ARTIFICIAL FIBERS : ACÉTATE AND TRIACETATE OF CELLULOSE

Origin

The processes for manufacturing and spinning cellulose triacetate have been developed respectively by M. Schutzenberger in 1869 and by the German firm Bayer in 1904. For cellulose acetate these processes were developed by British CF Cross and EJ Bevan in 1894 and Miles in 1905. The raw material of these fibers is one of main constituents of plants, cellulose (the natural material with which paper is also made)

Made from cotton linters or wood pulp, this cellulose is chemically transformed: it is reacted with anhydride or / and acetic acid, to give a cellulose ester. This ester is put in special solution (collodion) to be extruded through a spinneret (device pierced with many tiny holes) from which emerge cellulose acetate filaments. By an analogous method, cellulose triacetate (cellulose acetate of which at least 92% of the hydroxyl groups are acetylated) is produced.

use

Pure or mixed (with viscose, polyamide, ...), acetate is used to make fabrics that "look like silk". These fabrics are used in the manufacture of liners (jackets, coats, ...) or articles of clothing (blouses, lingerie, dresses, suits, ...) or furniture (curtains, bedspreads, .. .)

propertie

Acetate and triacetate are light, silky and shimmering fibers that have similar properties. Due to their good thermal insulation, these fibers are used indifferently for summer clothes (blouses), winter (linings), sun protection (curtains), ... Their water absorption capacity is relatively low (recovery rate: 6 to 9%). Sensitive to acids, bases and certain solvents, acetate and triacetate can be more or less degraded by products commonly used in stain removal such as acetone, acetic acid, ammonia, ... Their dyes can be weakened by alcohol. On traction, the resistance of acetate and triacetate is lower than that of natural cellulosic fibers (cotton, linen, etc.).

Behavior in use and maintenance

Violent agitation in aqueous media (twisting effect, spinning) can cause - thin fabrics - breaks, scratches, or even breakage of acetate threads, especially if they have been previously weakened by light. However, certain types of insufficiently protected acetates U.V (ULTRA VIOLET) can be attacked by light. then risks by photochemical reaction, to degrade articles long exposed to the sun.

An exemplary case is the curtain

untreated anti-UV acetate warp or weft threads are weakened by the aggression of light and, because of their weakening, torn by mechanical agitation during maintenance.By the combined action of heat and water, under a vaporizing iron for example, laundering may appear. This phenomenon is the more visible in the shiny and smooth fabric .Dry cleaning also requires precautions on acetate and triacetate because it s too hot and pressed,it may cause localized luster in the form of waxes. including Alcohol in perfume sprayed on the item,in stain of strong drink or stain of removal product, may be the cause of localized discolouration.

MAINTENANCE TIPS

WASHING

to carry out the washing of the acetate or triacetate under low mechanical agitation and at a moderate temperature, it is advisable to treat a (reduced load) and to select a short program, at 50 ° C maximum, the spin being limited or even suppressed . In addition, the washing bath should not be too alkaline (pH <9.5).

LAUNDERING

The bleaching can be performed on the acetate in accordance with the normal conditions of use.

PROFESSIONAL CLEANING

Cleaning with water

As for the washing, one must be vigilant on the mechanical action. of the

breaks can appear after maintenance difficult to eliminate ironing.

Dry cleaning

Acetate and triacetate can be dry cleaned with perchlorethylene provided a cold solvent with low water content is used. Thin clothes will be treated in cycle for sensitive items. It is advisable to make sure in case of use of alternative perchlorethylene solvents that the new solvent has no negative effect on the textile due to too aggressive chemical constituents: discoloration, loss of strength etc