To kill bacteria and fungi, one can use Ultra Violet or ozone, but they tend to dose biocides as its easier. Two types od defoamers, glycol fat, or water based, water mixes better. Catiofast, percol, Starch and Bentonite are also added.
Dear Dr. Mann, I have a question about pigment application, retention of whitening pigment. how can we bond titanium dioxide with pulp ? Thanks in advance.
Dear Dr. Mann, I have a question for you, why some paper mill add liquid alum in the approach flow system? What exactly the role of the liquid alum? thank you regards, -Oki-
Hi, thank you for your question. Alum does have several different uses: 1 It is used in conjunction with rosin, for rosin-alum sizing 2 It is used as a mordant (fixative), for acid dyes 3 It is used as a retention aid. 4 It is used as an anionic trash collector, (ATC) One of the very first uses of alum was in conjunction with gelatin as a sizing agent. The alum hardened the gelatin. Because of the versatility of alum, it used to have the nickname 'papermakers aspirin', because it cured all problems. Alum is less and less commonly used. This is because it is acidic. Not only does alum speed up the corrosion of equipment in the mill, it also shortens the lifetime of the paper. I hope this helps Best wishes, Steve
The exact amount of chemical depends on the furnish, the Papermaking system and the quality of the water. Also, how much you can afford to put in. Typical level range from 1-5 Kg per MT of OD fibre.- So - 1-5g per Kg of oven dry pulp
