PROCESS FOR MAKING CARDBOARD HAVING SAFETY MEANS

摘要

The invention relates to a process for making a cardboard having safety means which is suitable for such products as pharmaceutical packages. The safety means prevents forgery and confirms the legitimacy of the package. A multilayer cardboard is made by papermaking method. The multilayer cardboard (27) has a safety means which comprises a surface layer of white cellulose fibers (38) in admixture with several synthetic fibers (39) which are treated so as to be hardly visible to the naked eye but are visible under special lighting. The Safety means further has a colored core (41) in contrast to the other white cellulose layers (42). The color core cannot be accessed without rupture or destruction of the external layers.