. The carbon footprint of various fibers varies a lot, so start with the energy required to produce the fiber.
  2. Next, add the energy used to weave those yarns into fabric. Once any material becomes a “yarn” or “filament”, the amount of energy and conversion process to weave that yarn into a textile is pretty consistent, whether the yarn is wool, cotton, or synthetic.[7)

Let’s look at #1 first: the energy needed to make the fibers and create the yarn. For ease of comparison we’ll divide the fiber types into “natural” (from plants, animals and less commonly, minerals) and “synthetic” (man made):

For natural fibers you must look at field preparation, planting and field operations (mechanized irrigation, weed control, pest control and fertilizers (manure vs. synthetic chemicals)), harvesting and yields. Synthetic fertilizer use is a major component of the high cost of conventional agriculture: making just one ton of nitrogen fertilizer emits nearly 7 tons of CO2 equivalent greenhouse gases.
For synthetics, a crucial fact is that the fibers are made from fossil fuels. Very high amounts of energy are used in extracting the oil from the ground as well as in the production of the polymers.
A study done by the Stockholm Environment Institute on behalf of the BioRegional Development Group concludes that the energy used (and therefore the CO2 emitted) to create 1 ton of spun fiber is much higher for synthetics than for hemp or cotton:

KG of CO2 emissions per ton of spun fiber:
crop cultivation fiber production TOTAL
polyester USA 0 9.52 9.52
cotton, conventional, USA 4.2 1.7 5.9
hemp, conventional 1.9 2.15 4.05
cotton, organic, India 2 1.8 3.8
cotton, organic, USA 0.9 1.45 2.35

 

The table above only gives results for polyester; other synthetics have more of an impact: acrylic is 30% more energy intensive in its production than polyester [8] and nylon is even higher than that.
Not only is the quantity of GHG emissions of concern regarding synthetics, so too are the kinds of gasses produced during production of synthetic fibers. Nylon, for example, creates emissions of N2O, which is 300 times more damaging than CO2 [9] and which, because of its long life (120 years) can reach the upper atmosphere and deplete the layer of stratospheric ozone, which is an important filter of UV radiation. In fact, during the 1990s, N2O emissions from a single nylon plant in the UK were thought to have a global warming impact equivalent to more than 3% of the UK’s entire CO2 emissions.[10] A study done for the New Zealand Merino Wool Association shows how much less total energy is required for the production of natural fibers than synthetics:

 

Embodied Energy used in production of various fibers:
Energy use in MJ per KG of fiber:
flax fibre (MAT) 10
cotton 55
wool 63
Viscose 100
Polypropylene 115
Polyester 125
acrylic 175
Nylon 250
SOURCE: “LCA: New Zealand Merino Wool Total Energy Use”, Barber and Pellow, http://www.tech.plym.ac.uk/sme/mats324/mats324A9%20NFETE.htm

Natural fibers, in addition to having a smaller carbon footprint in the production of the spun fiber, have many additional benefits:

  • being able to be degraded by micro-organisms and composted (improving soil structure); in this way the fixed CO2 in the fiber will be released and the cycle closed. Synthetics do not decompose: in landfills they release heavy metals and other additives into soil and groundwater. Recycling requires costly separation, while incineration produces pollutants – in the case of high density polyethylene, 3 tons of CO2 emissions are produced for ever 1 ton of material burnt.[11] Left in the environment, synthetic fibers contribute, for example, to the estimated 640,000 tons of abandoned fishing nets in the world’s oceans.
  • sequestering carbon. Sequestering carbon is the process through which CO2 from the atmosphere is absorbed by plants through photosynthesis and stored as carbon in biomass (leaves, stems, branches, roots, etc.) and soils. Jute, for example, absorbs 2.4 tons of carbon per ton of dry fiber.[12]

Substituting organic fibers for conventionally grown fibers is not just a little better – but lots better in all respects:

  • uses less energy for production, emits fewer greenhouse gases and supports organic farming (which has myriad environmental, social and health benefits).  A study published by Innovations Agronomiques (2009) found that 43% fewer GHGs are emitted per unit area under organic agriculture than under conventional agriculture.[13] A study done by Dr. David Pimentel of Cornell University found that organic farming systems used just 63% of the energy required by conventional farming systems, largely because of the massive amounts of energy requirements needed to synthesize nitrogen fertilizers. Further it was found in controlled long term trials that organic farming adds between 100-400kg of carbon per hectare to the soil each year, compared to non-organic farming. When this stored carbon is included in the carbon footprint, it reduces the total GHG even further.[14] The key lies in the handling of organic matter (OM): because soil organic matter is primarily carbon, increases in soil OM levels will be directly correlated with carbon sequestration. While conventional farming typically depletes soil OM, organic farming builds it through the use of composted animal manures and cover crops

Taking it one step further beyond the energy inputs we’re looking at, which help to mitigate climate change, organic farming helps to ensure other environmental and social goals:

  • eliminates the use of synthetic fertilizers, pesticides and genetically modified organisims (GMOs) which is an improvement in human health and agrobiodiversity
  • conserves water (making the soil more friable so rainwater is absorbed better – lessening irrigation requirements and erosion)
  • ensures sustained biodiversity
  • and compared to forests, agricultural soils may be a more secure sink for atmospheric carbon, since they are not vulnerable to logging and wildfire.

Organic agriculture is an undervalued and underestimated climate change tool that could be one of the most powerful strategies in the fight against global warming, according to Paul Hepperly, Rodale Institute Research Manager. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years) provides convincing evidence that improved global terrestrial stewardship–specifically including regenerative organic agricultural practices–can be the most effective currently available strategy for mitigating CO2 emissions.

