The Exploration Of Optimizing High-level Cigarette Paper Wet-end Chemical Control

The No.18 machine of Ming Feng Special Paper Co. Ltd.. are a modernized paper production line of going into operation in 2000 and specially producing the top-grade cigarette paper. In the past four years, the machine ran steadily, the product quality was reliable. But the machine always has some difficult problems and not easy to solve, such as, system retention and filler retention are low in the process of production, the consumption of chemical additive is great and unstable, the runnability of the machine is dissatisfactory , the systematic sediment of paper machine is high, and the COD value of the white water is several high etc.. In order to solve above-mentioned problems completely , carrying on overall investigation and analysis to this wet-end part of paper machine is the best and reliable method of solving the problem completely to find out the origin that the question produces.Combining the real running situation of the paper machine, I know the problem to be solved first is the retention of the machine. Because of the particularity of the production technology of cigarette paper, the size and stability of the retention will influence ash content and porosity of cigarette paper directly, and then influence the combustion, hold the ash, the color of the ash of the cigarette etc.. So to stabilize and raise the retention become the problems that must be solved at first. For this reason first to survey the retention of the machine in laboratory, analyzing the experimental data I obtained from the survey, I find the retention of the machine and the retention of the filler are very low, the white water density is high, all of then are unstable. The main reason that question produce is to add cationic retention aid to control the retention of the machine, its adding amount is joined artificially and manually, can't really meet system's demands .In order to solve this problem, we have introduced a set of kajaani RMi retention control systems online from MESTO automatic company to control and help keeping the adding amount of the cationic retention aid through this system, and then to control the retention rate of system. Thus stabilize and improve the retention rate of system of this paper machine and retention rate of filler.After the online retention controlling system putting into operation, the retention rate of the paper machine get certain improvement, but the runnability of the papermachine that exist in the past is unsatisfactory either, system sediment many grade issue exist still. At the same time I find the consumption of the retention aid take heavy compared with before , and appear by a large scope and irregular fluctuation sometimes. In order to find out the origin that the question produces, making overall wet department investigation to the paper machine is the only way. The instrument of the wet-end survey in Laboratory I used are the particle charge measure apparatus PCD03 and system ZETA potential analysis instrument SZP06 that BTG Company offer. Combining the real running situation of the paper machine, select 8 point to take a sample, and measure their PCD charge demand value and Zeta potential value separately, analyze the data of the two can find the problem origin of the paper machine existing is the excessive anionic charge in the system. The excessive anionic charge not only will consume a large number of cationic chemical agency in the system, increase consumption of the chemical agency, produce anionic rubbish to influence normal running of paper machine. Through studying further I find the wet-end excessive anionic charge of paper machine comes from the broke primary, in order to solve and decrease the anionic charge problem that the paper brings completely, my company buy a set of online charge measurement system that is composed of a TSS that take a thick pulp sample and a PCT20 online analysis instrument, By connecting with some control systems of the paper machine make up a system to measure and control the wet-end charge of the system, and solve the systematic charge problem of paper machine completely.Through the optimization to that this wet-end chemistry of paper machine controlled, the problem of the paper machine exist all the time, such as, the retention rate of the machine and the retention rate of the filler are low, chemical additive consumption is great and unstable, paper machine runnability is unsatisfied, system sediment is more, and white water COD value is high, etc.. All have to be settled of a certain degree, which make the paper machine have remarkable improvement in such aspects as runnability, chemicals consumption, product quality etc..