Mercerized cotton: (Nordlandsbunadens shawl / apron)


Mercerisation is one of the most used but least publicized processes in the textile industry. The treatment is the reason why two different garments, both are marked as 100% cotton and knitted likewise, may look strange different and feels different.

The mercerization (English: mercerizing or mercerising) are cotton yarn, fabric or garment laid in the bath with concentrated sodium hydroxide. Other names for sodium hydroxide is caustic soda and sodium hydroxide (NaOH). In English designations sodium hydroxide, caustic soda and lye. The process is named after the explorer, John Mercer, who took a patent already in 1850.

Mercerized cotton is shinier and smoother. The gain increased strength and elasticity. The cotton is also more receptive to the dye and other chemicals. The fibers have a more circular cross section and straighten them out. Many see the process as an advantage.

Treatment involves however also disadvantages. The strong alkaline solution (high pH) are chemical compounds of cotton and modify its structure. (Other alkali metal hydroxides, particularly lithium hydroxide (LiOH) and calcium hydroxide (KOH) may also be used). After treatment with strong base, the cotton is neutralized with acid.

During mercerizing cotton fibers swell. They can swell to triple and the ability to retain moisture by 50%. It is formed "large" pores in the fibers.

The text above is based on the book: Cotton fiber chemistry and technology. Phillip J. Wakelyn. 2006.

Cotton is mercerized, no longer has the natural characteristics of cotton fibers. The fabrics are like art fiber. See bottom of page: Incognito, Polyester Boogies Onto the Playing Field at the New York Times.

Treatment may pollute the environment, and concentrated lye and acid are harmful to the workers if they do not is protected. Watch the movie: When in Scandinavia kills people in India. Workers tell here that they are working with sodium hydroxide (sodium hydroxide) and acid (acid) - without protection. Read also a U.S. report on injuries in textile factory.

About 35% of all cotton goods are mercerized. In addition, 90% of all cotton cleaned with caustic soda, write chemical manufacturer ERCO Worldwide on its website.

An experiment we conducted indicated that although baby's underwear from a Scandinavian fashion chain most likely mercerized. The garment we tested, drew a lot faster on the color (Cola) than untreated cotton. The fabric felt stiffer and more synthetic than non-mercerized cotton. It was also shinier and smoother. Under a magnifying glass fibers were completely symmetric and completely without loose, protruding fibers. However, the tag read: 100% cotton. See explanation for such an experiment: Physical and Chemical Properties of Fibers.

Although no research reports demonstrate direct correlation between mercerization and allergies, it will be safest to use untreated cotton next to your skin of babies and children. This will be most comfortable and breathable best.

Very few brands and shops provide about cotton in clothing is mercerized, and the yarn is only carded or combed well. Note that if the yarn is only carded, the mercerized to achieve the necessary fineness and strength.