Cellophane is a transparent thin sheet made of regenerated cellulose. The low permeability of air, oil, grease, bacteria, and water make it useful for food packaging.
"Cellophane" is a generic term in some countries, while in other countries it is a registered trademark.
Video Cellophane
Production
Cellulose from wood, cotton, hemp, or other sources is dissolved in alkali and carbon disulfide to create a solution called viscose, which is then extruded through a gap into a sulfuric acid bath and sodium sulfate to convert viscose into cellulose. The film then passes through several other baths, one to remove sulfur, one to whiten the film, and another to add a softener like glycerine to prevent the film from becoming brittle.
A similar process, using a hole (spinneret) instead of a gap, is used to create a fiber called rayon. Chemically, cellophane, rayon and cellulose are glucose polymers; they differ structurally rather than chemically.
Maps Cellophane
History
Cellophane was created by the Swiss chemist Jacques E. Brandenberger when employed by Blanchisserie et Teinturerie de Thaon . In 1900, inspired by seeing a spill of wine on the restaurant tablecloth, he decided to make a cloth that could reject the liquid rather than absorb it. His first step was to spray the waterproof layer into the fabric, and he chose to try viscose. The resulting upholstery is too rigid, but the clear film is easily separated from the buffer fabric, and it abandons the original idea as the possibility of new material becomes clear.
It took Brandenberger ten years to perfect his film, his major improvement over his previous work with such films was to add glycerin to soften the material. In 1912 he built a machine to produce a film, which he named Cellophane, from cellulose and diaphane ("transparent") words. Cellophane patented that year. The following year, the company Comptoir des Textiles Artificiels (CTA) bought the Thaon company in Cellophane and founded Brandenberger in the new company, La Cellophane SA.
The Whitman candy company started the use of plastic for candy wrappers in the United States in 1912 for their Whitman Sampler. They remained the largest user of imported fuel cells from France until nearly 1924, when DuPont built the first US cellophane manufacturing plant. Cellophane saw limited sales in the US initially since it was waterproof, it was not a proof of moisture - it retained water but could absorb water vapor. This means it is not suitable for packaging products that require moisture checks. DuPont hired a chemist William Hale Charch, who spent three years developing a nitrocellulose varnish which, when applied to Cellophane, made it waterproof. After the introduction of Cellophane anti-humidity in 1927, the sale of the material increased threefold between 1928 and 1930, and in 1938, Cellophane accounted for 10% of DuPont's sales and 25% of its profits.
The British Courtaulds' viscose textile technology company has made it possible to diversify in 1930 into a viscose film, named "Viscacelle". However, the competition with Cellophane became an obstacle to its sale, and in 1935, it founded British Cellophane Limited (BCL) along with Cellophane Company and its parent company, CTA. The main production facility was built in Bridgwater, Somerset, England, from 1935 to 1937, employing 3,000 workers. BCL then built a factory in Cornwall, Ontario (BCL Canada), in addition to the Viscose rayon viscose factory there (from which he purchased a viscose (AKA dope) solution), and in 1957 at Barrow-in-Furness, Cumbria. The last two plants were closed in the 1990s.
Today
Cellulose films have been produced continuously since the mid-1930s and are still in use today. As well as packaging of various foods, there are also industrial applications, such as the basis for self-adhesive tapes such as Sellotape and Scotch Tape, semi-permeable membranes in certain battery types, such as dialysis tubes (Visking tubing). ), and as a release agent in the manufacture of fiberglass and rubber products. Cellophane is the most popular material for cigar packaging; its permeability to moisture makes the perfect product cellophane for this application because the cigar must be allowed to "breathe" while in storage.
Cellophane sales have shrunk since the 1960s, due to alternative packaging options. The pollution effects of carbon disulfide and other by-products of the process used to make viscose may also contribute to this; However, the plastic itself is 100% biodegradable, and it has increased its popularity as a food wrapper.
Material properties
When placed between two polarized airplane filters, cellophane produces a prismal color due to its birefringent nature. Artists have used this effect to create creations like kinetic and interactive glass.
Cellophane is biodegradable, but highly toxic carbon disulfide is used in most plastics production. Viscose factories vary greatly in the amount of CS 2 they expose their workers, and most do not provide information about their quantitative security limits or how well they maintain them.
Branding
In the UK and in many other countries, cellophane is a registered trademark and belongs to Futamura Chemical UK Ltd, based in Wigton, Cumbria, England. In the US and several other countries "cellophane" has become generic, and is often used informally to refer to a wide range of plastic film products, even those not made of cellulose, such as plastic wrap.
See also
References
External links
- The discovery of a cellophane
Source of the article : Wikipedia
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