FOERFARANDE FOER DEFIBRERING AV TRYCKSENSITIVT RETURADHESIVPAPPER.

摘要

A method of obtaining regenerated pulp superior in quality by pulping waste pressure-sensitive adhesive paper to which no treatment other than discarding has hitherto been applicable comprises such processes that: waste paper is disaggregated; suspension of said disaggregated waste paper is diluted; diluted liquid is roughly filtered with a screen having slits 0.5 mm wide or less; pulp-containing suspension obtained is dehydrated and concentrated so that concentration of solid content is 15 to 40 % by weight; mechanical agitating treatment is applied to said concentrated material while keeping a temperature difference of said material before and after the treatment at 12 DEG C or lower; a material thus obtained is again diluted; the diluted liquid is finely filtered with a screen having slits 0.2 mm wide or less; surfactant is added to said material for floatation treatment; and cleaning treatment is applied to said material by means of a heavy-foreign-matter cleaner and/or light-foreign-matter cleaner prior to washing.