At the fiber level it is clear that synthetics have a much bigger footprint than does any natural fiber, including wool or conventionally produced cotton. So in terms of the carbon footprint at the fiber level, any natural fiber beats any synthetic – at this point in time. Best of all is an organic natural fiber.
And next let’s look at #2, the energy needed to weave those yarns into fabric.
There is no dramatic difference in the amount of energy needed to weave fibers into fabric depending on fiber type.[15] The processing is generally the same whether the fiber is nylon, cotton, hemp, wool or polyester: thermal energy required per meter of cloth is 4,500-5,500 Kcal and electrical energy required per meter of cloth is 0.45-0.55 kwh. [16] This translates into huge quantities of fossil fuels – both to create energy directly needed to power the mills, produce heat and steam, and power air conditioners, as well as indirectly to create the many chemicals used in production. In addition, the textile industry has one of the lowest efficiencies in energy utilization because it is largely antiquated.

#######
(1) http://www.usatoday.com/story/news/nation/2013/02/28/climate-change-remaking-america/1917169/
(2) Source: Energy Information Administration, Form EIA:848, “2002 Manufacturing Energy Consumption Survey,” Form EIA-810, “Monthly Refinery Report” (for 2002) and Documentatioin for Emissions of Greenhouse Gases in the United States 2003 (May 2005). http://www.eia.doe.gov/emeu/aer/txt/ptb1204.html
(3) Dev, Vivek, “Carbon Footprint of Textiles”, April 3, 2009, http://www.domain-b.com/environment/20090403_carbon_footprint.html
(4) Rupp, Jurg, “Ecology and Economy in Textile Finishing”, Textile World, Nov/Dec 2008
(5) Rose, Coral, “CO2 Comes Out of the Closet”, GreenBiz.com, September 24, 2007
(6) U.S. Energy Information Administration, “International Energy Annual 2006”, posted Dec 8, 2008.
(7) Many discussions of energy used to produce fabrics or final products made from fabrics (such as clothing) take the “use” phase of the article into consideration when evaluating the carbon footprint. The argument goes that laundering the blouse (or whatever) adds considerably to the final energy tally for natural fibers, while synthetics don’t need as much water to wash nor as many launderings. We do not take this component into consideration because
. it applies only to clothing; even sheets aren’t washed as often as clothing while upholstery is seldom cleaned.
. is biodegradeable detergent used?
. Is the washing machine used a new low water machine? Is the water treated by a municipal facility?
. Synthetics begin to smell if not treated with antimicrobials, raising the energy score.
Indeed, it’s important to evaluate the sponsors of any published studies, because the studies done which evaluate the energy used to manufacture fabrics are often sponsored by organizations which might have an interest in the outcome. Additionally, the data varies quite a bit so we have adopted the values which seem to be agreed upon by most studies.
(8) Ibid.
(9) “Tesco carbon footprint study confirms organic farming is energy efficient, but excludes key climate benefit of organic farming, soil carbon”, Prism Webcast News, April 30, 2008, http://prismwebcastnews.com/2008/04/30/tesco-carbon-footprint-study-confirms-organic-farming%E2%80%99s-energy-efficiency-but-excludes-key-climate-benefit-of-organic-farming-%E2%80%93-soil-carbon/
(10) Fletcher, Kate, Sustainable Fashion and Textiles, Earthscan, 2008, Page 13
(11) “Why Natural Fibers”, FAO, 2009: http://www.naturalfibres2009.org/en/iynf/sustainable.html
(12) Ibid.
(13) Aubert, C. et al., (2009) Organic farming and climate change: major conclusions of the Clermont-Ferrand seminar (2008) [Agriculture biologique et changement climatique : principales conclusions du colloque de Clermont-Ferrand (2008)]. Carrefours de l’Innovation Agronomique 4. Online at
(14) International Trade Centre UNCTAD/WTO and Research Institute of Organic Agriculture (FiBL); Organic Farming and Climate Change; Geneva: ITC, 2007.
(15) 24th session of the FAO Committee on Commodity Problems IGG on Hard Fibers of the United Nations
(16) “Improving profits with energy-efficiency enhancements”, December 2008, Journal for Asia on Textile and Apparel, http://textile.2456.com/eng/epub/n_details.asp?epubiid=4&id=3296





How to buy a quality sofa – part 4: natural fibers

10 10 2012

Since the 1960s, the use of synthetic fibers has increased dramatically,  causing the natural fiber industry to lose much of its market share. In December 2006, the United Nations General Assembly declared 2009 the International Year of Natural Fibres (IYNF); a year-long initiative focused on raising global awareness about natural fibers with specific focus on increasing market demand to help ensure the long-term sustainability for farmers who rely heavily on their production.

                       International Forum for Cotton Promotion

Natural fibers  have a history of being considered the fibers that are easiest to live with, valued for their comfort, soft hand and versatility.  They also carry a certain cachet:  cashmere, silk taffeta and 100% pure Sea Island cotton convey different images than does 100% rayon,  pure polyester or even Ultrasuede, don’t they?  And natural fibers, being a bit of an artisan product, are highly prized especially in light of campaigns by various trade associations to brand fiber:    “the fabric of our lives” from Cotton, Inc. and merino wool with the pure wool label are two examples.                                                              

Preferences for natural fibers seem to be correlated with income; in one study, people with higher incomes preferred natural fibers by a greater percentage than did those in lower income brackets.   Cotton Incorporated funded a study that demonstrated that  66% of all women with household incomes over $75,000 prefer natural fibers to synthetic.

