| Flocculation is one of the important research fields of pulp and paermaking. Fiber flocculation can affect the runnability of paper machine and the quality of papermaking product. In order to quest for the better parameter to reflect the characteristics of flocculation, in this paper flocculation and effect of flocculation on drainage and retention of stock are studied, and the application of computer vision technology on flocculation detecting methods of stock is also discribed. In the first part of the paper, working principle and components of the stock flocculation detecting system are introduced in detail, and the parameter such as flocculation index used to describe flocculation of stock is given. Stock flocs with different retention aids are detected by stock flocculation detecting system. According to the preliminary study, it can be seen that the image processing system can digitally characterize stock flocculation. The detecting results testify the theory of the stock flocculation. The detecting method is convenient for operation and the detecting results are objective and accurate. In the second part of the paper, specific filtration resistance (SFR) of stock is detected using the pulmac permeability tester. The effects of pressure.. temperature.. fillers.. additives and freeness on SFR are discussed. The mathematical model between SFR and the factors affecting SFR quantitatively is established by using SAS software. From the results, it can be seen that specific filtration resistance is a parameter to evaluate the dewater property of stock better. It also can be found that flocculation area can reflect drainage of stock. In the third part of the paper, the resistant property of stock added by different retention system under different shear conditions is studied by using Dynamic Drainage Jar. And stock flocculation images at different physical chemistry field and shearing field are analyzed by using the visual system.
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