Triacetate
From Biocrawler, the free encyclopedia.
Triacetate also known as 'cellulose triacetate', is manufactured from cellulose and acetate. Triacetate is typically used for the creation of fibres and films. It is similar chemically to cellulose acetate, with the distinguishing characteristics being that in triacetate, according to the Federal Trade Commission definition, at least "92 percent of the hydroxyl groups are acetylated". During the manufacture of triacetate the cellulose is completely acetylated whereas in regular cellulose acetate or cellulose diacetate, it is only partially acetylated. Triacetate is significantly more heat resistant than cellulose acetate.
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History
Triacetate was first produced commercially in the U.S. in 1954 by Celanese Corporation [1] (http://www.celanese.com). A subsidiary of Celanese, Celanese Acetate [2] (http://www.celaneseacetate.com), still produces the fibre.
Production
Triacetate is derived from cellulose by combining cellulose with acetate from acetic acid and acetic anhydride. The cellulose acetate is dissolved in a mixture of dichloromethane and methanol for spinning. As the filaments emerge from a spinneret, the solvent is evaporated in warm air, in a process known as dry spinning, leaving a fibre of almost pure triacetate.
A finishing process called S-Finishing or surface saponification is sometimes applied to acetate and triacetate fabrics using a sodium hydroxide solution. This removes part or all of the acetyl groups from the surface of the fibres leaving them with a cellulose coating. This reduces the tendency for the fibres to acquire static.
Chemistry
CAS number 9012-09-3
As a Fibre
Triacetate fibres have a crenular[3] (http://dictionary.reference.com/search?q=crenate) cross section.
Characteristics
- Shrink resistant
- Wrinkle resistant
- Easily washable
- Generally washable at high temperatures
- Maintains creases and pleats well
Usage Scenarios
Particularly effective in clothing where crease or pleat rentention is important, such as skirts and dresses
General Care Tips
Always refer to individual garmet care labels
- Ironable up to 200 °C
- Pleated garments are best hand laundered. Most other garments containing 100% triacetate can be machine washed and dried
- Articles containing triacetate fibres require very little special care due mainly to the fibre's resistance to high temperatures
As a film
Characteristics
- Resistant to grease, oil aromatic hydrocarbons and most common solvents
- Films have hard glossy surfaces
- Excellent optical clarity
- High dielectric constant
- Easily laminated, coated, folded and die-cut
Usage Scenarios
- Polarizer films for LCD projectors
- Specialised overhead projector transparencies
- Specialised Photographic film
- Motion picture film
- Production of animation cels
- Packaging
See also
References
- www.fibersource.com description of triacetate fibre (http://www.fibersource.com/f-tutor/triacetate.htm)
- www.islandgroup.com description of triacetate film (http://www.islandgroup.com/TriacetateFilm.html)
- Federal Trade Commission definition of triacetate (http://www.ftc.gov/os/statutes/textile/rr-textl.htm)
- Article on the long term archival of triacetate photographic films (http://www.bodley.ox.ac.uk/dept/preservation/information/photographic/messier/messier.htm)
- Glossary of terms relation to the manufacture of cellulose / acetate fibres (http://www.celaneseacetate.com/textile_glossary_filament_acetate.pdf)
