Linen

Natural fiber

Common flax

As linen or flax ( altgr. linon and Latin linum, flax ') is referred to both the fiber of the commons Leins and especially the fabric made ​​from it in the linen industry, called the latter also canvas, linen or linen. Since the late 19th century linen was replaced almost entirely in the textile industry by cotton, but wins since the end of the 20th century as an ecological natural fiber in importance again.

• 5.1 textile fiber
• 5.2 Technical Fiber

• 6.1 linen
• 6.2 insulation
• 6.3 Natural fiber composites

The fiber

The flax or linen fiber is obtained from the stems of the flax plant and is one of the bast fibers. The line fibers form bundles, as opposed to fibers, such as cotton seed, consisting of unbonded individual fibers. The 2.5 to 6 centimeters long elementary fibers of cellulose are connected by pectins to the 50 to 90 cm long fiber bundles, technical fibers.. Other constituents of the fiber hemicellulose and lignin. The quantity of each component depends on the maturity of the fiber, on average, there is a flat fiber to 71% of cellulose, 18.6 to 20.6 % hemicellulose, 2.3% pectin and 2.2% lignin and about 1.7 % wax, which can be found for the most part on the fiber surface. . By Kotonisierung ( or as Kotonisieren, Cotonisieren or Cottonisieren called ), the bundle by different methods are decomposed into elementary fibers. Since the Kottonisieren was based primarily on the use of thin bases for dissolving the pectin, it was no longer practiced longer period for reasons of environmental protection in Europe. Only since pulping process since the late 20th century as the steam digestion method, mechanical method and ultrasonic method improves be applied, it is currently playing.

The thus generated Flockenbast ( flakes flax) fits with its distribution of fiber lengths up to 40 mm in the length range of the cotton fiber and therefore can be spun in pure form or mixed with other short fibers into yarns in the short staple spinning ( three-cylinder spinning, cotton spinning ).

Harvest

At harvest, the flax plants are scuffled using special machines with the roots from the soil, that is torn because the fibers would be destroyed when mowing. The harvest is ripe with yellow, then the leaves have already fallen in the lower third. The straw is deposited on the ground in Schwadlage and aligned in parallel. During the subsequent drying, the epidermis ruptures, so here can penetrate microorganisms later. Through the ripples the seedpods are removed. The corrugations can also take place after retting. With the retting or rotting the bond between the fiber bundles and the surrounding tissue is achieved by bacteria and fungi. The composting must be interrupted at the right time, to prevent damage to the fibers.

The currently prevailing roasting method is the Tauröste applied to around three quarters of the world's arable land, especially in areas with oceanic climate, since this dew moisture is needed. Here, the flax straw is left on the fields. Through baptism lamp bacteria and fungi break down the pectins. This method is relatively environmentally friendly, get the nutrients during the retting partially in the back ground. Disadvantages are the weather vulnerability and the long duration.

In some areas, such as in Eastern Europe, Belgium, China and Egypt Warmwasserröste is used. Here, the straw is three to four days roasted in basins with 28 to 40 ° C warm water. This leads through the wastewater to very high environmental impact.

A historical process is the cold water retting, in which the flax straw was roasted in ponds or ditches. Chemical methods for retting have not prevailed, as they usually also attack the flax fibers. Enzymatic methods have not been enforced for reasons of cost.

Production of the fibers

After retting the straw is dried again and taken to the processing plants ( Schwingerei ). Here the straw is first broken: the wood core is called into small pieces, shives, crushed. During the subsequent swing the shives are separated from the flax, it also falls on the Schwungwerg, short flax fibers. Shives and Schwungwerg are separated in a Wergreinigungsanlage. The flax is hackled and parallelized it and further purified. The flax fibers, also called long fibers which Schwingerei to leave braids rotated and brought into the mills.

Short fibers either fall in long- fiber production as a by- product, or the entire production process is aimed at short fibers. Then, the processing is done in a so-called short fiber line: the straw is not processed in parallel lying. The resulting short fibers are not as highly purified as the long fibers and are mainly used for industrial purposes.

Textile finishing

Spinning

In spinning the fibers are spun into yarns. Long and short fibers are handled differently, a distinction is made between dry and wet spinning process.

Long fibers can be combined prior to spinning to form a band, stretched several times and mixed with the other belts ( doubled ), so as to achieve a very homogeneous quality. Long fibers are usually spun wet to high quality threads. The tapes are to fine, homogenous stretched threads. In a warm water bath at 70 ° C to dissolve the pectin, so that the fibers more easily forgiven each other. After winding yarn on the yarn is dried at about 80 ° C.

Case of short fibers by roughening ( carding ) is produced a two-dimensional "web", which is reduced to a strip. This band is combed ( hackled ), to cleanse it of shives and short fibers. Then, the strip is stretched and as the long fibers doubled. Short fibers are spun dry in the rule. The resulting yarns are rough and feel soft at the same time.

