A responsible approach to wool
Wool, a beautiful high performance fiber, is experiencing a strong revival. Being a natural source, it has found a huge fan base as an alternative to synthetic fibers. What are the different types of wool (merino, organic, recycled, loden, melton, worsted)? What are the properties of wool (i.e., care and durability, insulation, climatic, moisture, odor reduction, elasticity, flame retardant, allergic, and biodegradable)? What should you know with respect to animal welfare (i.e., nutrition, environment, animal health, behavior, and handling)? What farm practices deserve critical thinking (mulesing, climate change, soil damage, water pollution)? See a listing of all the certificates/standards and learn what each represents. Also, industrial processes like shearing as scouring are explained. What are the differences between treatment processes like chlorine-hercosett, non-chlorine/petry-lanazym, enzyme, and plasma?
The April 2015 Focus Topic explains all the do’s and don’ts of this highly functional natural fiber used in sportswear and casualwear and shows a way through the maze of certificates.
Where does wool come from?
Annual wool production is around 2.1 million tons. Australia produces about one fifth, while China, New Zealand, Argentina and the UK each produce more than 50 000 tons. An estimated 50% of wool, both raw and partially processed, is exported to major textile centres in other countries to be spun and woven.
China is the No.1 importer of raw wool (310 000 tons in 2007), followed by Italy. The retail value of sales of wool products is around US $ 80 billion a year.
Definition of wool
Wool, or fleece, is a product used in a variety of textiles and is shorn from sheep or other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, angora from rabbits, and other types of wool from camelids.
Two definitions for Virgin Wool:
- Wool taken from lambs (7 months old at first shearing), which is the softest and finest sheep wool
- Also refers to wool that has never been used, processed or woven before (comes from adult sheep (one year old)) The quality of wool is determined by fiber diameter, crimp, yield, color, and staple strength. Fiber diameter is the most important wool characteristic used in determining quality and price. Merino is typically 7-13 cm long and very fine (between 12 and 24 microns).
- Ultrafine Merino < 15.5 microns
- Superfine Merino 15.6-18.5 -Fine Merino 18.6-20
- Medium Merino 20.1-23 -Strong Merino > 23
- Any wool fibers less than 25 microns can be used for garments.
This type of wool fiber has superior shine, incredible softness and great breathability, along with excellent warmth-to-weight ratio. It is nearly pure white in color and so accepts dye very well. The fiber is very strong, naturally elastic, and soft against the skin.
This wool comes from sheep that have been raised without synthetic or harmful chemicals. The sheep graze on pesticide-free land that is not over-grazed and never sprayed or dipped and kept under humane and good farm conditions. The Organic Trade Association (OTA) identifies “land and livestock management, scouring, spinning and dyeing processes" as key factors in determining whether a wool yarn or product can be certified as organic.
- The sheep must be fed with certified organic forage;
- The use of synthetic hormones and genetic engineering are prohibited;
- The use of synthetic pesticides (internal, external, and on pastures) is prohibited;
- Producers must implement good cultural and management practices to encourage healthy environments for the animals.
To feed the increasing demand of wool products, recycled wool fibers can be blended with the normal production. This yarn can become a little more harsh or fuzzy. Recycled fiber is of a shorter length than new wool fiber. It can make the end product more resistant and therefore longer lasting.
Loden wool originated in the Tyrolean Alps in the 16th century and is still highly popular among sportsmen. It is characterized by a slightly 'greasy' feeling and is frequently used to make heavy coats. To produce Loden fabric, strong yarns are woven loosely into cloth, before undergoing a lengthy process of shrinking, eventually acquiring the texture of felt and becoming quite dense. It is then brushed with a fuller's teasel and the nap is clipped, a process which is repeated a number of times until the fabric provides good warmth for the weight, and is relatively supple, windproof, and extremely durable.
Melton wool fibers are thick with a smooth outer surface. The finishing processes completely conceal the weave. This type of wool makes very solid cloth that is durable and both water and wind resistant. The thickest weights of this wool are often used to make heavy outerwear, including jackets and wool pants. Thinner weights are used to make sweaters and socks.
Boiled Wool is created by putting sheep’s wool through a special washing process that creates a dense, durable and water-resistant fabric with a texture similar to thick felt. It has the suppleness of a knit with the shape retention of a woven fabric. Boiled wool is frequently used to make slippers, hats, gloves, scarves, and a variety of outerwear.
Other types of wool such as Cashmere, Alpaca, Mohair, Angora, and Camel Hair do not really have a role in functional wear.
Characteristics of wool
Wool can insulate the body, providing and retaining warmth. The crimped fibers help to produce tiny, insulating air spaces that retain more heat.
Wool acclimatizes to its surroundings. The natural ability to breathe and adapt to temperature changes gives it the ability to provide warmth in colder conditions and also breathes well as temperatures warm up.
Aside from blocking most external moisture, wool fibers can absorb up to 35% of their own weight in moisture due to the hydrophilic core.
Natural odor reduction
Wool absorbs moisture and reduces sweat on the body, which in return lowers the amount of body odor caused when sweat and bacteria on the skin are in contact.
Durable and elastic
Wool fiber can be bent 20,000 times without breaking and still have the power to recover and return to its natural shape.