What are the reasons, according to the United Nations, that make natural fibers so important?  The UN website, Discover Natural Fibers lists the following reasons why natural fibers are a good choice.  Please remember that this list does not include organic natural fibers, which provide even more benefits (but that’s another post):

  1. Natural fibers are a healthy choice.
    1. Natural fiber textiles absorb perspiration and release it into the air, a process called “wicking” that creates natural ventilation. Because of their more compact molecular structure, synthetic fibers cannot capture air and “breathe” in the same way. That is why a cotton T-shirt is so comfortable to wear on a hot summer’s day, and why polyester and acrylic garments feel hot and clammy under the same conditions. (It also explains why sweat-suits used for weight reduction are made from 100% synthetic material.) The bends, or crimp, in wool fibers trap pockets of air which act as insulators against both cold and heat – Bedouins wear thin wool to keep them cool. Since wool can absorb liquids up to 35% of its own weight, woollen blankets efficiently absorb and disperse the cup of water lost through perspiration during sleep, leaving sheets dry and guaranteeing a much sounder slumber than synthetic blankets.
    2. The “breathability” of natural fiber textiles makes their wearers less prone to skin rashes, itching and allergies often caused by synthetics. Garments, sheets and pillowcases of organic cotton or silk are the best choice for children with sensitive skins or allergies, while hemp fabric has both a high rate of moisture dispersion and natural anti-bacterial properties.   Studies by Poland’s Institute of Natural Fibers have shown that 100% knitted linen is the most hygienic textile for bed sheets – in clinical tests, bedridden aged or ill patients did not develop bedsores. The institute is developing underwear knitted from flax which, it says, is significantly more hygienic than nylon and polyester. Chinese scientists also recommend hemp fiber for household textiles, saying it has a high capacity for absorption of toxic gases.
  2. Natural fibers are a responsible choice.
    1. Natural fibers production, processing and export are vital to the economies of many developing countries and the livelihoods of millions of small-scale farmers and low-wage workers. Today, many of those economies and livelihoods are under threat: the global financial crisis has reduced demand for natural fibers as processors, manufacturers and consumers suspend purchasing decisions or look to cheaper synthetic alternatives.
    2. Almost all natural fibers are produced by agriculture, and the major part is harvested in the developing world.
      1. For example, more than 60% of the world’s cotton is grown in China, India and Pakistan. In Asia, cotton is cultivated mainly by small farmers and the sale of cotton provides the primary source of income for some 100 million rural households.
      2. In India and Bangladesh, an estimated 4 million marginal farmers earn their living – and support 20 million dependents – from the cultivation of jute, used in sacks, carpets, rugs and curtains. Competition from synthetic fibers has eroded demand for jute over recent decades and, in the wake of recession, reduced orders from Europe and the Middle East could cut jute exports even further.
      3. Silk is another important industry in Asia. Raising silkworms generates income for some 700 000 farm households in India, while silk processing provide jobs for 20 000 weaving families in Thailand and about 1 million textile workers in China.
      4. Each year, developing countries produce around 500 000 tonnes of coconut fiber – or coir – mainly for export to developed countries for use in rope, nets, brushes, doormats, mattresses and insulation panels. In Sri Lanka, the single largest supplier of brown coir fiber to the world market, coir goods account for 6% of agricultural exports, while 500 000 people are employed in small-scale coir factories in southern India.
      5. Across the globe in Tanzania, government and private industry have been working to revive once-booming demand for sisal fiber, extracted from the sisal agave and used in twine, paper, bricks and reinforced plastic panels in automobiles. Sisal cultivation and processing in Tanzania directly employs 120 000 people and the sisal industry benefits an estimated 2.1 million people.
  3. Natural fibers are a sustainable choice.
    1. Natural fibers will play a key role in the emerging “green” economy based on energy efficiency, the use of renewable feed stocks in bio-based polymer products, industrial processes that reduce carbon emissions and recyclable materials that minimize waste.  Natural fibers are a renewable resource, par excellence – they have been renewed by nature and human ingenuity for millennia. During processing, they generate mainly organic wastes and leave residues that can be used to generate electricity or make ecological housing material. And, at the end of their life cycle, they are 100% biodegradable.
    2. An FAO study estimated that production of one ton of jute fiber requires just 10% of the energy used for the production of one ton of synthetic fibers (since jute is cultivated mainly by small-scale farmers in traditional farming systems, the main energy input is human labor, not fossil fuels).
    3. Processing of some natural fibers can lead to high levels of water pollutants, but they consist mostly of biodegradable compounds, in contrast to the persistent chemicals, including heavy metals, released in the effluent from synthetic fiber processing. More recent studies have shown that producing one ton of polypropylene – widely used in packaging, containers and cordage – emits into the atmosphere more than 3 ton of carbon dioxide, the main greenhouse gas responsible for global warming. In contrast, jute absorbs as much as 2.4 tonnes of carbon per tonne of dry fiber.
    4. The environmental benefits of natural fiber products accrue well beyond the production phase. For example, fibers such as hemp, flax and sisal are being used increasingly as reinforcing in place of glass fibers in thermoplastic panels in automobiles. Since the fibers are lighter in weight, they reduce fuel consumption and with it carbon dioxide emissions and air pollution.
    5. But where natural fibers really excel is in the disposal stage of their life cycle. Since they absorb water, natural fibers decay through the action of fungi and bacteria – this releases the fixed CO2 in the fibers and closes the cycle; it also improves soil structure.  Synthetics present society with a range of disposal problems. In land fills they release heavy metals and other additives into soil and groundwater. Recycling requires costly separation, while incineration produces pollutants and, in the case of high-density polyethylene, 3 tonnes of carbon dioxide emissions for every tonne of material burnt. Left in the environment, synthetic fibers contribute, for example, to the estimated 640 000 tonnes of abandoned fishing nets and gear in the world’s oceans.
  4. Natural fibers are a high-tech choice.
    1. Natural fibers have intrinsic properties – mechanical strength, low weight and low cost – that have made them particularly attractive to the automobile industry.
      1. In Europe, car makers are using mats made from abaca, flax and hemp in press-molded      thermoplastic panels for door liners, parcel shelves, seat backs, engine shields and headrests.
        1. For consumers, natural fiber composites in automobiles provide better thermal and acoustic insulation than fiberglass, and reduce irritation of the skin and respiratory system. The low density of plant fibers also reduces vehicle weight, which cuts fuel consumption.
        2. For car manufacturers, the moulding process consumes less energy than that of fibreglass and produces less wear and tear on machinery, cutting production costs by up to 30%. The use of natural fibres by Europe’s car industry is projected to reach 100 000 tonnes by 2010. German companies lead the way. Daimler-Chrysler has developed a flax-reinforced polyester composite, and in 2005 produced an award-winning spare wheel well cover that incorporated abaca yarn from the Philippines. Vehicles in some BMW series contain up to 24 kg of flax and sisal. Released in July 2008, the Lotus Eco Elise (pictured above) features body panels made with hemp, along with sisal carpets and seats upholstered with hemp fabric. Japan’s carmakers, too, are “going green”. In Indonesia, Toyota manufactures door trims made from kenaf and polypropylene, and Mazda is using a bioplastic made with kenaf for car interiors.
    1. Worldwide, the construction industry is moving to natural fibres for a range of products, including light structural walls, insulation materials, floor and wall coverings, and roofing. Among recent innovations are cement blocks reinforced with sisal fibre, now being manufactured in Tanzania and Brazil. In India, a growing shortage of timber for the construction industry has spurred development of composite board made from jute veneer and coir ply – studies show that coir’s high lignin content makes it both stronger and more resistant to rotting than teak. In Europe, hemp hurd and fibres are being used in cement and to make particle boards half the weight of wood-based boards. Geotextiles are another promising new outlet for natural fibre producers. Originally developed in the Netherlands for the construction of dykes, geotextile nets made from hard natural fibres strengthen earthworks and encourage the growth of plants and trees, which provide further reinforcement. Unlike plastic textiles used for the same purpose, natural fibre nets – particularly those made from coir – decay over time as the earthworks stabilize.
  1. Natural fibers are a fashionable choice.
    John Patrick Organic Fall/Winter 2010
    1. Natural fibers are at the heart of a fashion movement that goes by various names: sustainable, green, uncycled, ethical, eco-, even eco-environmental. It focuses fashion on concern for the environment, the well-being of fiber producers and consumers, and the conditions of workers in the textile industry. Young designers now offer “100% carbon neutral” collections that strive for sustainability at every stage of their garments’ life cycle – from production, processing and packaging to transportation, retailing and ultimate disposal. Preferred raw materials include age-old fibres such as flax and hemp, which can be grown without agrochemicals and produce garments that are durable, recyclable and biodegradable. Fashion collections also feature organic wool, produced by sheep that have not been exposed to pesticide dips, and “cruelty-free” wild silk, which is harvested – unlike most silk – after the moths have left their cocoons.
    2. The Global Organic Textile Standard (GOTS)   sets strict standards on chemicals permitted in processing, on waste water treatment, packaging material and technical quality parameters, on factory working conditions and on residue testing.
    3. Sustainable fashion intersects with the “fair trade” movement, which offers producers in developing countries higher prices for their natural fibres and promotes social and environmental standards in fibre processing. Fair trade fashion pioneers are working with organic cotton producers’ cooperatives in Mali, hand-weavers groups in Bangladesh and Nepal, and alpaca producers in Peru. A major UK chain store launched in 2007 a fair trade range of clothing that uses cotton “ethically sourced” from farmers in the Gujarat region of India. It has since sold almost 5 million garments and doubled sales in the first six months of 2008.
    4. Another dimension of sustainable fashion is concern for the working conditions of employees in textile and garment factories, which are often associated with long working hours, exposure to hazardous chemicals used in bleaching and dyeing, and the scourge of child labor. The  Global Organic Textile Standard (GOTS), widely accepted by manufacturers, retailers and brand dealers, includes a series of “minimum social criteria” for textile processing, including a prohibition on the use of child labor, workers’ freedom of association and right to collective bargaining, safe and hygienic working conditions, and “living wages”.




