Cellophane
From Free net encyclopedia
Cellophane is a thin, transparent sheet made of processed cellulose. Cellulose fibres from wood or cotton are dissolved in alkali to make a solution called viscose, which is then extruded through a slit into an acid bath to reconvert the viscose into cellulose. A similar process, using a hole instead of a slit (a spinneret), is used to make a fibre called rayon.
Cellophane was invented by Jacques E. Brandenberger, a Swiss textiles engineer, in 1908. After witnessing a wine spill on a restaurant tablecloth, Brandenberger initially had the idea to develop a clear coating for cloth to make it waterproof. He experimented, and came up with a way to apply liquid viscose to cloth, but found the resultant combination of cloth and viscose film too stiff to be of use. However the clear film easily separated from the backing cloth, and he abandoned his original idea as the possibilities of the new material became apparent.
Cellophane's low permeability to air, grease and bacteria makes it useful for food packaging. Whitman's candy company initiated use of cellophane for candy wrapping in the United States in 1912 for their Whitman's Sampler. They remained the largest user of imported cellophane from France until nearly 1924, when DuPont built the first cellophane manufacturing plant in the US.
Cellulose film has been manufactured continuously since the mid-1930s and is still used today. As well as packaging a variety of food items, there are also industrial applications, such as a base for self-adhesive tapes like Sellotape and Scotch Tape, a semi-permeable membrane in certain types of battery, and as a release agent in the manufacture of fibreglass and rubber products. Typically, however, the use of the word "cellophane" has been genericized, and is often used informally to refer to a wide variety of plastic film products, even those not made of cellulose.