Theoretical substantiation of the conditions for capture of fiber by the working drum by the knife in roller gins

Abstract

Roller ginning provides 2–3 times less mechanical damage to cotton fiber than saw ginning. In recent years, these positive moments have predetermined attempts to gin medium-fiber cotton on roller gins. However, the low productivity of roller gins compared to saw gins does not yet allow for a complete transition to this process. To design high-efficiency roller gins, it is necessary to deeply study the mechanics of the basic processes of interaction of raw cotton with the working organs of the gin. It is necessary to determine the reserves for improving the efficiency of the process of capturing and tightening the fiber behind the knife, to investigate the mechanics of the process of rebounding seeds, and to find new solutions to reduce their damage. As a result of the research reported here, a mathematical model of the roller ginning process has been built, which makes it possible to determine the impact of technological and structural parameters of the roller gin on the efficiency of the process. This allows for the reasonable application of a variable periodic friction field between the knife and working drum. When studying the kinematics of the interaction of the surface of the working drum with the knife, dependences were established to accelerate the points of the surface of the working drum before it enters behind the knife, making it possible to determine the forces acting on the fiber when it is captured by the micro-irregularities of the drum. In the study of the process of tightening the fiber with a pair of working drum-fixed knife, the conditions for ginning the flyer fibers and the dependence of productivity on the average pressure in the contact of the knife with the drum were determined. The study of the influence of the rigid characteristics of the working drum-knife system on the ginning capacity of a roller gin has made it possible to reveal new reserves for improving the efficiency of roller ginning