What can be considered the “good” chemicals in textile processing?

9 02 2011

We’re often asked if ALL the chemicals used in textile processing are harmful.  And the answer is (surprisingly maybe)  no!   Many chemicals are used, many benign, but as with everything these days there are caveats.

Let’s look at the chemical that is used  most often in the textile industry:  salt.  That’s right.  Common table salt.  Safe, natural salt is used in textile dyeing.

Salt shaker painting by Jeff Hayes

The way the dyestuff bonds to the fibers is very important – and the most permanent, wash fast dyes are the most tightly attached to the fiber molecules (called reactive dyes).  Here’s how salt comes into the picture:

To dye a fabric made of a cellulosic fiber (i.e., cotton, hemp, linen) or its close cousin (viscose),  the fabric is put into water, where its surface gets covered in negative ionic charges.  The reactive dyes used most often to dye cellulosic fabrics also develops a negative charge, so the fibers actually repel the dye – like two magnets repelling each other.   If we try to dye a cellulosic fabric without using  salt, the dye molecules just roll off the surface of the fibers and the fabric does not show much color change.

But when salt is added to the water, the solution splits into positive sodium ions (Na+) and negative chlorine ions (Cl-).  The  positive Na+  ions then dive into the surface of the fabric to neutralize the negative charge.

The dye molecules are then attracted to the fiber by weak Van der Waals forces and as the dyes get close to the fiber molecules, the salt acts like a glue to hold the dyes in place.  If we add alkali, the dyestuff will permanently grab hold of the fiber and become a part of the fiber molecule rather than remaining as an independent chemical  entity.

The color fastness of reactive dyes is so good that  it’s no wonder that they have become so widely used.  And natural salt has been crucial to their success.

We sprinkle salt on our foods – indeed salt is essential for life itself.  But (there is always a “but”) the “dose makes the poison”  – and the textile industry uses a LOT of salt!

The concentrations to suppress those negative ions can be as high as 100 gm per liter.  In the worst cases, 1 kg of salt is used to apply reactive dye to 1 kg of fabric.  Think of the billions of yards of fabric that’s produced each year:   In Europe alone, 1 million tons of salt is discharged into our waterways each year.[1] In areas where salt is discharged into the ecosystem, it takes a long, long time for affected areas to recover, especially in areas of sparse rainfall – such as Tirupur, India.

