Stefan, you're really a grat technician!!!! Just an answer: years ago a technician specialised in OBA told me that, despite his anionic charge (mostra the dusulfonates and tetrasulfonate ones) OBAs have a strong affinity to cellulosa fibers, that allows to get a very good "white livel" to paper and whats more, if dosed in mixing chest, before cationic starch dosed on machine chest, it allows an higher livello of dosage of starch, increasing further the strenght of the sheet, coud you explain the chemical reaction of this strange behaviour?
Very helpful training videos on pulp and paper. A minor issue on this one is that the table of Dye and Pigment listed direct dye as Anionic, but the previous slides says it is Cationic?
Hi, thank you for your question. I think you are talking about Optical Brightening Agents, (OBA's) These are complex organic molecules, often based on the basic stilbene molecule. The take in UV light, and then re-emit it in the blue part of the spectrum. Because of the way the human eye is, it thinks the paper is whiter.
Very interesting and important
Stefan, you're really a grat technician!!!! Just an answer: years ago a technician specialised in OBA told me that, despite his anionic charge (mostra the dusulfonates and tetrasulfonate ones) OBAs have a strong affinity to cellulosa fibers, that allows to get a very good "white livel" to paper and whats more, if dosed in mixing chest, before cationic starch dosed on machine chest, it allows an higher livello of dosage of starch, increasing further the strenght of the sheet, coud you explain the chemical reaction of this strange behaviour?
Very helpful training videos on pulp and paper. A minor issue on this one is that the table of Dye and Pigment listed direct dye as Anionic, but the previous slides says it is Cationic?
Well spotted. I will correct this shortly, thank you
Very impressive sir
Sir very impressive
Voilet dye and blue dye can you explain here?
Hi, thank you for your question.
I think you are talking about Optical Brightening Agents, (OBA's) These are complex organic molecules, often based on the basic stilbene molecule. The take in UV light, and then re-emit it in the blue part of the spectrum. Because of the way the human eye is, it thinks the paper is whiter.
BAD gets better 😜