Mercerised cotton
From Wikipedia, the free
encyclopedia
Mercerization is a treatment for cotton fabric and thread that gives fabric or yarns a
lustrous appearance and strengthens them. The process is applied to cellulosic
materials like cotton or hemp.
Development
The process was devised in 1844 by John Mercer of Great Harwood,
Lancashire,
UK,
who treated cotton fibres with sodium hydroxide. The treatment caused the fibres to swell, which in
Mercer's version of the process shrank the overall fabric size and made it
stronger and easier to dye. The process did not become popular, however, until H. A. Lowe
improved it into its modern form in 1890. By holding the cotton during
treatment to prevent it from shrinking, Lowe found that the fibre gained a
lustrous appearance.[1][2]
Process
Mercerisation alters the chemical
structure of the cotton fibre. The structure of the fibre inter-converts from
alpha-cellulose to a thermodynamically more favourable beta-cellulose
polymorph.[citation needed] Mercerising results in the swelling of the cell wall
of the cotton fibre. This causes increase in the surface area and reflectance,
and gives the fibre a softer feel.[3]
An optional last step in the process is passing the thread over an open flame;
this incinerates stray fibers, improving the fabric's appearance. This is known
as "gassing the thread" due to the gas
burner that is typically used.
Thread
The modern production method for
mercerised cotton, also known as "pearl" or "pearle"
cotton, gives cotton thread (or cotton-covered thread with a polyester
core) a sodium hydroxide bath that is then neutralized with an acid bath. This treatment increases
lustre, strength, affinity to dye, resistance to mildew, but, on the other hand, increases
its affinity to lint.
Cotton with long staple
fibre
lengths responds best to mercerisation. Mercerised thread is commonly used to
produce fine crochet.
Applications
Mercerisation is now also being done
to wool fibre.
References
1.
^
J. Gordon Cook (1984). Handbook of Textile Fibres: Volume I: Natural Fibres.
Woodhead. p. 68. ISBN 1-85573-484-2.
3.
^
Textile Technology: Cotton/Kenaf Fabrics: a
Viable Natural Fabric, P.
Bel-Berger, et al. Journal of Cotton Science, 3:60–70 (1999).
"Cotton/kenaf fabrics can be further improved in softness and
"hand" (the feel of textiles when handled). The effects of different
fabric treatments such as enzymes, bleaching, and mercerization were compared
and measured for softness of hand. Two types of fabrics were treated, a
lightweight plain weave and a heavyweight twill. Mercerization dramatically
improved the softness and hand for both fabrics."
The entire wiki link on the subject can be found at: http://en.wikipedia.org/wiki/Mercerised_cotton
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