Tirupur is one of the world’s centers for clothing production , home of 765 dyeing and bleaching industries.  These dyehouses  had been dumping untreated effluent into the Noyyal River for years, rendering the water unsuitable or irrigation – or drinking.   In 2005, the government shut down 571 dyehouses  because of the effluent being discharged into the Noyyal.  The mill owners said they simply couldn’t afford to put pollution measures into place.   The industry is too important to India to keep the mills closed for long, so the government banned the discharge of salt and asked for an advance from the mills before allowing them to re-open.     But … on February 4, 2011, the Madras high court ordered 700 dye plants to be shut down because of the damage the effluent was doing to the local environment.  Sigh.  (Read more about Tirupur here.)

Unfortunately, the salt in textile effluent is not made harmless by treatment plants and can pass straight through  to our rivers even if treated.  This salt filled effluent can wreak havoc with living organisms.

There are some new “low salt” dyes that require only half the amount of “glue”, but these dyes are not widely used because they’re expensive – and manufacturers are following our lead in demanding ever cheaper fabrics.

Recycling the salt is possible, and this has been used by many of the dyers in Tirupur, and elsewhere, who operate zero discharge facilities.  The effluent is cleaned and then the salt is recovered using an energy intensive process to evaporate the water and leave the solid, re-useable salt.

This sounds like a good idea – it reduces the pollution levels – but the carbon footprint goes through the roof, so salt recovery isn’t necessarily the best option.  In fact, in some areas of the world where water is plentiful and the salt can be diluted in the rivers adequately, it may be better to simply discharge salt than to recover it.

But the best option is to avoid salt altogether.

Next week we’ll look at how to do that.


[1] Dyeing for a change: Current Conventions and New Futures in the Textile Color Industry (2006, July) www.betterthinking.co.uk





Linen

30 06 2010

Linen is a textile made from the fibers of the flax plant, Linum usitatissimum L., which is a delicate and graceful annual that stands about 3 feet high and produces attractive blue flowers. Its Latin name means “most useful,” and for good reason. Though technically a wildflower, flax  has been cultivated for thousands of years for a wide variety of important uses.  Common flax was one of the earliest domesticated plants.  A cousin of hemp, cannabis sativa L., flax is also known as a “bast” plant, meaning the fiber is collected from the inner bark, or bast,  of the steam. 

Flax  grows best at northern temperate latitudes, in cool,  humid climates and within moist, well-plowed soil.

Today, France, Belgium, Netherlands, Spain, Russia, Egypt and China are the foremost producers of flax for commercial textile purposes.   China is also a major buyer of raw flax for processing, with imports of 60 000 tons a year, including most of Europe’s flax fibers. Bulk linen production has shifted to Eastern Europe and China, but niche producers in Ireland, Italy and Belgium continue to supply the market for high quality fabrics in Europe, Japan and the USA.

There are two main types of flax grown worldwide:  fiber flax and seed flax.

FIBER FLAX:

Flax is one of the oldest fiber crops in the world.  It was used by the ancient Egyptians, Romans, Greeks and Hebrews for food, clothing and medicine.

The use of flax fiber in the manufacturing of cloth in northern Europe dates back to Neolithic times. In North America, flax was introduced by the Puritans, and today has become an essential commercial crop grown throughout the Midwest.

Today, flax is used to make linen cloth,  and it’s usually an expensive textile, produced in relatively small quantities.  Linen fabric maintains a strong traditional niche among high quality household textiles – bed linen, furnishing fabrics, and interior decoration accessories.  More than 70% of linen goes to clothing manufacture, where it is valued for its exceptional coolness in hot weather – the legendary linen suit is a symbol of breezy summer elegance.

Linen has a long staple (i.e., individual fiber length).  The best grades of flax  are used for fine fabrics such as damasks, lace and sheeting. Shorter flax fibers produce heavier yarns suitable for kitchen towels, sails, tents and canvas.  Lower fiber grades are used as reinforcement and filler in thermoplastic composites and resins used in automotive interior substrates, twine, rope,  furniture and other consumer products.  Flax fiber is also a raw material for the high-quality paper industry for the use of printed banknotes and rolling paper for cigarettes and tea bags.   Linen fabric is one of the preferred traditional supports for artists canvas. In the United States cotton is popularly used instead because linen is many times more expensive, restricting its use to professional painters. In Europe however, linen is usually the only fabric support available in art shops. Linen is preferred to cotton for its strength, durability and archival  integrity.

SEED FLAX:

Flax seed is grown for human and animal consumption. Flax seeds can be eaten raw or cooked, cracked or whole, and can be ground into flour. They are often sprinkled on top of bread, cooked into foods like chips, muffins and cakes or added to granola cereal. Flax seeds contain high amounts of Omega-3, 6 and 9 fatty acids, which are believed to reduce cholesterol, boost the immune system and lower the risk of heart disease. They also contain potassium, magnesium, fiber and protein, and make a good natural laxative.                    

Flax seed oil (also called linseed oil) is used for culinary as well as industrial purposes.  A good source of essential omega-3 fatty acids, the oil is believed to provide benefits to arthritis and lupus patients by reducing inflammation.   For industry, it serves as a pigment binder for oil paint and a drying agent for paints, lacquers and inks. It is sometimes used as a wood finish, in varnishes, printing inks, and soaps and can be combined with cork to make linoleum.

Once oil is cold pressed from flax seeds, the husks, which are high in protein,  are often used as feed for chickens and other livestock. The seeds provide animals with much needed fiber and protein. Eggs from chickens that were fed flax seeds are  purported to be high in omega fatty acids and have added health benefits.