Weave

Is woven linen in classic plain weave, but also jacquard, twill and other types of bonds are common. Batiste, veil and Leno were also made of flax, they are not counted for linen fabric. In the weaving of linen a very uniform and thus expensive yarn must be used for the warp threads. Warps with the typical linen irregularities would suffer from the abrasion stress and often tear.

Half Linen is a fabric with a minimum content of linen fibers, it is typically woven with linen as the weft and mostly cotton warp.

Properties

Textile fiber

Compared to other bast the linen fiber is divisible good and fine spinnability, which distinguishes them for laundry and clothing. The linen fiber is smooth and linen fabric includes a little air, so linen is lint-free and less susceptible to dirt and bacteria, the fiber is inherently bactericidal, almost antistatic and stain-resistant.

Linen takes up to 35% humidity and moisture exchanges these quickly with the ambient air, thus has a cooling effect, is still dry warm. Therefore, the fabric is often used for summer clothing. The water storage on the surface is also the cause of the anti-static (and dirt-repellent ) property. The linen fiber is very tear resistant and extremely inelastic. Due to the low elasticity linen is wrinkle- prone; the tensile strength makes the linen durable and long lasting. Linen is strong and does not have to be nachgestärkt like cotton. It has natural shine and strength.

However, linen is prone to friction. Its abrasion resistance is lower than that of the cotton; it should therefore be used in the wash gentle cycle or are just squashed at hand wash and not rubbed.

Linen is insensitive to wash liquors, laundry detergent, hot wash, dry cleaning and high temperature ironing. Dry heat damages the tissue, so it must still be slightly damp for ironing, tumble dryer are unsuitable.

The bleaching of linen is problematic. Full bleaching leads to weight losses of up to one -fifth. The dyeing of linen is possible in the yarn or the fabric. The blue workwear is due to the dyeing of linen, which could be colored to some extent genuine with natural colors with indigo. This is due to the property of the canvas as a cellulose fiber, which enables the dyeing no chemical bond. The coloring is possible addition to the aforementioned vat dyes with the class of substantive dyes, while the dye molecule (only mechanically trapped ) inside the ball of the polymeric cellulose molecule.

Technical Fiber

The technical flax fibers are relatively stiff and tear resistant. Combined with their low density, this results in a very high specific strength and stiffness, similar to glass fibers. Therefore flax fibers can also be found for technical fabrics as well as a replacement for asbestos fibers using. The quality of the fibers, however, strongly depends on the growing conditions and digestion process, which results in a relatively large scatter of the properties. Through strict quality management to these fluctuations but control.

Use

Linen

Linen fabrics have traditionally been used for bed and household linen. In this use, they were displaced by the cheaper cotton. New application areas, such as clothing and decorative fabrics are added, particularly in the form of hand-woven high-priced products. Linen is used as reference material for book covers, in addition to shoes and bags. Name factors were linen fabrics for covering for Screens in painting. Flax-straw is rapidly gaining importance as a bedding in horse husbandry. This is done with the woody part of the stem flat. The suction power is ten times as high as from ordinary straw, four times as high as that of wood chips.

Insulation

For short fibers, which are obtained as a by-product of the extraction line, natural insulating materials are produced in the form of slabs, sheets or darning wool, sometimes they are the purpose of higher stability even added some polyester. Flax has a WLG- value of 040, and is thus comparable to wood fiber, cellulose, rock wool or polystyrene and stores with a heat capacity of 1550 J / (kg x K) heat well. It is classified in the class B2, so it is normal flammability. Although the corresponding products have established themselves as thermal insulation products, the market share of lines in the insulation area is, however, currently - calculated together with hemp - with less than 0.5%, even under optimal conditions is expected for the future with a market share of more than 5 %.

Natural fiber composites

The flax fiber is, increasingly used due to their good mechanical properties and regional availability as reinforcing fibers for natural fiber composites. In addition, the price of was clearly subjected to a euro per kilogram for technical fibers in recent years, only small fluctuations. One of the most important application areas for flat fiber-reinforced plastics is the automotive industry, nearly two -thirds of the natural fibers used here are flax fibers. In recent years, however, also include other industries to customers.

The fibers used for the production of natural-fiber -reinforced plastics are priced due, mainly short fibers. One of the most important processing methods for natural fibers is the molding, pressed at the so-called fiber mats together with thermosetting or thermoplastic materials under the action of temperature. Flax fibers are also utilized in plastic granules for injection molding and extrusion processing. These materials are characterized by a low density combined with relatively high strength and stiffness from. In combination with the sustainability of the natural fibers, their CO2 neutrality and medical safety results in major savings for glass fiber reinforced and filled plastics.

Description and quality

The CELC awards the masters of linen Seal, a registered trademark, of linen products from Western European cultivation. The four characters with the stylized "L " stand for qualities of pure linen and half-linen.

