Acetate fibre

ACETATE

Acetate fibres are chemical compounds of cellulose and not the pure cellulose as in rayon fibres. These chemical com-pounds have their own unique properties and in fact the various types of cellulose acetate fibres differ from each other in properties. In 1865, Pant Schutzenberger discovered the reaction of cellulose ace-tate. Later in 1903, the German chem-ists Arthur Eiechengeun and Theodore Becker invented the fast soluble form of cellulose acetate.

In 1904, cellulose acetate was developed by Camille Dreyfus and his younger brother Henri in England, during World War I. It was used as a non flam-mable lacquer for the fabrics used for cov-ering the wings and fuselage of aircrafts. In 1918, they perfected the technique of spinning this substance into lustrous fil-aments of “artificial silk”. Subsequently, British Celanese Ltd. started the produc-tion of this fibre. In 1924, the commercial production of acetate fabric started in the United States by Celanese Corp. In 1954, The Celanese Corp. of America undertook the production of a variation of this chem-ical called cellulose triacetate. This prod-uct is marketed by the Celanese Fibres Marketing Co. under the trademark Arnel.

Types of Acetate

The different types of acetate are

1.        Diacetate

2.        Triacetate.

Manufacturing Process of Acetate

Pure cellulose is formed by converting cotton linters or wood sheets. This pure cellulose is steeped in glacial acetic acid and aged under controlled temperature for a period of time. It is then mixed with acetic anhydride and a small amount of sulphuric acid as a catalyst to facilitate the reaction which produces a thick and clear liquid solution of cellulose acetate. This liquid is then passed through the spin-neret to form these fibres which is solidi-fied and rolled on the bobbins for later use (Figure 3.2).

Properties of Acetate and Triacetate

Shape : Can be modified as per requirement

Size : Thin long filament

Luster  : Variation from brightness to dullness

Strength : Good

Elongation : Good up to 25%

Elastic recovery : Good

Resiliency : Low for acetate, but for triacetate it is good.

Dimensional stability: Good

Resistance to acids : Fair resistance to dilute acid, but cannot withstand concentrated acid.

Resistance to alkalis : Good resistance to dilute alkalis but cannot withstand concentrated alkalis.

Resistance to flame : Burns easily

Finishing Process

Depending upon the kind of yarns used and the final effect desired, different fin-ishes can be given to acetate fabrics. The most common finishes are :

Embossing : For pattern or design

Heat setting  : For crease and shape retention

Moireing : For permanent watermarking effect

Napping : On spun acetate for softness and warmth

Sizing : For better appearance

Water repellency : For resistance to water and rain

Wrinkle resistance : For better shape retention

Uses of Acetate

The uses of acetate are :

·           The breathable nature of the fabric makes it suitable for use as a lining fabric­ for apparels.

·           Acetate is used for making cigarette filters­ and other filters, ink reser-voirs for fibre tip pens.

·           It is used for making high absor-bency products like diapers and sur-gical products.

·           It is also used for making eyeglass frames.