How is acetate fiber made?
Since acetate is a regenerated fiber the raw material is obtained from the natural sources that are cotton linters (these are the remnant fibers procured during the ginning process) and wood pulp.
The steps involved in the manufacturing of acetate are as follows:
• Purification of cellulose: The cotton linters and wood pulp are boiled with alkali and then bleached with hypochlorite bleach to purify the cellulosic content.
• Activation: The raw material obtained from the above step is then mixed with glacial acetic acid and acetic anhydride under carefully controlled conditions. A catalyst that is meant to speed up the reaction is added in a small amount i.e. sulphuric acid.
• Acetylation: The mixture is then added to an acetylator which mixes and blends the entire set of chemicals with the raw material.
• In the next step, the mixture is then stored in tanks and water is added. The purpose of water addition is to precipitate acetate in the form of small flakes.
• The acetate so obtained is then washed and dried.
• Dry Spinning: The acetate is then dissolved in acetone which acts as a solvent and filtered. The solution is then passed through the spinneret in a warm air chamber. The solvent as a result evaporates and acetate rayon filaments are thus obtained.