Flax  fibers range in length up to 90 cm, and average 12 to 16 microns in diameter.  They are not as long as hemp, which has fibers that measure from 90 cm to 460 cm, yet they are much longer than cotton fibers, which measure only as much as 3.5 cm.
Harvesting:

There are three degrees in the ripening of the flax grown to make linen: green, yellow and brown. The yellow has proved to be the most suitable for fiber production. Flax that is pulled too early – green – produces very fine but weak fibers. On the other hand, in overripe flax – brown – the stems are strong but brittle and produce too high a proportion of undesirable short fibers (‘tow’). When the flax is yellow, the fibers are long and supple, and therefore ideal for further processing.  (This is where we get the term “flaxen” to describe a yellow haired person.) The plant must be harvested as soon as it appears ready since any delay results in linen without the prized luster.  It is important that the stalk not be cut in the harvesting process but removed from the ground intact; if the stalk is cut the sap is lost, and this affects the quality of the linen.

These plants are often pulled out of the ground by hand, grasped just under the seed heads and gently tugged. The tapered ends of the stalk must be preserved so that a smooth yarn may be spun. The stalks are tied in bundles (called beets) and are ready for extraction of the flax fiber in the stalk. However, fairly efficient machines can pull the plants from the ground as well.

Once the plants have been harvested, the fibers must be released from the stalk.  This process is called “retting” – actually a process of rotting away the woody bark of the plant which also loosens the pectin or gum that attaches the fiber to the stem:

  • Retting may be accomplished in a variety of ways. In some parts of the world, linen is still retted by hand, using moisture  to rot  away the bark. The stalks are spread on dewy slopes, submerged in stagnant pools of water, or placed in running streams. Workers must wait for the water to begin rotting or fermenting the stem—sometimes more than a week or two. However, most manufacturers today use chemicals for retting. The plants are placed in a solution either of alkali or oxalic acid,  then pressurized and boiled. This method is easy to monitor and rather quick, although some believe that chemical retting adversely affects the color and strength of the fiber and hand retting produces the finest linen. Vat or mechanical retting requires that the stalks be submerged in vats of warm water, hastening the decomposition of the stem. The flax is then removed from the vats and passed between rollers to crush the bark as clean water flushes away the pectin and other impurities.
  • If flax is not fully retted, the stalk of the plant cannot be separated from the fiber without injuring the delicate fiber. Thus, retting has to be carefully executed. Too little retting, or under retting,  may not permit the fiber to be separated from the stalk with ease; it produces a coarse yarn suitable only for ropes.  Too much retting (over retting or rotting) will weaken fibers so they will have limited application.  The value of a batch can vary by 100% depending on the quality of the retting.
  • After the retting process, the flax plants are squeezed and allowed to dry out before they undergo the process called breaking. In order to crush the decomposed stalks, they are sent through fluted rollers which break up the stem and separate the exterior fibers from the bast that will be used to make linen. This process breaks the stalk into small pieces of bark called shives. Then, the shives are scutched. The scutching machine removes the broken shives with rotating paddles, finally releasing the flax fiber from stalk.
  • The fibers are now combed and straightened in preparation for spinning. This separates the short fibers (called tow and used for making more coarse, sturdy goods) from the longer and more luxurious linen fibers. The very finest flax fibers are called line or dressed flax, and the fibers may be anywhere from 12-20 in (30.5-51 cm) in length, but first class fibers are at least 60 cm.   Color of light grey, steel grey and silver grey are considered the best.

Spinning:

  • Line fibers (long linen fibers) are put through machines called spreaders, which combine fibers of the same length, laying the fibers parallel so that the ends overlap, creating a sliver. The sliver passes through a set of rollers, making a  roving which is ready to spin.
  • The linen rovings, resembling tresses of blonde hair, are put on a spinning frame and drawn out into thread and ultimately wound on bobbins or spools. Many such spools are filled on a spinning frame at the same time. The fibers are formed into a continuous ribbon by being pressed between rollers and combed over fine pins. This operation constantly pulls and elongates the ribbon-like linen until it is given its final twist for strength and wound on the bobbin. While linen is a strong fiber, it is rather inelastic. Thus, the atmosphere within the spinning factory must be both humid and warm in order to render the fiber easier to work into yarn. In this hot, humid factory the linen is wet spun in which the roving is run through a hot water bath in order to bind the fibers together thus creating a fine yarn. Dry spinning does not use moisture for spinning. This produces rough, uneven yarns that are used for making inexpensive twines or coarse yarns.
  • These moist yarns are transferred from bobbins on the spinning frame to large take-up reels. These linen reels are taken to dryers, and when the yarn is dry, it is wound onto bobbins for weaving or wound into yarn spools of varying weight. The yarn now awaits transport to the loom for weaving into fabrics, toweling, or for use as twine or rope.

A great concern to the environment is the chemicals used in retting. These chemicals must be neutralized before being released into water supplies. The stalks, leaves, seed pods, etc. are natural organic materials and are not hazardous unless impregnated with much of the chemicals left behind in the retting process. The only other concern with the processing of linen is the smell—it is said that hand-retted linen produces quite a stench and is most unpleasant to experience.

The first flax-spinning mill was opened in England in 1787, but only in 1812 was linen successfully woven with power looms. The linen industry suffered in relation to cotton because many textile inventions were not applicable to linen.   Although linen exceeds cotton in coolness, luster, strength, and length of fiber, the expense of production limits its use.

The decrease in use of linen may be attributed to the increasing quality of synthetic fibers, and a decreasing appreciation of buyers for very high quality yarn and fabric. Very little top-quality linen is produced now, and most is used in low volume applications like hand weaving and as an art material.

Over 90% of the world’s spinning equipment are designed to quickly and effectively spin fibers based on the length and diameter of cotton fibers.  This is referred to as the “cotton” system.  No other spinning system is as productive or cost-effective as the cotton system.  Flax fibers can be broken down into their shortest components, and this is called cottonization and the product is called cottonized flax.  Flax has traditionally been cottonized using mechanical systems (i.e., mechanical cottonization) but it can also be done using enzymes, steam explosion and ultra-sound.  This “cottonization” is done to be able to spin linen fibers on cotton machines – it means the process is quicker and requires less equipment.  However, the finished fibers often lose the characteristic linen look.

