The most important mixtures are with cotton. “Half linen” or Union is a fabric with cotton warp yarns and linen weft. Flax is also mixed with other bast fibres, such as hemp and ramie, and with cellulosic or synthetic man-made fibres, such as modal, polyamide, polyester, or polyacrylics. The linen look (yarn structure, color, and luster) can be imitated to some extent by synthetic fibres, but without the typical linen properties.
In recent years, the processing of flax and cotton blends in the short staple spinning system has gained increasing interest among researchers and textile manufacturer. Traditionally cotton and flax fibres are processed on different spinning systems because of the particularities in the structure and properties of the two categories of fibres.
Linen Fibre Tests
Test Method for Color Measurement Of Flax Fibre
The natural color of flax fibre is light amber. Retting methods, however, influence the color of processed fibres. Water retting results in a light-colored fibre. Dew retting, in contrast, imparts hues from gray to black to the fibres, depending upon the extent of retting among other factors (see Table 1 below). Experimentally produced enzyme-retted or chemical-retted fibres are very light due to some bleaching action of the chemicals.
|Table 1 — CIELab color values of dew-retted, water-retted and enzyme-retted flax fibresa|
|Dew retted (N=3)||59.428 ± 1.369 a||2.873 ±|
|11.080 ± 1.663 a|
|Water retted (N=2)||67.541 ± 1.048 b||2.598 ±|
|14.540 ± 0.488 b|
|Enzyme retted (N=6)||72.019 ± 3.259 b||3.445 ±|
|16.300 ± 1.565 b|
|L is the amount of lightness from black (0) to white (100)|
a* is redness/greenness value (the higher the number the redder the sample)
b* is a yellowness-blueness value (the higher the number the yellower the sample)
abc values within columns with different letters differ at P<0.05.
From Akin, D. E., H. H Epps, D. D. Archibald, and H. S. S. Sharma. 2000. Color measurement of flax retted by various means. Textile Res. J. 70(10):852-858.
In addition to lightness, color measurement systems can show other color scales, such as the red-green and yellow-blue, and thereby provide other information. In one study, the water- and dew-retted fibres differed in yellow values, while enzyme-retted flax showed more redness.when the chelator levels increased in an enzyme-retting formulation (Table 1). In practical usage, much of the fibre sold for linen is blended among harvests to have color consistency in the final product. The use of a standard method for color values could help in blending for particular properties of a fibre sample arising from a variety of sources and processing methods.
When the chelator levels increased in an enzyme-retting formulation (Table 1). In practical usage, much of the fibre sold for linen is blended among harvests to have color consistency in the final product. The use of a standard method for color values could help in blending for particular properties of a fibre sample arising from a variety of sources and processing methods.
Test Method For Assessing Clean Flax Fibre Fineness
Fineness is one of the most important properties of textile fibres. A European effort in the 1970s resulted in ISO 2370, which estimated fineness based on air flow. To our knowledge, this standard has not been updated since 1980.
An air flow test was developed based on a modified cotton micronaire system and using a series of flax fibre grades purchased from the Institute Textile de France – Lille (now the Institute Francis Textile – Habillement).
This test provides a number as a comparative score for ranking fibres. This ranking showed good agreement with fibre widths determined by image analysis (see Table 2 below). This standard was approved in 2004.
|Table 2 — Image analysis and airflow fineness measurements of flax fibres|
|The frequency of occurrence of fibre widths by image analysis:|
|fibre samplea||10-30 µm||40-100 µm||110-200 µm||210-300 µm||Airflow|
|a IFS Standards (and airflow values for fineness) from Institute Francais Textile – Habillement.|
b Modified cotton micronaire method using 5.0 g flax fibres cut to 2.5 cm, which resulted in a reading within the accepted range for the micronaire.
Adapted from Akin, D. E., I. R. Hardin, L. L. Rigsby, and H. H. Epps. 1999. Properties of enzymatically retted flax for linen fibre, pp. 486-492. Book of Papers, American Association of Textile Chemists and Colorists, Research Triangle Park, N.C.
Test Method For The Measurement Of Shives In Retted Flax
The presence of non-fibre, trash particles is particularly troublesome in high-value products like textiles. Production efficiency, for example, the spinning of yarn without interruption, and final product quality are both diminished with trash.
One of the particular problems with flax is the close association of non-fibre tissues with fibres. After retting and subsequent cleaning, shives and cuticularized epidermis often still remain with the fibre.
The amount of trash (that is, non-fibre materials) depends upon the quality of retting to a large extent. Flax fibres are mostly cellulose, that is, around 65-89 percent, with other non-cellulosic sugars present.
The shives contain substantially more aromatics and lignin than fibres, and the different chemistries of these components provide a relatively easy way to differentiate between them. Table 3 below shows variations in chemical components of bast fibres and shive.
|Table 3 — Carbohydrate and aromatic constituents in flax fractions|
|Fraction||Non-cellulose carbohydrates||Non-cellulose Glucose||Aromatics|
|Data adapted from Akin, D. E., G. R. Gamble, W. H. Morrison III, L. L. Rigsby, and R. B.Dodd. 1996. Chemical and structural analysis of fibre and core tissues from flax. J. Sci. Food Agric. 72:155-165.|
The standards for color, fineness, and shive content were based on interlaboratory data; obviously, there is no bias for different laboratories with these standards.
Thermal Insulation: Yarns and fabrics made from the smooth flax fibres do not enclose much air and have relatively poor insulation properties. Linen fabrics feel fresh and cool, a distinct advantage for summer clothing.
Moisture Absorption: Linen is highly absorbent. It takes up water rapidly and releases it quickly again to the surroundings. In hot weather, this helps in regulating the microclimate between body and clothing.
Next-To-Skin Comfort: Fabrics made from flax fibres are comfortable due to the smooth surface and good moisture absorption.
Other Important Properties
Strength: Flax has a very good tenacity and durability. It is stronger wet than dry.
Extensibility: The extensibility of flax, about 2%, is the lowest of all apparel fibres.
Elasticity/Creasing: Flax has a low elasticity; it creases very easily.
Electrostatic Charge: Practically nil, under normal conditions, since the fibre always contains moisture. Surface,
Luster: Because of its smooth surface, linen fabric has a subdued luster, Does not soil easily, and does not shed lint.
Fineness: The coarse fibre bundles give linen firm handles.
- Burning Test
- Tearing Test
- Light Test, Oil Test