Wool fiber has a higher ignition threshold than many other fibers and is flame retardant up to 600°C.
Wool has naturally high UV protection.
Natural and renewable
Wool is grown not manufactured; every year sheep grow a new fleece. Wool products also consume less energy during manufacture than products with man-made fibers.
Wool is not known to cause allergies and does not promote the growth of bacteria. With microscopic scales, wool fibers can trap dust in the top layers until vacuumed away.
Modern wool is machine-washable; retaining a small amount of natural oil, wool fiber is resistant to dirt and grease.
When disposed of, natural wool fiber takes only a few years to decompose, and with high nitrogen content, wool can even act as a fertilizer.
Animal Welfare / Farming
Sheep farming is the breeding and raising of domestic sheep. Sheep are raised principally for wool, milk, and meat (lamb or mutton). Sheep are kept in flocks, in paddocks, in pens, or barns, or in the open. For today’s discerning consumers, ethical and environmentally-sensitive farming can be as important as the quality of the clothing itself.
Sheep should be provided access to food and water for a healthy physiological state.
The environment should provide the conditions and facilities needed for good health, comfort, and natural behavior including active movement, rest, and socialization.
A positive, proactive, preventative health care plan for the animals should be developed.
Sheep should be able to express innate, non-harmful behavior, including social behavior.
Management should include appropriate design of facilities, careful treatment of sheep during handling and transport, and ensure a minimum of fear and stress.
These five freedoms were developed in the UK in the late 1970’s and have been adopted by representative groups internationally including the World Organization for Animal Health and the Royal Society for the Prevention of Cruelty to Animals.
Mulesing is specifically banned by most certification programs.
Mulesing is a controversial practice in Australia as a way to prevent flystrike (myiasis), particularly on highly wrinkled Merino sheep. Mulesing involves the surgical removal of loose folds of skin from the breech area of merino sheep to reduce the incidence of flystrike. The wool-bearing skin around the buttocks can retain feces and urine, so scar tissue that regrows in the place of the removed skin is less likely to attract flies. The operation is usually performed when the sheep are very young, often without painkillers.
Alternatives to Mulesing
- “Plain bodied” merinos are generally more resistant to flystrike
- Topical protein-based treatments (intradermal injections in the breech area) kill wool follicles and tighten skin
- Biological control of blowflies.
- Plastic clips on the sheep's skin folds which act like castration bands, removing the skin (breech clips)
- Studies of tea tree oil as a 1% formulation have shown a 100% kill rate of first stage maggots and a strong repellent effect against adult flies, which prevents eggs being laid on the wool for up to six weeks.
“Enteric fermentation” or livestock belching and passing gas accounts for roughly one-quarter of annual agricultural methane emissions. In New Zealand, methane emissions from enteric fermentation, coming mostly from sheep, make up more than 90 percent of the nation’s greenhouse gas emissions.
Large sheep flocks can be the cause of vegetation change and soil erosion leading to the formation of Badlands (heavily eroded areas).
Sheep “dip,” a toxic chemical used to rid sheep of parasites, presents disposal problems and can easily become a pollution risk. In areas where sheep are farmed, fecal matter contamination of waterways is also a problem.
Scapegoats and other wildlife
The wool industry also causes “collateral damage” on wildlife. In Australia, many kangaroos get killed during farming and in the USA, coyotes are considered a threat to the sheep.
Traceability and certificates
Each end-consumer has different values and perceptions of life. The price or brand name is not the only thing relevant to the consumer when making point-of-sale decisions. The quality of a garment is also determined by the production circumstances, for example:
- Social conditions for employees
- Living conditions for animals
- Environmental impacts of production
Therefore, traceability throughout the supply chain is seen as an added value for both customers and brands.
Shearing is the process of cutting and collecting the wool fleece of sheep.
Prior to commercial use, the raw wool needs to be washed and cleaned to remove the impurities. The by-products of the cleaning can range from organic matter to pesticide residues and surfactants. Treatment of the wastewater is indispensable.
The standard industry treatment for wool removes scales and adds a resin to complete the treatment.
- Excellent anti-felt effect and super-wash
- Little weight-loss and damaging of the fibers
- Improved dyeing results
- Improved pilling behavior
- Loss of natural wool character
- Synthetic handle
- Yellowing of wool
! This treatment is questionable, particularly with regard to sustainability because of AOX pollutants in the waste water and the effects on fabric biodegradability !
(compatible with GOTS certificate) This single-step process partially degrades the scales of the wool.
- Washable up to 40C
- Maintains natural cooling effect of wool
- Improved dyeing results
- Improved pilling behavior
- No tumble-dry
- More expensive
- Less anti-shrink performance
Plasma (compatible with bluesign)
A waterless technology that uses activated gas to remove the scales and provide anti-shrinkage and enhanced wettability.
- Improved dyeing, printing
- application of subsequent
- chemical treatments
- More expensive
- Less capacity than chlorine treatment
Dyeing process / Coloration
The position of the dyeing step is determined by the nature of the final article. For both wool and worsted processes, the coloring process depends on the qualities of the final product and the desired labeling certifications.
Certificates for industrial processing
bluesign® covers all industrial processes.
GOTS covers the entire supply chain.