In the manufacturing process, an alkaline solution of cellulose fibers (usually wood or cotton) known as viscose is extruded through a narrow slit into an acid bath. The acid regenerates the cellulose, forming a film. Further treatment, such as washing and bleaching, yields cellophane

Between the two, viscose is trans-formed into cellulose film. In the passes, it passes 266 special designed rollers and through a series of baths which either treat or clean the film.
At the casting lips the first property of the finished film its thickness variation is controlled by the use of adjuster bolts which vary the distance between the lips and the thickness itself is controlled by varying the rate at which the viscose is pumped through by the metering pump relative to machine speed . When viscose is extruded into a bath of sulfuric acid it forms a continuous wed of re-generated cellulose film. At this stage the film is very pliable and flimsy , and is quite opaque . A number of by-products formed as the film passes through the acid bath are then removed by washing the film with almost boiling water , and passing it through various chemical treatment baths including a bleach . Carbon disulphide released in this process is recovered.
After the bleach bath the wed is washed thoroughly with a counter current flow of water .The continuous wed has become pure cellulose film. However in this form it is too brittle and inelastic for most of the end uses normally associated with Cellophane. Therefore it is further treated by being passed through softening baths containing chemical agents such as glycerin or glycols. This treatment gives it the strength and flexibility it needs in use , and modifications of the softeners can be made to endow the film with the properties most appropriate for different uses.
By this time the film contains over three times its own weight of water and , to remove the bulk of this , it is passed through a dryer containing 90heated rollers and removed superfluous moisture. Because the moisture content of the film is of critical importance , the last stage of the casting machine consists of a humidity chamber which ensures that the film moisture content is maintained at the right level before the film is wound into a mill roll ,and is delivered to packing .(content of water is 7-8%)
The wet-end of a casting machine consists mainly of feed viscose system ,casting lips ,18 bath , specially-designed driver or mot-driver rolls and etc.
The dryer of a casting machine consists mainly of housing , 90 heated rolls , 84 heat-air engine, humidity chamber ,exhaust of heated rolls ,insulated cover, slitter, wind up system and etc.