The Living Linen Project was set up in 1995 as an Oral Archive of the knowledge of the Irish linen industry still available within a nucleus of people who were formerly working in the industry in Ulster.  There is a long history of linen in Ireland.

For those of you with linguistic interests, linen has given rise to a number of words:

  • line, derived from the use of a linen threadto determine a straight line;
  • liniment, due to the use of finely ground flax seeds as a mild irritant applied to the skin to ease muscle pain
  • lining, because linen was often used to create a lining for wool and leather clothing
  • lingerie, via French, originally denotes underwear made of linen
  • linseed oil, an oil derived from flaxseed
  • linoleum, a floor covering made from linseed oil and other materials

CHARACTERISTICS of Linen:

Linen is among the strongest of the vegetable fibers, with 2 to 3 times the strength of cotton.  It is a very durable, strong fabric, and one of the few that are stronger wet than dry. It is smooth, making the finished fabric lint free, and gets softer the more it is washed.  The fibers  are resistant to damage from abrasion.

However, constant creasing in the same place in sharp folds will tend to break the linen threads. This wear can show up in collars, hems, and any area that is iron creased during laundering. Linen has poor elasticity and does not spring back readily, explaining why it wrinkles so easily.

Linen fabrics have a high natural luster; their natural color ranges between shades of ivory,  ecru,  tan, or grey. Pure white linen is created by heavy bleaching. Linen typically has a thick and thin character with a crisp and textured feel to it, but it can range from stiff and rough, to soft and smooth.

When freed from impurities, linen is highly absorbent and will quickly remove perspiration from the skin. Linen is a stiff fabric and is less likely to cling to the skin; when it billows away, it tends to dry out and become cool so that the skin is being continually touched by a cool surface.  It’s valued for its exceptional coolness and freshness in hot weather.

Mildew, perspiration, and bleach can also damage the fabric, but it is resistant to moths and  carpet beetles. Linen is relatively easy to take care of, since it resists dirt and stains, has no lint or pilling tendency, and can be dry cleaned, machine washed or steamed. It can withstand high temperatures, and has only moderate initial shrinkage.

Linen should not be dried too much by tumble drying: it is much easier to iron when damp. Linen wrinkles very easily, and so some more formal linen garments require ironing often, in order to maintain perfect smoothness. Nevertheless the tendency to wrinkle is often considered part of the fabric’s particular “charm”, and a lot of modern linen garments are designed to be air dried on a good hanger and worn without the necessity of ironing.

A characteristic often associated with contemporary linen yarn is the presence of “slubs”, or small knots which occur randomly along its length. In the past, these slubs were considered defects associated with low quality. The finest linen had very consistent diameter threads, with no slubs.  Today, however, the presence of slubs is considered appealing, and fashion dictates that even the finest linens have these slubs.





Characteristics of hemp

2 06 2010

We were charmed by this quote, which was written by Yitzac Goldstein of Earth Protex, many years ago:

Before Huang-Ti’s time                                      
clothing was made from skins of birds and animals.

But as time went on

people increased and animals were few

Causing great hardship.

So Huang-Ti ordained that

Clothing should be made from hemp fiber.

This is how the spiritual leader  changed matters

For the people’s benefit.

6th century A.D. historian Khung Ying-Ta on

The Yellow Emperor, Huang-Ti, 27th century B.C.

I love hemp, maybe just because of the lore associated with the plant – and I don’t mean the lore surrounding the hallucinogenic properties of the plants that are bred for high THC content!  So let’s get that part out of the way fast:

Hemp is another word for the plant Cannabis sativa. Yes, marijuana comes from this same plant genus – and so does broccoli and cauliflower. But what we call “industrial hemp” is a different variety (or subspecies), called Cannabis sativa sativa.  Marijuana is from Cannabis sativa indica, which is bred to contain between 5 – 10% of the intoxicating substance delta-9 tetrahydrocannabinol, or THC.  Industrial hemp, Cannabis sativa sativa, contains less than one tenth that amount.  Industrial grade hemp is not marijuana – it doesn’t look the same and if you tried to smoke it you’d probably die of carbon monoxide poisoning before you felt anything but sick. For more about the differences between the two varieties click here or go to the Industrial Hemp website.

Hemp is unique among other crops in that every part of the plant has utility and potential market value.  Here are some interesting facts about hemp that contribute to the lore I’m referring to:

  • In 1941 Henry Ford built a car with a plastic made from hemp and wheat straw.
  • Both George Washington and Thomas Jefferson grew hemp on their plantations; in fact the colonial government mandated that people grow hemp.  Settlers used hemp fiber as money and to pay taxes.
  • The original Levi Strauss jeans were made from hemp.
  • The July 4, 1776 Declaration of Independence  was written on hemp paper.

The plant has been used for millennia for food, fibers and fuel.   Today it is said that over 30,000 different products can be made from hemp.  Hemp’s oilseed makes high-grade food and beauty products.  The stalks produce fiber and cellulose.  And today, because of its length and strength, hemp fiber is woven into natural advanced composites, which can then be fashioned into anything from fast food containers to skateboard decks to the body of a stealth fighter.  There are over two million cars on the road today with hemp composite components.

But hemp for luxurious fabrics?  I remember those macramé plant hangers that were all the rage in the 1970’s.  Hemp has a public relations campaign to wage, because when I thought of hemp a few years ago (before my enlightenment) all I could imagine was burlap bag and sisal rugs.  Turns out the technical revolution has even found hemp:  new developments from the 1980’s  in retting and processing the stalks has meant that the hemp fibers produced today are soft and lustrous enough for even the finest fabrics.

Many end users look for comfort and durability in choosing a fabric, so hemp’s softness and high abrasion resistance make it a competitive choice.  Hemp fiber’s positive qualities have been recognized over thousands of years of real life applications.  The texture of pure hemp textiles resembles that of flax linen, appealing to the eye with its subtle variations in thickness, but it is also versatile and can be blended with other fibers to create many different looks.  Hemp’s versatility as a textile is stunning:  hemp fibers can be woven alone or with other fibers to produce weaves from rugged canvas to the lightest, silkiest  gauze,  in an unlimited array of colors and finishes.  Hemp has a beautiful natural luster and a lush hand and drape not found with any other natural or synthetic fiber, even linen.

