Cellulose acetate is a man-made substance that is derived from the naturally occurring organic compound – cellulose. Cellulose is the main structural ingredient of plants, and is usually considered to be the most common organic compound on Earth. Cellulose acetate is manufactured out of wood pulp by a purification process. It is a renewable and biodegradable substance, providing a cheap source of quality fiber that can be used in many manufacturing processes.
In addition to its importance as a synthetic fiber, particularly for use in the clothing industry, cellulose acetate has a number of other applications. These include magnetic computer tape, absorbent surgical dressings, and some types of adhesives. Cellulose acetate film is also used in photography. Fiber made of this substance is sometimes confused with cellulose triacetate, which is a similar compound that contains a higher proportion of cellulose. Cellulose acetate propionate is another similar substance, used for manufacturing a number of plastic items such as spectacle frames, blister packages, and plastic handles such as those on cutlery or tools.
Commercial production of this compound is usually performed by treating cellulose in the form of wood pulp with various chemicals. Chief among these is acetic acid. Acetic anhydride is also usually also used in the treatment, along with sulfuric acid. This process is called acetylation, and on a molecular level, the hydrogen atoms of the cellulose molecules are being replaced by acetyl groups, a carbon-based molecular group. Following acetylation, the substance can be dissolved, and then spun into its fibrous form to produce the textile end product.
The process of acetylation was discovered as long ago as 1865, by a chemist named Paul Schützenberger, who worked in France. It was not, however, patented as an industrial process until 1894, by Charles Cross and Edward Bevan in the UK. From the 1920s onwards, cellulose acetate has been in commercial production.
When used for clothing, this fiber is soft and resilient, drapes well, and allows the skin to “breathe”. Some other benefits of this kind of fiber include its resistance to shrinking when washed, its hypoallergenic qualities, and its resistance to mildew and some molds. In modern production lines, these fibers are often blended with other substances such as cotton, silk, nylon, or wool. The demand for cellulose acetate fiber has decreased in more recent years due to the discovery of various polyester fibers.