According to Textile Labelling Act ( TKG) In Germany, the terms flax or linen for bast fibers from the bast of the flax plant ( Linum usitatissimum ) and half-linen for products with a pure cotton warp and a pure flax weft, in which the proportion of the linen not less than 40 % of the total weight of the unsized fabric accounts, the indication " pure cotton warp - pure flax weft " must be added. Must be pure linen warp and weft yarns contain pure flat. The symbol for the fiber raw material flax / linen is LI ( share of raw materials in mixed fabrics ); only lines with no other fibers may as " linen, pure" are referred to ( both warp and weft of linen only ).

Economy and the Environment

The share of the linen in the global fiber volume is only around two percent. The largest growing areas are China, with 161,000, the EU and 102 740 ( esp. France and Belgium ), Russia with 89 210, 71 000 with Belarus, Ukraine and Egypt with 23,600 with 8,900 hectares. In Germany and Austria with 30 129 hectares of cultivation is meaningless. World production is estimated at about two million tons.

The bulk of the value added at Faserleinanbau done with the long fibers which make up around 88 percent of sales in the EU. 2003, the price of the ton textile long fibers at 1593 €, for textile short fibers at 345 €, for short fibers for paper at 170 €, and for short fibers for insulation materials or composites at 400 to 500 euros. The bulk of European long fiber production is exported, mainly to China.

The linen production is dependent, in contrast to cotton on little use of chemicals (fertilizers, pesticides). Even without modern technology can lines are produced, but the production of linen fiber is expensive and labor intensive. Cotton sat down only with the industrialization, a trend that a mass product in turn influenced the growing crowd. On the other hand, linen is the only natural fiber that is certified organic quality locally grown (Western Europe) on the market. An ecological production of flax fibers on a larger scale is limited by the problems of harvesting and Taurotte. Waste water from the water retting are loaded, so the Taurotte is recommended and encouraged.

History

488 flax fibers - including 58 suspected dyed fibers - are the oldest evidence of the making of clothes. They come from the Dzudzuana Cave in Georgia and in 2007 and 2008 recovered from a soil layer whose age has been dated to 36000-31000 years ( yr BP ka). The oldest Flat processing means Europe is detectable in the Czech cave Dolni Vestonice and is about 28,000 years old. Egyptian mummies are wrapped in strips of linen.

From the Greek and Roman antiquity to the Middle Ages in Europe was linen wool next to the material for clothing. Its heyday was the linen in pre-industrial Europe. When cotton was not yet imported in large quantities, was linen (besides a few exceptions) the only vegetable fiber. Until the late 18th century, 18% of the processed fibers of flax and 78 % wool.

In the Middle Ages linen was (unlike wool) used by the soil release property preferred for use close to the body, due to its strength also filled tanks. Since it was difficult to dye, it was offered mainly in pale tones; opaque and dark tones were expensive. Linen was processed for a long time only by hand, and later industrial methods were added. Until the 20th century handspun, but also machine- spun yarn was woven in homework on handlooms. The linen was processed mainly in Ireland, Holland, Westphalia, Saxony, Silesia, and Bohemia.

The National Socialist regime forced in its political self-sufficiency efforts the cultivation of flax. The cultivated area increased from 5,000 ha in 1933 to 100,000 ha in 1937. For processing the fiber flax plants were built, so 1937 in Künzelsau.

Following qualities are historically distinguished:

• Flat screen - pure long-fiber flax in plain weave

• Halbflächsene or Halbhedeleinen - woven with yarn made from long flax fiber and tow
• Half sheets - woven with flax yarn as the warp and weft tow as
• Half cotton and half linen - woven with yarn from cotton and linen
• Home screen - woven by hand
• Irish or Irish - woven with cotton warp and flax yarn as the weft
• Weißgarnleinwand and Löwentlinnen - woven with bleached yarn
• Wergleinwand or Hedeleinen - woven with yarn from Hechelwerg, or vice versa.

Also fabric from hemp plain weave were referred to as linen (hemp canvas).

With the perfecting of the mechanical cotton processing at the beginning of the 19th century the linen was first later pushed back in America and with growing cotton imports in Europe. After a new low point in the early 1980s, the consumption increases slowly with the trend to natural fabrics, hand-woven products and high-priced crafts tissue and cultural and historical reproductions promote growth.

Museums

• Active Museum " Henni Jaensch - Zeymer " - Hand weaving Geltow near Potsdam Sanssouci. Here, the processing of linen in the production of handicraft weaving can be visited. The holdings include a high loom and ten Flachwebstühle, is still woven on which despite its age of 200 to 300 years.
• A flat- Museum is located in Beeck ( Wegberg ).
• Flat crushing hut Creglingen - Postal
• National Flax Museum in Kortrijk Belgium.