Hemp’s characteristics as a textile make it a desirable choice in many applications:

  • Hemp is stronger and more durable than any other natural fabric, including linen, which almost matches hemps abrasion resistance and tensile strength.  The result is that hemp has a longer lifespan than other natural fabrics.[1] (Patagonia is just one of the many companies which has published studies which demonstrate hemp’s superior strength; results for these studies range from 3 to 8 times stronger.)  Products made from hemp will outlast their competitors by many years.
  • Not only is hemp strong, but it also holds its shape, stretching less than any other natural fiber. This prevents hemp fabric used in upholstery, demountable panels, acoustic paneling or as wallcovering from stretching out or becoming distorted with use.
  • Hemp fabric withstands, even benefits from, commercial laundering. Its inherent luster and light reflective qualities are enhanced by washing; it becomes finer and more luxurious with use. Hemp also possesses excellent soil-release properties because it sheds a microscopic layer each time it is laundered. This eliminates soiling and exposes a fresh surface. In effect, this means that hemp retains its sleek sheen every time it is washed, that it never dulls, and that it releases stains more easily than other fabrics.
  • Hemp may be known for its durability, but its comfort and style are second to none.  The more hemp is used, the softer it gets: it wears in, not out, thriving on regular use and machine washing without suffering fabric degradation. Hemp actually becomes softer, more resilient and more lustrous as a result of washing.
  • Hemp’s superior absorbency, due to its porous nature, means that it is very breathable and quick drying. Hemp can absorb up to 20% its own weight while still feeling dry to the touch (vs. polyester, which can absorb a maximum of 6%). This is important in the case of any fabric that is in contact with human skin, such as sheets, as perspiration is rapidly absorbed. It feels cooler in summer yet during cool weather, air which is trapped in the fibers is warmed by the body, making it naturally warm.
  • Hemp’s absorbency allows it to accept dyes readily and retain color better than other natural fibers, including cotton.
  • Hemp has a high resistance to ultraviolet light; it will not fade or disintegrate from sunlight as quickly as other natural fibers. (Tilly Endurables introduced a new hat in 2004 after testing its hemp fabric to a UPF of 50+, the maximum ultraviolet protection rating given.[2]) UV damage is especially a problem for draperies and marine interiors, so hemp would be a good natural fiber choice for these applications.
  • Hemp fiber is highly resistant to rotting, and its resistance to mildew, mold and salt water led to its premier use in marine fittings:  the majority of all twine, rope, ship’s sails, rigging and nets up to the late 19th century were made from hemp.  The word canvas itself is derived from cannabis.
  • Finally, any product made of hemp is fully biodegradable and easily recyclable.

Hemp as a crop is also a standout.  The bio-regional model of agriculture focuses on obtaining high value for the resources of the local land, recycling the waste and end products ad infinitum and thereby creating a “closed circle” of farming and industry.  Hemp is an elegant solution to the crises created by modern agribusiness and conventional cotton production because:

  • Hemp grows well without the use of chemicals:  usually no pesticides or fungicides are used because it has few serious fungus or pest problems – although the degree of immunity to attacking organisms has been greatly exaggerated.  Several insects and fungi specialize exclusively in hemp!  But despite this, the use of pesticides and fungicides are usually unnecessary to get a good yield.    No herbicides are generally used because dense plantings shade out weeds; no defoliants are needed (as they are with machine harvested cotton) because the dried foliage is not a problem for harvesting.
  • Hemp requires less water to thrive than cotton – is actually drought tolerant –  and usually grows well without irrigation.  Globally, 77% of cotton crops are irrigated.
  • Hemp has a fiber yield higher than any other agricultural crop, thereby requiring less land for equal yield:

Average fiber production, in pounds, per acre:

Conventional cotton Organic cotton Flax Wool Hemp
121 – 445 lbs. 80  –  102 lbs. 323 – 465 lbs. 62  lbs. 485 – 809 lbs.

Source: UK-government funded project at University of London, “Demi: design for sustainability” (www.demi.org.uk), © Kate Fletcher, 1999

This yield translates into high biomass, which can be converted into fuel in the form of clean-burning alcohol, or no-sulphur man-made coal.

The most widespread claim for the environmental friendliness of hemp is that it has the potential to save trees that otherwise would be harvested for the production of pulp.  If  hemp reduces the need to harvest trees for building materials or other products, its use as a wood substitute will tend to contribute to preserving biodiversity.  Hemp may also enhance forestry management by responding to short-term fiber demand while trees reach their ideal maturation. In developing countries where fuel wood is becoming increasingly scarce and food security is a concern, the introduction of a dual-purpose crop such as hemp to meet food, shelter, and fuel needs may contribute significantly to preserving biodiversity.

For more on hemp, here are some resources to get you started:

Organizations

Web

Journals

  • Journal of the International Hemp Association. Vol. 1 (1994)–Vol. 6 (1999). (Vols. 1–5 and part of Vol. 6 available online at mojo.calyx.net/~olsen/HEMP/IHA/). Superseded by Journal of Industrial Hemp.
  • Journal of Cannabis Therapeutics. Hawarth Press. Vol. 1 published 2001.
  • Journal of Industrial Hemp. Haworth Press. Vol. 1 to be published 2002.

[1] Kerr, Nancy, PhD, “Fabulous Fibers? Can hemp compete with natural and manufactured fibers?” AgFibe2002 conference, Winnipeg, MB, Nov. 13 – 15, 2002.

[2] Press release, Tilly Endurables 2004; also see http://www.backpackgeartest.org/News/article.php?story=20050210193045692.








Follow

Get every new post delivered to your Inbox.

Join 1,569 other followers