Transparency prodn. esp. for daylight projections - by heating zinc oxide copy of original in contact with uncoated thermoplastics, pref. polypropylene, film

摘要

In the prodn. of transparencies, esp. for daylight projection, from non-transparent originals, using uncoated transparent films, a ZnO copy of the original is made, a transparent thermoplastics film placed in close contact with this is heated in a continuous process, so that the toner image coalesces with the film and then the film is removed from the ZnO copy. The ZnO copy pref. is dried before contact with the film. The film pref. is 0.04-0.15, esp. 0.06-0.10 mm thick and pref. consists of polypropylene.