Sliver irregularity, straightness and separation degree of fibers are three crucial factors in sliver quality. Considering the straightness and separation degree, the drafting model based on the fiber arrangement in the sliver was applied to simulate the drawing process. First, the fiber arrangement in the carding sliver was developed. Then, the drafting process was divided into the low-velocity stage, straightening stage and high-velocity stage to carry out the redistribution of the fiber arrangement so that the sliver quality after drafting can be recalculated from the new fiber arrangement after the drafting procedure. Combining the doubling procedure, the simulated sliver quality of each drawing process was demonstrated to be close to the actual values, taking the straightness and separation degree into consideration. The relative errors between the simulated straightness and percentage of separated fibers and the tested one were all less than 10%. The prediction accuracy of sliver irregularity was raised by about 40%. In addition, the simulated results strongly confirmed the theory that the drawing process has an influence on straightening the hooked fibers, separating the fiber in the assembly and improving the sliver evenness, which cannot be reflected in previous models.
Improved Fiber Separation and Energy Reduction in Thermomechanical Pulp Refining Using Enzyme-Pretreated Wood
