28/08/2015
FLEX COTTON
Flax (also known as common flax or linseed), with the binomial name Linum usitatissimum, is a member of the genus Linum in the family Linaceae. It is a food and fiber crop that is grown in cooler regions of the world. The textiles made from flax are known in the West as linen, and traditionally used for bed sheets, underclothes and table linen. TheOIL is known as linseed oil. In addition to referring to the plant itself, the word "flax" may refer to the unspun fibers of the flax plant. The plant species is known only as a cultivated plant,[2] and appears to have been domesticated just once from the wild species Linum bienne, called pale flax.
Several other species in the genus Linum are similar in appearance to Linum usitatissimum, cultivated flax, including some that have similar blue flowers, and others with white, yellow, or re
d flowers.[4] Some of these are perennial plants, unlike L. usitatissimum, which is an annual plant.
Cultivated flax plants grow to 1.2 m (3 ft 11 in) tall, with slender stems. The leaves are glaucous green, slender lanceolate, 20–40 mm long and 3 mm broad.
The flowers are pure pale blue, 15–25 mm diameter, with five petals. The fruit is a round, dry capsule 5–9 mm diameter, containing several glossy brown seeds shaped like an apple pip, 4–7 mm long
Flax is two to three times stronger than cotton, making it one of the strongest natural fibers known.
The flax plant species Linum usitatissimum is made into linen fabrics, linseed oil, and even linoleum flooring. Its acreage in the United States dropped in the 1920s with the arrival of synthetic fibers. But new, high-yielding and disease-resistant flax varieties could help reestablish a North American flax fiber industry.
Mechanical engineer Jonn A. Foulk, with the ARS Cotton Quality Research Station, Clemson, South Carolina, has been spinning cotton with flax at a ratio that imparts better moisture management to denim fabric. The blend’s fibers naturally absorb and transfer moisture away from the body.
The work is being done at the station’s onsite high-tech pilot spinning laboratory.
Adding flax to clothing fabrics helps keep skin cool partly because the flax improves moisture wicking, which means channeling moisture away from the skin’s surface. Another important feature of moisture management is air permeability, which allows fabrics to dry quickly.
If a fabric dries fast because it has high air permeability but it also has low moisture-wicking capacity, the moisture won’t absorb sufficiently to be pulled away from the skin.
“Because cotton denim doesn’t dry very fast after sponging water up, adding flax provides enough air permeability to speed up drying, providing the best of both worlds,” says textile technologist David D. McAlister, who heads the Clemson station.
A good example of fabrics with low wicking are those made with traditional synthetic fibers, such as polyesters. They tend to hold moisture close to the skin, rather than wicking it away from the body.
“This natural flax fiber blend can enhance cotton’s utilization and can compete with specialty moisture-management synthetic fibers on the market,” says McAlister. “We’re finding that adding a relatively small amount of these particular flax fibers provides important performance features to finished textiles.”
Friendly Flax Features
The new denims produced at the pilot spinning laboratory were blended using selected varieties of flax to produce fabrics that are low-cost and environmentally friendly. For example, byproducts from processing natural flax fibers are fully recyclable, whereas the byproducts generated from processing many synthetic fibers are not as readily recyclable.
Flax has been found to be a good candidate for growing in rotation with cotton in the Southeast, particularly along coastal areas. The relatively warmer climate allows cool-season flax crops to be grown in winter to produce seed, oil, and fiber that can be used as healthy food ingredients, flax-containing yarns or textiles, composites, nonwovens, paper, and other industrial goods.
A producer, for example, might grow a cotton crop in early April for harvest from September through early November. In late November, the same producer might then plant a flax crop to grow through March. The flax crop could then be harvested in time to plant another cotton crop in April. The cotton-flax crop rotation provides producers an alternative crop for traditionally dormant fields.
